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https://issues.apache.org/jira/browse/HDFS-14588?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16869595#comment-16869595
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Kihwal Lee commented on HDFS-14588:
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bq.The issue we had in the past is the namenoderpcaddress being the address of
the active NN.
The namenode address used in the redirect param is set by
{{NameNode#setClientNamenodeAddress()}}. You will see a log line on NN startup.
It is supposed to be the service address, not the individual namenode address.
and {{NamenodeAddressParam}} calls {{getTokenServiceName()}} to get it.
Something might have broken this behavior.
> Client retries Standby NN continuously even if Active NN is available
> (WebHDFS)
> -------------------------------------------------------------------------------
>
> Key: HDFS-14588
> URL: https://issues.apache.org/jira/browse/HDFS-14588
> Project: Hadoop HDFS
> Issue Type: Bug
> Reporter: CR Hota
> Priority: Major
>
> This is a behavior we have observed in our HA setup of HDFS.
> # Active NN is up and serving traffic.
> # Stand By NN is restarted for maintenance.
> # After step 2 all new clients (webhdfs only) which connect to Stand By keep
> seeing Retriable Exception as Stand By NN is not yet started (Rpc server is
> yet to come up as FS image is loading) but http server is started and ready
> to accept traffic. This keeps happening till rpcserver is up and SNN knows
> that it's truely standby. Based on start up time this behavior can continue
> based on start-up times which is high (many minutes) for big clusters.
> This above behavior is causing low availability of HDFS when HDFS is actually
> still available.
> Ideally webhdfs should throw standby exception (if HA is enabled) and let
> clients connect to active following that. If active is also not available
> clients will bounce and automatically connect to the right active.
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