Application Stopped due to upstream unreachable

During Chef Server troubleshooting time, found chef is unreachable from localhost

Description

• Nginx was shown as started in chef-server-ctl status command, pid could be found
• TCP port 443 was inaccessable from localhost.
• Reboot server, but still the same issue
• Used ps -ef | grep nginx, found nginx is running without indication of master
• Run nginx command line which found in ps
• Shows upstream server and port was not reachable, which is automate server

Result

• Can not find IP address, then add IP and host into /etc/host file, result shows

  • NGINX running with master indicator
  • TCP port 443 was listening

• Still can not reach upstream server

Consolution

The problem could be related to following issues caused application stopped due to no IP can be found for upstream servers.

• Routing issue
• Firewall issue