RECORDS.CONFIG(5)

NAME
records.config - Traffic Server configuration file

The records.config file (by default, located in /usr/local/etc/trafficserver/) is a list of configurable variables used by the Traffic Server software. Many of the variables in the records.config file are set automatically when you set configuration options in Traffic Line. After you modify the records.config file, run the command traffic_line -x to apply the changes. When you apply changes to one node in a cluster, Traffic Server automatically applies the changes to all other nodes in the cluster.

FORMAT

Each variable has the following format:

        SCOPE variable_name DATATYPE variable_value

where

SCOPE is related to clustering and is either CONFIG (all members of the cluster) or LOCAL (only the local machine)

DATATYPE is one of INT (integer), STRING (string), FLOAT (floating point). : A variable marked as Deprecated is still functional but should be avoided as it may be removed in a future release without warning.

A variable marked as Reloadable can be updated via the command:

        traffic_line -x

INT type configurations are expressed as any normal integer, e.g. 32768. They can also be expressed using more human readable values using standard prefixes, e.g. 32K. The following prefixes are supported for all INT type configurations

            •   K Kilobytes (1024 bytes)

            •   M Megabytes (1024^2 or 1,048,576 bytes)

            •   G Gigabytes (1024^3 or 1,073,741,824 bytes)

            •   T Terabytes (1024^4 or 1,099,511,627,776 bytes)

NOTE:
        Traffic Server currently writes back configurations to disk periodically, and when doing so, will not preserve the prefixes.

EXAMPLES

In the following example, the variable proxy.config.proxy_name is a STRING datatype with the value my_server. This means that the name of the Traffic Server proxy is my_server.

        CONFIG proxy.config.proxy_name STRING my_server

If the server name should be that_server the line would be

        CONFIG proxy.config.proxy_name STRING that_server

In the following example, the variable proxy.config.arm.enabled is a yes/no flag. A value of 0 (zero) disables the option; a value of 1 enables the option.

        CONFIG proxy.config.arm.enabled INT 0

In the following example, the variable sets the cluster startup timeout to 10 seconds.

        CONFIG proxy.config.cluster.startup_timeout INT 10

The last examples configures a 64GB RAM cache, using a human readable prefix.

        CONFIG proxy.config.cache.ram_cache.size INT 64G

ENVIRONMENT OVERRIDES

Every records.config configuration variable can be overridden by a corresponding environment variable. This can be useful in situations where you need a static records.config but still want to tweak one or two settings. The override variable is formed by converting the records.config variable name to upper case, and replacing any dot separators with an underscore.

Overriding a variable from the environment is permanent and will not be affected by future configuration changes made in records.config or applied with traffic_line.

For example, we could override the proxy.config.product_company variable like this:

        $ PROXY_CONFIG_PRODUCT_COMPANY=example traffic_cop &
        $ traffic_line -r proxy.config.product_company

CONFIGURATION VARIABLES

The following list describes the configuration variables available in the records.config file.

  System Variables

    proxy.config.product_company

    Scope
        CONFIG.TP Type STRING.TP Default Apache Software Foundation.UNINDENT The name of the organization developing Traffic Server.

        proxy.config.product_vendor

        Scope
            CONFIG.TP Type STRING.TP Default Apache.UNINDENT The name of the vendor providing Traffic Server.

            proxy.config.product_name

            Scope
                CONFIG.TP Type STRING.TP Default Traffic Server.UNINDENT The name of the product.

                proxy.config.proxy_name

                Scope
                    CONFIG.TP Type STRING.TP Default ``build_machine``.TP Reloadable Yes.UNINDENT The name of the Traffic Server node.

                    proxy.config.bin_path

                    Scope
                        CONFIG.TP Type STRING.TP Default bin.UNINDENT The location of the Traffic Server bin directory.

                        proxy.config.proxy_binary

                        Scope
                            CONFIG.TP Type STRING.TP Default traffic_server.UNINDENT The name of the executable that runs the traffic_server process.

                            proxy.config.proxy_binary_opts

                            Scope
                                CONFIG.TP Type STRING.TP Default -M.UNINDENT The command-line options for starting Traffic Server.

                                proxy.config.manager_binary

                                Scope
                                    CONFIG.TP Type STRING.TP Default traffic_manager.UNINDENT The name of the executable that runs the traffic_manager process.

                                    proxy.config.env_prep

                                    Scope
                                        CONFIG.TP Type STRING.TP Default *NONE*.UNINDENT The script executed before the traffic_manager process spawns the traffic_server process.

                                        proxy.config.config_dir

                                        Scope
                                            CONFIG.TP Type STRING.TP Default etc/trafficserver.UNINDENT The directory that contains Traffic Server configuration files. This is a read-only configuration option that contains the SYSCONFDIR value specified at build time relative to the installation prefix. The $TS_ROOT environment variable can be used alter the installation prefix at run time.

                                            proxy.config.syslog_facility

                                            Scope
                                                CONFIG.TP Type STRING.TP Default LOG_DAEMON.UNINDENT The facility used to record system log files. Refer to understanding-traffic-server-log-files.

                                                proxy.config.cop.core_signal

                                                Scope
                                                    CONFIG.TP Type INT.TP Default 0.UNINDENT The signal sent to traffic_cop's managed processes to stop them.

                                                    A value of 0 means no signal will be sent.

                                                    proxy.config.cop.linux_min_memfree_kb

                                                    Scope
                                                        CONFIG.TP Type INT.TP Default 0.UNINDENT The minimum amount of free memory space allowed before Traffic Server stops the traffic_server and traffic_manager processes to prevent the system from hanging.

                                                        proxy.config.cop.linux_min_swapfree_kb

                                                        Scope
                                                            CONFIG.TP Type INT.TP Default 0.UNINDENT The minimum amount of free swap space allowed before Traffic Server stops the traffic_server and traffic_manager processes to prevent the system from hanging. This configuration variable applies if swap is enabled in Linux 2.2 only.

                                                            proxy.config.output.logfile

                                                            Scope
                                                                CONFIG.TP Type STRING.TP Default traffic.out.UNINDENT The name and location of the file that contains warnings, status messages, and error messages produced by the Traffic Server processes. If no path is specified, then Traffic Server creates the file in its logging directory.

                                                                proxy.config.snapshot_dir

                                                                Scope
                                                                    CONFIG.TP Type STRING.TP Default snapshots.UNINDENT The directory in which Traffic Server stores configuration snapshots on the local system. Unless you specify an absolute path, this directory is located in the Traffic Server SYSCONFDIR directory.

                                                                    proxy.config.exec_thread.autoconfig

                                                                    Scope
                                                                        CONFIG.TP Type INT.TP Default 1.UNINDENT When enabled (the default, 1), Traffic Server scales threads according to the available CPU cores. See the config option below.

                                                                        proxy.config.exec_thread.autoconfig.scale

                                                                        Scope
                                                                            CONFIG.TP Type FLOAT.TP Default 1.5.UNINDENT Factor by which Traffic Server scales the number of threads. The multiplier is usually the number of available CPU cores. By default this is scaling factor is 1.5.

                                                                            proxy.config.exec_thread.limit

                                                                            Scope
                                                                                CONFIG.TP Type INT.TP Default 2.UNINDENT XXX What does this do?

                                                                                proxy.config.accept_threads

                                                                                Scope
                                                                                    CONFIG.TP Type INT.TP Default 1.UNINDENT When enabled (1), runs a separate thread for accept processing. If disabled (0), then only 1 thread can be created.

                                                                                    proxy.config.thread.default.stacksize

                                                                                    Scope
                                                                                        CONFIG.TP Type INT.TP Default 1048576.UNINDENT The new default thread stack size, for all threads. The original default is set at 1 MB.

                                                                                        proxy.config.exec_thread.affinity

                                                                                        Scope
                                                                                            CONFIG.TP Type INT.TP Default 0.UNINDENT Bind threads to specific processing units.
                                                                                            Value | Effect
                                                                                            0 | assign threads to machine
                                                                                            1 | assign threads to NUMA nodes
                                                                                            2 | assign threads to sockets
                                                                                            3 | assign threads to cores
                                                                                            4 | assign threads to processing units

                                                                                            NOTE:
                                                                                                This option only has an affect when Traffic Server has been compiled with --enable-hwloc.

                                                                                            proxy.config.system.file_max_pct

                                                                                            Scope
                                                                                                CONFIG.TP Type FLOAT.TP Default 0.9.UNINDENT Set the maximum number of file handles for the traffic_server process as a percentage of the the fs.file-max proc value in Linux. The default is 90%.

                                                                                                proxy.config.crash_log_helper

                                                                                                Scope
                                                                                                    CONFIG.TP Type STRING.TP Default traffic_crashlog.UNINDENT This option directs traffic_server to spawn a crash log helper at startup. The value should be the path to an executable program. If the path is not absolute, it is located relative to configured bin directory. Any user-provided program specified here must behave in a fashion compatible with traffic_crashlog. Specifically, it must implement the traffic_crashlog --wait behavior.

                                                                                                    This setting not reloadable because the helper must be spawned before traffic_server drops privilege. If this variable is set to NULL, no helper will be spawned.

                                                                                                    proxy.config.restart.active_client_threshold

                                                                                                    Scope
                                                                                                        CONFIG.TP Type INT.TP Default 0
                                                                                                         :reloadable:.UNINDENT This setting specifies the number of active client connections for use by traffic_line --drain.

NETWORK

    proxy.config.net.connections_throttle

    Scope
        CONFIG.TP Type INT.TP Default 30000.UNINDENT The total number of client and origin server connections that the server can handle simultaneously. This is in fact the max number of file descriptors that the traffic_server process can have open at any given time. Roughly 10% of these connections are reserved for origin server connections, i.e. from the default, only ~9,000 client connections can be handled. This should be tuned according to your memory size, and expected work load.

        proxy.config.net.default_inactivity_timeout

        Scope
            CONFIG.TP Type INT.TP Default 86400.TP Reloadable Yes.UNINDENT The connection inactivity timeout (in seconds) to apply when Traffic Server detects that no inactivity timeout has been applied by the HTTP state machine. When this timeout is applied, the proxy.process.net.default_inactivity_timeout_applied metric is incremented.

            proxy.local.incoming_ip_to_bind

            Scope
                LOCAL.TP Type STRING.TP Default 0.0.0.0 [::].UNINDENT Controls the global default IP addresses to which to bind proxy server ports. The value is a space separated list of IP addresses, one per supported IP address family (currently IPv4 and IPv6).

                Unless explicitly specified in proxy.config.http.server_ports the server port will be bound to one of these addresses, selected by IP address family. The built in default is any address. This is used if no address for a family is specified. This setting is useful if most or all server ports should be bound to the same address.

                NOTE:
                    This is ignored for inbound transparent server ports because they must be able to accept connections on arbitrary IP addresses.

  Example

Set the global default for IPv4 to 192.168.101.18 and leave the global default for IPv6 as any address.:

        LOCAL proxy.local.incoming_ip_to_bind STRING 192.168.101.18

  Example

Set the global default for IPv4 to 191.68.101.18 and the global default for IPv6 to fc07:192:168:101::17.:

        LOCAL proxy.local.incoming_ip_to_bind STRING 192.168.101.18 [fc07:192:168:101::17]

    proxy.local.outgoing_ip_to_bind

    Scope
        LOCAL.TP Type STRING.TP Default 0.0.0.0 [::].UNINDENT This controls the global default for the local IP address for outbound connections to origin servers. The value is a list of space separated IP addresses, one per supported IP address family (currently IPv4 and IPv6).

        Unless explicitly specified in proxy.config.http.server_ports one of these addresses, selected by IP address family, will be used as the local address for outbound connections. This setting is useful if most or all of the server ports should use the same outbound IP addresses.

        NOTE:
            This is ignored for outbound transparent ports as the local outbound address will be the same as the client local address.

  Example

Set the default local outbound IP address for IPv4 connections to 192.168.101.18.:

        LOCAL proxy.local.outgoing_ip_to_bind STRING 192.168.101.18

  Example

Set the default local outbound IP address to 192.168.101.17 for IPv4 and fc07:192:168:101::17 for IPv6.:

        LOCAL proxy.local.outgoing_ip_to_bind STRING 192.168.101.17 [fc07:192:168:101::17]

CLUSTER

    proxy.local.cluster.type

    Scope
        LOCAL.TP Type INT.TP Default 3.UNINDENT Sets the clustering mode:
        Value | Effect
        1 | full-clustering mode
        2 | management-only mode
        3 | no clustering

        proxy.config.cluster.ethernet_interface

        Scope
            CONFIG.TP Type INT.TP Default eth0.UNINDENT

            The network interface to be used for cluster communication. This has to be identical on all members of a clsuter. ToDo: Is that reasonable ?? Should this be local"

            proxy.config.cluster.rsport

            Scope
                CONFIG.TP Type INT.TP Default 8088.UNINDENT The reliable service port. The reliable service port is used to send configuration information between the nodes in a cluster. All nodes in a cluster must use the same reliable service port.

                proxy.config.cluster.threads

                Scope
                    CONFIG.TP Type INT.TP Default 1.UNINDENT The number of threads for cluster communication. On heavy cluster, the number should be adjusted. It is recommend that take the thread CPU usage as a reference when adjusting.

                    proxy.config.clustger.ethernet_interface

                    Scope
                        CONFIG.TP Type STRING.TP Default *NONE*.UNINDENT Set the interface to use for cluster communications.

