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From Joe Baldwin <>
Subject Excessive Load Times (Status)
Date Tue, 22 Jun 2010 19:17:10 GMT
RE Previous Excessive Load Times (60+ secs) /so-called  "Cayenne Connection Pool Errors" /so-called
"Memory Management Errors" / etc

I wanted to thank everyone for commenting on the array of problems that is summarized above.
 This is my feedback and what I believe to be the cause of the problem(s).

A few months ago, I had noticed a recurring and intermittent problem that showed itself as
extremely long load times (sometimes 1-2 mins) even under very light load.  After reading
through the log files and following suggestions from this forum, there was little change in
the problem.  Since the webapp was hosted on a production server by commercial company, I
had to work closely with the tech support guy who was first convinced that it was a problem
in my ISP, then he was convinced it was Cayenne, then he was convinced that it was my code,
and so on ...

However, this problem never once manifested itself on our development server under any kind
of load.  So I doubted his analysis.

After a long process of testing and elimination, and following increasingly eccentric suggestions
by the webhost tech guy, we fired the webhost and moved all of our code to a new webhost who
had installed the newest stable versions of Java, Tomcat, and MySQL (something the previous
webhost refused to do).

As a result, we have not experienced the load-time problem or Connection Pool errors since
we changed webhosts.  We are using the same code, the same Cayenne configuration and version,
and the same connector.   It looks like it was either some configuration parameters the webhost
tech guy had overlooked or it was the 3 year old version of MySQL that they were running (that
I found has documented table locking bugs).  

Anyway thanks for helping out, this was a difficult problem to crack.


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