How to see semaphore status currently?

[Scott Chapman]

I have a situation where one of the semaphore resources are fully utilized and software needing semaphores (semaphore undo structures specifically) is bombing on HPUX 10.20. Is there a utility to show me what all of the semaphore structures are in use beyond ipcs -as?

[ramesh_6]

Hi Scott,

You can use the /usr/sbin/sydef to display the kernel parameters of which semaphores in also one.

Sydef analyzes teh currently running system and reports and reports on its tunable parameters.

[A. Clay Stephenson]

Hi:

If you know Perl, then you can use the IPC::Semaphore module to look at any semaphore values. About 20 lines of Perl in this case would replace 250 or so lines of C to do the same thing.

[Jeff Schussele]

Hi Scott,

The sar util (sar -m) will give semaphore usage in calls per second & you could set it up to create a file over time to get some historical usage data.
Also I believe you can get more detailed info from the lsof utility.

Rgds,
Jeff

[Sandip Ghosh]

You can get it through gpm (glance). Run gpm go to report ->System info ->System Tables Report.

Sandip

[Michael Tully]

If you don't have access to the GUI of glance
here's how to get the information.

# /opt/perf/bin/glance

Once the screen is open:
F5 (NextKeys)
F3 (SysTabls)
This will show something like this:

SYSTEM TABLES REPORT Users= 9

System Table Available Used Utilization High(%)
--------------------------------------------------------------------------------
Proc Table (nproc) 8212 259 3 3
File Table (nfile) 20989 3863 18 18
Shared Mem Table (shmmni) 1024 25 2 2
Message Table (msgmni) 1024 46 4 4
Semaphore Table (semmni) 8192 34 0 0
File Locks (nflocks) 800 33 4 4
Pseudo Terminals (npty) 1024 0 0 0
Buffer Headers (nbuf) na 70176 na na

If you don't have glance loaded, there is a trial version that you ca load from your application CD set.

-Michael