Monitoring and Troubleshooting DGC
DGC events (both periodic and inline) are reported in a Terracotta server instance's logs. DGC events can also be monitored using the Terracotta Management Console.
If DGC does not seem to be collecting objects at the expected rate, one of the following issues may be the cause:
Java GC is not able to collect objects fast enough. Client nodes may be under resource pressure, causing GC collection to run behind, which then causes DGC to run behind.
Certain client nodes continue to hold references to objects that have become garbage on other nodes, thus preventing DGC from being able to collect those objects.
If possible, shut down all Terracotta clients to see if DGC then collects the objects that were expected to be collected.