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https://issues.apache.org/jira/browse/OAK-3398?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14743655#comment-14743655
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Stefan Egli commented on OAK-3398:
----------------------------------
second point done too:
* background lease update thread now has MAX_PRIORITY :
http://svn.apache.org/r1702968
> make lease update more robust
> -----------------------------
>
> Key: OAK-3398
> URL: https://issues.apache.org/jira/browse/OAK-3398
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: core
> Affects Versions: 1.3.6
> Reporter: Stefan Egli
> Assignee: Stefan Egli
> Fix For: 1.3.7
>
>
> With the lease check introduced in OAK-2739 (and refined to do a oak-core
> stop in OAK-3397) it becomes more critical that the lease is always properly
> updated (to avoid an unnecessary oak-core stop). The following issues exist
> atm:
> * currently the lease is valid 60sec by default, updated every 20sec, the
> lease check fails with a margin of 20sec *before* it times out. this means if
> the lease update thread is not operating for 20sec it will cause a stop.
> that's quite a low figure probably
> ** the suggestion is to increase the lease timeout to 120sec from 60sec -
> update it as soon as 10sec has been eaten off it, and leave the 20sec safety
> margin at the end. This would result in 90sec 'idle equals faulty'
> * on a machine with heavy load it seems likely that the lease-update-thread
> doesn't get scheduled timely enough - as it races for cpu against all the
> other busy threads
> ** the suggestion is to increase the thread priority of the lease update
> thread - so if the VM supports thread priorities, that would help reduce
> lease failure 'just because the cpu is too busy'
> * the ClusterNodeInfo, when renewing the lease, doesn't check if the lease
> has been marked as timed-out/recovering by another instance. it just
> overwrites whatever is there.
> ** It should, however, only update the lease when it has not yet been marked
> as timed out.
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