Hung httpd process

[Sivasingam Santhakumar]

Dear Admins,

I have a starnge situation that from time to time httpd process hungs and even root can't kill it only reboot will clear it. OS Redhat AS2.1 with Apache 1.3.1. Any suggestions?

Thanks.

[RAC_1]

A hung process is dead process. You can not kill it even with kill -9. The only optio is reboot if you have to.

But find out why it hangs. You can start with running tusc against it and see what system call it hangs on.

tusc -vfp "httpd_start_command"

[Steven E. Protter]

If its PPID is 1 and kill -9 does not work:

service httpd restart

If that does not work, restart the system.

SEP

[Ivan Ferreira]

If you can, you should upgrade your apache version.

Also, you should investigate why the process hungs. Verify the log files.

Are there any indications?

[Sivasingam Santhakumar]

Is tusc a hp-ux command? My server is RedHatAS 2.1

[NiCK_76]

Hi Sivasingam ,

I ever encounter same symptom. I found the root cause is I/O system problem. Maybe you too.

If it is. I suggest you upgrade I/O controller driver and linux kernel to have a try.

NiCK

[Ralf Hildebrandt]

Try "strace -p pid_of_the_process" to see what it does and why it hangs. Also check to logs to see what was logged before the condition you observe.

[Sivasingam Santhakumar]

Thanks for the input, the logs and other tolls doesn't tell much. I will continue my research.

[Sivasingam Santhakumar]

When I was looking deep into it I found (with lsof) that rotate logs delete the logs files while a processor looking at it. Does it make that processor hang?