Tune apache2 for more concurrent connections - Revision history

Dominik.epple at 10:11, 6 September 2018

2018-09-06T10:11:51Z

← Older revision		Revision as of 10:11, 6 September 2018
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	=The ~~problem~~=		= Apache Configuration =

			== MPM Module ==

			Please ensure that your apache is using the <code>mpm_worker</code> or <code>mpm_event</code> module. This allows us to serve lots of concurrent connections by using less RAM than with <code>mpm_prefork</code> as we are going to start much less processes. Unfortunately the default MPM module seems to differ from distro to distro, so doublecheck and make sure you are on the right setting.

			The method to configure the MPM module differes of course also from distribution to distribution:

			* CentOS7/RHEL7: adjust <code>/etc/httpd/conf.modules.d/00-mpm.conf</code>
			* Debian: use <code>a2dismod</code> / <code>a2enmod</code> to disable the wrong and enable the desired MPM Module.

			About <code>mpm_worker</code> vs <code>mpm_event</code>: we assume they are equivalent for our purpose. <code>mpm_worker</code> is the older one and just works fine. <code>mpm_event</code> should improve on it further but we have been unable to observe any actual advantages.

			== Concurrent Connections ==

	By default apache2 is configured to support 150 concurrent connections.		By default apache2 is configured to support 150 concurrent connections.
	This forces all parallel requests beyond that limit to wait.		This forces all parallel requests beyond that limit to wait.
	Especially if, for example, active sync clients maintain a permanent connection for push events to arrive.		Especially if, for example, active sync clients maintain a permanent connection for push events to arrive.

	~~=The solution=~~
	This is an example configuration to provide 8000 concurrent connections.		This is an example configuration to provide 8000 concurrent connections.
	Please ensure that your apache is using the mpm_worker. This allows us to serve lots of concurrent connections by using less RAM than with mpm_prefork as we are going to start much less processes. (mpm_event, which is stated to be stable by Apache nowaways, shows problems in load tests, with connection timeouts.)

	<pre><nowiki>		<pre><nowiki>
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	Note: MaxRequestWorkers was previously named MaxClients and MaxConnectionsPerChild was previously named MaxRequestsPerChild. If you are using old (pre 2.4) verions of apache you might need to use the old names.		Note: MaxRequestWorkers was previously named MaxClients and MaxConnectionsPerChild was previously named MaxRequestsPerChild. If you are using old (pre 2.4) verions of apache you might need to use the old names.

	==Short explanation of the parameters:==		Short explanation of the parameters:

	<table border="1" cellpadding="5" cellspacing="0">		<table border="1" cellpadding="5" cellspacing="0">

Dominik.epple at 07:54, 26 March 2017

2017-03-26T07:54:50Z

← Older revision		Revision as of 07:54, 26 March 2017
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	This forces all parallel requests beyond that limit to wait.		This forces all parallel requests beyond that limit to wait.
	Especially if, for example, active sync clients maintain a permanent connection for push events to arrive.		Especially if, for example, active sync clients maintain a permanent connection for push events to arrive.

	To calculate the number of concurrent sessions each of your apache nodes must be able to provide, consider the total number of concurrent sessions in your OX cluster and divide it by the number of apache nodes involved in serving those sessions. Then add some room for statistical fluctuations.

	=The solution=		=The solution=
	This is an example configuration to provide 8000 concurrent connections.		This is an example configuration to provide 8000 concurrent connections.
	Please ensure that your apache is using the mpm_worker ~~or mpm_event module~~. This allows us to serve lots of concurrent connections by using less RAM than with mpm_prefork as we are going to start much less processes.		Please ensure that your apache is using the mpm_worker. This allows us to serve lots of concurrent connections by using less RAM than with mpm_prefork as we are going to start much less processes. (mpm_event, which is stated to be stable by Apache nowaways, shows problems in load tests, with connection timeouts.)

	<pre><nowiki>		<pre><nowiki>
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	For further information on these parameters see ~~http://httpd.apache.org/docs/2.4/mod/event.html,~~ http://httpd.apache.org/docs/2.4/mod/worker.html and http://httpd.apache.org/docs/2.4/mod/mpm_common.html.		For further information on these parameters see http://httpd.apache.org/docs/2.4/mod/worker.html and http://httpd.apache.org/docs/2.4/mod/mpm_common.html.

