# Benchmarks

## pyftpdlib 0.7.0 vs. pyftpdlib 1.0.0

benchmark type | 0.7.0 | 1.0.0 | speedup
--- | --- | --- | ---
STOR (client -> server) | 528.63 MB/sec | 585.90 MB/sec | +0.1x
RETR (server -> client) | 1702.07 MB/sec | 1652.72 MB/sec | -0.02x
300 concurrent clients (connect, login) | 1.70 secs | 0.19 secs | +8x
STOR (1 file with 300 idle clients) | 60.77 MB/sec | 585.59 MB/sec | +8.6x
RETR (1 file with 300 idle clients) | 63.46 MB/sec | 1497.58 MB/sec | +22.5x
300 concurrent clients (RETR 10M file) | 4.68 secs | 3.41 secs | +0.3x
300 concurrent clients (STOR 10M file) | 10.13 secs | 8.78 secs | +0.1x
300 concurrent clients (QUIT) | 0.02 secs | 0.02 secs | 0x

## pyftpdlib vs. proftpd 1.3.4

benchmark type | pyftpdlib | proftpd | speedup
--- | --- | --- | ---
STOR (client -> server) | 585.90 MB/sec | 600.49 MB/sec | -0.02x
RETR (server -> client) | 1652.72 MB/sec | 1524.05 MB/sec | +0.08
300 concurrent clients (connect, login) | 0.19 secs | 9.98 secs | +51x
STOR (1 file with 300 idle clients) | 585.59 MB/sec | 518.55 MB/sec | +0.1x
RETR (1 file with 300 idle clients) | 1497.58 MB/sec | 1478.19 MB/sec | 0x
300 concurrent clients (RETR 10M file) | 3.41 secs | 3.60 secs | +0.05x
300 concurrent clients (STOR 10M file) | 8.60 secs | 11.56 secs | +0.3x
300 concurrent clients (QUIT) | 0.03 secs | 0.39 secs | +12x

## pyftpdlib vs. vsftpd 2.3.5

benchmark type | pyftpdlib | vsftpd | speedup
--- | --- | --- | ---
STOR (client -> server) | 585.90 MB/sec | 611.73 MB/sec | -0.04x
RETR (server -> client) | 1652.72 MB/sec | 1512.92 MB/sec | +0.09
300 concurrent clients (connect, login) | 0.19 secs | 20.39 secs | +106x
STOR (1 file with 300 idle clients) | 585.59 MB/sec | 610.23 MB/sec | -0.04x
RETR (1 file with 300 idle clients) | 1497.58 MB/sec | 1493.01 MB/sec | 0x
300 concurrent clients (RETR 10M file) | 3.41 secs | 3.67 secs | +0.07x
300 concurrent clients (STOR 10M file) | 8.60 secs | 9.82 secs | +0.07x
300 concurrent clients (QUIT) | 0.03 secs | 0.01 secs | +0.14x

## pyftpdlib vs. Twisted 12.3

By using sendfile() (Twisted does not support sendfile()):

benchmark type | pyftpdlib | twisted | speedup
--- | ---
STOR (client -> server) | 585.90 MB/sec | 496.44 MB/sec | +0.01x
RETR (server -> client) | 1652.72 MB/sec | 283.24 MB/sec | +4.8x
300 concurrent clients (connect, login) | 0.19 secs | 0.19 secs | +0x
STOR (1 file with 300 idle clients) | 585.59 MB/sec | 506.55 MB/sec | +0.16x
RETR (1 file with 300 idle clients) | 1497.58 MB/sec | 280.63 MB/sec | +4.3x
300 concurrent clients (RETR 10M file) | 3.41 secs | 11.40 secs | +2.3x
300 concurrent clients (STOR 10M file) | 8.60 secs | 9.22 secs | +0.07x
300 concurrent clients (QUIT) | 0.03 secs | 0.09 secs | +2x

By using plain send():

benchmark type | tpdlib* | twisted | speedup
--- | --- | --- | ---
RETR (server -> client) | 894.29 MB/sec | 283.24 MB/sec | +2.1x
RETR (1 file with 300 idle clients) | 900.98 MB/sec | 280.63 MB/sec | +2.1x