                        proxy.config.http.cache.cluster_cache_local

                        Scope
                            CONFIG.TP Type INT.TP Default 0.UNINDENT This turns on the local caching of objects in cluster mode. The point of this is to allow for popular or hot content to be cached on all nodes in a cluster. Be aware that the primary way to configure this behavior is via the cache.config configuration file using action=cluster-cache-local directives.

                            This particular records.config configuration can be controlled per transaction or per remap rule. As such, it augments the cache.config directives, since you can turn on the local caching feature without complex regular expression matching.

                            This implies that turning this on in your global records.config is almost never what you want; instead, you want to use this either via e.g. conf_remap.so overrides for a certain remap rule, or through a custom plugin using the appropriate APIs.

LOCAL MANAGER

    proxy.config.lm.sem_id

    Scope
        CONFIG.TP Type INT.TP Default 11452.UNINDENT The semaphore ID for the local manager.

        proxy.config.admin.autoconf_port

        Scope
            CONFIG.TP Type INT.TP Default 8083.UNINDENT The autoconfiguration port.

            proxy.config.admin.number_config_bak

            Scope
                CONFIG.TP Type INT.TP Default 3.UNINDENT The maximum number of copies of rolled configuration files to keep.

                proxy.config.admin.user_id

                Scope
                    CONFIG.TP Type STRING.TP Default nobody.UNINDENT Option used to specify who to run the traffic_server process as; also used to specify ownership of config and log files.

                    The nonprivileged user account designated to Traffic Server.

                    As of version 2.1.1 if the user_id is prefixed with pound character (#) the remaining of the string is considered to be a numeric user identifier. If the value is set to #-1 Traffic Server will not change the user during startup.

                    Setting user_id to root or #0 is now forbidden to increase security. Trying to do so, will cause the traffic_server fatal failure. However there are two ways to bypass that restriction

                    •   Specify -DBIG_SECURITY_HOLE in CXXFLAGS during compilation.

                    •   Set the user_id=#-1 and start trafficserver as root.

                    proxy.config.admin.api.restricted

                    Scope
                        CONFIG.TP Type INT.TP Default 1.UNINDENT

                        This setting specifies whether the management API should be restricted to root processes. If this is set to 0, then on platforms that support passing process credentials, non-root processes will be allowed to make read-only management API calls. Any management API calls that modify server state (eg. setting a configuration variable) will still be restricted to root processes.

                        This setting is not reloadable, since it is must be applied when program:traffic_manager initializes.

                        NOTE:
                            In Traffic Server 6.0, the default value of proxy.config.admin.api.restricted will be changed to 0.

PROCESS MANAGER

    proxy.config.process_manager.mgmt_port

    Scope
        CONFIG.TP Type INT.TP Default 8084.UNINDENT The port used for internal communication between the traffic_manager and traffic_server processes.

ALARM CONFIGURATION

    proxy.config.alarm_email

    Scope
        CONFIG.TP Type STRING.TP Default *NONE*.TP Reloadable Yes.UNINDENT The address to which the alarm script should send email.

        proxy.config.alarm.bin

        Scope
            CONFIG.TP Type STRING.TP Default example_alarm_bin.sh.TP Reloadable Yes.UNINDENT Name of the script file that can execute certain actions when an alarm is signaled. The script is invoked with up to 4 arguments:

                    •   the alarm message

                    •   the value of proxy.config.product_name

                    •   the value of proxy.config.admin.user_id

                    •   the value of proxy.config.alarm_email

            proxy.config.alarm.abs_path

            Scope
                CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The absolute path to the directory containing the alarm script. If this is not set, the script will be located relative to proxy.config.bin_path.

                proxy.config.alarm.script_runtime

                Scope
                    CONFIG.TP Type INT.TP Default 5.TP Reloadable Yes.UNINDENT The number of seconds that Traffic Server allows the alarm script to run before aborting it.

HTTP ENGINE

    proxy.config.http.server_ports

    Scope
        CONFIG.TP Type STRING.TP Default 8080.UNINDENT Ports used for proxying HTTP traffic.

        This is a list, separated by space or comma, of port descriptors. Each descriptor is a sequence of keywords and values separated by colons. Not all keywords have values, those that do are specifically noted. Keywords with values can have an optional '=' character separating the keyword and value. The case of keywords is ignored. The order of keywords is irrelevant but unspecified results may occur if incompatible options are used (noted below). Options without values are idempotent. Options with values use the last (right most) value specified, except for ip-out as detailed later.

        Quick reference chart.
        Name | Note | Definition
        number | Required | The local port.
        blind |  | Blind (CONNECT) port.
        compress | N/I | Compressed. Not implemented.
        ipv4 | Default | Bind to IPv4 address family.
        ipv6 |  | Bind to IPv6 address family.
        ip-in | Value | Local inbound IP address.
        ip-out | Value | Local outbound IP address.
        ip-resolve | Value | IP address resolution style.
        proto | Value | List of supported session protocols.
        ssl |  | SSL terminated.
        tr-full |  | Fully transparent (inbound and outbound)
        tr-in |  | Inbound transparent.
        tr-out |  | Outbound transparent.
        tr-pass |  | Pass through enabled.

        number
            Local IP port to bind. This is the port to which ATS clients will connect.

        blind
            Accept only the CONNECT method on this port.

            Not compatible with: tr-in, ssl.

        compress
            Compress the connection. Retained only by inertia, should be considered "not implemented".

        ipv4
            Use IPv4. This is the default and is included primarily for completeness. This forced if the ip-in option is used with an IPv4 address.

        ipv6
            Use IPv6. This is forced if the ip-in option is used with an IPv6 address.

        ssl Require SSL termination for inbound connections. SSL must be configured for this option to provide a functional server port.

            Not compatible with: blind.

        proto
            Specify the session level protocols supported. These should be separated by semi-colons. For TLS proxy ports the default value is all available protocols. For non-TLS proxy ports the default is HTTP only. SPDY can be enabled on non-TLS proxy ports but that must be done explicitly.

        tr-full
            Fully transparent. This is a convenience option and is identical to specifying both tr-in and tr-out.

            Not compatible with: Any option not compatible with tr-in or tr-out.

        tr-in
            Inbound transparent. The proxy port will accept connections to any IP address on the port. To have IPv6 inbound transparent you must use this and the ipv6 option. This overrides proxy.local.incoming_ip_to_bind for this port.

            Not compatible with: ip-in, blind

        tr-out
            Outbound transparent. If ATS connects to an origin server for a transaction on this port, it will use the client's address as its local address. This overrides proxy.local.outgoing_ip_to_bind for this port.

            Not compatible with: ip-out, ip-resolve

        tr-pass
            Transparent pass through. This option is useful only for inbound transparent proxy ports. If the parsing of the expected HTTP header fails, then the transaction is switched to a blind tunnel instead of generating an error response to the client. It effectively enables proxy.config.http.use_client_target_addr for the transaction as there is no other place to obtain the origin server address.

        ip-in
            Set the local IP address for the port. This is the address to which clients will connect. This forces the IP address family for the port. The ipv4 or ipv6 can be used but it is optional and is an error for it to disagree with the IP address family of this value. An IPv6 address must be enclosed in square brackets. If this option is omitted proxy.local.incoming_ip_to_bind is used.

            Not compatible with: tr-in.

        ip-out
            Set the local IP address for outbound connections. This is the address used by ATS locally when it connects to an origin server for transactions on this port. If this is omitted proxy.local.outgoing_ip_to_bind is used.

            This option can used multiple times, once for each IP address family. The address used is selected by the IP address family of the origin server address.

            Not compatible with: tr-out.

        ip-resolve
            Set the host resolution style for transactions on this proxy port.

            Not compatible with: tr-out - this option requires a value of client;none which is forced and should not be explicitly specified.

  Example

Listen on port 80 on any address for IPv4 and IPv6.:

        80 80:ipv6

  Example

Listen transparently on any IPv4 address on port 8080, and transparently on port 8080 on local address fc01:10:10:1::1 (which implies ipv6).:

        IPv4:tr-FULL:8080 TR-full:IP-in=[fc02:10:10:1::1]:8080

  Example

Listen on port 8080 for IPv6, fully transparent. Set up an SSL port on 443. These ports will use the IP address from proxy.local.incoming_ip_to_bind. Listen on IP address 192.168.17.1, port 80, IPv4, and connect to origin servers using the local address 10.10.10.1 for IPv4 and fc01:10:10:1::1 for IPv6.:

        8080:ipv6:tr-full 443:ssl ip-in=192.168.17.1:80:ip-out=[fc01:10:10:1::1]:ip-out=10.10.10.1

  Example

Listen on port 9090 for TSL enabled SPDY or HTTP connections, accept no other session protocols.:

        9090:proto=spdy;http:ssl

    proxy.config.http.connect_ports

    Scope
        CONFIG.TP Type STRING.TP Default 443 563.UNINDENT The range of origin server ports that can be used for tunneling via CONNECT.

        Traffic Server allows tunnels only to the specified ports. Supports both wildcards ('*') and ranges ("0-1023").

        NOTE:
            These are the ports on the origin server, not Traffic Server proxy ports.

        proxy.config.http.insert_request_via_str

        Scope
            CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Set how the Via field is handled on a request to the origin server.
            Value | Effect
            0 | Do not modify / set this via header
            1 | Update the via, with normal verbosity
            2 | Update the via, with higher verbosity
            3 | Update the via, with highest verbosity

            NOTE:
                The Via header string can be decoded with the Via Decoder Ring.

            proxy.config.http.insert_response_via_str

            Scope
                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Set how the Via field is handled on the response to the client.
                Value | Effect
                0 | Do not modify / set this via header
                1 | Update the via, with normal verbosity
                2 | Update the via, with higher verbosity
                3 | Update the via, with highest verbosity

                NOTE:
                    The Via header string can be decoded with the Via Decoder Ring.

                proxy.config.http.send_100_continue_response

                Scope
                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT You can specify one of the following:

                    •   0 ATS buffer the request until the post body has been recieved and then send the request to origin.

                    •   1 immediately return a 100 Continue from ATS without waiting for the post body

                    proxy.config.http.response_server_enabled

                    Scope
                        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT You can specify one of the following:

                        •   0 no Server: header is added to the response.

                        •   1 the Server: header is added (see string below).

                        •   2 the Server: header is added only if the response from origin does not have one already.

                        proxy.config.http.insert_age_in_response

                        Scope
                            CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT This option specifies whether Traffic Server should insert an Age header in the response. The Age field value is the cache's estimate of the amount of time since the response was generated or revalidated by the origin server.

                            •   0 no Age header is added

                            •   1 the Age header is added

                            proxy.config.http.response_server_str

                            Scope
                                CONFIG.TP Type STRING.TP Default ATS/.TP Reloadable Yes.UNINDENT The Server: string that ATS will insert in a response header (if requested, see above). Note that the current version number is always appended to this string.

                                proxy.config.http.enable_url_expandomatic

                                Scope
                                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) .com domain expansion. This configures the Traffic Server to resolve unqualified hostnames by prepending with www. and appending with .com before redirecting to the expanded address. For example: if a client makes a request to host, then Traffic Server redirects the request to www.host.com.

                                    proxy.config.http.chunking_enabled

                                    Scope
                                        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Specifies whether Traffic Sever can generate a chunked response:

                                        •   0 Never

                                        •   1 Always

                                        •   2 Generate a chunked response if the server has returned HTTP/1.1 before

                                        •   3 = Generate a chunked response if the client request is HTTP/1.1 and the origin server has returned HTTP/1.1 before

                                    NOTE:
                                            If HTTP/1.1 is used, then Traffic Server can use keep-alive connections with pipelining to origin servers. If HTTP/0.9 is used, then Traffic Server does not use keep-alive connections to origin servers. If HTTP/1.0 is used, then Traffic Server can use keep-alive connections without pipelining to origin servers.

                                        proxy.config.http.send_http11_requests

                                        Scope
                                            CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Specifies when and how Traffic Sever uses HTTP/1.1 to communicate with the origin server

                                            •   0 Never

                                            •   1 Always

                                            •   2 If the server has returned HTTP/1.1 before

                                            •   3 If the client request is HTTP/1.1 and the server has returned HTTP/1.1 before

                                        NOTE:
                                                If proxy.config.http.use_client_target_addr is set to 1, options 2 and 3 cause the proxy to use the client HTTP version for upstream requests.

                                            proxy.config.http.share_server_sessions

                                            Scope
                                                CONFIG.TP Type INT.TP Default 2.TP Deprecated Yes.UNINDENT Enables (1) or disables (0) the reuse of server sessions. The default (2) is similar to enabled, except it creates a server session pool per network thread. This has the best performance characteristics. Note that setting this parameter to (2) will not work correctly unless the dedicated SSL threads are disabled (proxy.config.ssl.number.threads is set to (-1)).

                                                proxy.config.http.auth_server_session_private

                                                Scope
                                                    CONFIG.TP Type INT.TP Default 1.UNINDENT If enabled (1) anytime a request contains a (Authorization), (Proxy-Authorization) or (Www-Authenticate) header the connection will be closed and not reused. This marks the connection as private. When disabled (0) the connection will be available for reuse.

                                                    proxy.config.http.server_session_sharing.match

                                                    Scope
                                                        CONFIG.TP Type STRING.TP Default both.UNINDENT Enable and set the ability to re-use server connections across client connections. The valid values are

                                                        none
                                                            Do not match, do not re-use server sessions.

