The production support team of xFusionCorp Industries has deployed some of the latest monitoring tools to keep an eye on every service, application, etc. running on the systems. One of the monitoring systems reported about Apache service unavailability on one of the app servers in Stratos DC.
Identify the faulty app host and fix the issue. Make sure Apache service is up and running on all app hosts. They might not have hosted any code yet on these servers, so you don’t need to worry if Apache isn’t serving any pages. Just make sure the service is up and running. Also, make sure Apache is running on port
3004on all app servers.
Check httpd status
root@stapp01 ~]# systemctl status httpd.service
● httpd.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Fri 2025-08-08 05:04:33 UTC; 12s ago
Docs: man:httpd(8)
man:apachectl(8)
Process: 1004 ExecStop=/bin/kill -WINCH ${MAINPID} (code=exited, status=1/FAILURE)
Process: 1003 ExecStart=/usr/sbin/httpd $OPTIONS -DFOREGROUND (code=exited, status=1/FAILURE)
Main PID: 1003 (code=exited, status=1/FAILURE)
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com systemd[1]: Starting The Apache HTTP Server...
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com httpd[1003]: (98)Address already in use: AH0007...4
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com httpd[1003]: no listening sockets available, sh...n
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com httpd[1003]: AH00015: Unable to open logs
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com systemd[1]: httpd.service: main process exited,...E
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com kill[1004]: kill: cannot find process ""
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com systemd[1]: httpd.service: control process exit...1
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com systemd[1]: Failed to start The Apache HTTP Server.
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com systemd[1]: Unit httpd.service entered failed s....
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com systemd[1]: httpd.service failed.
Hint: Some lines were ellipsized, use -l to show in full.
I see two problems:
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com httpd[1003]: (98)Address already in use: AH0007...4
Aug 08 05:04:33 stapp01.stratos.xfusioncorp.com httpd[1003]: no listening sockets available, sh...n
Lets check the port status
sudo netstat -tlnup
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN 1/init
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 443/sshd
tcp 0 0 127.0.0.11:35047 0.0.0.0:* LISTEN -
tcp 0 0 127.0.0.1:3004 0.0.0.0:* LISTEN 680/sendmail: accep
tcp6 0 0 :::111 :::* LISTEN 424/rpcbind
tcp6 0 0 :::22 :::* LISTEN 443/sshd
udp 0 0 0.0.0.0:111 0.0.0.0:* 1/init
udp 0 0 0.0.0.0:1021 0.0.0.0:* 424/rpcbind
udp 0 0 127.0.0.11:35464 0.0.0.0:* -
udp6 0 0 :::111 :::* 424/rpcbind
udp6 0 0 :::1021 :::* 424/rpcbind
So 3004 port already being used by sendmail. We already fixed this port conflict in the previous day. Lets fix the issue using the same way describe there.
Verify the status:
curl http://stapp01:3004 # from jump host
systemctl status service-namejournalctl -u service-name -fps aux | grep process-nametop, htop, ps aux --sort=-%cpunetstat -tlnup or ss -tlnuplsof -i :port-numberkill -9 PID (force kill)systemctl stop service-namehttpd -t or nginx -t/var/log/httpd/error_log/var/log/httpd/access_loghttpd -M (loaded modules)