Forum OpenACS Q&A: Help diagnosing Postgres/AOLserver "freezing" problem

I have been using an AOLserver 3.3 / Postgres 7.0.1 /  pgdriver 2.0.1
combination for a while now and keep encountering a problem that I
can't diagnose.

Generally, the system runs well, and I can hit the web server /
database "hard" and there are no problems. After a period of idleness
though (possibly after some of the OpenACS scheduled fuctions have run
in the meantime), I find that any attempt to load a web page simply
hangs. (Cancelling the page load shows that a partial load has
actually taken place, and the only missing element seems to be style
information.) Further investigation shows that both AOLserver and
Postgres are still running, but there seem to be an excessive number
of threads for each. One (sometimes two) of the Postgres threads (not
the parent process) is always found to have used a ridiculously large
amount of CPU time.

Stopping AOLserver and running ipcclean has no effect. Killing any of
the Postgres threads leaves all the others running, and they can only
be cleared by killing individually, deleting the pid file and
restarting Postgres. The quickest fix is to kill one of the Postgres
threads (not the parent) with AOLserver still running, which has the
result of collapsing Postgres back to its parent thread and killing
AOLserver. Restarting AOLserver then brings everything back to working
order again.

Any ideas on what might be causing this, or how I might go about
diagnosing the problem further would be appreciated.


I was having problems with Postgres hanging -- specifically, the DB transactions on some pages were not being executed on the initial page load (reloading the pages caused the DB transactions to execute and the data to appear).

I resolved the issue by upgrading from Postgres 7.0 to 7.1 (for help upgrading, see

Thanks. Thought I'd try this, but can't compile PostgreSQL 7.1.3. Even after fixing a few linker things, still fails with an assembler error, which is beyond my knowledge to fix. I'm stuck with 7.0.3 until somebody at SGI compiles a later version for their freeware releases.
For anyone who's interested, I found the solution to the PostgreSQL / IRIX compilation problem at least on the postgres archives at:

Will see whether my newly compiled 7.1.3 fixes the freezing problem.