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WAS PMI metrics - Connection Pool Allocate vs Create Count

I am not able to understand the values in WAS PMI for ConnectionPoolModule.

In one application I am monitoring, I am getting perf metrics for "Allocate Count", and in other I am getting perf metrics for "Create Count"

In the case of the AllocateCount - i can see that this value keeps increasing over time, and not sure what the effects of this state is.

What are the differences between these count types? What should I be looking for to review connection pools? Why are these metrics not showing up at the same time? Should I be bothered about the increase in AllocateCount, or should I match it with other metrics to review the application state?

Thanks!

Solution

  • With these metrics, an allocate is an application request for a connection, e.g. a DataSource.getConnection(). The WebSphere pool manager either satisfies the request with an already-pooled connection, or creates a new one, and in the latter case the create count gets incremented. So if your allocate and create counts were the same, you'd be doing no pooling, probably a bad thing!

    But that's not necessarily the best thing to monitor. Things like the average wait time could be the best starting point.

    Let me refer you to some other links to help you monitor WebSphere JDBC connection pool data: