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HBase, mail # user - Handling regionserver crashes in production cluster


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RE: Handling regionserver crashes in production cluster
Sandeep L 2013-09-02, 11:23
Even we are facing same problem, is it fixed in hbase 0.94.8 or 0.97.6 ?
If it is fixed we will migrate, can some one conform about this?
Thanks,Sandeep.

> From: [EMAIL PROTECTED]
> Date: Thu, 13 Jun 2013 09:00:46 +0200
> Subject: Re: Handling regionserver crashes in production cluster
> To: [EMAIL PROTECTED]
>
> Hum... So even a simple get shows the issue?
> It would be a (surprising) critical bug. Could you please try the 95.1 or
> the 94.8? Or write an unit test?
>
> Thanks,
>
> Nicolas
>
>
> On Thu, Jun 13, 2013 at 5:43 AM, kiran <[EMAIL PROTECTED]> wrote:
>
> > Its a simple kill...
> > Scan is used using startrow and stoprow
> > Scan scan = new Scan(Bytes.toBytes("adidas"), Bytes.toBytes("adidas1"));
> >
> >
> > Our cluster size is 15. The load average when I see in master is 78%...It
> > is not that overloaded. but writes are happening in the cluster...
> >
> > Thanks
> > Kiran
> >
> >
> >
> > On Wed, Jun 12, 2013 at 10:49 PM, Nicolas Liochon <[EMAIL PROTECTED]>
> > wrote:
> >
> > > Yeah, it should not block the other regions.
> > >
> > > For the region server, was it a kill -9 or in simple kill (the former
> > > triggers a recovery, the later will close the region before stopping the
> > > process)?
> > >
> > > How do you select the scan scope? With stop/start rows?
> > > Can you share the client code you're using?
> > > What's the cluster size? Was it already very loaded before you killed the
> > > region server?
> > >
> > > Nicolas
> > >
> > >
> > >
> > > On Wed, Jun 12, 2013 at 6:11 PM, kiran <[EMAIL PROTECTED]>
> > > wrote:
> > >
> > > > Yes we killed the region server but datanode is still running on the
> > > > node...
> > > >
> > > > Sample Test scenario: Assume, I have table with pre-splits a upto z
> > > (about
> > > > 26 regions). I brought down region server purposefully with regions
> > > having
> > > > prefixes c and d. Then I used client API to scan data from regions with
> > > > prefixes other than c and d. The response was very slow and sometimes
> > not
> > > > coming at all.
> > > >
> > > > My doubt was if only regions with prefix c and d are getting relocated
> > or
> > > > in transition. Why is it affecting the regions with other prefixes....
> > > But
> > > > once the region transition is over, the response is very fast as
> > > expected.
> > > >
> > > >
> > > >
> > > > On Wed, Jun 12, 2013 at 8:50 PM, rajesh babu chintaguntla <
> > > > [EMAIL PROTECTED]> wrote:
> > > >
> > > > > You can configure below to more value to close more regions at a
> > time.
> > > > >
> > > > >  <property>
> > > > >     <name>hbase.regionserver.executor.closeregion.threads</name>
> > > > >     <value>3</value>
> > > > >   </property>
> > > > >
> > > > >
> > > > > On Wed, Jun 12, 2013 at 7:38 PM, Nicolas Liochon <[EMAIL PROTECTED]>
> > > > > wrote:
> > > > >
> > > > > > What was your test exactly? You killed -9 a region server but kept
> > > the
> > > > > > datanode alive?
> > > > > > Could you detail the queries you were doing?
> > > > > >
> > > > > >
> > > > > > On Wed, Jun 12, 2013 at 2:10 PM, kiran <
> > [EMAIL PROTECTED]>
> > > > > > wrote:
> > > > > >
> > > > > > > It is not possible for us to migrate to new version immediately.
> > > > > > >
> > > > > > > @Anoop we purposefully brought down one regionserver, then we
> > > > observed
> > > > > > the
> > > > > > > website is taking too much time to respond. We observed the
> > pattern
> > > > for
> > > > > > > about 5 min till the regions are relocated.
> > > > > > > Also we issued queries in our website taking care that the
> > queries
> > > > did
> > > > > > n't
> > > > > > > come under the regions in the regionserver we brought down.
> > > > > > >
> > > > > > > Is there any configuration workaround to mitigate it??
> > > > > > >
> > > > > > > Thanks
> > > > > > > Kiran
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > On Thu, Jun 6, 2013 at 8:27 PM, Jean-Marc Spaggiari <
> > > > > > > [EMAIL PROTECTED]
>