We have an Nginx instance serving as a reverse proxy for a couple of domains, each hosted on their own box. Or, well, we used to. Yesterday I had barely finished updating the Nginx box with Pacman when apparently the UPC failed and the whole system lost power. When the UPC was swapped out, the system turned back on and everything worked perfectly - except Nginx.
After trying various permutations of the config file, it seems as though it's lost the ability to contact other servers, but I can't definitively confirm this because all the log says is worker process nnn exited on signal 11 (core dumped) and, though I've added in the lines to tell it to store the dumps, none are actually being produced. It's able to serve files stored locally, and I'm able to curl the other servers from the command line, but when I try accessing any domain with a proxy_pass entry it craps out and gives an empty response.
The install is now version 1.6.3, though I believe it was that before the update too.
Edit: Output of nginx -V:
nginx version: nginx/1.6.3
TLS SNI support enabled
configure arguments: --prefix=/etc/nginx --conf-path=/etc/nginx/nginx.conf --sbin-path=/usr/bin/nginx --pid-path=/run/nginx.pid --lock-path=/run/lock/nginx.lock --user=http --group=http --http-log-path=/var/log/nginx/access.log --error-log-path=stderr --http-client-body-temp-path=/var/lib/nginx/client-body --http-proxy-temp-path=/var/lib/nginx/proxy --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --with-imap --with-imap_ssl_module --with-ipv6 --with-pcre-jit --with-file-aio --with-http_dav_module --with-http_gunzip_module --with-http_gzip_static_module --with-http_realip_module --with-http_spdy_module --with-http_ssl_module --with-http_stub_status_module --with-http_addition_module --with http_degradation_module --with-http_flv_module --with-http_mp4_module --with-http_secure_link_module --with-http_sub_module