                                                        ip  Re-use server sessions, check only that the IP address and port of the origin server matches.

                                                        host
                                                            Re-use server sessions, check only that the fully qualified domain name matches.

                                                        both
                                                            Re-use server sessions, but only if the IP address and fully qualified domain name match.

                                                    It is strongly recommended to use either none or both for this value unless you have a specific need to use ip or host. The most common reason is virtual hosts that share an IP address in which case performance can be enhanced if those sessions can be re-used. However, not all web servers support requests for different virtual hosts on the same connection so use with caution.

                                                        proxy.config.http.server_session_sharing.pool

                                                        Scope
                                                            CONFIG.TP Type STRING.TP Default thread.UNINDENT Control the scope of server session re-use if it is enabled by proxy.config.http.server_session_sharing.match. The valid values are

                                                            global
                                                                Re-use sessions from a global pool of all server sessions.

                                                            thread
                                                                Re-use sessions from a per-thread pool.

                                                            proxy.config.http.attach_server_session_to_client

                                                            Scope
                                                                CONFIG.TP Type INT.TP Default 0.UNINDENT Control the re-use of an server session by a user agent (client) session.

                                                                If a user agent performs more than one HTTP transaction on its connection to Traffic Server a server session must be obtained for the second (and subsequent) transaction as for the first. This settings affects how that server session is selected.

                                                                If this setting is 0 then after the first transaction the server session for that transaction is released to the server pool (if any). When a server session is needed for subsequent transactions one is selected from the server pool or created if there is no suitable server session in the pool.

                                                                If this setting is not 0 then the current server session for the user agent session is "sticky". It will be preferred to any other server session (either from the pool or newly created). The server session will be detached from the user agent session only if it cannot be used for the transaction. This is determined by the proxy.config.http.server_session_sharing.match value. If the server session matches the next transaction according to this setting then it will be used, otherwise it will be released to the pool and a different session selected or created.

                                                                proxy.config.http.record_heartbeat

                                                                Scope
                                                                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) traffic_cop heartbeat logging.

                                                                    proxy.config.http.use_client_target_addr

                                                                    Scope
                                                                        CONFIG.TP Type INT.TP Default 0.UNINDENT For fully transparent ports use the same origin server address as the client.

                                                                        This option causes Traffic Server to avoid where possible doing DNS lookups in forward transparent proxy mode. The option is only effective if the following three conditions are true -

                                                                        •   Traffic Server is in forward proxy mode.

                                                                        •   The proxy port is inbound transparent.

                                                                        •   The target URL has not been modified by either remapping or a plugin.

                                                                    If any of these conditions are not true, then normal DNS processing is done for the connection.

                                                                    There are three valid values. * 0 - Disables the feature. * 1 - Enables the feature with address verification. The Proxy does the regular DNS processing. If the client-specified origin address is not in the set of addresses found by the Proxy, the request continues to the client specified address, but the result is not cached. * 2 - Enables the feature with no address verification. No DNS processing is performed. The result is cached (if allowed otherwise). This option is vulnerable to cache poisoning if an incorrect Host header is specified, so this option should be used with extreme caution. See bug TS-2954 for details.

                                                                    If all of these conditions are met, then the origin server IP address is retrieved from the original client connection, rather than through HostDB or DNS lookup. In effect, client DNS resolution is used instead of Traffic Server DNS.

                                                                    This can be used to be a little more efficient (looking up the target once by the client rather than by both the client and Traffic Server) but the primary use is when client DNS resolution can differ from that of Traffic Server. Two known uses cases are:

                                                                        1.  Embedded IP addresses in a protocol with DNS load sharing. In this case, even though Traffic Server and the client both make the same request to the same DNS resolver chain, they may get different origin server addresses. If the address is embedded in the protocol then the overall exchange will fail. One current example is Microsoft Windows update, which presumably embeds the address as a security measure.

                                                                        2.  The client has access to local DNS zone information which is not available to Traffic Server. There are corporate nets with local DNS information for internal servers which, by design, is not propagated outside the core corporate network. Depending a network topology it can be the case that Traffic Server can access the servers by IP address but cannot resolve such addresses by name. In such as case the client supplied target address must be used.

                                                                    This solution must be considered interim. In the longer term, it should be possible to arrange for much finer grained control of DNS lookup so that wildcard domain can be set to use Traffic Server or client resolution. In both known use cases, marking specific domains as client determined (rather than a single global switch) would suffice. It is possible to do this crudely with this flag by enabling it and then use identity URL mappings to re-disable it for specific domains.

                                                                        proxy.config.http.keep_alive_enabled_in

                                                                        Scope
                                                                            CONFIG.TP Type INT.TP Default 1.UNINDENT Enables (1) or disables (0) incoming keep-alive connections.

                                                                            proxy.config.http.keep_alive_enabled_out

                                                                            Scope
                                                                                CONFIG.TP Type INT.TP Default 1.UNINDENT
                                                                                    Enables (1) or disables (0) outgoing keep-alive connections.

                                                                            NOTE:
                                                                                    Enabling keep-alive does not automatically enable purging of keep-alive requests when nearing the connection limit, that is controlled by proxy.config.http.server_max_connections.

                                                                                proxy.config.http.keep_alive_post_out

                                                                                Scope
                                                                                    CONFIG.TP Type INT.TP Default 1.UNINDENT Controls wether new POST requests re-use keep-alive sessions (1) or create new connections per request (0).

                                                                                    proxy.config.http.send_408_post_timeout_response

                                                                                    Scope
                                                                                        CONFIG.TP Type INT.TP Default 0.UNINDENT Controls wether POST timeout sends a HTTP status 408 response (1)

                                                                                        proxy.config.http.disallow_post_100_continue

                                                                                        Scope
                                                                                            CONFIG.TP Type INT.TP Default 0.UNINDENT Allows you to return a 405 Method Not Supported with Posts also containing an Expect: 100-continue.

                                                                                            When a Post w/ Expect: 100-continue is blocked the stat proxy.process.http.disallowed_post_100_continue will be incremented.

PARENT PROXY CONFIGURATION

    proxy.config.http.parent_proxy_routing_enable

    Scope
        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) the parent caching option. Refer to hierarchical-caching.

        proxy.config.http.parent_proxy.retry_time

        Scope
            CONFIG.TP Type INT.TP Default 300.TP Reloadable Yes.UNINDENT The amount of time allowed between connection retries to a parent cache that is unavailable.

            proxy.config.http.parent_proxy.fail_threshold

            Scope
                CONFIG.TP Type INT.TP Default 10.TP Reloadable Yes.UNINDENT The number of times the connection to the parent cache can fail before Traffic Server considers the parent unavailable.

                proxy.config.http.parent_proxy.total_connect_attempts

                Scope
                    CONFIG.TP Type INT.TP Default 4.TP Reloadable Yes.UNINDENT The total number of connection attempts allowed to a parent cache before Traffic Server bypasses the parent or fails the request (depending on the go_direct option in the parent.config file).

                    proxy.config.http.parent_proxy.per_parent_connect_attempts

                    Scope
                        CONFIG.TP Type INT.TP Default 2.TP Reloadable Yes.UNINDENT The total number of connection attempts allowed per parent, if multiple parents are used.

                        proxy.config.http.parent_proxy.connect_attempts_timeout

                        Scope
                            CONFIG.TP Type INT.TP Default 30.TP Reloadable Yes.UNINDENT The timeout value (in seconds) for parent cache connection attempts.

                            proxy.config.http.forward.proxy_auth_to_parent

                            Scope
                                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Configures Traffic Server to send proxy authentication headers on to the parent cache.

                                proxy.config.http.no_dns_just_forward_to_parent

                                Scope
                                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Don't try to resolve DNS, forward all DNS requests to the parent. This is off (0) by default.

HTTP CONNECTION TIMEOUTS

    proxy.config.http.keep_alive_no_activity_timeout_in

    Scope
        CONFIG.TP Type INT.TP Default 115.TP Reloadable Yes.UNINDENT Specifies how long Traffic Server keeps connections to clients open for a subsequent request after a transaction ends. A value of 0 will disable the no activity timeout.

        proxy.config.http.keep_alive_no_activity_timeout_out

        Scope
            CONFIG.TP Type INT.TP Default 120.TP Reloadable Yes.UNINDENT Specifies how long Traffic Server keeps connections to origin servers open for a subsequent transfer of data after a transaction ends. A value of 0 will disable the no activity timeout.

            proxy.config.http.transaction_no_activity_timeout_in

            Scope
                CONFIG.TP Type INT.TP Default 30.TP Reloadable Yes.UNINDENT Specifies how long Traffic Server keeps connections to clients open if a transaction stalls.

                proxy.config.http.transaction_no_activity_timeout_out

                Scope
                    CONFIG.TP Type INT.TP Default 30.TP Reloadable Yes.UNINDENT Specifies how long Traffic Server keeps connections to origin servers open if the transaction stalls.

                    proxy.config.http.transaction_active_timeout_in

                    Scope
                        CONFIG.TP Type INT.TP Default 900.TP Reloadable Yes.UNINDENT The maximum amount of time Traffic Server can remain connected to a client. If the transfer to the client is not complete before this timeout expires, then Traffic Server closes the connection.

                        The value of 0 specifies that there is no timeout.

                        proxy.config.http.transaction_active_timeout_out

                        Scope
                            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT The maximum amount of time Traffic Server waits for fulfillment of a connection request to an origin server. If Traffic Server does not complete the transfer to the origin server before this timeout expires, then Traffic Server terminates the connection request.

                            The default value of 0 specifies that there is no timeout.

                            proxy.config.http.accept_no_activity_timeout

                            Scope
                                CONFIG.TP Type INT.TP Default 120.TP Reloadable Yes.UNINDENT The timeout interval in seconds before Traffic Server closes a connection that has no activity.

                                proxy.config.http.background_fill_active_timeout

                                Scope
                                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Specifies how long Traffic Server continues a background fill before giving up and dropping the origin server connection.

                                    proxy.config.http.background_fill_completed_threshold

                                    Scope
                                        CONFIG.TP Type FLOAT.TP Default 0.0.TP Reloadable Yes.UNINDENT The proportion of total document size already transferred when a client aborts at which the proxy continues fetching the document from the origin server to get it into the cache (a background fill).

ORIGIN SERVER CONNECT ATTEMPTS

    proxy.config.http.connect_attempts_max_retries

    Scope
        CONFIG.TP Type INT.TP Default 6.TP Reloadable Yes.UNINDENT The maximum number of connection retries Traffic Server can make when the origin server is not responding. Each retry attempt lasts for proxy.config.http.connect_attempts_timeout seconds. Once the maximum number of retries is reached, the origin is marked dead. After this, the setting proxy.config.http.connect_attempts_max_retries_dead_server is used to limit the number of retry attempts to the known dead origin.

        proxy.config.http.connect_attempts_max_retries_dead_server

        Scope
            CONFIG.TP Type INT.TP Default 3.TP Reloadable Yes.UNINDENT Maximum number of connection retries Traffic Server can make while an origin is marked dead. Typically this value is smaller than proxy.config.http.connect_attempts_max_retries so an error is returned to the client faster and also to reduce the load on the dead origin. The timeout interval proxy.config.http.connect_attempts_timeout in seconds is used with this setting.

            proxy.config.http.server_max_connections

            Scope
                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Limits the number of socket connections across all origin servers to the value specified. To disable, set to zero (0).

                NOTE:
                    This value is used in determining when and if to prune active origin sessions. Without this value set connections to origins can consume all the way up to ts:cv:proxy.config.net.connections_throttle connections, which in turn can starve incoming requests from available connections.

                proxy.config.http.origin_max_connections

                Scope
                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Limits the number of socket connections per origin server to the value specified. To enable, set to one (1).

                    proxy.config.http.origin_min_keep_alive_connections

                    Scope
                        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT As connection to an origin server are opened, keep at least 'n' number of connections open to that origin, even if the connection isn't used for a long time period. Useful when the origin supports keep-alive, removing the time needed to set up a new connection from the next request at the expense of added (inactive) connections. To enable, set to one (1).

                        proxy.config.http.connect_attempts_rr_retries

                        Scope
                            CONFIG.TP Type INT.TP Default 3.TP Reloadable Yes.UNINDENT The maximum number of failed connection attempts allowed before a round-robin entry is marked as 'down' if a server has round-robin DNS entries.

                            proxy.config.http.connect_attempts_timeout

                            Scope
                                CONFIG.TP Type INT.TP Default 30.TP Reloadable Yes.UNINDENT The timeout value (in seconds) for time to first byte for an origin server connection.

                                proxy.config.http.post_connect_attempts_timeout

                                Scope
                                    CONFIG.TP Type INT.TP Default 1800.TP Reloadable Yes.UNINDENT The timeout value (in seconds) for an origin server connection when the client request is a POST or PUT request.

                                    proxy.config.http.down_server.cache_time

                                    Scope
                                        CONFIG.TP Type INT.TP Default 300.TP Reloadable Yes.UNINDENT Specifies how long (in seconds) Traffic Server remembers that an origin server was unreachable.

                                        proxy.config.http.down_server.abort_threshold

                                        Scope
                                            CONFIG.TP Type INT.TP Default 10.TP Reloadable Yes.UNINDENT The number of seconds before Traffic Server marks an origin server as unavailable after a client abandons a request because the origin server was too slow in sending the response header.

