[
https://issues.apache.org/jira/browse/HDFS-6452?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14010623#comment-14010623
]
Jing Zhao commented on HDFS-6452:
---------------------------------
I agree with [~atm]. The NameNode failover is not common in practice, and the
administrator can easily control which NN is the active one while starting the
cluster. Given that, to randomize currentProxyIndex on client initialization
will actually increase the number of RPC in normal cases.
> ConfiguredFailoverProxyProvider should randomize currentProxyIndex on
> initialization
> ------------------------------------------------------------------------------------
>
> Key: HDFS-6452
> URL: https://issues.apache.org/jira/browse/HDFS-6452
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: ha, hdfs-client
> Affects Versions: 2.4.0
> Reporter: Gera Shegalov
> Assignee: Gera Shegalov
>
> We observe that the clients iterate proxies in the fixed order. Depending on
> the order of namenodes in dfs.ha.namenodes.<nameservice> (e.g. 'nn1,nn2') and
> the current standby (nn1), all the clients will hit nn1 first, and then
> failover to nn2. Chatting with [~lohit] we think we can simply select the
> initial value of {{currentProxyIndex}} randomly, and keep the logic of
> {{performFailover}} of iterating from left-to-right. This should halve the
> unnecessary load on standby NN.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
