Re: Haproxy server timeouts?

From: XANi <xani666#gmail.com>
Date: Fri, 04 Dec 2009 20:06:26 +0100


Hi
Dnia 2009-12-04, pią o godzinie 13:48 -0500, Naveen Ayyagari pisze:

> Hello,
> We have come across a situation where occasionally our backend servers get overwhelmed with connections.
>
> It appears as though haproxy 'timeout server' value is getting hit which drops the connection to the server, however the server continues to execute the request even though the response will be ignored.
>
> We are using apache on our backend servers and have not been able to figure out how to get apache to abort processing on a connection when haproxy times out. What ends up happening is that, haproxy times out the connection, then it thinks that it has an available connection to serve a new client and opens a new connection to the apache server. This ends up with the apache server getting way more concurrent connections than we have configured haproxy to allow, and in some cases brings our servers to halt as they run out of memory because of the number of connections being opened.
>
> Has anyone else had issues like this or have suggestions on a best practice to manage this kind issue? I would have hoped that apache would terminate the process when haproxy dropped the connection, but it does not appear to behave in this manner.

Have you tried lowering max connections per server (so instead of queuing connections on backend you will have queue on haproxy)? Also, what u serve thru apache, php(mod_php/mod_fgid), python, ruby ? Regards

-- 
Mariusz Gronczewski (XANi) <xani666#gmail.com>
GnuPG: 0xEA8ACE64
http://devrandom.pl


Received on 2009/12/04 20:06

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