id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	uname	nginx_version
753	Nginx leaves UNIX domain sockets after SIGQUIT	launchpad.net/~cpburnz	Ruslan Ermilov <ru@…>	"According to the Nginx documentation, ''SIGQUIT'' will cause a ""graceful shutdown"" while ''SIGTERM'' will cause a ""fast shutdown"". If you send ''SIGQUIT'' to Nginx, it will leave behind stale UNIX domain socket files that were created using the ''listen'' directive. If there are any stale UNIX domain socket files when Nginx starts up, it will fail to listen on the socket because it already exists. However if you use ''SIGTERM'', the UNIX domain socket files will be properly removed. I've encountered this with Nginx 1.6.2, 1.6.3, and '''1.8.0''' on Ubuntu 14.04.

Example `/etc/nginx/nginx.conf`:

{{{
http {
    ##
    # Basic Settings
    ##

    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;

    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_disable ""msie6"";

    ##
    # Virtual Host Configs
    ##

    include /etc/nginx/sites-enabled/*;
}
}}}

Example `/etc/nginx/sites-enabled/serve-files`:

{{{
server {
    listen unix:/run/serve-files.socket;
    root /var/www/files;
    location / {
        try_files $uri =404;
    }
}
}}}

Then start Nginx:

{{{
sudo nginx
# OR
sudo service nginx start
}}}

On first start, `/run/serve-files.socket` will be created because of the `listen unix:/run/serve-files.socket;` directive.

Then stop Nginx with SIGQUIT:

{{{
sudo kill -SIGQUIT $(cat /run/nginx.pid)
# OR
sudo service nginx stop # Sends SIGQUIT
}}}

The socket at `/run/serve-files.socket` will remain because it was not properly removed. If you try to restart Nginx, it will fail to start with the following logged to `/var/log/nginx/error.log`:

{{{
2015/04/24 10:16:27 [emerg] 5782#0: bind() to unix:/run/serve-files.socket failed (98: Address already in use)
2015/04/24 10:16:27 [emerg] 5782#0: bind() to unix:/run/serve-files.socket failed (98: Address already in use)
2015/04/24 10:16:27 [emerg] 5782#0: bind() to unix:/run/serve-files.socket failed (98: Address already in use)
2015/04/24 10:16:27 [emerg] 5782#0: bind() to unix:/run/serve-files.socket failed (98: Address already in use)
2015/04/24 10:16:27 [emerg] 5782#0: bind() to unix:/run/serve-files.socket failed (98: Address already in use)
2015/04/24 10:16:27 [emerg] 5782#0: still could not bind()
}}}"	defect	closed	minor		nginx-core	1.6.x	fixed	nginx 1.6 1.8 sigquit sigterm unix domain socket		"Linux test1 3.13.0-32-generic #57-Ubuntu SMP Tue Jul 15 03:51:08 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

"	"nginx version: nginx/1.6.3
TLS SNI support enabled
configure arguments: --with-cc-opt='-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2' --with-ld-opt='-Wl,-Bsymbolic-functions -Wl,-z,relro' --prefix=/usr/share/nginx --conf-path=/etc/nginx/nginx.conf --http-log-path=/var/log/nginx/access.log --error-log-path=/var/log/nginx/error.log --lock-path=/var/lock/nginx.lock --pid-path=/run/nginx.pid --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-debug --with-pcre-jit --with-ipv6 --with-http_ssl_module --with-http_stub_status_module --with-http_realip_module --with-http_auth_request_module --with-http_addition_module --with-http_dav_module --with-http_geoip_module --with-http_gzip_static_module --with-http_image_filter_module --with-http_spdy_module --with-http_sub_module --with-http_xslt_module --with-mail --with-mail_ssl_module --add-module=/build/buildd/nginx-1.6.3/debian/modules/nginx-auth-pam --add-module=/build/buildd/nginx-1.6.3/debian/modules/nginx-dav-ext-module --add-module=/build/buildd/nginx-1.6.3/debian/modules/nginx-echo --add-module=/build/buildd/nginx-1.6.3/debian/modules/nginx-upstream-fair --add-module=/build/buildd/nginx-1.6.3/debian/modules/ngx_http_substitutions_filter_module



nginx version: nginx/1.8.0
built by gcc 4.8.2 (Ubuntu 4.8.2-19ubuntu1) 
built with OpenSSL 1.0.1f 6 Jan 2014
TLS SNI support enabled
configure arguments: --with-http_ssl_module"