[HDFS-17154] EC: Fix bug in updateBlockForPipeline after failover

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.0
• Component/s: erasure-coding
• Labels: pull-request-available
• Target Version/s: 3.4.0
• Hadoop Flags: Reviewed
• Assignee: Shuyan Zhang
• Reporter: Shuyan Zhang
• Created: 11/Aug/23 09:16
• Updated: 28/Jan/24 01:46
• Resolved: 16/Aug/23 12:30

Description

In the method `updateBlockForPipeline`, NameNode uses the `BlockUnderConstructionFeature` of a BlockInfo to generate the member `blockIndices` of `LocatedStripedBlock`. 

And then, NameNode uses `blockIndices` to generate block tokens for client.

However, if there is a failover, the location info in BlockUnderConstructionFeature may be incomplete, which results in the absence of the corresponding block tokens.

When the client receives these incomplete block tokens, it will throw a NPE because `updatedBlks[i]` is null.

NameNode should just return block tokens for all indices to the client. Client can pick whichever it likes to use. 

 

Issue Links

• links to: GitHub Pull Request #5941