	--[[User:Steffen.templin\|Steffen.templin]] 12:10, 23 May 2011 (UTC)		--[[User:Steffen.templin\|Steffen.templin]] 12:10, 23 May 2011 (UTC)

Dominik.epple at 14:35, 25 March 2017

2017-03-25T14:35:45Z

← Older revision		Revision as of 14:35, 25 March 2017
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	=The solution=		=The solution=
	This is an example configuration to provide 8000 concurrent connections.		This is an example configuration to provide 8000 concurrent connections.
	Please ensure that your apache is using the mpm_worker module. This allows us to serve lots of concurrent connections by using less RAM than with mpm_prefork as we are going to start much less processes.		Please ensure that your apache is using the mpm_worker or mpm_event module. This allows us to serve lots of concurrent connections by using less RAM than with mpm_prefork as we are going to start much less processes.

	<pre><nowiki>		<pre><nowiki>
	<IfModule mpm_worker_module>		<IfModule mpm_worker_module>
	ServerLimit 250		ServerLimit 250
	StartServers 10		StartServers 10
	MinSpareThreads 75		MinSpareThreads 75
	MaxSpareThreads 250		MaxSpareThreads 250
	ThreadLimit 64		ThreadLimit 64
	ThreadsPerChild 32		ThreadsPerChild 32
	~~MaxClients~~ 8000		MaxRequestWorkers 8000
	~~MaxRequestsPerChild~~ 10000		MaxConnectionsPerChild 10000
	</IfModule>		</IfModule>
	</nowiki></pre>		</nowiki></pre>

			Note: MaxRequestWorkers was previously named MaxClients and MaxConnectionsPerChild was previously named MaxRequestsPerChild. If you are using old (pre 2.4) verions of apache you might need to use the old names.

	==Short explanation of the parameters:==		==Short explanation of the parameters:==
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	</tr>		</tr>
	<tr>		<tr>
	<td><b>~~MaxClients~~</b></td><td>This declares how many concurrent connections we provide. Devided by '''ThreadsPerChild''' you get the suitable ServerLimit value. May be less than '''ServerLimit * ThreadsPerChild''' to reserve some resources that can be engaged during runtime with increasing '''~~MaxClients~~''' and reloading the configuration.</td>		<td><b>MaxRequestWorkers</b></td><td>This declares how many concurrent connections we provide. Devided by '''ThreadsPerChild''' you get the suitable ServerLimit value. May be less than '''ServerLimit * ThreadsPerChild''' to reserve some resources that can be engaged during runtime with increasing '''MaxRequestWorkers''' and reloading the configuration.</td>
	</tr>		</tr>
	<tr>		<tr>
	<td><b>~~MaxRequestsPerChild~~</b></td><td>Defines the number of Connections that a process can handle during its lifetime (keep-alives are counted once). After that it will be killed. This can be used to prevent possible apache memory leaks. If set to 0 the lifetime is infinite.</td>		<td><b>MaxConnectionsPerChild</b></td><td>Defines the number of Connections that a process can handle during its lifetime (keep-alives are counted once). After that it will be killed. This can be used to prevent possible apache memory leaks. If set to 0 the lifetime is infinite.</td>
	</tr>		</tr>
	</table>		</table>


	For further information on these parameters see http://httpd.apache.org/docs/2.2/mod/worker.html and http://httpd.apache.org/docs/2.2/mod/mpm_common.html.		For further information on these parameters see http://httpd.apache.org/docs/2.4/mod/event.html, http://httpd.apache.org/docs/2.4/mod/worker.html and http://httpd.apache.org/docs/2.4/mod/mpm_common.html.

	--[[User:Steffen.templin\|Steffen.templin]] 12:10, 23 May 2011 (UTC)		--[[User:Steffen.templin\|Steffen.templin]] 12:10, 23 May 2011 (UTC)

Dominik.epple: /* The solution */

2014-05-22T13:38:59Z

The solution

← Older revision		Revision as of 13:38, 22 May 2014
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	ThreadLimit 64		ThreadLimit 64
	ThreadsPerChild 32		ThreadsPerChild 32
	MaxClients ~~800~~		MaxClients 8000
	MaxRequestsPerChild 10000		MaxRequestsPerChild 10000
	</IfModule>		</IfModule>

Dominik.epple: /* The solution */

2014-05-22T13:38:32Z

The solution

← Older revision		Revision as of 13:38, 22 May 2014
Line 7:		Line 7:

	=The solution=		=The solution=
	This is an example configuration to provide ~~800~~ concurrent connections.		This is an example configuration to provide 8000 concurrent connections.
	Please ensure that your apache is using the mpm_worker module. This allows us to serve lots of concurrent connections by using less RAM than with mpm_prefork as we are going to start much less processes.		Please ensure that your apache is using the mpm_worker module. This allows us to serve lots of concurrent connections by using less RAM than with mpm_prefork as we are going to start much less processes.

