nginx/Win2008R2 stops responding after few sessions

[Maxim Dounin]

Hello!

On Fri, Dec 09, 2011 at 06:05:12PM +0100, Kurien Mathew wrote:

> Hello,
> 
> I am running nginx 1.0.10 (native build) on Windows 2008 R2 with 2 worker
> processes.
> 
> I am serving a static file (chunk.ts 375000 bytes) to a httperf client
> running on CentOS 6. The client executes 4 concurrent connections and sends
> out 96 requests on each. The client has a response timeout set at 2
> seconds. In the first execution of the client all 4 sessions succeed but in
> the second execution 2 sessions timeout due the lack of a response. In the
> third & fourth execution all sessions timeout.
> 
> I have some debug data available at
> http://www.mediafire.com/?yct3s1720flgvz3. The archive contains
> 
> chunk.ts - the static file being served
> error.log - nginx error log (debug level)
> httperfout.txt - output of httperf executions
> NetworkMonitor.cap - Packet capture from nginx server (using Network
> Monitor)
> nginx.conf - nginx conf used
> 
> The network capture shows TCP ACK for the request but no response from
> nginx during 2 seconds. The nginx log shows 6 successfult sessions but
> nothing much after that. If the server is restarted a few sessions would
> succeed before it stops responding.
> 
> And importantly, there is no problem when the number of worker processes is
> set to 1.
> 
> Would you have any additional clues about what is going wrong?

The worker_processes under windows must be set to 1 or you must 
switch off accept_mutex.  In either case only one worker will 
actually do any work.

Maxim Dounin