Running Jenkins with hundreds of nodes and jobs, monitoring metaspace and heap with
jcmd GC.heap_info,
I got growing used metaspace while used heap is stable (after gc). see attached picture.

My java options:
-Xmx400g -Xms200g -XX:MetaspaceSize=8192m -XX:MaxMetaspaceSize=8192m -XX:+ExplicitGCInvokesConcurrent -XX:+UseG1GC

Jenkins ran out of metaspace and unresponsive finally:
2022-07-15 16:36:52.921  [Pipeline] End of Pipeline
2022-07-15 16:36:52.967  java.lang.OutOfMemoryError: Metaspace
2022-07-15 16:36:52.973  Finished: FAILURE

top class_stats after 10 hours. the used metaspace increased around 22%, see attached picture.

metaspace issue disappeared on 7/19 suddenly.