[
https://issues.apache.org/jira/browse/HDFS-11014?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
James Clampffer updated HDFS-11014:
-----------------------------------
Attachment: HDFS-11014.HDFS-8707.000.patch
Patch ready for review. I also fixed a typo in the HA logging where we said
trying a new Datanode rather than trying a new Namenode.
> libhdfs++: Make connection to HA clusters faster
> ------------------------------------------------
>
> Key: HDFS-11014
> URL: https://issues.apache.org/jira/browse/HDFS-11014
> Project: Hadoop HDFS
> Issue Type: Sub-task
> Components: hdfs-client
> Reporter: James Clampffer
> Assignee: James Clampffer
> Priority: Minor
> Attachments: HDFS-11014.HDFS-8707.000.patch
>
>
> Right now when we get a StandbyException from the NN we inject a 20 second
> delay before we try the alternate NN even if it's the first failover. The
> first failover shouldn't have a delay (java client skips delay on first
> failover).
> Another minor change I'd like to make is to reduce the default number of
> failover attempts from 15 (used in the apache config) to 4. My impression is
> that higher numbers of failovers are really handy for longer running batch
> jobs but in the libhdfs++ case the client is often an interactive
> application. In this case it's generally preferable to fail sooner so a user
> doesn't have to wait the ~8 minutes to time out when using default settings.
> 4 failovers is based on the assumption that if we can't immediately connect
> there is either a GC pause which will most likely be finished before the
> second connection attempt or it's a network or config issue that will take
> some sorting out by an admin. It'd still be possible to override these in
> the config for more tuning if a specific deployment tends to have more or
> less network issues.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