                                            proxy.config.http.uncacheable_requests_bypass_parent

                                            Scope
                                                CONFIG.TP Type INT.TP Default 1.UNINDENT When enabled (1), Traffic Server bypasses the parent proxy for a request that is not cacheable.

CONGESTION CONTROL

    proxy.config.http.congestion_control.enabled

    Scope
        CONFIG.TP Type INT.TP Default 0.UNINDENT Enables (1) or disables (0) the Congestion Control option, which configures Traffic Server to stop forwarding HTTP requests to origin servers when they become congested. Traffic Server sends the client a message to retry the congested origin server later. Refer to using-congestion-control.

        proxy.config.http.flow_control.enabled

        Scope
            CONFIG.TP Type INT.TP Default 0.UNINDENT Transaction buffering / flow control is enabled if this is set to a non-zero value. Otherwise no flow control is done.

            proxy.config.http.flow_control.high_water

            Scope
                CONFIG.TP Type INT.TP Default 0.TP Metric bytes.UNINDENT The high water mark for transaction buffer control. External source I/O is halted when the total buffer space in use by the transaction exceeds this value.

                proxy.config.http.flow_control.low_water

                Scope
                    CONFIG.TP Type INT.TP Default 0.TP Metric bytes.UNINDENT The low water mark for transaction buffer control. External source I/O is resumed when the total buffer space in use by the transaction is no more than this value.

NEGATIVE RESPONSE CACHING

    proxy.config.http.negative_caching_enabled

    Scope
        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server caches negative responses (such as 404 Not Found) when a requested page does not exist. The next time a client requests the same page, Traffic Server serves the negative response directly from cache. When disabled (0) Traffic Server will only cache the response if the response has Cache-Control headers.

        NOTE:
            The following negative responses are cached by Traffic Server::

                    204  No Content
                    305  Use Proxy
                    400  Bad Request
                    403  Forbidden
                    404  Not Found
                    405  Method Not Allowed
                    500  Internal Server Error
                    501  Not Implemented
                    502  Bad Gateway
                    503  Service Unavailable
                    504  Gateway Timeout

    The cache lifetime for objects cached from this setting is controlled via proxy.config.http.negative_caching_lifetime.

        proxy.config.http.negative_caching_lifetime

        Scope
            CONFIG.TP Type INT.TP Default 1800.UNINDENT How long (in seconds) Traffic Server keeps the negative responses valid in cache. This value only affects negative responses that do have explicit Expires: or Cache-Control: lifetimes set by the server.

PROXY USER VARIABLES

    proxy.config.http.anonymize_remove_from

    Scope
        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server removes the From header to protect the privacy of your users.

        proxy.config.http.anonymize_remove_referer

        Scope
            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server removes the Referrer header to protect the privacy of your site and users.

            proxy.config.http.anonymize_remove_user_agent

            Scope
                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server removes the User-agent header to protect the privacy of your site and users.

                proxy.config.http.anonymize_remove_cookie

                Scope
                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server removes the Cookie header to protect the privacy of your site and users.

                    proxy.config.http.anonymize_remove_client_ip

                    Scope
                        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server removes Client-IP headers for more privacy.

                        proxy.config.http.anonymize_insert_client_ip

                        Scope
                            CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server inserts Client-IP headers to retain the client IP address.

                            proxy.config.http.anonymize_other_header_list

                            Scope
                                CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT Comma separated list of headers Traffic Server should remove from outgoing requests.

                                proxy.config.http.insert_squid_x_forwarded_for

                                Scope
                                    CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server adds the client IP address to the X-Forwarded-For header.

                                    proxy.config.http.normalize_ae_gzip

                                    Scope
                                        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enable (1) to normalize all Accept-Encoding: headers to one of the following:

                                        •   Accept-Encoding: gzip (if the header has gzip or x-gzip with any q) OR

                                        •   blank (for any header that does not include gzip)

                                    This is useful for minimizing cached alternates of documents (e.g. gzip, deflate vs. deflate, gzip). Enabling this option is recommended if your origin servers use no encodings other than gzip.

SECURITY

    proxy.config.http.push_method_enabled

    Scope
        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) the HTTP PUSH option, which allows you to deliver content directly to the cache without a user request.

        IMPORTANT:
            If you enable this option, then you must also specify a filtering rule in the ip_allow.config file to allow only certain machines to push content into the cache.

CACHE CONTROL

    proxy.config.cache.enable_read_while_writer

    Scope
        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Specifies when to enable the ability to read a cached object while another connection is completing the write to cache for that same object. The goal here is to avoid multiple origin connections for the same cacheable object upon a cache miss. The possible values of this config are:

        •   0 = never read while writing

        •   1 = always read while writing

        •   2 = always read while writing, but allow non-cached Range requests through to the origin

    The 2 option is useful to avoid delaying requests which can not easily be satisfied by the partially written response.

    Several other configuration values need to be set for this to be usable. See Reducing Origin Server Requests.

        proxy.config.cache.force_sector_size

        Scope
            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Forces the use of a specific hardware sector size (512 - 8192 bytes).

            proxy.config.http.cache.http

            Scope
                CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) caching of HTTP requests.

                proxy.config.http.cache.allow_empty_doc

                Scope
                    CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) caching objects that have an empty response body. This is particularly useful for caching 301 or 302 responses with a Location header but no document body. This only works if the origin response also has a Content-Length header.

                    proxy.config.http.cache.ignore_client_no_cache

                    Scope
                        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server ignores client requests to bypass the cache.

                        proxy.config.http.cache.ims_on_client_no_cache

                        Scope
                            CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server issues a conditional request to the origin server if an incoming request has a No-Cache header.

                            proxy.config.http.cache.ignore_server_no_cache

                            Scope
                                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server ignores origin server requests to bypass the cache.

                                proxy.config.http.cache.cache_responses_to_cookies

                                Scope
                                    CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Specifies how cookies are cached:

                                    •   0 = do not cache any responses to cookies

                                    •   1 = cache for any content-type

                                    •   2 = cache only for image types

                                    •   3 = cache for all but text content-types

                                    proxy.config.http.cache.ignore_authentication

                                    Scope
                                        CONFIG.TP Type INT.TP Default 0.UNINDENT When enabled (1), Traffic Server ignores WWW-Authentication headers in responses WWW-Authentication headers are removed and not cached.

                                        proxy.config.http.cache.cache_urls_that_look_dynamic

                                        Scope
                                            CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) caching of URLs that look dynamic, i.e.: URLs that end in ``.asp`` or contain a question mark (``?``), a semicolon (``;``), or ``cgi``. For a full list, please refer to HttpTransact::url_looks_dynamic

                                            proxy.config.http.cache.enable_default_vary_headers

                                            Scope
                                                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) caching of alternate versions of HTTP objects that do not contain the Vary header.

                                                proxy.config.http.cache.when_to_revalidate

                                                Scope
                                                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Specifies when to revalidate content:

                                                    •   0 = use cache directives or heuristic (the default value)

                                                    •   1 = stale if heuristic

                                                    •   2 = always stale (always revalidate)

                                                    •   3 = never stale

                                                    •

                                                        4 = use cache directives or heuristic (0) unless the request
                                                            has an If-Modified-Since header

                                                If the request contains the If-Modified-Since header, then Traffic Server always revalidates the cached content and uses the client's If-Modified-Since header for the proxy request.

                                                    proxy.config.http.cache.required_headers

                                                    Scope
                                                        CONFIG.TP Type INT.TP Default 2.TP Reloadable Yes.UNINDENT The type of headers required in a request for the request to be cacheable.

                                                        •   0 = no headers required to make document cacheable

                                                        •   1 = either the Last-Modified header, or an explicit lifetime header, Expires or Cache-Control: max-age, is required

                                                        •   2 = explicit lifetime is required, Expires or Cache-Control: max-age

                                                        proxy.config.http.cache.max_stale_age

                                                        Scope
                                                            CONFIG.TP Type INT.TP Default 604800.TP Reloadable Yes.UNINDENT The maximum age allowed for a stale response before it cannot be cached.

                                                            proxy.config.http.cache.range.lookup

                                                            Scope
                                                                CONFIG.TP Type INT.TP Default 1.UNINDENT When enabled (1), Traffic Server looks up range requests in the cache.

                                                                proxy.config.http.cache.range.write

                                                                Scope
                                                                    CONFIG.TP Type INT.TP Default 0.UNINDENT When enabled (1), Traffic Server will attempt to write (lock) the URL to cache. This is rarely useful (at the moment), since it'll only be able to write to cache if the origin has ignored the Range:` header. For a use case where you know the origin will respond with a full (``200) response, you can turn this on to allow it to be cached.

                                                                    proxy.config.http.cache.ignore_accept_mismatch

                                                                    Scope
                                                                        CONFIG.TP Type INT.TP Default 2.TP Reloadable Yes.UNINDENT When enabled with a value of 1, Traffic Server serves documents from cache with a Content-Type: header even if it does not match the Accept: header of the request. If set to 2 (default), this logic only happens in the absence of a Vary header in the cached response (which is the recommended and safe use).

                                                                        NOTE:
                                                                            This option should only be enabled with 1 if you're having problems with caching and you origin server doesn't set the Vary header. Alternatively, if the origin is incorrectly setting Vary: Accept or doesn't respond with 406 (Not Acceptable), you can also enable this configuration with a 1.

                                                                        proxy.config.http.cache.ignore_accept_language_mismatch

                                                                        Scope
                                                                            CONFIG.TP Type INT.TP Default 2.TP Reloadable Yes.UNINDENT When enabled with a value of 1, Traffic Server serves documents from cache with a Content-Language: header even if it does not match the Accept-Language: header of the request. If set to 2 (default), this logic only happens in the absence of a Vary header in the cached response (which is the recommended and safe use).

                                                                            NOTE:
                                                                                This option should only be enabled with 1 if you're having problems with caching and you origin server doesn't set the Vary header. Alternatively, if the origin is incorrectly setting Vary: Accept-Language or doesn't respond with 406 (Not Acceptable), you can also enable this configuration with a 1.

                                                                            proxy.config.http.cache.ignore_accept_encoding_mismatch

                                                                            Scope
                                                                                CONFIG.TP Type INT.TP Default 2.TP Reloadable Yes.UNINDENT When enabled with a value of 1, Traffic Server serves documents from cache with a Content-Encoding: header even if it does not match the Accept-Encoding: header of the request. If set to 2 (default), this logic only happens in the absence of a Vary header in the cached response (which is the recommended and safe use).

                                                                                NOTE:
                                                                                    This option should only be enabled with 1 if you're having problems with caching and you origin server doesn't set the Vary header. Alternatively, if the origin is incorrectly setting Vary: Accept-Encoding or doesn't respond with 406 (Not Acceptable) you can also enable this configuration with a 1.

                                                                                proxy.config.http.cache.ignore_accept_charset_mismatch

                                                                                Scope
                                                                                    CONFIG.TP Type INT.TP Default 2.TP Reloadable Yes.UNINDENT When enabled with a value of 1, Traffic Server serves documents from cache with a Content-Type: header even if it does not match the Accept-Charset: header of the request. If set to 2 (default), this logic only happens in the absence of a Vary header in the cached response (which is the recommended and safe use).

                                                                                    NOTE:
                                                                                        This option should only be enabled with 1 if you're having problems with caching and you origin server doesn't set the Vary header. Alternatively, if the origin is incorrectly setting Vary: Accept-Charset or doesn't respond with 406 (Not Acceptable), you can also enable this configuration with a 1.

                                                                                    proxy.config.http.cache.ignore_client_cc_max_age

                                                                                    Scope
                                                                                        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server ignores any Cache-Control: max-age headers from the client. This technically violates the HTTP RFC, but avoids a problem where a client can forcefully invalidate a cached object.

                                                                                        proxy.config.cache.max_doc_size

                                                                                        Scope
                                                                                            CONFIG.TP Type INT.TP Default 0.UNINDENT Specifies the maximum object size that will be cached. 0 is unlimited.

                                                                                            proxy.config.cache.permit.pinning

                                                                                            Scope
                                                                                                CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT When enabled (1), Traffic Server will keep certain HTTP objects in the cache for a certain time as specified in cache.config.

                                                                                                proxy.config.cache.hit_evacuate_percent

                                                                                                Scope
                                                                                                    CONFIG.TP Type INT.TP Default 0.UNINDENT The size of the region (as a percentage of the total content storage in a cache stripe) in front of the write cursor that constitutes a recent access hit for evacutating the accessed object.

                                                                                                    When an object is accessed it can be marked for evacuation, that is to be copied over the write cursor and thereby preserved from being overwritten. This is done if it is no more than a specific number of bytes in front of the write cursor. The number of bytes is a percentage of the total number of bytes of content storage in the cache stripe where the object is stored and that percentage is set by this variable.

                                                                                                    By default, the feature is off (set to 0).

                                                                                                    proxy.config.cache.hit_evacuate_size_limit

                                                                                                    Scope
                                                                                                        CONFIG.TP Type INT.TP Default 0.TP Metric bytes.UNINDENT Limit the size of objects that are hit evacuated.

                                                                                                        Objects larger than the limit are not hit evacuated. A value of 0 disables the limit.

