Nginx fails to accept new connection if active worker crashes

[faskiri.devel]

Hi All

I use nginx configured with multiple workers. I also have an nginx
module that crashed due to an error when I noticed that the module crash
leaves nginx in a state where it cannot accept new calls.

Removing my module and killing the "active" worker (the one which seems
to take the new request) with a SIGHUP again caused nginx to hang.
Killing the other worker(s) seem to be working just fine.

Further investigations(with nginx at debug level) showed that all
threads are fine but none of the workers are getting the
ngx_accept_mutex_lock.

Master tries to release the ngx_accept_mutex_lock if the dead process
was holding it [
 https://svn.nginx.org/nginx/browser/nginx/trunk/src/os/unix/ngx_process.c?annotate=blame#L503]
but doesnt look like the value is set anywhere.

I have been using nginx only for a couple of months now so I am not very
sure of the diagnosis, please feel free to correct.


uname -a:	 Linux faskiri-pc 2.6.32-24-generic #43-Ubuntu SMP Thu Sep 16
14:58:24 UTC 2010 x86_64 GNU/Linux

nginx -V:	 nginx: nginx version: nginx/1.0.5 nginx: built by gcc 4.4.5
(Ubuntu/Linaro 4.4.4-14ubuntu5) nginx: configure arguments:
--without-http_ssi_module --without-http_geo_module
--without-http_fastcgi_module --without-http_uwsgi_module
--without-http_scgi_module --without-http_memcached_module
--without-mail_pop3_module --without-mail_imap_module
--without-mail_smtp_module --with-pcre --with-debug

I will be grateful for any advice.

Best Regards
+Fasih

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,218359,218359#msg-218359