Bug 46231 - Connection Pooling with ajp depends on syntax ?
Summary: Connection Pooling with ajp depends on syntax ?
Alias: None
Product: Apache httpd-2
Classification: Unclassified
Component: mod_proxy (show other bugs)
Version: 2.2.10
Hardware: PC Windows Server 2003
: P2 major (vote)
Target Milestone: ---
Assignee: Apache HTTPD Bugs Mailing List
Keywords: MassUpdate
Depends on:
Reported: 2008-11-18 09:33 UTC by gie syn
Modified: 2018-11-07 21:09 UTC (History)
0 users


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Description gie syn 2008-11-18 09:33:09 UTC

I think there's a bug with mod_proxy_ajp and connection pooling. I explain myself ...

I've run some tests with brand new Apache 2.2.6 and 2.2.10 instalations.
After that I enable mod_proxy and mod_proxy_ajp and add these lines :

ProxyRequests Off
ProxyPass /servlets-examples/servlet/HelloWorldExample ajp://localhost/servlets-examples/servlet/HelloWorldExample

There's a Tomcat 5.5.25 as the backend server with AJP 8009 port open

Then I use JMeter to pound on the same Servlet, ever and ever, with 10 threads.

Apache opens a socket for every HTTP requests and closes it causing a TIME_WAIT.
When too many ports are on TIME_WAIT, Apache cannot create new sockets and this comes to an error in the error.log and a 503 "server too busy" for the user browser.

Apache can't stand this treatment for more than 30 secs before causing 503s.

Then starts the weird thing :

When I change the proxyPass line with this :
ProxyPass /servlets-examples/servlet/HelloWorldExample ajp://localhost:8009/servlets-examples/servlet/HelloWorldExample

There's no more problem !!! No TIME_WAIT ... connection pool is used ... only 10 ESTABLISHED connections ... It's a kind of magic for me ...

This is a simple example to reproduce the "bug" but I have the same TIME_WAIT 503 bug with another Servlet Name even with the :8009 port specified ...
I've tried to mess with the pool settings with no more luck than letting the default (no specifiing pool params)

for testing how many TIME_WAIT I have I use "netstat -an | find ":8009" | find /c "TIME"
This command is supposed to return always 0 if the connection pool is used.

This behaviour is reproduced on XP too.
Comment 1 William A. Rowe Jr. 2018-11-07 21:09:26 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.