                                                                                                        proxy.config.cache.limits.http.max_alts

                                                                                                        Scope
                                                                                                            CONFIG.TP Type INT.TP Default 5.UNINDENT The maximum number of alternates that are allowed for any given URL. Disable by setting to 0.

                                                                                                            proxy.config.cache.target_fragment_size

                                                                                                            Scope
                                                                                                                CONFIG.TP Type INT.TP Default 1048576.UNINDENT Sets the target size of a contiguous fragment of a file in the disk cache. When setting this, consider that larger numbers could waste memory on slow connections, but smaller numbers could increase (waste) seeks.

RAM CACHE

    proxy.config.cache.ram_cache.size

    Scope
        CONFIG.TP Type INT.TP Default -1.UNINDENT By default the RAM cache size is automatically determined, based on disk cache size; approximately 10 MB of RAM cache per GB of disk cache. Alternatively, it can be set to a fixed value such as 20GB (21474836480)

        proxy.config.cache.ram_cache_cutoff

        Scope
            CONFIG.TP Type INT.TP Default 4194304.UNINDENT Objects greater than this size will not be kept in the RAM cache. This should be set high enough to keep objects accessed frequently in memory in order to improve performance. 4MB (4194304)

            proxy.config.cache.ram_cache.algorithm

            Scope
                CONFIG.TP Type INT.TP Default 0.UNINDENT Two distinct RAM caches are supported, the default (0) being the CLFUS (Clocked Least Frequently Used by Size). As an alternative, a simpler LRU (Least Recently Used) cache is also available, by changing this configuration to 1.

                proxy.config.cache.ram_cache.use_seen_filter

                Scope
                    CONFIG.TP Type INT.TP Default 0.UNINDENT Enabling this option will filter inserts into the RAM cache to ensure that they have been seen at least once. For the LRU, this provides scan resistance. Note that CLFUS already requires that a document have history before it is inserted, so for CLFUS, setting this option means that a document must be seen three times before it is added to the RAM cache.

                    proxy.config.cache.ram_cache.compress

                    Scope
                        CONFIG.TP Type INT.TP Default 0.UNINDENT The CLFUS RAM cache also supports an optional in-memory compression. This is not to be confused with Content-Encoding: gzip compression. The RAM cache compression is intended to try to save space in the RAM, and is not visible to the User-Agent (client).

                        Possible values are:

                        •   0 = no compression

                        •   1 = fastlz (extremely fast, relatively low compression)

                        •   2 = libz (moderate speed, reasonable compression)

                        •   3 = liblzma (very slow, high compression)

                    NOTE:
                            Compression runs on task threads. To use more cores for RAM cache compression, increase proxy.config.task_threads.

HEURISTIC EXPIRATION

    proxy.config.http.cache.heuristic_min_lifetime

    Scope
        CONFIG.TP Type INT.TP Default 3600.TP Reloadable Yes.UNINDENT The minimum amount of time an HTTP object without an expiration date can remain fresh in the cache before is considered to be stale.

        proxy.config.http.cache.heuristic_max_lifetime

        Scope
            CONFIG.TP Type INT.TP Default 86400.TP Reloadable Yes.UNINDENT The maximum amount of time an HTTP object without an expiration date can remain fresh in the cache before is considered to be stale.

            proxy.config.http.cache.heuristic_lm_factor

            Scope
                CONFIG.TP Type FLOAT.TP Default 0.10.TP Reloadable Yes.UNINDENT The aging factor for freshness computations. Traffic Server stores an object for this percentage of the time that elapsed since it last changed.

                proxy.config.http.cache.fuzz.time

                Scope
                    CONFIG.TP Type INT.TP Default 240.TP Reloadable Yes.UNINDENT How often Traffic Server checks for an early refresh, during the period before the document stale time. The interval specified must be in seconds. See fuzzy-revalidation

                    proxy.config.http.cache.fuzz.probability

                    Scope
                        CONFIG.TP Type FLOAT.TP Default 0.005.TP Reloadable Yes.UNINDENT The probability that a refresh is made on a document during the specified fuzz time.

                        proxy.config.http.cache.fuzz.min_time

                        Scope
                            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Handles requests with a TTL less than fuzz.time – it allows for different times to evaluate the probability of revalidation for small TTLs and big TTLs. Objects with small TTLs will start "rolling the revalidation dice" near the fuzz.min_time, while objects with large TTLs would start at fuzz.time. A logarithmic like function between determines the revalidation evaluation start time (which will be between fuzz.min_time and fuzz.time). As the object gets closer to expiring, the window start becomes more likely. By default this setting is not enabled, but should be enabled anytime you have objects with small TTLs. The default value is 0.

DYNAMIC CONTENT & CONTENT NEGOTIATION

    proxy.config.http.cache.vary_default_text

    Scope
        CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The header on which Traffic Server varies for text documents.

        For example: if you specify User-agent, then Traffic Server caches all the different user-agent versions of documents it encounters.

        proxy.config.http.cache.vary_default_images

        Scope
            CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The header on which Traffic Server varies for images.

            proxy.config.http.cache.vary_default_other

            Scope
                CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The header on which Traffic Server varies for anything other than text and images.

CUSTOMIZABLE USER RESPONSE PAGES

    proxy.config.body_factory.enable_customizations

    Scope
        CONFIG.TP Type INT.TP Default 1.UNINDENT Specifies whether customizable response pages are language specific or not:

        •   1 = enable customizable user response pages in the default directory only

        •   2 = enable language-targeted user response pages

        proxy.config.body_factory.enable_logging

        Scope
            CONFIG.TP Type INT.TP Default 0.UNINDENT Enables (1) or disables (0) logging for customizable response pages. When enabled, Traffic Server records a message in the error log each time a customized response page is used or modified.

            proxy.config.body_factory.template_sets_dir

            Scope
                CONFIG.TP Type STRING.TP Default etc/trafficserver/body_factory.UNINDENT The customizable response page default directory. If this is a relative path, Traffic Server resolves it relative to the PREFIX directory.

                proxy.config.body_factory.response_suppression_mode

                Scope
                    CONFIG.TP Type INT.TP Default 0.UNINDENT Specifies when Traffic Server suppresses generated response pages:

                    •   0 = never suppress generated response pages

                    •   1 = always suppress generated response pages

                    •   2 = suppress response pages only for intercepted traffic

                    proxy.config.http_ui_enabled

                    Scope
                        CONFIG.TP Type INT.TP Default 0.UNINDENT Specifies which http UI endpoints to allow within remap.config:

                        •   0 = disable all http UI endpoints

                        •   1 = enable only cache endpoints

                        •   2 = enable only stats endpoints

                        •   3 = enable all http UI endpoints

                    To enable any enpoint there needs to be an entry in remap.config which specifically enables it. Such a line would look like:

                            map / http://{stat}

                    The following are the cache endpoints:

                        •   cache = UI to interact with the cache

                    The following are the stats endpoints:

                        •   cache-internal = statistics about cache evacuation and volumes

                        •   hostdb = lookups against the hostdb

                        •   http = HTTPSM details, this endpoint is also gated by proxy.config.http.enable_http_info

                        •   net = lookup and listing of open connections

                        •   stat = list of all records.config options and metrics

                        •   test = test callback page

                        proxy.config.http.enable_http_info

                        Scope
                            CONFIG.TP Type INT.TP Default 0.UNINDENT Enables (1) or disables (0) access to an endpoint within proxy.config.http_ui_enabled which shows details about inflight transactions (HttpSM).

DNS

    proxy.config.dns.search_default_domains

    Scope
        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) local domain expansion.

        Traffic Server can attempt to resolve unqualified hostnames by expanding to the local domain. For example if a client makes a request to an unqualified host (host_x) and the Traffic Server local domain is y.com , then Traffic Server will expand the hostname to host_x.y.com.

        proxy.config.dns.splitDNS.enabled

        Scope
            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) DNS server selection. When enabled, Traffic Server refers to the splitdns.config file for the selection specification. Refer to Configuring DNS Server Selection (Split DNS).

            proxy.config.dns.url_expansions

            Scope
                CONFIG.TP Type STRING.TP Default NULL.UNINDENT Specifies a list of hostname extensions that are automatically added to the hostname after a failed lookup. For example: if you want Traffic Server to add the hostname extension .org, then specify org as the value for this variable (Traffic Server automatically adds the dot (.)).

                NOTE:
                    If the variable proxy.config.http.enable_url_expandomatic is set to 1 (the default value), then you do not have to add ``www.`` and ``.com`` to this list because Traffic Server automatically tries www. and .com after trying the values you've specified.

                proxy.config.dns.resolv_conf

                Scope
                    CONFIG.TP Type STRING.TP Default /etc/resolv.conf.UNINDENT Allows to specify which resolv.conf file to use for finding resolvers. While the format of this file must be the same as the standard resolv.conf file, this option allows an administrator to manage the set of resolvers in an external configuration file, without affecting how the rest of the operating system uses DNS.

                    proxy.config.dns.round_robin_nameservers

                    Scope
                        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) DNS server round-robin.

                        proxy.config.dns.nameservers

                        Scope
                            CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The DNS servers.

                            proxy.config.srv_enabled

                            Scope
                                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Indicates whether to use SRV records for orgin server lookup.

                                proxy.config.dns.dedicated_thread

                                Scope
                                    CONFIG.TP Type INT.TP Default 0.UNINDENT Create and dedicate a thread entirely for DNS processing. This is probably most useful on system which do a significant number of DNS lookups, typically forward proxies. But even on other systems, it can avoid some contention on the first worker thread (which otherwise takes on the burden of all DNS lookups).

                                    proxy.config.dns.validate_query_name

                                    Scope
                                        CONFIG.TP Type INT.TP Default 0.UNINDENT When enabled (1) provides additional resilience against DNS forgery (for instance in DNS Injection attacks), particularly in forward or transparent proxies, but requires that the resolver populates the queries section of the response properly.

HOSTDB

    proxy.config.hostdb.lookup_timeout

    Scope
        CONFIG.TP Type INT.TP Default 120.TP Metric seconds.TP Reloadable Yes.UNINDENT Time to wait for a DNS response in seconds.

        proxy.config.hostdb.serve_stale_for

        Scope
            CONFIG.TP Type INT.TP Default *NONE*.TP Metric seconds.TP Reloadable Yes.UNINDENT The number of seconds for which to use a stale NS record while initiating a background fetch for the new data.

            If not set then stale records are not served.

            proxy.config.hostdb.storage_size

            Scope
                CONFIG.TP Type INT.TP Default 33554432.TP Metric bytes.UNINDENT The amount of space (in bytes) used to store hostdb. The value of this variable must be increased if you increase the size of the proxy.config.hostdb.size variable.

                proxy.config.hostdb.size

                Scope
                    CONFIG.TP Type INT.TP Default 120000.UNINDENT The maximum number of entries that can be stored in the database.

                    NOTE:
                        For values above 200000, you must increase proxy.config.hostdb.storage_size by at least 44 bytes per entry.

                    proxy.config.hostdb.ttl_mode

                    Scope
                        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT A host entry will eventually time out and be discarded. This variable controls how that time is calculated. A DNS request will return a TTL value and an internal value can be set with proxy.config.hostdb.timeout. This variable determines which value will be used.
                        Value | TTL
                        0 | The TTL from the DNS response.
                        1 | The internal timeout value.
                        2 | The smaller of the DNS and internal TTL values. The internal timeout value becomes a maximum TTL.
                        3 | The larger of the DNS and internal TTL values. The internal timeout value become a minimum TTL.

                        proxy.config.hostdb.timeout

                        Scope
                            CONFIG.TP Type INT.TP Default 1440.TP Metric minutes.TP Reloadable Yes.UNINDENT Internal time to live value for host DB entries, in minutes.

                            See proxy.config.hostdb.ttl_mode for when this value is used.

                            proxy.config.hostdb.strict_round_robin

                            Scope
                                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Set host resolution to use strict round robin.

                                When this and proxy.config.hostdb.timed_round_robin are both disabled (set to 0), Traffic Server always uses the same origin server for the same client, for as long as the origin server is available. Otherwise if this is set then IP address is rotated on every request. This setting takes precedence over proxy.config.hostdb.timed_round_robin.

                                proxy.config.hostdb.timed_round_robin

                                Scope
                                    CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Set host resolution to use timed round robin.

                                    When this and proxy.config.hostdb.strict_round_robin are both disabled (set to 0), Traffic Server always uses the same origin server for the same client, for as long as the origin server is available. Otherwise if this is set to N the IP address is rotated if more than N seconds have past since the first time the current address was used.

                                    proxy.config.hostdb.host_file.path

                                    Scope
                                        CONFIG.TP Type STRING.TP Default /etc/hosts.UNINDENT Set the file path for an external host file.

                                        If this is set (non-empty) then the file is presumed to be a hosts file in the standard host file format. It is read and the entries there added to the HostDB. The file is periodically checked for a more recent modification date in which case it is reloaded. The interval is set by the value proxy.config.hostdb.host_file.interval.

                                        While not technically reloadable, the value is read every time the file is to be checked so that if changed the new value will be used on the next check and the file will be treated as modified.

                                        proxy.config.hostdb.host_file.interval

                                        Scope
                                            CONFIG.TP Type INT.TP Default 86400.TP Metric seconds.TP Reloadable Yes.UNINDENT Set the file changed check timer for proxy.config.hostdb.host_file.path.

                                            The file is checked every this many seconds to see if it has changed. If so the HostDB is updated with the new values in the file.

