If you have really lo load on application it is possible I think to show it as 0 in some timeframes. If you have some unusual driver for pools it is possible that dynatrace is not able to count it. You can always try to make custom chart with pool usage and check how it looks over time.
Thanks for your help.
It is able to capture the pool size,so I think it may not a unsupported driver.
I drill down to the purepath. From the purepath tree ,I can see the api like "connection pooling".
Any advice measure to make a custom chart?I didn't see measure about pool usage.
Here you have example for tomcat. I don't know what application server do you use 🙂