[HDFS-12050] Ozone: StorageHandler: Implementation of "close" for releasing resources during shutdown

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Component/s: ozone
• Assignee: Nandakumar
• Reporter: Nandakumar
• Created: 27/Jun/17 19:49
• Updated: 26/Apr/18 21:51
• Resolved: 29/Jun/17 21:45

Description

When we use DistributedStorageHandler and call newKeyWriter, it will create XceiverClientSpi and add it to clientCache which will create a non-daemon nioEventLoopGroup thread. Since XceiverClientManager#releaseClient doesn't invalidate the client, close is not called on the client object. Cleanup is triggered as part of both eviction as well as releaseClient, but the connection is closed only when both of the conditions are satisfied.

This StorageHandler#close can be used to close the connections during shutdown.