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https://issues.apache.org/jira/browse/OAK-2682?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14483380#comment-14483380
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Stefan Egli commented on OAK-2682:
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Not sure how the mechanism via the second option would in detail look like -
depending on that it seems more robust but I fear it would need more
coordination and be more complex to implement.
The first option however sounds quite simple. It would only have one potential
flaw: if the oak clients would be connected to different mongo servers (if
that's a feasible deployment option). Then they would rely on those mongo
servers to have their clocks in sync.
Overall I think the mechanism should be as KISS as possible..
> Introduce time difference detection for mongoMk
> -----------------------------------------------
>
> Key: OAK-2682
> URL: https://issues.apache.org/jira/browse/OAK-2682
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: core, mongomk
> Reporter: Stefan Egli
> Fix For: 1.3.0
>
>
> Currently the lease mechanism in DocumentNodeStore/mongoMk is based on the
> assumption that the clocks are in perfect sync between all nodes of the
> cluster. The lease is valid for 60sec with a timeout of 30sec. If clocks are
> off by too much, and background operations happen to take couple seconds, you
> run the risk of timing out a lease. So introducing a check which WARNs if the
> clocks in a cluster are off by too much (1st threshold, eg 5sec?) would help
> increase awareness. Further drastic measure could be to prevent a startup of
> Oak at all if the difference is for example higher than a 2nd threshold
> (optional I guess, but could be 20sec?).
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