[
https://issues.apache.org/jira/browse/HDFS-15024?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16985190#comment-16985190
]
Chen Liang commented on HDFS-15024:
-----------------------------------
Thanks for reporting [~haiyang Hu]! This is an interesting issue. If I
understand correctly, this only happens when the order of NNs in ha conf is
standby -> observer -> active, is this correct? Because in our practice, we
have been setting observer the last one in the conf, so we haven't ran into
this issue. But we should definitely resolve the issue.
And thanks for uploading a patch, I will take a deeper look.
> [SBN read] In FailoverOnNetworkExceptionRetry , Number of NameNodes as a
> condition of calculation of sleep time
> ---------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-15024
> URL: https://issues.apache.org/jira/browse/HDFS-15024
> Project: Hadoop HDFS
> Issue Type: Improvement
> Affects Versions: 2.10.0, 3.3.0, 3.2.1
> Reporter: huhaiyang
> Priority: Major
> Attachments: HDFS-15024.001.patch, client_error.log
>
>
> When we enable the ONN , there will be three NN nodes for the client
> configuration,
> Such as configuration
> <property>
> <name>dfs.ha.namenodes.ns1</name>
> <value>nn2,nn3,nn1</value>
> </property>
> Currently,
> nn2 is in standby state
> nn3 is in observer state
> nn1 is in active state
> When the user performs an access HDFS operation
> ./bin/hadoop --loglevel debug fs
> -Ddfs.client.failover.proxy.provider.ns1=org.apache.hadoop.hdfs.server.namenode.ha.ObserverReadProxyProvider
> -mkdir /user/haiyang1/test8
> You need to request nn1 when you execute the msync method,
> Actually connect nn2 first and failover is required
> In connection nn3 does not meet the requirements, failover needs to be
> performed, but at this time, failover operation needs to be performed during
> a period of hibernation
> Finally, it took a period of hibernation to connect the successful request to
> nn1
> In FailoverOnNetworkExceptionRetry getFailoverOrRetrySleepTime The current
> default implementation is Sleep time is calculated when more than one
> failover operation is performed
> I think that the Number of NameNodes as a condition of calculation of sleep
> time is more reasonable
> That is, in the current test, executing failover on connection nn3 does not
> need to sleep time to directly connect to the next nn node
> See client_error.log for details
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
