monitoring JMS connection pool using JMX/PMI

Anbu — Thu, 11 Dec 2025 07:39:17 GMT

I have created a JMX/PMI extension and configured it to collect JMS connection pool metrics from WebSphere.
In the WebSphere Admin Console, the JMS connection pool size is set to 30.

However, in Dynatrace I notice something strange:

The free pool size and pool size always show the same values.
When I change the timeframe to Last 2 hours, the values are different.
But when I select Today, the values change completely and do not match the 2-hour values.

Because of these inconsistent values, I am not sure whether my PMI/JMX extension is working correctly.

Steps I followed:

Dynatrace Managed
Settings → Monitoring → Monitored technologies
Add new technology monitoring
Add JMX/PMI extension
Use JMX/PMI Extension Editor
Under the J2C module, I selected the metrics for Pool Size and Free Pool Size

I am using WebSphere with MQ.
Could you please guide me on how to verify whether my JMX/PMI extension is capturing the correct JMS connection pool metrics?

Re: monitoring JMS connection pool using JMX/PMI

sujit_k_singh — Wed, 10 Dec 2025 22:09:17 GMT

When using a JMX/PMI extension for WebSphere JMS connection pool metrics, the behavior you’re seeing (values changing with different timeframes) is usually due to aggregation and resolution differences, not an extension failure. Dynatrace aggregates data differently for “Last 2 hours” vs. “Today” (rollups like min/avg/max), so the displayed values can vary.
To verify your extension is working correctly: Go to Metrics → Data Explorer -> Select your custom JMX metrics (like PoolSize, FreePoolSize).
Set the resolution to 1 min or 5 min and compare with WebSphere Admin Console values.

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