[Spacewalk-list] API requests overloading Tomcat???

[Matthew Madey]

Thanks for the information. I had set my maxThreads and maxClients to 1024,
but still see the issue. When we're at peak load, I gathered the number of
active http and ajp connections:

HTTP connections is 2564 (netstat -tunlap | grep httpd | wc -l)
AJP Connections: 775 (netstat -tunlap | grep 8009 | wc -l)

Is it possible I have my settings set too high? I need to be able to serve
requests for 1600+ clients more or less simultaneously. I know AJP
connection can have a backlog, which I had set to 512 when previously
tinkering with the settings. Ideally I'd like to be able to process a
reasonable amount of requests without suffering huge performance hits, and
backlog the rest.



On Thu, Aug 27, 2015 at 1:24 AM, Silvio Moioli <smoioli at suse.com> wrote:

> On 26/08/2015 18:52, Matthew Madey wrote:
>
>> [Tue Aug 25 04:21:18 2015] [error] (70007)The timeout specified has
>> expired: ajp_ilink_receive() can't receive header
>>
>
> In my experience this means that the maximum number of Tomcat worker
> threads (maxThreads parameter on Tomcat 6, maxConnections parameter on
> Tomcat 7 and above) is lower than the maximum number of Apache httpd server
> processes (MaxClients).
>
> This leads to a situation in which the AJP connector tries to open one
> more connection but fails, because Tomcat cannot provide it.
>
> In our customer's case, it helped to set both parameters to the same value
> - 100 being a good ballpark figure to start playing around. It's unlikely
> your server can manage more than 100 XMLRPC calls at the same time anyway.
>
> You can find detailed information here (this is for SUSE Manager but it
> equally applies to Spacewalk):
>
>
> https://wiki.microfocus.com/index.php/SUSE_Manager/optimizing-apache-and-tomcat
>
> Other articles explaining the same issue are here:
>
>
> http://stackoverflow.com/questions/16394682/tomcat-stops-responding-to-apache
>
> http://javaworkbench.blogspot.co.at/2013/09/apache-web-server-tomcat-ajp.html
>
> Hope this helps, feedback welcome.
>
> Regards,
> --
> Silvio Moioli
> SUSE Manager Development Team
>
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