worker process exited on signal 11

[Lintu]

Today is the third time within the last week that the nginx server crashed
down, causing the website to only return "502 Bad Gateway" errors. In the
error log, I can find the following line:

2014/04/24 05:11:53 [alert] 32094#0: worker process 32095 exited on signal
11

I have searched for other users having the same error message, but usually
it was caused by some custom plugin they installed. I don't use any plugins
(by that I mean I use debian's stable repository of the "nginx-full"
package. I'm not sure if they deliver some custom plugins by default).

What could be causing the issue for me?



#nginx -v
nginx version: nginx/1.2.1

#nginx -V
nginx version: nginx/1.2.1
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --conf-path=/etc/nginx/nginx.conf
--error-log-path=/var/log/nginx/error.log
--http-client-body-temp-path=/var/lib/nginx/body
--http-fastcgi-temp-path=/var/lib/nginx/fastcgi
--http-log-path=/var/log/nginx/access.log
--http-proxy-temp-path=/var/lib/nginx/proxy
--http-scgi-temp-path=/var/lib/nginx/scgi
--http-uwsgi-temp-path=/var/lib/nginx/uwsgi --lock-path=/var/lock/nginx.lock
--pid-path=/var/run/nginx.pid --with-pcre-jit --with-debug
--with-http_addition_module --with-http_dav_module --with-http_geoip_module
--with-http_gzip_static_module --with-http_image_filter_module
--with-http_realip_module --with-http_stub_status_module
--with-http_ssl_module --with-http_sub_module --with-http_xslt_module
--with-ipv6 --with-sha1=/usr/include/openssl --with-md5=/usr/include/openssl
--with-mail --with-mail_ssl_module
--add-module=/tmp/buildd/nginx-1.2.1/debian/modules/nginx-auth-pam
--add-module=/tmp/buildd/nginx-1.2.1/debian/modules/nginx-echo
--add-module=/tmp/buildd/nginx-1.2.1/debian/modules/nginx-upstream-fair
--add-module=/tmp/buildd/nginx-1.2.1/debian/modules/nginx-dav-ext-module

#uname -a
Linux [hostname removed] 3.2.0-4-amd64 #1 SMP Debian 3.2.54-2 x86_64
GNU/Linux

nginx.conf
user www-data;
worker_processes 8;
pid /var/run/nginx.pid;

events {
        worker_connections 16384;
        # multi_accept on;
}

worker_rlimit_nofile 32768;

http {

        ##
        # Basic Settings
        ##

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 5;
        types_hash_max_size 2048;
        server_tokens off;

        server_names_hash_bucket_size 64;
        server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ##
        # Logging Settings
        ##

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;

        ##
        # Gzip Settings
        ##

        gzip on;
        gzip_buffers 16 8k;
        gzip_comp_level 6;
        gzip_http_version 1.1;
        gzip_min_length 10;
        gzip_types text/plain text/css image/png image/gif image/jpeg
application/json application/x-javascript text/xml application/xml
application/xml+rss text/javascript image/x-icon;
        gzip_vary on;
        gzip_proxied any;
        gzip_disable "MSIE [1-6]\.(?!.*SV1)";

        ##
        # Proxy Settings
        ##

        proxy_send_timeout 90;
        proxy_read_timeout 90;
        proxy_buffer_size 4k;
        proxy_buffers 4 32k;
        proxy_busy_buffers_size 64k;
        proxy_temp_file_write_size 64k;

        include /etc/nginx/conf.d/*.conf; # there is no file in that dir
        include /etc/nginx/sites-enabled/*; # only some files with pretty
basic server{} blocks
}

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,249524,249524#msg-249524