httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Eric Covener" <>
Subject Re: strange usage pattern for child processes
Date Wed, 15 Oct 2008 12:27:52 GMT
On Wed, Oct 15, 2008 at 7:55 AM, Lars Eilebrecht <> wrote:
> Hi,
> The first odd thing is that I would have expected that Apache
> uses all child processes about equally. Especially I would
> have expected that there are at least 25 threads for the second
> process in state "_" (waiting for connection), because the
> MinSpareThread directive is set to 25.

requests check in, but they don't check out -- but only for this
process.  That would explain the backlog here, the other two processes
are not ignores they're just doing their work in a timely fashion.

> The second odd thing is that the connections/threads in W state
> seem to be hanging, i.e., no data is being transferred over the
> connection and these threads/connection time out after about 256
> seconds. However, the general Timeout setting is 30s so why
> isn't the connection killed after 30s?

This timeout only applies to an individual read/write, and the meter
isn't running if we're not talking to the client (e.g. cgi chugging

> What happens during peek times is that all threads of one
> child process end up in state W, then Apache starts using
> another child process, etc. and at some point basically
> all threads are in state W and we are hitting the MaxClients
> limit which makes the server unusable.

take a few pstack snapshots of one of those spinning processes?

Eric Covener

View raw message