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From André Warnier>
Subject Re: [users@httpd] Apache Close-Wait ports issue
Date Thu, 29 Oct 2009 10:47:17 GMT
Welcome ;-)

Darren Kukulka wrote:
> Painting a brief picture ;
> Several applications running on Tomcat 6.0.19 (64-bit) - several cluster
> groups
> Backend SQL Server 2005 clustered DBs (several)
> Front end Apache Web servers (2.2.9 with mod_jk 1.2.19), load balanced
> via secure network appliance
> The problem is that all the web servers stop responding to external
> requests.  Looking at the ports in use on each server...
.  All of the web servers also have exactly 30 close-wait sessions
> with the secure network appliance.

If I get this right, you have

browsers <--> network appliance <--> Apache httpd servers <--> other
and your CLOSE_WAIT sockets are on the Apache httpd servers, for 
connections with the network appliance, right ?

Did you check (with "netstat -pan" e.g.) if that is really the case ?

If that is correct, it would mean that Apache has closed these sockets, 
but is waiting for the network appliance to close it's side of these 
connections, which never happens.  Any idea why that might be ?

Another question : when that happens, how many Apache children/threads 
are running ?
Maybe you just have 30 Apache children/threads that are "stuck" because 
they are waiting for the network appliance to close these sockets, and 
it never happens.
As long as they would be waiting for that, they would never be recycled 
by Apache to handle new requests, which may explain what you're seeing ?

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