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