Postfix: smtp-source
SMTP-SOURCE(1) SMTP-SOURCE(1)
NAME
smtp-source - parallelized SMTP/LMTP test generator
SYNOPSIS
smtp-source [options] [inet:]host[:port]
smtp-source [options] unix:pathname
DESCRIPTION
smtp-source connects to the named host and TCP port (default: port 25)
and sends one or more messages to it, either sequentially or in paral-
lel. The program speaks either SMTP (default) or LMTP. Connections can
be made to UNIX-domain and IPv4 or IPv6 servers. IPv4 and IPv6 are the
default.
Note: this is an unsupported test program. No attempt is made to main-
tain compatibility between successive versions.
Arguments:
-4 Connect to the server with IPv4. This option has no effect when
Postfix is built without IPv6 support.
-6 Connect to the server with IPv6. This option is not available
when Postfix is built without IPv6 support.
-A Don't abort when the server sends something other than the
expected positive reply code.
-c Display a running counter that is incremented each time an SMTP
DATA command completes.
-C count
When a host sends RESET instead of SYN|ACK, try count times
before giving up. The default count is 1. Specify a larger count
in order to work around a problem with TCP/IP stacks that send
RESET when the listen queue is full.
-d Don't disconnect after sending a message; send the next message
over the same connection.
-f from
Use the specified sender address (default: <foo@myhostname>).
-F file
Send the pre-formatted message header and body in the specified
file, while prepending '.' before lines that begin with '.', and
while appending CRLF after each line.
-l length
Send length bytes as message payload. The length does not
include message headers.
-L Speak LMTP rather than SMTP.
-m message_count
Send the specified number of messages (default: 1).
-M myhostname
Use the specified hostname or [address] in the HELO command and
in the default sender and recipient addresses, instead of the
machine hostname.
-N Prepend a non-repeating sequence number to each recipient
address. This avoids the artificial 100% hit rate in the resolve
and rewrite client caches and exercises the trivial-rewrite dae-
mon, better approximating Postfix performance under real-life
work-loads.
-o Old mode: don't send HELO, and don't send message headers.
-r recipient_count
Send the specified number of recipients per transaction
(default: 1). Recipient names are generated by prepending a
number to the recipient address.
-R interval
Wait for a random period of time 0 <= n <= interval between mes-
sages. Suspending one thread does not affect other delivery
threads.
-s session_count
Run the specified number of SMTP sessions in parallel (default:
1).
-S subject
Send mail with the named subject line (default: none).
-t to Use the specified recipient address (default: <foo@myhostname>).
-T windowsize
Override the default TCP window size. To work around broken TCP
window scaling implementations, specify a value > 0 and < 65536.
-v Make the program more verbose, for debugging purposes.
-w interval
Wait a fixed time between messages. Suspending one thread does
not affect other delivery threads.
[inet:]host[:port]
Connect via TCP to host host, port port. The default port is
smtp.
unix:pathname
Connect to the UNIX-domain socket at pathname.
BUGS
No SMTP command pipelining support.
SEE ALSO
smtp-sink(1), SMTP/LMTP message dump
LICENSE
The Secure Mailer license must be distributed with this software.
AUTHOR(S)
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Menjalankan
11. Stress Testing How much mail will my box be able to handle?
To find out how much traffic your installation can handle, you need to perform some kind of stress testing. To put an adequate load on the server, you need a fast mail generator. Postfix comes with a pair of testing programs named smtp-source and smtp-sink for just this purpose. Here's how they work:
smtp-source
This program connects to a host on a TCP port (port 25 by default) and sends one or more messages, either sequentially or in parallel. The program speaks both SMTP (default) or LMTP and is meant to aid in measuring server performance.
smtp-sink
This test server listens on the named host (or address) and port. It recieves messages from the network and throws them away. You can measure client and network performance with this program.
Let's start with smtp-source to stress-test your Postfix installation. The following example injects 100 total messages of size 5k each in 20 parallel sessions to a Postfix server running on localhost port 25. Because you're also interested in how much time this takes, use the time command:
$ time ./smtp-source -s 20 (1) -l 5120 (2) -m 100 (3) -c (4) \ -f sender@example.com (5) -t recipient@example.com (6) localhost:25 (7)
100 real 0m4.294s user 0m0.060s sys 0m0.030s
(1)
20 parallel sessions (2)
5k message size (3)
100 total messages (4)
display a counter (5)
envelope sender (6)
envelope recipient (7)
target SMTP server
In the example above, injection took 4.294s. However, you also want to know how long actual delivery takes? Check your logs for this, and also to verify that every last message arrived for <recipient@example.com> received.