[
https://issues.apache.org/jira/browse/HBASE-13832?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14612488#comment-14612488
]
Enis Soztutar commented on HBASE-13832:
---------------------------------------
bq. to get the same behavior you need to force running to false when you set
syncException. so you prevent other procedure to be added.
Not sure whether we gain by ensuring that running is set to false before the
next execution for syncLoop. Wal store will abort when the master calls abort.
Before this happens, concurrent calls to {{pushData()}} will still get the
exception because the exception from sync is not cleared at all. So the
semantics is that if {{snyc()}} + wal roll fails, we effectively start
rejecting all requests for {{pushData()}}, which is kind of similar to making
sure to check isRunning().
> Procedure V2: master fail to start due to WALProcedureStore sync failures
> when HDFS data nodes count is low
> -----------------------------------------------------------------------------------------------------------
>
> Key: HBASE-13832
> URL: https://issues.apache.org/jira/browse/HBASE-13832
> Project: HBase
> Issue Type: Sub-task
> Components: master, proc-v2
> Affects Versions: 2.0.0, 1.1.0, 1.2.0
> Reporter: Stephen Yuan Jiang
> Assignee: Matteo Bertozzi
> Priority: Critical
> Fix For: 2.0.0, 1.1.2, 1.3.0, 1.2.1
>
> Attachments: HBASE-13832-v0.patch, HBASE-13832-v1.patch,
> HBASE-13832-v2.patch, HDFSPipeline.java, hbase-13832-test-hang.patch,
> hbase-13832-v3.patch
>
>
> when the data node < 3, we got failure in WALProcedureStore#syncLoop() during
> master start. The failure prevents master to get started.
> {noformat}
> 2015-05-29 13:27:16,625 ERROR [WALProcedureStoreSyncThread]
> wal.WALProcedureStore: Sync slot failed, abort.
> java.io.IOException: Failed to replace a bad datanode on the existing
> pipeline due to no more good datanodes being available to try. (Nodes:
> current=[DatanodeInfoWithStorage[10.333.444.555:50010,DS-3c7777ed-93f4-47b6-9c23-1426f7a6acdc,DISK],
>
> DatanodeInfoWithStorage[10.222.666.777:50010,DS-f9c983b4-1f10-4d5e-8983-490ece56c772,DISK]],
>
> original=[DatanodeInfoWithStorage[10.333.444.555:50010,DS-3c7777ed-93f4-47b6-9c23-1426f7a6acdc,DISK],
> DatanodeInfoWithStorage[10.222.666.777:50010,DS-f9c983b4-1f10-4d5e-8983-
> 490ece56c772,DISK]]). The current failed datanode replacement policy is
> DEFAULT, and a client may configure this via
> 'dfs.client.block.write.replace-datanode-on-failure.policy' in its
> configuration.
> at
> org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.findNewDatanode(DFSOutputStream.java:951)
> {noformat}
> One proposal is to implement some similar logic as FSHLog: if IOException is
> thrown during syncLoop in WALProcedureStore#start(), instead of immediate
> abort, we could try to roll the log and see whether this resolve the issue;
> if the new log cannot be created or more exception from rolling the log, we
> then abort.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
