After updating from Wildfly 37.0.1.Final to Wildfly 38.0.0.Final we started to receive alerts about high CPU usage after weekend of running (very low usage time).

Initial investigation showed that we were spending a lot of time in GC (ZGC on 

21.0.8).

I took a heap dump and then rolled back to Wildfly 37.0.1.Final where everything returned to normal. 

I analyzed the heap dump and it shows an increasing amount of JaxWsClientProxy

Where Wildfly 37 after running for a few hours during a far busier time shows 

There were no other changes to how our JaxWS client code is handled or created. Simply rolling back to 37.0.1.Final resolves the issue.

I have the heap dumps, but I'm at the limit of what I can investigate without some direction.