Re: What is the impact of setting ServerLimit higher than MaxClients?

["Rose, John B" <jbrose@xxxxxxx>]

Thanks for replying.

Yes, it is prefork MPM. 

Reading this in the Apache documentation …

"Do not set the value of this directive any higher than what you might want to set MaxClients to."

It also says …

"Special care must be taken when using this directive. If ServerLimit is set to a value much higher than necessary, extra, unused shared memory will be allocated"

What is classified as "much higher?"

Is there a negative (or positive) impact of any kind of, for example, setting ServerLimit to 2000 and MaxClients to 512?

http://httpd.apache.org/docs/2.2/mod/mpm_common.html#serverlimit

Thanks

From: Jeff Trawick <trawick@xxxxxxxxx>
Reply-To: "users@xxxxxxxxxxxxxxxx" <users@xxxxxxxxxxxxxxxx>
Date: Tuesday, August 20, 2013 4:50 PM
To: "users@xxxxxxxxxxxxxxxx" <users@xxxxxxxxxxxxxxxx>
Subject: Re: What is the impact of setting ServerLimit higher than MaxClients?

On Aug 20, 2013 4:26 PM, "Rose, John B" <jbrose@xxxxxxx> wrote:
>
> What is the impact of setting the ServerLimit to a value significantly more than your MaxClients value? Say with a MaxClients set to 512 and ServerLimit of 2000?
>

Assuming prefork MPM:

You can increase maxclients across graceful restart, up to serverlimit

Threaded MPMs: comparing maxclients vs server limit doesn't work without also accounting for threadsperchild

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