[IGNITE-12350] MVCC activated and causing memory leak (OOM) despite no mvccEnabled caches

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.5
• Fix Version/s: 2.9
• Component/s: mvcc
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Vladislav Pyatkov
• Reporter: Ming Vuong
• Reviewer: Igor Seliverstov
• Created: 04/Nov/19 02:44
• Updated: 14/Oct/20 06:06
• Resolved: 15/Aug/20 22:29

Description

We have a critical memory leak where mvccCoordinator is still selected and mvcc is still 'activated' despite having no mvccEnabled caches, this is causing constant OOM crashes and issues on both server and client nodes.

All client CacheAtomicityModes are of type ATOMIC, and for server config persistence is false, TCPDiscoverySpi used and PeerClassLoadingEnabled=true.

There are two server JVM instances on two separate nodes. One of the servers consistently get an OOM error, as well as all clients, due to the same recoveryBallotBoxes HashMap constantly increasing in size and unable to be Garbage Collected.

Attached is Eclipse Memory Analyzer Tool screenshot on the heap dump close to one of the server JVM OOM crashes. The same heap analysis result is apparent for all clients as well.

Issue Links

• links to: GitHub Pull Request #8152