                                            proxy.config.hostdb.ip_resolve

                                            Scope
                                                CONFIG.TP Type STRING.TP Default NULL.UNINDENT Set the host resolution style.

                                                This is an ordered list of keywords separated by semicolons that specify how a host name is to be resolved to an IP address. The keywords are case insensitive.
                                                Keyword | Meaning
                                                ipv4 | Resolve to an IPv4 address.
                                                ipv6 | Resolve to an IPv6 address.
                                                client | Resolve to the same family as the client IP address.
                                                none | Stop resolving.

                                                The order of the keywords is critical. When a host name needs to be resolved it is resolved in same order as the keywords. If a resolution fails, the next option in the list is tried. The keyword none means to give up resolution entirely. The keyword list has a maximum length of three keywords, more are never needed. By default there is an implicit ipv4;ipv6 attached to the end of the string unless the keyword none appears.

  Example

Use the incoming client family, then try IPv4 and IPv6.

        client;ipv4;ipv6

Because of the implicit resolution this can also be expressed as just

        client

  Example

Resolve only to IPv4.

        ipv4;none

  Example

Resolve only to the same family as the client (do not permit cross family transactions).

        client;none

This value is a global default that can be overridden by proxy.config.http.server_ports.

NOTE:
        This style is used as a convenience for the administrator. During a resolution the resolution order will be one family, then possibly the other. This is determined by changing client to ipv4 or ipv6 based on the client IP address and then removing duplicates.

IMPORTANT:
        This option has no effect on outbound transparent connections The local IP address used in the connection to the origin server is determined by the client, which forces the IP address family of the address used for the origin server. In effect, outbound transparent connections always use a resolution style of "client".

LOGGING CONFIGURATION

    proxy.config.log.logging_enabled

    Scope
        CONFIG.TP Type INT.TP Default 3.TP Reloadable Yes.UNINDENT Enables and disables event logging:

        •   0 = logging disabled

        •   1 = log errors only

        •   2 = log transactions only

        •   3 = full logging (errors + transactions)

    Refer to working-with-log-files.

        proxy.config.log.max_secs_per_buffer

        Scope
            CONFIG.TP Type INT.TP Default 5.TP Reloadable Yes.UNINDENT The maximum amount of time before data in the buffer is flushed to disk.

            proxy.config.log.max_space_mb_for_logs

            Scope
                CONFIG.TP Type INT.TP Default 25000.TP Metric megabytes.TP Reloadable Yes.UNINDENT The amount of space allocated to the logging directory (in MB).

                NOTE:
                    All files in the logging directory contribute to the space used, even if they are not log files. In collation client mode, if there is no local disk logging, or proxy.config.log.max_space_mb_for_orphan_logs is set to a higher value than proxy.config.log.max_space_mb_for_logs, TS will take proxy.config.log.max_space_mb_for_orphan_logs for maximum allowed log space.

                proxy.config.log.max_space_mb_for_orphan_logs

                Scope
                    CONFIG.TP Type INT.TP Default 25.TP Metric megabytes.TP Reloadable Yes.UNINDENT The amount of space allocated to the logging directory (in MB) if this node is acting as a collation client.

                    NOTE:
                        When max_space_mb_for_orphan_logs is take as the maximum allowed log space in the logging system, the same rule apply to proxy.config.log.max_space_mb_for_logs also apply to proxy.config.log.max_space_mb_for_orphan_logs, ie: All files in the logging directory contribute to the space used, even if they are not log files. you may need to consider this when you enable full remote logging, and bump to the same size as proxy.config.log.max_space_mb_for_logs.

                    proxy.config.log.max_space_mb_headroom

                    Scope
                        CONFIG.TP Type INT.TP Default 1000.TP Metric megabytes.TP Reloadable Yes.UNINDENT The tolerance for the log space limit (in megabytes). If the variable proxy.config.log.auto_delete_rolled_files is set to 1 (enabled), then autodeletion of log files is triggered when the amount of free space available in the logging directory is less than the value specified here.

                        proxy.config.log.hostname

                        Scope
                            CONFIG.TP Type STRING.TP Default localhost.TP Reloadable Yes.UNINDENT The hostname of the machine running Traffic Server.

                            proxy.config.log.logfile_dir

                            Scope
                                CONFIG.TP Type STRING.TP Default var/log/trafficserver.TP Reloadable Yes.UNINDENT The path to the logging directory. This can be an absolute path or a path relative to the PREFIX directory in which Traffic Server is installed.

                                NOTE:
                                    The directory you specify must already exist.

                                proxy.config.log.logfile_perm

                                Scope
                                    CONFIG.TP Type STRING.TP Default rw-r--r--.TP Reloadable Yes.UNINDENT The log file permissions. The standard UNIX file permissions are used (owner, group, other). Permissible values are:

                                    - no permission r read permission w write permission x execute permission

                                    Permissions are subject to the umask settings for the Traffic Server process. This means that a umask setting of002 will not allow write permission for others, even if specified in the configuration file. Permissions for existing log files are not changed when the configuration is changed.

                                    proxy.config.log.custom_logs_enabled

                                    Scope
                                        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) custom logging.

                                        proxy.config.log.squid_log_enabled

                                        Scope
                                            CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) the squid log file format.

                                            proxy.config.log.squid_log_is_ascii

                                            Scope
                                                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT The squid log file type:

                                                •   1 = ASCII

                                                •   0 = binary

                                                proxy.config.log.squid_log_name

                                                Scope
                                                    CONFIG.TP Type STRING.TP Default squid.TP Reloadable Yes.UNINDENT The squid log filename.

                                                    proxy.config.log.squid_log_header

                                                    Scope
                                                        CONFIG.TP Type STRING.TP Default NULL.UNINDENT The squid log file header text.

                                                        proxy.config.log.common_log_enabled

                                                        Scope
                                                            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) the Netscape common log file format.

                                                            proxy.config.log.common_log_is_ascii

                                                            Scope
                                                                CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT The Netscape common log file type:

                                                                •   1 = ASCII

                                                                •   0 = binary

                                                                proxy.config.log.common_log_name

                                                                Scope
                                                                    CONFIG.TP Type STRING.TP Default common.TP Reloadable Yes.UNINDENT The Netscape common log filename.

                                                                    proxy.config.log.common_log_header

                                                                    Scope
                                                                        CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The Netscape common log file header text.

                                                                        proxy.config.log.extended_log_enabled

                                                                        Scope
                                                                            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) the Netscape extended log file format.

                                                                            proxy.config.log.extended_log_is_ascii

                                                                            Scope
                                                                                CONFIG.TP Type INT.TP Default 0.UNINDENT The Netscape extended log file type:

                                                                                •   1 = ASCII

                                                                                •   0 = binary

                                                                                proxy.config.log.extended_log_name

                                                                                Scope
                                                                                    CONFIG.TP Type STRING.TP Default extended.UNINDENT The Netscape extended log filename.

                                                                                    proxy.config.log.extended_log_header

                                                                                    Scope
                                                                                        CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The Netscape extended log file header text.

                                                                                        proxy.config.log.extended2_log_enabled

                                                                                        Scope
                                                                                            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) the Netscape Extended-2 log file format.

                                                                                            proxy.config.log.extended2_log_is_ascii

                                                                                            Scope
                                                                                                CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT The Netscape Extended-2 log file type:

                                                                                                •   1 = ASCII

                                                                                                •   0 = binary

                                                                                                proxy.config.log.extended2_log_name

                                                                                                Scope
                                                                                                    CONFIG.TP Type STRING.TP Default extended2.TP Reloadable Yes.UNINDENT The Netscape Extended-2 log filename.

                                                                                                    proxy.config.log.extended2_log_header

                                                                                                    Scope
                                                                                                        CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The Netscape Extended-2 log file header text.

                                                                                                        proxy.config.log.separate_icp_logs

                                                                                                        Scope
                                                                                                            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), configures Traffic Server to store ICP transactions in a separate log file.

                                                                                                            •   0 = separation is disabled, all ICP transactions are recorded in the same file as HTTP transactions

                                                                                                            •   1 = all ICP transactions are recorded in a separate log file.

                                                                                                            •   -1 = filter all ICP transactions from the default log files; ICP transactions are not logged anywhere.

                                                                                                            proxy.config.log.separate_host_logs

                                                                                                            Scope
                                                                                                                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), configures Traffic Server to create a separate log file for HTTP transactions for each origin server listed in the log_hosts.config file. Refer to HTTP Host Log Splitting.

                                                                                                                proxy.local.log.collation_mode

                                                                                                                Scope
                                                                                                                    LOCAL.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Set the log collation mode.
                                                                                                                    Value | Effect
                                                                                                                    0 | collation is disabled
                                                                                                                    1 | this host is a log collation server
                                                                                                                    2 | this host is a collation client and sends entries using standard formats to the collation server
                                                                                                                    3 | this host is a collation client and sends entries using the traditional custom formats to the collation server
                                                                                                                    4 | this host is a collation client and sends entries that use both the standard and traditional custom formats to the collation server

                                                                                                                    For information on sending XML-based custom formats to the collation server, refer to logs_xml.config.

                                                                                                                    NOTE:
                                                                                                                        Although Traffic Server supports traditional custom logging, you should use the more versatile XML-based custom formats.

                                                                                                                    proxy.config.log.collation_host

                                                                                                                    Scope
                                                                                                                        CONFIG.TP Type STRING.TP Default NULL.UNINDENT The hostname of the log collation server.

                                                                                                                        proxy.config.log.collation_port

                                                                                                                        Scope
                                                                                                                            CONFIG.TP Type INT.TP Default 8085.TP Reloadable Yes.UNINDENT The port used for communication between the collation server and client.

                                                                                                                            proxy.config.log.collation_secret

                                                                                                                            Scope
                                                                                                                                CONFIG.TP Type STRING.TP Default foobar.TP Reloadable Yes.UNINDENT The password used to validate logging data and prevent the exchange of unauthorized information when a collation server is being used.

                                                                                                                            proxy.config.log.collation_host_tagged

                                                                                                                            Scope
                                                                                                                                CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT When enabled (1), configures Traffic Server to include the hostname of the collation client that generated the log entry in each entry.

                                                                                                                            proxy.config.log.collation_retry_sec

                                                                                                                            Scope
                                                                                                                                CONFIG.TP Type INT.TP Default 5.TP Reloadable Yes.UNINDENT The number of seconds between collation server connection retries.

                                                                                                                            proxy.config.log.rolling_enabled

                                                                                                                            Scope
                                                                                                                                CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Specifies how log files are rolled. You can specify the following values:

                                                                                                                            •   0 = disables log file rolling

                                                                                                                            •

                                                                                                                            1 = enables log file rolling at specific intervals during the day (specified with the
                                                                                                                                proxy.config.log.rolling_interval_sec and proxy.config.log.rolling_offset_hr variables)

                                                                                                                        •   2 = enables log file rolling when log files reach a specific size (specified with the proxy.config.log.rolling_size_mb variable)

                                                                                                                        •   3 = enables log file rolling at specific intervals during the day or when log files reach a specific size (whichever occurs first)

                                                                                                                        •

                                                                                                                            4 = enables log file rolling at specific intervals during the day when log files reach a specific size (i.e., at a specified
                                                                                                                                time if the file is of the specified size)

                                                                                                                        proxy.config.log.rolling_interval_sec

                                                                                                                        Scope
                                                                                                                            CONFIG.TP Type INT.TP Default 86400.TP Reloadable Yes.UNINDENT The log file rolling interval, in seconds. The minimum value is 60 (1 minute). The maximum, and default, value is 86400 seconds (one day).

                                                                                                                            NOTE:
                                                                                                                            If you start Traffic Server within a few minutes of the next rolling time, then rolling might not occur until the next rolling time.

                                                                                                                        proxy.config.log.rolling_offset_hr

                                                                                                                        Scope
                                                                                                                            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT The file rolling offset hour. The hour of the day that starts the log rolling period.

                                                                                                                            proxy.config.log.rolling_size_mb

                                                                                                                            Scope
                                                                                                                                CONFIG.TP Type INT.TP Default 10.TP Reloadable Yes.UNINDENT The size that log files must reach before rolling takes place.

                                                                                                                            proxy.config.log.auto_delete_rolled_files

                                                                                                                            Scope
                                                                                                                                CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) automatic deletion of rolled files.

                                                                                                                            proxy.config.log.sampling_frequency

                                                                                                                            Scope
                                                                                                                                CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Configures Traffic Server to log only a sample of transactions rather than every transaction. You can specify the following values:

                                                                                                                            •   1 = log every transaction

                                                                                                                            •   2 = log every second transaction

                                                                                                                            •   3 = log every third transaction and so on...

                                                                                                                            proxy.config.http.slow.log.threshold

                                                                                                                            Scope
                                                                                                                                CONFIG.TP Type INT.TP Default 0.TP Metric milliseconds.TP Reloadable Yes.UNINDENT If set to a non-zero value N then any connection that takes longer than N milliseconds from accept to completion will cause its timing stats to be written to the debugging log file. This is identifying data about the transaction and all of the transaction milestones.

