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https://issues.apache.org/jira/browse/SLIDER-1161?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15632013#comment-15632013
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Sumit Nigam commented on SLIDER-1161:
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Do we know which release will this be fixed in?
> Improve regionserver status check in HBase Slider app package
> -------------------------------------------------------------
>
> Key: SLIDER-1161
> URL: https://issues.apache.org/jira/browse/SLIDER-1161
> Project: Slider
> Issue Type: Improvement
> Components: app-package
> Affects Versions: Slider 0.80
> Environment: RHEL-6 (64 Bit)
> Reporter: Sandeep Nemuri
>
> *PROBLEM* :
> Using slider for launching Hbase containers.
> Following is the problem statement and details :
> 1. Assume region server went into a big pause and lost its heartbeat with
> zookeeper
> 2. HMaster notices this and marks the region server as DEAD
> 3. However, slider agent continues to 'ps' the region server process in every
> heartbeat.monitor.interval (45000ms in my case) and because it is just
> checking for region server process being alive, it does not consider it dead
> 4. After that big delay, region server finally recovers and goes to HMaster
> 5. HMaster informs region server YouAreAlreadyDeadException
> 6. Now, this region server brings itself down and slider also notices that
> process is no longer running.
> 7. Slider now launches a new region server.
> The issue as clearly mentioned in steps above is that there can be a huge
> delay between step 4 and 6. This means that we are now operating with lesser
> region servers and this puts more and more load on existing region servers.
> The issue can be solved if slider would sync up with HMaster to find whether
> region server is alive or not. That way, it would immediately know that
> HMaster has already marked a region server as dead and will then bring down
> the region server and launch a new one.
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