Re: [Sqlrelay-discussion] sqlr-listeners on hawking

[Firstworks/4access <dav...@fi...>]

Hey Tian,

Is it happening with only the 0.28 instances or the 0.32 instances as
well?  Either way, those are pretty old versions.  It wouldn't surprise
me if there was a bug in both of them.

It's normal for there to be a lot of sqlr-listner processes, but not so
many that the machine gets bogged down.  Each time a client connects,
the sqlr-listener process forks a child process to handle the
connection.  The child process should wait for an available sqlr-
connection-oracle daemon, hand the client off to it and then die.  Maybe
they're not dying.

I know that I fixed a problem somewhere after 0.32 where the main
sqlr-listener process didn't properly wait() on child processes and
child processes wouldn't die off.  I believe the problem was that the
parent process would receive a SIGCHLD when the child died and do a wait
(), but the wait() would get interrupted by another SIGCHLD as another
child died and wouldn't finish.  Or something like that.

Someone else recently reported a similar problem with the current
version on FreeBSD.  I'm planning on looking into it tonight.  I'll look
a little closer into this one too and let you know what I come up with.

Another thing that can cause that is if the database connection daemons
get hung up.  sqlr-listener processes will quickly pile up waiting for
the connection daemons to free up.  I believe there was a bug in both of
those versions where if the database went down or the connection to the
database went bad for a while, then SQL Relay couldn't log back into it
even though it was supposed to be able to.  Ask the admins if this
behavior tends to happen shortly after the bouncing the database.

You probably also ought to consider upgrading to a newer version :)
I think 0.28 was back before SQL Relay supported cursors.  What apps are
still using 0.28?

Dave

On Tue, 2005-06-07 at 14:01 -0400, Tian Sun wrote:
> Dave,
> 
> Our Hawking (SCO Web Server) is having some issues with sqlr-listener.
> Currently we have both v0.28 and v0.32 SQL-Relays running on Hawking,
> three of v0.28 and five of v0.32. Here is the report from our UNIX
> admin staff:
> 
> "For the past few months, we have been having problems with sqlr-
> listener process self-generating on hawking.  This would happen to the
> point of completely locking up hawking so that a power cycle was
> needed to correct the problem.  Lately, this has been happening very
> frequently - every one or two days."
> 
> Do you have any ideas on this?
> Thanks.
> 
> 
> 
> 
> Tian Sun
> BISYS - Education Services
> Email: tia...@bi...
> Phone: (800) 241-9095 ext. 6135
> Direct: (770)659-6135
> Fax:    (770)659-6011
> www.bisys-education.com
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