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I am having a hard time understanding what is happening in our WebSphere 7 on AIX environment. We have a JDBC Datasource that has a connection pool with a Min/Max of 1/10.

We are running a Performance Test with HP LoadRunner and when our test finishes we gather the data for the JDBC connection pool.

The Max Pool sizes shows as 10, the Avg pool size shows as 9, the Percent Used is 12%. With just this info would you make any changes or keep things the same? The pool size is growing from 1 to 9 during our test but it says its only 12% used overall. The final question is everytime our test is in the last 15 min before stopping we see an Avg Wait time of 1.8 seconds and avg thread wait of .5 but the percent used is still 10%. FYI, the last 15 min of our test does not add additional users or load its steady.

Can anyone provide any clarity or recommendations on if we should make any changes? thx!

roacha
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  • Have you opened a PMR? There may be a JVM setting you need to set or some such nonsense. We are experiencing a similar issue but with activation specs (act specs on multiple servers listening to the same queue, but only one of the servers actually picking up messages). After researching the issue and contacting IBM it looks like setting a custom property will get it to work as we intend. – Kaleb Brasee Dec 16 '11 at 01:42

1 Answers1

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First, I'm not an expert in this, so take this for whatever it's worth.

You're looking at WebSphere's PMI data, correct? PercentUsed is "Average percent of the pool that is in use." The pool size includes connections that were created, but not all of those will be in-use at any point in time. See FreePoolSize, "The number of free connections in the pool".

Based on just that, I'd say your pool is large enough for the load you gave it.

Your decreasing performance at the end of the test, though, does seem to indicate a performance bottleneck of some sort. Have you isolated it enough to know for certain that it's in database access? If so, can you tell if your database server, for instance, may be limiting things?

dbreaux
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