topic Re: Semaphore Table (semmni) fill up in 2 weeks in Operating System - HP-UX

Semaphore Table (semmni) fill up in 2 weeks

John Jimenez — Mon, 08 Sep 2003 15:15:18 GMT

I have some scipts that are not releasing semaphores after they are complete. I have narrowed the problems to some scripts in cron that are using "PGP" encryption. But I do not know needs to be added to these scripts or if it might be the PGP program intself. Has anyone ever seen this problem before?
Thanks a bunch.

Re: Semaphore Table (semmni) fill up in 2 weeks

Massimo Bianchi — Mon, 08 Sep 2003 15:18:37 GMT

Hi,
if you know the user under which these scripts are running, i would use "ipcrm -S " to clean the improperly left there semaphores.

Scripts by themselves do not use semaphores (AFAIK), so i think of PGP. Which version ? maybe there are specific issues, but we need:

- O.S. version
- PGP version
- the version of other programs involved.

Massimo

Re: Semaphore Table (semmni) fill up in 2 weeks

Steven E. Protter — Mon, 08 Sep 2003 15:25:18 GMT

You might want to check and see if your semmni shmmax and shmseg figures are realistic.

ipcs

this command will show open shared memory areas.

ipcrm -m or ipcrm -s

to get rid of dead ones.

If you try and hammer something that is active, you might impact users.

SEP

Re: Semaphore Table (semmni) fill up in 2 weeks

A. Clay Stephenson — Mon, 08 Sep 2003 15:34:52 GMT

You have to be careful in removing sema4's in that although no processes may be using one at the moment, it may be needed later. It's not unusual for a process to create and initialize them and then other processes simply access them but absolutely expect that these sema4's exist. Typically sema4's are left dangling when processes terminate unexpectedly or if you use kill -9. I suspect that if you fix the real problem (e.g. bad code) the symptoms (dangling sema4's) will disappear.

Re: Semaphore Table (semmni) fill up in 2 weeks

John Jimenez — Mon, 08 Sep 2003 17:38:47 GMT

Thanks for the input. I did use the ipcrm -s instead of the ipcrm -S. Because they all has a unique ID. But all the ones from the 4 users had the same key 0x00000000 including some that I did not want to touch from root.

I have been runing ipcs -sbp many times a day for a couple of weeks. I will only delete the ones that I know should be deleted. I deleted only 1 user today but will do another one from another tomorrow. We will continue to find out what is causing this. Since it seems like the only these scripts that are not releasing semaphores all use PGP, I will call Network Associates to see if they know any bugs on their software that might be doing this. Thanks again for your help...