Re: JDBC over OCI -- degenerative performance & stability

I switched to the thin driver not too long after posting my first message. Interesting things to note:

• performance was maybe 10% worse. Not as bad as I was expecting...
• I still get crashes, but now these are java.lang.OutOfMemoryError rather than core dumps. It seems to hit both my servlet engines (on one box) at the same time, which is bizarre. From everything I can tell, though, the memory consumption of my java processes is completely steady; I've never seen memory use swell up when running top or /usr/ucb/ps...

I've also upgraded to JServ 1.1 final & JDK 1.1.8, but the OutOfMemoryError persists after running the servlet under heavy test load for a few hours. I increased the Max heap size via the -mx parameter to the JVM, but still to no avail...

Looks like its time to do some serious memory profiling w/ JProbe...

creamy_e_at_yahoo.com wrote:

> Michael,
> I'm in the process of setting up a servlet for
> use within the intranet of the company I work
> for. I'm using OAS 4.0.8.1 to serve servlets, JDK
> 1.2, and we use Oracle 8i(for Spatial cartridge)
> 8.1.6. My servlet will serve about 7000+ users,
> and we haven't deployed yet. Being that a lot of
> the development is so unknown, I am reluctant to
> use OCI. Is the thin driver so awful that it
> cannot handle the throughput of 6 trans/sec?
> I have just tried using the OCI driver and I have
> gotten NO response. The thin driver has been
> consistent, but again, I am only querying, not
> updating.
>
> Eric Smith
>
> In article <3904A142.7A7208D3_at_bigfoot.com>,
> Michael Grafton <mgrafton_at_bigfoot.com> wrote:
> > Hey Folks --
> >
> > We have run into a degenerative condition running JDBC over Oracle
 OCI.
> > At first, we were just getting worse & worse performance given the
 same
> > number of connections in our pool. Now, the JVM has become very
> > unstable and crashes with a mean time to failure of, oh, roughly 6
> > hours.
> >
> > We have the following system setup on our load-balanced web tier:
> >
> > Solaris 2.7
> > Apache 1.3.9
> > JDK 1.1.6
> > JServ 1.1b3
> > Oracle Client 8.0.5
> >
> > The Oracle Server is running 8.1.5.
> >
> > We are running 2 servlet engines per web machine right now, with Jserv
> > load-balancing across them. From our servlets we are making JDBC
 calls
> > using the Oracle OCI JDBC driver. We have a fairly high number of
> > transactions per second at a very consistent rate (roughly 6 a second
> > per servlet engine, although we were doing more than that until the
> > instability surfaced -- we had to turn some things off). The
> > transactions are quite simple -- simple updates & inserts and 2-table
> > joins (4-table joins at a lower frequency).
> >
> > The instability is showing up on the JVMs across several of our web
> > boxes, even those that have just recently had the servlets installed.
> > This is what confuses me the most; I have heard bad things about the
> > oracle OCI driver, but why would a brand new installation show the
 same
> > instability as one that has been running for weeks? That would seem
 to
> > point to the DB server, but that box is quiet (relatively unloaded),
 and
> > the DB instance has been bounced many times recently to no avail.
 What
> > persistent server-side problem could possibly cause this instability
 in
> > our client?
> >
> > I understand I am running a lot of older code, and am debating which
> > upgrade is likely to help this problem (JDK1.1.7? JServ 1.1 final?
> > Oracle client and/or server 8.1.6?). Trying the oracle thin driver or
 a
> > third-party driver would probably prevent the core-dump, but I'm very
> > keen on figuring out what component is to blame for the current
> > problems...
> >
> > Thanks for any help, and would love to discuss further what I'm
> > seeing...
> >
> > Michael A. Grafton
> > Senior Software Engineer
> > Live365.com
> > ***Check Out My Broadcasts***
> > [music to code to]
> > http://www.live365.com/cgi-bin/directory.cgi?autostart=djgrafton
> > [kitchen-sink]
> > http://www.live365.com/cgi-bin/directory.cgi?autostart=homie
> >
> >
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
Received on Mon May 01 2000 - 00:00:00 CDT