Michael,

> I'm not saying it is definitely a MySQL issue, but it could be the JDBC 
> driver or the backend storage implementation.

True.  The production box is using a very old version of MySQL with documented 
innodb bugs, so it could be anything from innodb to the connector that is 
causing the problem.

>  I'd be surprised if it was a direct Cayenne issue.

I agree, if there are no open Cayenne bugs, and you have personally deployed 
configured for only 1-2 connections with no errors, that appears to rule out 
Cayenne.  My code is pretty standard cayenne select queries and updates, and 
has been using Cayenne for over a year on the development box without any such 
errors.

>   It would be good if you could test (locally) on a different setup and see 
> if it still happens.


These exceptions and 60sec load times only occur on the production machine and 
have never occurred on the development machine. The only difference is the 
hardware and the version of MySQL.

All the evidence seems to be pointing to MySQL and/or the JDBC connector.   In 
my opinion, the unresolved innodb bug is the proverbial "elephant in the living 
room". How it is being triggered is simple to understand, however the cascade 
effects are probably due to a combination requests by the small number of 
concurrent users.

Thanks so much for your attention to this.  I think Cayenne has been ruled out.
Joe





On Apr 17, 2010, at 5:21 PM, Michael Gentry wrote:

> It should also be noted that I was running against Sybase, so a
> completely different JDBC driver and database.  I'm not saying it is
> definitely a MySQL issue, but it could be the JDBC driver or the
> backend storage implementation.  I'd be surprised if it was a direct
> Cayenne issue.  It would be good if you could test (locally) on a
> different setup and see if it still happens.
> 
> mrg
> 
> 
> On Sat, Apr 17, 2010 at 4:18 AM, Joe Baldwin <[email protected]> wrote:
>> However Michael was able to run his app configured for only two connections.

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