KevinWikant opened a new pull request #3746: URL: https://github.com/apache/hadoop/pull/3746
### Description of PR Fixes a bug in Hadoop HDFS where if more than "dfs.namenode.decommission.max.concurrent.tracked.nodes" datanodes are lost while in state decommissioning, then all forward progress towards decommissioning any datanodes (including healthy datanodes) is blocked JIRA: https://issues.apache.org/jira/browse/HDFS-16303 ### Additional Details To solve this HDFS bug, there are 2 different proposals: - the [original proposal in this PR](https://github.com/apache/hadoop/pull/3675) which continues to track a dead DECOMMISSION_INPROGRESS node in the DatanodeAdminManager until there are no LowRedundancy blocks on HDFS - this new PR which removes a dead DECOMMISSION_INPROGRESS node from the DatanodeAdminManager immediately leaving the dead node in DECOMMISSION_INPROGRESS indefinitely unless it comes alive again These 2 different implementations will largely behave the same from a user perspective. There is however 1 key difference: - in the original PR when there a no LowRedundancy blocks a dead DECOMMISSION_INPROGRESS node will be transitioned to DECOMMISSIONED - in the new PR a dead DECOMMISSION_INPROGRESS node will remain in DECOMMISSION_INPROGRESS indefinitely regardless of if there are no LowRedundancy blocks. That is, unless the node either comes alive again or the user removes it from the exclude file. ### How was this patch tested? 3 new unit tests added to both "TestDecommission" & "TestDecommissionWithBackoffMonitor": - testDeadNodesRemainDecommissionInProgress - testRevivedDeadNodeIsDecommissioned - testDeadNodeWithDecommissionInProgressRemovedFromExcludeFile ### For code changes: - [yes] Does the title or this PR starts with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')? - [n/a] Object storage: have the integration tests been executed and the endpoint declared according to the connector-specific documentation? - [n/a] If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under [ASF 2.0](http://www.apache.org/legal/resolved.html#category-a)? - [no] If applicable, have you updated the `LICENSE`, `LICENSE-binary`, `NOTICE-binary` files? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