DIAGNOSTIC LOGGING CONFIGURATION

    proxy.config.diags.output.diag

    Scope
        CONFIG.TP Type STRING.TP Default E.UNINDENT

        proxy.config.diags.output.debug

        Scope
            CONFIG.TP Type STRING.TP Default E.UNINDENT

            proxy.config.diags.output.status

            Scope
                CONFIG.TP Type STRING.TP Default L.UNINDENT

                proxy.config.diags.output.note

                Scope
                    CONFIG.TP Type STRING.TP Default L.UNINDENT

                    proxy.config.diags.output.warning

                    Scope
                        CONFIG.TP Type STRING.TP Default L.UNINDENT

                        proxy.config.diags.output.error

                        Scope
                            CONFIG.TP Type STRING.TP Default SL.UNINDENT

                            proxy.config.diags.output.fatal

                            Scope
                                CONFIG.TP Type STRING.TP Default SL.UNINDENT

                                proxy.config.diags.output.alert

                                Scope
                                    CONFIG.TP Type STRING.TP Default L.UNINDENT

                                    proxy.config.diags.output.emergency

                                    Scope
                                        CONFIG.TP Type STRING.TP Default SL.UNINDENT The diagnosic output configuration variables control where Traffic Server should log diagnostic output. Messages at each diagnostic level can be directed to any combination of diagnostic destinations. Valid diagnostic message destinations are:

                                        •   'O' = Log to standard output

                                        •   'E' = Log to standard error

                                        •   'S' = Log to syslog

                                        •   'L' = Log to diags.log

  Example

To log debug diagnostics to both syslog and diags.log:

        CONFIG proxy.config.diags.output.debug STRING SL

    proxy.config.diags.show_location

    Scope
        CONFIG.TP Type INT.TP Default 1.UNINDENT Annotates diagnostic messages with the source code location.

        proxy.config.diags.debug.enabled

        Scope
            CONFIG.TP Type INT.TP Default 0.UNINDENT Enables logging for diagnostic messages whose log level is diag or debug.

            proxy.config.diags.debug.tags

            Scope
                CONFIG.TP Type STRING.TP Default http.*|dns.*.UNINDENT Each Traffic Server diag and debug level message is annotated with a subsytem tag. This configuration contains a regular expression that filters the messages based on the tag. Some commonly used debug tags are:
                Tag | Subsytem usage
                dns | DNS query resolution
                http_hdrs | Logs the headers for HTTP requests and responses
                privileges | Privilege elevation
                ssl | TLS termination and certificate processing
                    Traffic Server plugins will typically log debug messages using the TSDebug() API, passing the plugin name as the debug tag.

REVERSE PROXY

    proxy.config.reverse_proxy.enabled

    Scope
        CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) HTTP reverse proxy.

        proxy.config.header.parse.no_host_url_redirect

        Scope
            CONFIG.TP Type STRING.TP Default NULL.TP Reloadable Yes.UNINDENT The URL to which to redirect requests with no host headers (reverse proxy).

URL REMAP RULES

    proxy.config.url_remap.filename

    Scope
        CONFIG.TP Type STRING.TP Default remap.config.UNINDENT Sets the name of the remap.config file.

        proxy.config.url_remap.default_to_server_pac

        Scope
            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) requests for a PAC file on the proxy service port (8080 by default) to be redirected to the PAC port. For this type of redirection to work, the variable proxy.config.reverse_proxy.enabled must be set to 1.

            proxy.config.url_remap.default_to_server_pac_port

            Scope
                CONFIG.TP Type INT.TP Default -1.TP Reloadable Yes.UNINDENT Sets the PAC port so that PAC requests made to the Traffic Server proxy service port are redirected this port. -1 is the default setting that sets the PAC port to the autoconfiguration port (the default autoconfiguration port is 8083). This variable can be used together with the proxy.config.url_remap.default_to_server_pac variable to get a PAC file from a different port. You must create and run a process that serves a PAC file on this port. For example: if you create a Perl script that listens on port 9000 and writes a PAC file in response to any request, then you can set this variable to 9000. Browsers that request the PAC file from a proxy server on port 8080 will get the PAC file served by the Perl script.

                proxy.config.url_remap.remap_required

                Scope
                    CONFIG.TP Type INT.TP Default 1.TP Reloadable Yes.UNINDENT Set this variable to 1 if you want Traffic Server to serve requests only from origin servers listed in the mapping rules of the remap.config file. If a request does not match, then the browser will receive an error.

                    proxy.config.url_remap.pristine_host_hdr

                    Scope
                        CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Set this variable to 1 if you want to retain the client host header in a request during remapping.

SSL TERMINATION

    proxy.config.ssl.SSLv2

    Scope
        CONFIG.TP Type INT.TP Default 0.UNINDENT Enables (1) or disables (0) SSLv2. Please don't enable it.

        proxy.config.ssl.SSLv3

        Scope
            CONFIG.TP Type INT.TP Default 0.UNINDENT Enables (1) or disables (0) SSLv3.

            proxy.config.ssl.TLSv1

            Scope
                CONFIG.TP Type INT.TP Default 1.UNINDENT Enables (1) or disables (0) TLSv1.

                proxy.config.ssl.TLSv1_1

                Scope
                    CONFIG.TP Type INT.TP Default 1.UNINDENT Enables (1) or disables (0) TLS v1.1. If not specified, enabled by default. [Requires OpenSSL v1.0.1 and higher]

                    proxy.config.ssl.TLSv1_2

                    Scope
                        CONFIG.TP Type INT.TP Default 1.UNINDENT Enables (1) or disables (0) TLS v1.2. If not specified, DISABLED by default. [Requires OpenSSL v1.0.1 and higher]

                        proxy.config.ssl.client.certification_level

                        Scope
                            CONFIG.TP Type INT.TP Default 0.UNINDENT Sets the client certification level:

                            •

                                0 = no client certificates are required. Traffic Server does
                                    not verify client certificates during the SSL handshake. Access to Traffic Server depends on Traffic Server configuration options (such as access control lists).

                            •

                                1 = client certificates are optional. If a client has a
                                    certificate, then the certificate is validated. If the client does not have a certificate, then the client is still allowed access to Traffic Server unless access is denied through other Traffic Server configuration options.

                            •

                                2 = client certificates are required. The client must be
                                    authenticated during the SSL handshake. Clients without a certificate are not allowed to access Traffic Server.

                            proxy.config.ssl.number.threads

                            Scope
                                CONFIG.TP Type INT.TP Default 0.UNINDENT Sets the number of SSL threads to use, this defaults to 0 (autoconfigure).

                                •   0 = autoconfigure, this will allow Traffic Server to determine the appropriate number of threads

                                •   -1 = disable, this makes ET_NET threads behave like ET_SSL threads Note: this does not disable SSL, it simply allows another thread pool to assist in SSL tasks without dedicated SSL threads.

                                •   >0 = Use a non-zero number of SSL threads

                                proxy.config.ssl.server.multicert.filename

                                Scope
                                    CONFIG.TP Type STRING.TP Default ssl_multicert.config.UNINDENT The location of the ssl_multicert.config file, relative to the Traffic Server configuration directory. In the following example, if the Traffic Server configuration directory is /etc/trafficserver, the Traffic Server SSL configuration file and the corresponding certificates are located in /etc/trafficserver/ssl:

                                        CONFIG proxy.config.ssl.server.multicert.filename STRING ssl/ssl_multicert.config
                                        CONFIG proxy.config.ssl.server.cert.path STRING etc/trafficserver/ssl
                                        CONFIG proxy.config.ssl.server.private_key.path STRING etc/trafficserver/ssl

                                    proxy.config.ssl.server.cert.path

                                    Scope
                                        CONFIG.TP Type STRING.TP Default /config.UNINDENT The location of the SSL certificates and chains used for accepting and validation new SSL sessions. If this is a relative path, it is appended to the Traffic Server installation PREFIX. All certificates and certificate chains listed in ssl_multicert.config will be loaded relative to this path.

                                        proxy.config.ssl.server.private_key.path

                                        Scope
                                            CONFIG.TP Type STRING.TP Default NULL.UNINDENT The location of the SSL certificate private keys. Change this variable only if the private key is not located in the SSL certificate file. All private keys listed in ssl_multicert.config will be loaded relative to this path.

                                            proxy.config.ssl.server.cert_chain.filename

                                            Scope
                                                CONFIG.TP Type STRING.TP Default NULL.UNINDENT The name of a file containing a global certificate chain that should be used with every server certificate. This file is only used if there are certificates defined in ssl_multicert.config. Unless this is an absolute path, it is loaded relative to the path specified by proxy.config.ssl.server.cert.path.

                                                proxy.config.ssl.server.dhparams_file

                                                Scope
                                                    CONFIG.TP Type STRING.TP Default NULL.UNINDENT The name of a file containing a set of Diffie-Hellman key exchange parameters. If not specified, 2048-bit DH parameters from RFC 5114 are used. These parameters are only used if a DHE (or EDH) cipher suite has been selected.

                                                    proxy.config.ssl.CA.cert.path

                                                    Scope
                                                        CONFIG.TP Type STRING.TP Default NULL.UNINDENT The location of the certificate authority file that client certificates will be verified against.

                                                        proxy.config.ssl.CA.cert.filename

                                                        Scope
                                                            CONFIG.TP Type STRING.TP Default NULL.UNINDENT The filename of the certificate authority that client certificates will be verified against.

                                                            proxy.config.ssl.server.ticket_key.filename

                                                            Scope
                                                                CONFIG.TP Type STRING.TP Default ssl_ticket.key.UNINDENT The location of the ssl_ticket.key file, relative to the proxy.config.ssl.server.cert.path directory.

                                                                proxy.config.ssl.max_record_size

                                                                Scope
                                                                    CONFIG.TP Type INT.TP Default 0.UNINDENT This configuration specifies the maximum number of bytes to write into a SSL record when replying over a SSL session. In some circumstances this setting can improve response latency by reducing buffering at the SSL layer. This setting can have a value between 0 and 16383 (max TLS record size).

                                                                    The default of 0 means to always write all available data into a single SSL record.

                                                                    A value of -1 means TLS record size is dynamically determined. The strategy employed is to use small TLS records that fit into a single TCP segment for the first ~1 MB of data, but, increase the record size to 16 KB after that to optimize throughput. The record size is reset back to a single segment after ~1 second of inactivity and the record size ramping mechanism is repeated again.

                                                                    proxy.config.ssl.session_cache

                                                                    Scope
                                                                        CONFIG.TP Type INT.TP Default 2.UNINDENT Enables the SSL Session Cache: - 0 = Disables the session cache entirely

                                                                        •   1 = Enables the session cache using OpenSSLs implementation.

                                                                        •

                                                                            2 = (default) Enables the session cache using Traffic Server's implementation.
                                                                                This implentation should perform much better than the OpenSSL implementation.

                                                                        proxy.config.ssl.session_cache.timeout

                                                                        Scope
                                                                            CONFIG.TP Type INT.TP Default 0.UNINDENT This configuration specifies the lifetime of SSL session cache entries in seconds. If it is 0, then the SSL library will use a default value, typically 300 seconds. Note: This option has no affect when using the Traffic Server session cache (option 2 in proxy.config.ssl.session_cache)

                                                                            proxy.config.ssl.session_cache.auto_clear

                                                                            Scope
                                                                                CONFIG.TP Type INT.TP Default 1.UNINDENT This will set the OpenSSL auto clear flag. Auto clear is enabled by default with 1 it can be disabled by changing this setting to 0.

                                                                                proxy.config.ssl.session_cache.size

                                                                                Scope
                                                                                    CONFIG.TP Type INT.TP Default 102400.UNINDENT This configuration specifies the maximum number of entries the SSL session cache may contain.

                                                                                    proxy.config.ssl.session_cache.num_buckets

                                                                                    Scope
                                                                                        CONFIG.TP Type INT.TP Default 1024.UNINDENT This configuration specifies the number of buckets to use with the Traffic Server SSL session cache implementation. The TS implementation is a fixed size hash map where each bucket is protected by a mutex.

                                                                                        proxy.config.ssl.session_cache.skip_cache_on_bucket_contention

                                                                                        Scope
                                                                                            CONFIG.TP Type INT.TP Default 0.UNINDENT This configuration specifies the behavior of the Traffic Server SSL session cache implementation during lock contention on each bucket:

                                                                                            •   0 = (default) Don't skip session caching when bucket lock is contented.

                                                                                            •   1 = Don't use the SSL session cache for this connection during lock contention.

                                                                                            proxy.config.ssl.hsts_max_age

                                                                                            Scope
                                                                                                CONFIG.TP Type INT.TP Default -1.UNINDENT This configuration specifies the max-age value that will be used when adding the Strict-Transport-Security header. The value is in seconds. A value of 0 will set the max-age value to 0 and should remove the HSTS entry from the client. A value of -1 will disable this feature and not set the header. This option is only used for HTTPS requests and the header will not be set on HTTP requests.

                                                                                                proxy.config.ssl.hsts_include_subdomains

                                                                                                Scope
                                                                                                    CONFIG.TP Type INT.TP Default 0.UNINDENT Enables (1) or disables (0) adding the includeSubdomain value to the Strict-Transport-Security header. proxy.config.ssl.hsts_max_age needs to be set to a non -1 value for this configuration to take effect.

                                                                                                    proxy.config.ssl.allow_client_renegotiation

                                                                                                    Scope
                                                                                                        CONFIG.TP Type INT.TP Default 0.UNINDENT This configuration specifies whether the client is able to initiate renegotiation of the SSL connection. The default of 0, means the client can't initiate renegotiation.

