Hi, thanks for the replys.

ulimit output: unilimited To run dstat I will have to wait until php becomes unresponsive, it could be
hours or days, I can't reproduce it since it's not releated to the load on the
server, I tried stressing it with Apache Benchmark but even with all the cpus at
100% the site was still working fine (only slow), I use munin and every time it
happens I don't see any weird behavior apart form the mysql threads that have a
spike.

PHP_FCGI_MAX_REQUESTS = 500 I'm using dynamic child with php-fpm (but I've already tried many setting here
even without php-fpm)

Here's the first part of the nginx configuration, let me know if you need the
whole thing

user www-data www-data; worker_processes 12; error_log logs/error.log; pid /dev/shm/nginx.pid; worker_rlimit_nofile 10000;

events { worker_connections 1024; use epoll; }

http { include mime.types; #include /etc/nginx/proxy.conf; include /usr/local/nginx/conf/fastcgi_params;

default_type application/octet-stream;

log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"';

access_log logs/access.log main; sendfile on; tcp_nopush on; server_names_hash_bucket_size 128; # this seems to be required for some
vhosts client_max_body_size 12m; large_client_header_buffers 8 32k;

# output compression saves bandwidth gzip on; gzip_proxied any; gzip_http_version 1.1; #gzip_min_length 1100; gzip_comp_level 2; #gzip_buffers 4 8k; gzip_types text/plain text/css application/x-javascript text/xml
application/xml application/xml+rss text/javascript application/atom+xml; #gzip_vary on; #gzip_disable "MSIE [1-6]\.";

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,40332,71034#msg-71034