users@glassfish.java.net

Problems with Glassfish <-> Apache mod_proxy_ajp

From: <glassfish_at_javadesktop.org>
Date: Tue, 26 Aug 2008 00:22:21 PDT

Dear Glassfish Community,

we are using glassfish v2ur2 in combination with Apache 2.2 and mod_proxy_ajp on our production server. At least once per week, the communication between apache and glassfish seems to come to a halt.

As a result, users cannot load any java-generated pages (it loads for ages until the browser generates a timeout error). In the glassfish log, we see a lot of broken pipe exceptions, and the apache error_log shows the following errors (several hundreds of them, in different combinations):

[code]
[Mon Aug 25 13:57:56 2008] [error] (120006)APR does not understand this error code: proxy: read response failed from (null) (localhost)
[Mon Aug 25 13:57:56 2008] [error] ajp_read_header: ajp_ilink_receive failed
[Mon Aug 25 13:57:56 2008] [error] (120006)APR does not understand this error code: proxy: read response failed from 127.0.0.1:8009 (localhost)
[Mon Aug 25 13:57:57 2008] [error] ajp_read_header: ajp_ilink_receive failed
...
[Mon Aug 25 14:01:16 2008] [error] (120006)APR does not understand this error code: proxy: read response failed from 127.0.0.1:8009 (localhost)
[Mon Aug 25 14:01:22 2008] [error] (110)Connection timed out: proxy: AJP: attempt to connect to 127.0.0.1:8009 (localhost) failed
[Mon Aug 25 14:01:22 2008] [error] ap_proxy_connect_backend disabling worker for (localhost)
[Mon Aug 25 14:01:22 2008] [error] proxy: AJP: failed to make connection to backend: localhost
[Mon Aug 25 14:01:24 2008] [error] proxy: AJP: disabled connection for (localhost)
...
[/code]

Sometimes restarting apache helps to solve the problem, sometimes both apache and glassfish need to be restarted.

BTW, the glassfish stacktrace does not show any busy threads, and there definitely is no garbage collection problem.

What can we do to find the cause of this error?

Kind regards
Bastian
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