	<pre><nowiki>		<pre><nowiki>
	<IfModule mpm_worker_module>		<IfModule mpm_worker_module>
	ServerLimit 25		ServerLimit 250
	StartServers 10		StartServers 10
	MinSpareThreads 75		MinSpareThreads 75

Dominik.epple at 14:49, 29 April 2014

2014-04-29T14:49:15Z

← Older revision		Revision as of 14:49, 29 April 2014
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	This forces all parallel requests beyond that limit to wait.		This forces all parallel requests beyond that limit to wait.
	Especially if, for example, active sync clients maintain a permanent connection for push events to arrive.		Especially if, for example, active sync clients maintain a permanent connection for push events to arrive.

			To calculate the number of concurrent sessions each of your apache nodes must be able to provide, consider the total number of concurrent sessions in your OX cluster and divide it by the number of apache nodes involved in serving those sessions. Then add some room for statistical fluctuations.

	=The solution=		=The solution=

Steffen.templin at 07:32, 29 May 2012

2012-05-29T07:32:00Z

← Older revision		Revision as of 07:32, 29 May 2012
Line 10:		Line 10:
	<pre><nowiki>		<pre><nowiki>
	<IfModule mpm_worker_module>		<IfModule mpm_worker_module>
	ServerLimit 25		ServerLimit 25
	StartServers 10		StartServers 10
	MinSpareThreads 75		MinSpareThreads 75
	MaxSpareThreads 250		MaxSpareThreads 250
	ThreadLimit 64		ThreadLimit 64
	ThreadsPerChild 32		ThreadsPerChild 32
	MaxClients 800		MaxClients 800
	MaxRequestsPerChild 0		MaxRequestsPerChild 10000
	</IfModule>		</IfModule>
	</nowiki></pre>		</nowiki></pre>
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	</tr>		</tr>
	<tr>		<tr>
	<td><b>MaxRequestsPerChild</b></td><td>Defines the number of Connections that a process can handle during its lifetime (keep-alives are counted once). After that it will be killed.</td>		<td><b>MaxRequestsPerChild</b></td><td>Defines the number of Connections that a process can handle during its lifetime (keep-alives are counted once). After that it will be killed. This can be used to prevent possible apache memory leaks. If set to 0 the lifetime is infinite.</td>
	</tr>		</tr>
	</table>		</table>

Holgi: moved Development:Tune apache2 for more concurrent connections to Tune apache2 for more concurrent connections

2011-12-14T07:51:25Z

moved Development:Tune apache2 for more concurrent connections to Tune apache2 for more concurrent connections

← Older revision

Revision as of 07:51, 14 December 2011

Holgi: /* The problem */

2011-12-14T07:50:46Z

The problem

← Older revision		Revision as of 07:50, 14 December 2011
Line 1:		Line 1:
	=The problem=		=The problem=
	By default apache2 is configured to support ~~about~~ 150 concurrent connections.		By default apache2 is configured to support 150 concurrent connections.
	This forces all ~~further connection~~ requests to wait ~~what is unnecessary since apache2 and the OX Server support~~ a ~~lot more concurrent connections on suitable hardware~~.		This forces all parallel requests beyond that limit to wait.
			Especially if, for example, active sync clients maintain a permanent connection for push events to arrive.

	=The solution=		=The solution=

Steffen.templin: moved Development:Apache2 configuration to increase the number of possible simultaneously connections to Development:Tune apache2 for more concurrent connections: Shorter title.

2011-05-23T12:28:24Z

moved Development:Apache2 configuration to increase the number of possible simultaneously connections to Development:Tune apache2 for more concurrent connections: Shorter title.

← Older revision	Revision as of 12:28, 23 May 2011
(No difference)