[Opensource] SEC: UNCLASSIFIED - RE: Urgent Help! Horrendous Expresso DBObject per formance problem.

[McAuliffe, Robert]

Yeah (the subject line) we're in the middle of a project with a deadline
looming, and we can't release with the performance as it is.

We actually logged the calls from the database side, and aside from some
miscellaneous stuff (I'm assuming expresso setup), there is only one actual
call to the database, so its actually using the cache for the other 9999,
but its still taking 2ms (oops I said 4ms before, I meant 2ms).


I'll try setting up logging, though, and reply

Rob

		-----Original Message-----
		From:	larry hamel [mailto:expresso at codeguild.com]
		Sent:	Thursday, 3 April 2003 14:46
		To:	opensource at jcorporate.com
		Subject:	Re: [Opensource] SEC: UNCLASSIFIED - Urgent
Help! Horrendous Expresso DBObject per formance problem.

		hi Rob,

		quite a subject line :-)

		it would be instructive to figure out is what DB calls are
being made.

		can you turn on logging for SQL calls? 

		do this by going to expressoLogging.xml and find these lines

		        <category name="expresso.core.db.SQL">
		                <!-- turn value="debug" will trace each and
every SQL statement
		            issued to the database -->
		        </category>


		and add this
		                <priority value="debug"/>

		where the comment is.  then we'll know what queries are
happening.

		BTW, the expresso forums are faster for replies than this
mailing list.

		larry

		At 04:11 PM 4/2/2003, you wrote:

		>We're using Expresso DBObjects as our data access for our
web based
		>application.  Because of the kind of application, in one
web request, we are
		>making 4000 requests to expresso for data.  We need this to
take under 1s
		>(approx under 250ns each).  These requests are all simple
'get this field
		>from the record with this key' type requests, and there are
only 140 unique
		>accesses, so theoretically, caching should eliminate any
performance
		>problems.  However, we're getting horrendous performance.
		>
		>We setup a test class that hit expresso for a single field
(of the same
		>record), based on the primary key 10000 times, and got an
average response
		>of 4ms (startup costs were removed from the timings, and
expresso was
		>'warmed up' with 2000 hits'.   This results in a total time
of 16s for our
		>response, which is well above our 1s expectation.  We have
caching enabled
		>('y' in the config file) and we have an entry in the
DBObjLimit table that
		>gives ample room for entries, but this doesn't seem to
improve the
		>performance enough (we got an initial 1/3 performance
improvement through
		>this).
		> 
		>Is this an expected time (4ms for a cached retrieval), and
has anyone else
		>had any experiences in this area/know of a solution?
		>
		>Rob 
		>
		>PS the database is in the other room, so network should be
almost ideal.
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