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https://issues.apache.org/jira/browse/SPARK-20608?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16006454#comment-16006454
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Steve Loughran commented on SPARK-20608:
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One thing to consider here is starting with a test to see what happens,
https://github.com/apache/hadoop/blob/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/ha/TestHASafeMode.java
shows to to set up MiniDFSCluster to run HA
But yes, Marcelo is right: you don't go hdfs://hostname1:8000/ you do
{{hdfs://hacluster:8000/}} and rely on the list of hosts in
{{dfs.ha.namenodes.hacluster}} to tell HDFS who to try to talk to. I suspect
it's important to have a cluster name which is not a resolvable hostname, as
that may confuse the client (just a guess; haven't looked at the source to see)
> Standby namenodes should be allowed to included in
> yarn.spark.access.namenodes to support HDFS HA
> -------------------------------------------------------------------------------------------------
>
> Key: SPARK-20608
> URL: https://issues.apache.org/jira/browse/SPARK-20608
> Project: Spark
> Issue Type: Improvement
> Components: Spark Submit, YARN
> Affects Versions: 2.0.1, 2.1.0
> Reporter: Yuechen Chen
> Priority: Minor
> Original Estimate: 672h
> Remaining Estimate: 672h
>
> If one Spark Application need to access remote namenodes,
> yarn.spark.access.namenodes should be only be configged in spark-submit
> scripts, and Spark Client(On Yarn) would fetch HDFS credential periodically.
> If one hadoop cluster is configured by HA, there would be one active namenode
> and at least one standby namenode.
> However, if yarn.spark.access.namenodes includes both active and standby
> namenodes, Spark Application will be failed for the reason that the standby
> namenode would not access by Spark for org.apache.hadoop.ipc.StandbyException.
> I think it won't cause any bad effect to config standby namenodes in
> yarn.spark.access.namenodes, and my Spark Application can be able to sustain
> the failover of Hadoop namenode.
> HA Examples:
> Spark-submit script:
> yarn.spark.access.namenodes=hdfs://namenode01,hdfs://namenode02
> Spark Application Codes:
> dataframe.write.parquet(getActiveNameNode(...) + hdfsPath)
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