                                                                                                        proxy.config.ssl.cert.load_elevated

                                                                                                        Scope
                                                                                                            CONFIG.TP Type INT.TP Default 0.UNINDENT Enables (1) or disables (0) elevation of traffic_server privileges during loading of SSL certificates. By enabling this, SSL certificate files' access rights can be restricted to help reduce the vulnerability of certificates.

                                                                                                            This feature requires Traffic Server to be built with POSIX capabilities enabled.

  Client-Related Configuration

    proxy.config.ssl.client.verify.server

    Scope
        CONFIG.TP Type INT.TP Default 0.UNINDENT Configures Traffic Server to verify the origin server certificate with the Certificate Authority (CA).

        proxy.config.ssl.client.cert.filename

        Scope
            CONFIG.TP Type STRING.TP Default NULL.UNINDENT The filename of SSL client certificate installed on Traffic Server.

            proxy.config.ssl.client.cert.path

            Scope
                CONFIG.TP Type STRING.TP Default /config.UNINDENT The location of the SSL client certificate installed on Traffic Server.

                proxy.config.ssl.client.private_key.filename

                Scope
                    CONFIG.TP Type STRING.TP Default NULL.UNINDENT The filename of the Traffic Server private key. Change this variable only if the private key is not located in the Traffic Server SSL client certificate file.

                    proxy.config.ssl.client.private_key.path

                    Scope
                        CONFIG.TP Type STRING.TP Default NULL.UNINDENT The location of the Traffic Server private key. Change this variable only if the private key is not located in the SSL client certificate file.

                        proxy.config.ssl.client.CA.cert.filename

                        Scope
                            CONFIG.TP Type STRING.TP Default NULL.UNINDENT The filename of the certificate authority against which the origin server will be verified.

                            proxy.config.ssl.client.CA.cert.path

                            Scope
                                CONFIG.TP Type STRING.TP Default NULL.UNINDENT Specifies the location of the certificate authority file against which the origin server will be verified.

ICP CONFIGURATION

    proxy.config.icp.enabled

    Scope
        CONFIG.TP Type INT.TP Default 0.UNINDENT Sets ICP mode for hierarchical caching:

        •   0 = disables ICP

        •   1 = allows Traffic Server to receive ICP queries only

        •   2 = allows Traffic Server to send and receive ICP queries

    Refer to <admin-icp-peering>.

        proxy.config.icp.icp_interface

        Scope
            CONFIG.TP Type STRING.TP Default your_interface.UNINDENT Specifies the network interface used for ICP traffic.

            NOTE:
                The Traffic Server installation script detects your network interface and sets this variable appropriately. If your system has multiple network interfaces, check that this variable specifies the correct interface.

            proxy.config.icp.icp_port

            Scope
                CONFIG.TP Type INT.TP Default 3130.TP Reloadable Yes.UNINDENT Specifies the UDP port that you want to use for ICP messages.

                proxy.config.icp.query_timeout

                Scope
                    CONFIG.TP Type INT.TP Default 2.TP Reloadable Yes.UNINDENT Specifies the timeout used for ICP queries.

HTTP/2 CONFIGURATION

    proxy.config.http2.enabled

    Scope
        CONFIG.TP Type INT.TP Default 0.UNINDENT Enable the experimental HTTP/2 feature. This implements most of the specifications, with the one big exception being server PUSH.

        NOTE:
            This configuration will be eliminated for v6.0.0, where HTTP/2 is enabled by default and controlled via the ports configuration.

        proxy.config.http2.max_concurrent_streams_in

        Scope
            CONFIG.TP Type INT.TP Default 100.TP Reloadable Yes.UNINDENT The maximum number of concurrent streams per inbound connection.

            NOTE:
                Reloading this value affects only new HTTP/2 connections, not the ones already established.

            proxy.config.http2.initial_window_size_in

            Scope
                CONFIG.TP Type INT.TP Default 65536.TP Reloadable Yes.UNINDENT The initial window size for inbound connections.

                proxy.config.http2.max_frame_size

                Scope
                    CONFIG.TP Type INT.TP Default 16384.TP Reloadable Yes.UNINDENT Indicates the size of the largest frame payload that the sender is willing to receive.

                    proxy.config.http2.header_table_size

                    Scope
                        CONFIG.TP Type INT.TP Default 4096.TP Reloadable Yes.UNINDENT The maximum size of the header compression table used to decode header blocks.

                        proxy.config.http2.max_header_list_size

                        Scope
                            CONFIG.TP Type INT.TP Default 4294967295.TP Reloadable Yes.UNINDENT This advisory setting informs a peer of the maximum size of header list that the sender is prepared to accept blocks. The default value, which is the unsigned int maximum value in Traffic Server, implies unlimited size.

SPDY CONFIGURATION

    proxy.config.spdy.accept_no_activity_timeout

    Scope
        CONFIG.TP Type INT.TP Default 30.TP Reloadable Yes.UNINDENT How long a SPDY connection will be kept open after an accept without any streams created.

        proxy.config.spdy.no_activity_timeout_in

        Scope
            CONFIG.TP Type INT.TP Default 30.TP Reloadable Yes.UNINDENT How long a stream is kept open without activity.

            proxy.config.spdy.initial_window_size_in

            Scope
                CONFIG.TP Type INT.TP Default 65536.TP Reloadable Yes.UNINDENT The initial window size for inbound connections.

                proxy.config.spdy.max_concurrent_streams_in

                Scope
                    CONFIG.TP Type INT.TP Default 100.TP Reloadable Yes.UNINDENT The maximum number of concurrent streams per inbound connection.

                    NOTE:
                        Reloading this value affects only new SPDY connections, not the ones already established..

SCHEDULED UPDATE CONFIGURATION

    proxy.config.update.enabled

    Scope
        CONFIG.TP Type INT.TP Default 0.UNINDENT Enables (1) or disables (0) the Scheduled Update option.

        proxy.config.update.force

        Scope
            CONFIG.TP Type INT.TP Default 0.TP Reloadable Yes.UNINDENT Enables (1) or disables (0) a force immediate update. When enabled, Traffic Server overrides the scheduling expiration time for all scheduled update entries and initiates updates until this option is disabled.

            proxy.config.update.retry_count

            Scope
                CONFIG.TP Type INT.TP Default 10.TP Reloadable Yes.UNINDENT Specifies the number of times Traffic Server can retry the scheduled update of a URL in the event of failure.

                proxy.config.update.retry_interval

                Scope
                    CONFIG.TP Type INT.TP Default 2.TP Reloadable Yes.UNINDENT Specifies the delay (in seconds) between each scheduled update retry for a URL in the event of failure.

                    proxy.config.update.concurrent_updates

                    Scope
                        CONFIG.TP Type INT.TP Default 100.TP Reloadable Yes.UNINDENT Specifies the maximum simultaneous update requests allowed at any time. This option prevents the scheduled update process from overburdening the host.

PLUG-IN CONFIGURATION

    proxy.config.plugin.plugin_dir

    Scope
        CONFIG.TP Type STRING.TP Default config/plugins.UNINDENT Specifies the location of Traffic Server plugins.

        proxy.config.remap.num_remap_threads

        Scope
            CONFIG.TP Type INT.TP Default 0.UNINDENT When this variable is set to 0, plugin remap callbacks are executed in line on network threads. If remap processing takes significant time, this can be cause additional request latency. Setting this variable to causes remap processing to take place on a dedicated thread pool, freeing the network threads to service additional requests.

SOCKETS

    proxy.config.net.defer_accept

    Scope
        CONFIG.TP Type INT.TP Default 1.UNINDENT default: 1 meaning on all Platforms except Linux: 45 seconds

        This directive enables operating system specific optimizations for a listening socket. defer_accept holds a call to accept(2) back until data has arrived. In Linux' special case this is up to a maximum of 45 seconds.

        proxy.config.net.sock_send_buffer_size_in

        Scope
            CONFIG.TP Type INT.TP Default 0.UNINDENT Sets the send buffer size for connections from the client to Traffic Server.

            proxy.config.net.sock_recv_buffer_size_in

            Scope
                CONFIG.TP Type INT.TP Default 0.UNINDENT Sets the receive buffer size for connections from the client to Traffic Server.

                proxy.config.net.sock_option_flag_in

                Scope
                    CONFIG.TP Type INT.TP Default 0x0.UNINDENT Turns different options "on" for the socket handling client connections::

                        TCP_NODELAY  (1)
                        SO_KEEPALIVE (2)
                        SO_LINGER (4) - with a timeout of 0 seconds

                NOTE:
                        This is a bitmask and you need to decide what bits to set. Therefore, you must set the value to 3 if you want to enable nodelay and keepalive options above.

                    proxy.config.net.sock_send_buffer_size_out

                    Scope
                        CONFIG.TP Type INT.TP Default 0.UNINDENT Sets the send buffer size for connections from Traffic Server to the origin server.

                        proxy.config.net.sock_recv_buffer_size_out

                        Scope
                            CONFIG.TP Type INT.TP Default 0.UNINDENT Sets the receive buffer size for connections from Traffic Server to the origin server.

                            proxy.config.net.sock_option_flag_out

                            Scope
                                CONFIG.TP Type INT.TP Default 0x1.UNINDENT Turns different options "on" for the origin server socket::

                                    TCP_NODELAY  (1)
                                    SO_KEEPALIVE (2)
                                    SO_LINGER (4) - with a timeout of 0 seconds

                            NOTE:
                                    This is a bitmask and you need to decide what bits to set. Therefore, you must set the value to 3 if you want to enable nodelay and keepalive options above.
                                            When SO_LINGER is enabled, the linger timeout time is set to 0. This is useful when ATS and origin server were installed This is useful when Traffic Server and the origin server are co-located and large numbers of sockets are retained in the TIME_WAIT state.

                                proxy.config.net.sock_mss_in

                                Scope
                                    CONFIG.TP Type INT.TP Default 0.UNINDENT Same as the command line option --accept_mss that sets the MSS for all incoming requests.

                                    proxy.config.net.sock_packet_mark_in

                                    Scope
                                        CONFIG.TP Type INT.TP Default 0x0.UNINDENT Set the packet mark on traffic destined for the client (the packets that make up a client response).

                                        SEE ALSO:
                                            Traffic Shaping

                                        proxy.config.net.sock_packet_mark_out

                                        Scope
                                            CONFIG.TP Type INT.TP Default 0x0.UNINDENT Set the packet mark on traffic destined for the origin (the packets that make up an origin request).

                                            SEE ALSO:
                                                Traffic Shaping

                                            proxy.config.net.sock_packet_tos_in

                                            Scope
                                                CONFIG.TP Type INT.TP Default 0x0.UNINDENT Set the ToS/DiffServ Field on packets sent to the client (the packets that make up a client response).

                                                SEE ALSO:
                                                    Traffic Shaping

                                                proxy.config.net.sock_packet_tos_out

                                                Scope
                                                    CONFIG.TP Type INT.TP Default 0x0.UNINDENT Set the ToS/DiffServ Field on packets sent to the origin (the packets that make up an origin request).

                                                    SEE ALSO:
                                                        Traffic Shaping

                                                    proxy.config.net.poll_timeout

                                                    Scope
                                                        CONFIG.TP Type INT.TP Default 10 (or 30 on Solaris).UNINDENT Same as the command line option --poll_timeout, or -t, which specifies the timeout used for the polling mechanism used. This timeout is always in milliseconds (ms). This is the timeout to epoll_wait() on Linux platforms, and to kevent() on BSD type OSs. The default value is 10 on all platforms.

                                                        Changing this configuration can reduce CPU usage on an idle system, since periodic tasks gets processed at these intervals. On busy servers, this overhead is diminished, since polled events triggers morefrequently. However, increasing the setting can also introduce additional latency for certain operations, and timed events. It's recommended not to touch this setting unless your CPU usage is unacceptable at idle workload. Some alternatives to this could be:

                                                            Reduce the number of worker threads (net-threads)
                                                            Reduce the number of disk (AIO) threads
                                                            Make sure accept threads are enabled

                                                    The relevant configurations for this are:

                                                            CONFIG proxy.config.exec_thread.autoconfig INT 0
                                                            CONFIG proxy.config.exec_thread.limit INT 2
                                                            CONFIG proxy.config.accept_threads INT 1
                                                            CONFIG proxy.config.cache.threads_per_disk INT 8

                                                        proxy.config.task_threads

                                                        Scope
                                                            CONFIG.TP Type INT.TP Default 2.UNINDENT Specifies the number of task threads to run. These threads are used for various tasks that should be off-loaded from the normal network threads.

                                                            proxy.config.allocator.thread_freelist_size

                                                            Scope
                                                                CONFIG.TP Type INT.TP Default 512.UNINDENT Sets the maximum number of elements that can be contained in a ProxyAllocator (per-thread) before returning the objects to the global pool

                                                                proxy.config.allocator.thread_freelist_low_watermark

                                                                Scope
                                                                    CONFIG.TP Type INT.TP Default 32.UNINDENT Sets the minimum number of items a ProxyAllocator (per-thread) will guarantee to be holding at any one time.

                                                                    proxy.config.http.enabled

                                                                    Scope
                                                                        CONFIG.TP Type INT.TP Default 1.UNINDENT Turn on or off support for HTTP proxying. This is rarely used, the one exception being if you run Traffic Server with a protocol plugin, and would like for it to not support HTTP requests at all.

COPYRIGHT
2014, dev@trafficserver.apache.org