Bug 55556 - apachebench (ab) doesn't use so_reuseaddr
Summary: apachebench (ab) doesn't use so_reuseaddr
Alias: None
Product: Apache httpd-2
Classification: Unclassified
Component: Core (show other bugs)
Version: 2.2.15
Hardware: PC Linux
: P2 normal (vote)
Target Milestone: ---
Assignee: Apache HTTPD Bugs Mailing List
Keywords: MassUpdate
Depends on:
Reported: 2013-09-13 22:39 UTC by Penelope Fudd
Modified: 2018-11-07 21:09 UTC (History)
1 user (show)


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Description Penelope Fudd 2013-09-13 22:39:26 UTC
I've been running the command:

ulimit -n 20010 ; ab -n 20000 -c 20000 http://my.host.com/

And found that after running it a few times, it refuses to run and gives the following error:

apr_socket_connect(): Cannot assign requested address (99)

It would appear that all tcp sockets are in a WAIT state, and can't be reused until the timer expires on some of the sockets.

If the sockets that ab uses were marked with 'SO_REUSEADDR', this problem might go away.

Comment 1 Yann Ylavic 2013-09-14 00:23:02 UTC
Even with SO_REUSEADDR, you can't reuse a TIME_WAITing client's IP:port to connect the same server's IP:port.

On linux, you can do things like "sysctl -w net.ipv4.tcp_tw_recycle=1" to kind of ignore TIME_WAIT delays, but your network should better not loose/retransmit packets that could interfere with subsequent connections, that's the purpose of the TIME_WAIT state, however it can be a temporary setting for the duration of the bench...

The best option (though more expensive) is to use multiple ab clients on as much machines or NICs (with "ip route add ... dev NIC").
Comment 2 William A. Rowe Jr. 2018-11-07 21:09:24 UTC
Please help us to refine our list of open and current defects; this is a mass update of old and inactive Bugzilla reports which reflect user error, already resolved defects, and still-existing defects in httpd.

As repeatedly announced, the Apache HTTP Server Project has discontinued all development and patch review of the 2.2.x series of releases. The final release 2.2.34 was published in July 2017, and no further evaluation of bug reports or security risks will be considered or published for 2.2.x releases. All reports older than 2.4.x have been updated to status RESOLVED/LATER; no further action is expected unless the report still applies to a current version of httpd.

If your report represented a question or confusion about how to use an httpd feature, an unexpected server behavior, problems building or installing httpd, or working with an external component (a third party module, browser etc.) we ask you to start by bringing your question to the User Support and Discussion mailing list, see [https://httpd.apache.org/lists.html#http-users] for details. Include a link to this Bugzilla report for completeness with your question.

If your report was clearly a defect in httpd or a feature request, we ask that you retest using a modern httpd release (2.4.33 or later) released in the past year. If it can be reproduced, please reopen this bug and change the Version field above to the httpd version you have reconfirmed with.

Your help in identifying defects or enhancements still applicable to the current httpd server software release is greatly appreciated.