When the RM state store is restored expired delegation tokens are restored and added to the system. These expired tokens do not get cleaned up or removed. The exact reason why the tokens are still in the store is not clear. We have seen as many as 250,000 tokens in the store some of which were 2 years old.
This has two side effects:
- for the zookeeper store this leads to a jute buffer exhaustion issue and prevents the RM from becoming active.
- restore takes longer than needed and heap usage is higher than it should be
We should not restore already expired tokens since they cannot be renewed or used.