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https://issues.apache.org/jira/browse/HDFS-14758?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16914770#comment-16914770
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Chen Zhang commented on HDFS-14758:
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Hi [~jojochuang] and [~hemanthboyina], HDFS-14694 actually want to address the
broken state of open file for long running client(e.g. HBase), in this
situation hard limit can't help to recover file state.
Decreasing hard limit may be helpful in the scenarios that client crash or
client dead(closed) on any exception (e.g. MR job), but in our experience, If
some client want to access the file before hard limit and found that the file
is not closed correctly, it can call recoverLease() and try again, so I think
it's not necessary to decrease hard limit.
> Decrease lease hard limit
> -------------------------
>
> Key: HDFS-14758
> URL: https://issues.apache.org/jira/browse/HDFS-14758
> Project: Hadoop HDFS
> Issue Type: Improvement
> Reporter: Eric Payne
> Assignee: hemanthboyina
> Priority: Minor
>
> The hard limit is currently hard-coded to be 1 hour. This also determines the
> NN automatic lease recovery interval. Something like 20 min will make more
> sense.
> After the 5 min soft limit, other clients can recover the lease. If no one
> else takes the lease away, the original client still can renew the lease
> within the hard limit. So even after a NN full GC of 8 minutes, leases can be
> still valid.
> However, there is one risk in reducing the hard limit. E.g. Reduced to 20
> min. If the NN crashes and the manual failover takes more than 20 minutes,
> clients will abort.
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