## Memory usage

Values on UNIX are calculated as (rss - shared).

benchmark type | pyftpdlib | proftpd 1.3.4 | vsftpd 2.3.5 | twisted 12.3
--- | --- | --- | --- | ---
Starting with | 6.7M | 1.4M | 352.0K | 13.4M
STOR (1 client) | 6.7M | 8.5M | 816.0K | 13.5M
RETR (1 client) | 6.8M | 8.5M | 816.0K | 13.5M
300 concurrent clients (connect, login) | 8.8M | 568.6M | 140.9M | 13.5M
STOR (1 file with 300 idle clients) | 8.8M | 570.6M | 141.4M | 13.5M
RETR (1 file with 300 idle clients) | 8.8M | 570.6M | 141.4M | 13.5M
300 concurrent clients (RETR 10.0M file) | 10.8M | 568.6M | 140.9M | 24.5M
300 concurrent clients (STOR 10.0M file) | 12.6 | 568.7M | 140.9M | 24.7M

## Interpreting the results

pyftpdlib and proftpd / vsftpd look pretty much equally fast. The huge difference is noticeable in scalability though, because of the concurrency model adopted. Both proftpd and vsftpd spawn a new process for every connected client, where pyftpdlib doesn’t (see the C10k problem). The outcome is well noticeable on connect/login benchmarks and memory benchmarks.

The huge differences between 0.7.0 and 1.0.0 versions of pyftpdlib are due to fix of issue 203. On Linux we now use epoll() which scales considerably better than select(). The fact that we’re downloading a file with 300 idle clients doesn’t make any difference for epoll(). We might as well had 5000 idle clients and the result would have been the same. On Windows, where we still use select(), 1.0.0 still wins hands down as the asyncore loop was reimplemented from scratch in order to support fd un/registration and modification (see issue 203). All the benchmarks were conducted on a Linux Ubuntu 12.04 Intel core duo - 3.1 Ghz box.

## Setup

The following setup was used before running every benchmark:

### proftpd

    # /etc/proftpd/proftpd.conf

    MaxInstances        2000

…followed by:

    $ sudo service proftpd restart

### vsftpd

    # /etc/vsftpd.conf

    local_enable=YES
    write_enable=YES
    max_clients=2000
    max_per_ip=2000

…followed by:

    $ sudo service vsftpd restart

### twisted FTP server

    from twisted.protocols.ftp import FTPFactory, FTPRealm
    from twisted.cred.portal import Portal
    from twisted.cred.checkers import AllowAnonymousAccess, FilePasswordDB
    from twisted.internet import reactor
    import resource

    soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
    resource.setrlimit(resource.RLIMIT_NOFILE, (hard, hard))
    open('pass.dat', 'w').write('user:some-passwd')
    p = Portal(FTPRealm('./'),
    [AllowAnonymousAccess(), FilePasswordDB("pass.dat")])
    f = FTPFactory(p)
    reactor.listenTCP(21, f)
    reactor.run()

…followed by:

    $ sudo python twist_ftpd.py

### pyftpdlib

The following patch was applied first:

    Index: pyftpdlib/servers.py
    ===================================================================
    --- pyftpdlib/servers.py    (revisione 1154)
    +++ pyftpdlib/servers.py    (copia locale)
    @@ -494,3 +494,10 @@

    def _map_len(self):
    return len(multiprocessing.active_children())
    +
    +import resource
    +soft, hard = resource.getrlimit(resource.RLIMIT_NOFILE)
    +resource.setrlimit(resource.RLIMIT_NOFILE, (hard, hard))
    +FTPServer.max_cons = 0

…followed by:

    $ sudo python demo/unix_daemon.py

The benchmark script was run as:

    python scripts/ftpbench -u USERNAME -p PASSWORD -b all -n 300

…and for the memory test:

    python scripts/ftpbench -u USERNAME -p PASSWORD -b all -n 300 -k FTP_SERVER_PID