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Walter Su commented on HDFS-8461: --------------------------------- I was reviwing Blockmanager and too focus on solving {{chooseSourceDatanodes}} problem, and forgot HDFS-8010 existed. Sorry. Next time I'll search before create jira. > Erasure coding: fix priority level of UnderReplicatedBlocks for striped block > ----------------------------------------------------------------------------- > > Key: HDFS-8461 > URL: https://issues.apache.org/jira/browse/HDFS-8461 > Project: Hadoop HDFS > Issue Type: Sub-task > Reporter: Walter Su > Assignee: Walter Su > Attachments: HDFS-8461-HDFS-7285.001.patch > > > {code:title=UnderReplicatedBlocks.java} > private int getPriority(int curReplicas, > ... > } else if (curReplicas == 1) { > //only on replica -risk of loss > // highest priority > return QUEUE_HIGHEST_PRIORITY; > ... > {code} > For stripe blocks, we should return QUEUE_HIGHEST_PRIORITY when curReplicas > == 6( Suppose 6+3 schema). > That's important. Because > {code:title=BlockManager.java} > DatanodeDescriptor[] chooseSourceDatanodes(BlockInfo block, > ... > if(priority != UnderReplicatedBlocks.QUEUE_HIGHEST_PRIORITY > && !node.isDecommissionInProgress() > && node.getNumberOfBlocksToBeReplicated() >= maxReplicationStreams) > { > continue; // already reached replication limit > } > ... > {code} > It may return not enough source DNs ( maybe 5), and failed to recover. > A busy node should not be skiped if a block has highest risk/priority. The > issue is the striped block doesn't have priority. -- This message was sent by Atlassian JIRA (v6.3.4#6332)