Re: Weird database hanging

  • From: Sunil Kanderi <sunil.kanderi@xxxxxxxxx>
  • To: oracle-l <oracle-l@xxxxxxxxxxxxx>
  • Date: Mon, 17 Sep 2007 16:08:50 -0500

I have gone through all the responses to this problem and this seems very similar to a problem that I am seeing on one of my 9i database. We have lots of web applications running from that database and once in a while there is a sudden spike in the number of connections from a Oracle user related to one of the web applications and the concurrent connections for that particular web application user jumps from 10 or 15 concurrent connections to 100s in less than a couple of minutes. The database and the server hang until these connections are cleared. At times we cannot even get a connection to the server when this happens. I usually don't see any alerts in the alert log when this happens.


Thanks,
Sunil.

Don Seiler wrote:
Running 10gR2 (10.2.0.2) on RHEL4 on 4 64-bit dual-core box.  Earlier
today users complained en masse about not being able to connect to the
database.  I got to a term and found that even trying to log in
locally as sysdba was hanging.

The alert log had this:
Fri Sep 14 11:23:36 2007
kkjcre1p: unable to spawn jobq slave process
Fri Sep 14 11:23:36 2007
Errors in file /u00/app/oracle/admin/foo/bdump/foo_cjq0_11519.trc:
Fri Sep 14 11:25:46 2007
kkjcre1p: unable to spawn jobq slave process
Fri Sep 14 11:25:46 2007
Errors in file /u00/app/oracle/admin/foo/bdump/foo_cjq0_11519.trc:
Fri Sep 14 11:26:49 2007
PMON failed to acquire latch, see PMON dump

I hit the Google but before I came back, my login was ready and things
seemed back to normal.  Checking back in the alert log I saw a lot of
these:

WARNING: inbound connection timed out (ORA-3136)

I'm assuming those are just symptoms of the original cause, and I've
already found suggestions for treating timeouts in sqlnet.ora and
listener.ora.

The trace files mentioned have lines such as:

Waited for process J000 to initialize for 60 seconds

repeated for 70, 80, 90 seconds, etc.

So in summary, there was hanging for everyone, it seemed to clear
itself up.  One post on Google suggested that the PROCESSES init
parameter might be too low.  Any other possibilities?

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