# Transport classes

List of transport classes that can be used, simply import your choice and pass it to the constructor of `Elasticsearch` as connection_class. Note that the `RequestsHttpConnection` requires `requests` to be installed.

For example to use the `requests`-based connection just import it and use it:

    from elasticsearch import Elasticsearch, RequestsHttpConnection
    es = Elasticsearch(connection_class=RequestsHttpConnection)

The default connection class is based on `urllib3` which is more performant and lightweight than the optional `requests`-based class. Only use `RequestsHttpConnection` if you have need of any of `requests` advanced features like custom auth plugins etc.

## Connection

class `elasticsearch.connection.``Connection`(host='localhost', port=9200, use_ssl=False, url_prefix='', timeout=10, **kwargs)

  Class responsible for maintaining a connection to an Elasticsearch node. It holds persistent connection pool to it and it’s main interface (perform_request) is thread-safe.

  Also responsible for logging.

  Parameters:

  - host – hostname of the node (default: localhost)
  - port – port to use (integer, default: 9200)
  - url_prefix – optional url prefix for elasticsearch
  - timeout – default timeout in seconds (float, default: 10)

## Urllib3HttpConnection

class `elasticsearch.connection.``Urllib3HttpConnection`(host='localhost', port=9200, http_auth=None, use_ssl=False, verify_certs=None, ssl_show_warn=True, ca_certs=None, client_cert=None, client_key=None, ssl_version=None, ssl_assert_hostname=None, ssl_assert_fingerprint=None, maxsize=10, headers=None, ssl_context=None, http_compress=False, cloud_id=None, api_key=None, **kwargs)

  Default connection class using the urllib3 library and the http protocol.

  Parameters:

  - host – hostname of the node (default: localhost)
  - port – port to use (integer, default: 9200)
  - url_prefix – optional url prefix for elasticsearch
  - timeout – default timeout in seconds (float, default: 10)
  - http_auth – optional http auth information as either ‘:’ separated string or a tuple
  - use_ssl – use ssl for the connection if True
  - verify_certs – whether to verify SSL certificates
  - ssl_show_warn – show warning when verify certs is disabled
  - ca_certs – optional path to CA bundle. See https://urllib3.readthedocs.io/en/latest/security.html#using-certifi-with-urllib3 for instructions how to get default set
  - client_cert – path to the file containing the private key and the certificate, or cert only if using client_key
  - client_key – path to the file containing the private key if using separate cert and key files (client_cert will contain only the cert)
  - ssl_version – version of the SSL protocol to use. Choices are: SSLv23 (default) SSLv2 SSLv3 TLSv1 (see `PROTOCOL_*` constants in the `ssl` module for exact options for your environment).
  - ssl_assert_hostname – use hostname verification if not False
  - ssl_assert_fingerprint – verify the supplied certificate fingerprint if not None
  - maxsize – the number of connections which will be kept open to this host. See https://urllib3.readthedocs.io/en/1.4/pools.html#api for more information.
  - headers – any custom http headers to be add to requests
  - http_compress – Use gzip compression
  - cloud_id – The Cloud ID from ElasticCloud. Convient way to connect to cloud instances.
  - api_key – optional API Key authentication as either base64 encoded string or a tuple. Other host connection params will be ignored.

## RequestsHttpConnection

class `elasticsearch.connection.``RequestsHttpConnection`(host='localhost', port=9200, http_auth=None, use_ssl=False, verify_certs=True, ssl_show_warn=True, ca_certs=None, client_cert=None, client_key=None, headers=None, cloud_id=None, api_key=None, **kwargs)

  Connection using the requests library.

  Parameters:

  - http_auth – optional http auth information as either ‘:’ separated string or a tuple. Any value will be passed into requests as auth.
  - use_ssl – use ssl for the connection if True
  - verify_certs – whether to verify SSL certificates
  - ssl_show_warn – show warning when verify certs is disabled
  - ca_certs – optional path to CA bundle. By default standard requests’ bundle will be used.
  - client_cert – path to the file containing the private key and the certificate, or cert only if using client_key
  - client_key – path to the file containing the private key if using separate cert and key files (client_cert will contain only the cert)
  - headers – any custom http headers to be add to requests
  - cloud_id – The Cloud ID from ElasticCloud. Convient way to connect to cloud instances.
  - api_key – optional API Key authentication as either base64 encoded string or a tuple. Other host connection params will be ignored.