Subject Re: [firebird-support] FB 1.5 RC6 linear slowdown
Author Rajesh Punjabi
Hi Thomas,

Thomas Miller wrote:

>The problem is likely one of two issues (or both)
>
>#1) Memory leak in client. You mentioned you have a pool. Structure
>the pool
>to periodically close a pool connection and restart a new one.
>
There is no memory leak. The memory graph stays within a narrow band.
Maybe I did not communicate this right, but the client (our application)
has been stress tested with Oracle and MySQL with InnoDB transactions
and is able to process hundreds of concurrent requests and for days in a
stress test environment without any performance degradation. With
Firebird, the degradation is apparent in about 30 minutes.

>#2) There has been a problem with the garbage collection running in its
>own
>thread. It seems that the amount of garbage that may accumulate is more
>then
>the threads alloted time to do the clean up, so it does no clean up. During
>the day, this kills performance. Supposedly it was fixed for RC5??, but
>maybe
>not.
>
Should this not cause memory usage to go up as well? We do not see any
gradual increase in memory consumption.

>
>Try #1 first and see if it helps. Maybe if a connection is more then
>one hour
>old and idle, kill it and make a new one.
>
We have the feature turned on in JBoss where it will refresh (close and
renew) a connection after every 15 idle mins.

Thanks,
Rajesh