I have the LAMP stack running fir about half a year now and it's becoming less and less stable with one/some/all of the following symptoms :
- SSH sessions from other computers get terminated
- SFTP sessions are disconnected
- git pull / git push requests are denied
- MySQL connections are broken off
- Browsers that access the server suddenly display "Web page cannot be displayed"
However when I view the "console" tab in vSphere, I can do anything I want there, albeit locally on the VM. When I run the linux command "top" and or "vmstat", no erratic values show up. I'm also sure that the server did not kernel-panic and/or reboot (I have a local mysql-tuner that displays the uptime, so a reboot would show there in an uptime of a few minutes).
Apache logs, Mysql-slow logs, PHP Error logs show no signs of flaw at the time of unresponsive behaviour. Also a "service ssh status" shows that the ssh daemon still runs while a client cannot connect... Sometimes commanding "service apache2 restart" will do the trick; sometimes not. Sometimes a "service mysql restart" will do the trick; sometimes not. A reboot works most of the time, but today even that only worked for 5 minutes. Then the problem went away by itself.
The LAMP stack has 1GB of RAM for a handful of PHP/MySQL applications on our intranet.
Can anyone please give me pointers on where to start troubleshooting this? any and all help would be much appreciated.