Berkeley DB 4.2.52 on HP-UX 11.11

[John Hawkes-Reed]

Hello.

We've been running into regular resource starvation problems with programs using the Berkeley DB libraries, and I suspect we're missing a config tweak when building the libraries from source. The last 'n' times I've built the db package (using HP ANSI C) I've just let configure work it out for itself. Sendmail and Postfix behave themselves (he said, confidently) but I can blow OpenLDAP up merely by adding a few hundred records, and Amavis will run for a few hours before expiring with a "BDB no dbS: Lock table is out of available locker entries" error.

As a test, I tried the HP-built version of OpenLDAP, but that expired as quickly as our locally compiled version. (Not entirely surprising if the problem's with the db libraries)

So, the question is - What should we be looking at to get a reliable db build?

[RAC_1]

Lock table is out of available locker entries" error.

makes me think that you may be running out of no. of file system locks -i.e. kernel tunable nflocks. What is your setting?? kmtune -lq nflocks. Also see the real time usage of it by following commands.

sar -v 5 5
glance -t

You will have to increase it, if that is what is causing the problem.

Anil

[Steve Lewis]

Does it use semaphores (sysV IPC locking mechanism) ?

If so, you may need to bump up your kernel parameters like this example for my 500 user system:

semmni 4096
semmns 4096
semmnu 2048
semume 512

[John Hawkes-Reed]

(Some fiddling later while I rebuild a test rig I can break things on)nflocks is 200. According to Glance, it never gets above 8 in use.As regards semaphores, the numbers are thus:semmni 64semmns 128semmnu 30semume 10... Which are, um, different. Admittedly, it's not a multi-user box, it just has to run postfix, openldap and amavis. I'll tweak them and see what happens.(And the formatting of this has gone dismal. Apologies.)