db-ojb-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Chris Giordano <giord...@more.net>
Subject OJB usability - part 5 of 5: caching
Date Wed, 15 Oct 2003 14:51:05 GMT
OJB developers:

The following feedback intends to provide constructive comments to the
OJB developers to improve the project as a whole.  The experiences and
observations are meant to stimulate development of world class software.
An open source dB persistence layer solution is needed and OJB may be
positioned to provide this in the future.

Our intention to use OJB was, in part, driven by the performance gain we
could potentially achieve as queried Objects became accessible via the 
cache.
Then we did some performance testing.

With MySQL as a backend datastore, we configured the JDBC driver to log SQL
and found OJB's use of a cache is extremely limited.  In fact, the only 
type of
query that will actually look up an object in the cache is a query by object
identity 
(Reference:org.apache.ojb.broker.core.PersistenceBrokerImpl.getObjectByIdentity()).

We found that using OJB within Tomcat was such a performance drain it 
clearly
wasn't scalable by any measure.  This was the single most determining 
reason why
we've backed out of using OJB entirely.  The use of the cache is going to be
critical if OJB is going to prove itself scalable for high volume production
use.  In fact, we're simply at a loss as to why anyone would logically 
choose
OJB for their next development effort due to this alone.

The OJB documentation is extremely deficient in describing the use of the
cache.  It implies a much broader implementation and is very 
misleading.  The
recommendation here is for clear and thorough documentation - complete with
limitations of usage, performance benchmarks, expectations etc.

Chris Giordano
giordano@more.net



---------------------------------------------------------------------
To unsubscribe, e-mail: ojb-dev-unsubscribe@db.apache.org
For additional commands, e-mail: ojb-dev-help@db.apache.org


Mime
View raw message