Most versions of 0.98 since 0.98.1, but I haven't run a punishing high
scale bulk ingest for its own sake, high-ish rate ingest and a setting of
blockingStoreFiles to 200 have been in service of getting data in for
subsequent testing.


On Thu, Dec 4, 2014 at 12:43 PM, Vladimir Rodionov <[email protected]>
wrote:

> Andrew,
>
> What HBase version have you run your test on?
>
> This issue probably does not exist anymore in a latest Apache releases, but
> still exists in not so latest, but still actively used, versions of CDH,
> HDP etc. We have discovered it during large data set loading ( 100s of GB)
> in our cluster (4 nodes).
>
> -Vladimir
>
> On Thu, Dec 4, 2014 at 10:23 AM, Andrew Purtell <[email protected]>
> wrote:
>
> > Actually I have set hbase.hstore.
> ​​
> blockingStoreFiles to 200 in testing
> > exactly :-), but must not have generated sufficient load to encounter the
> > issue you are seeing. Maybe it would be possible to adapt one of the
> ingest
> > integration tests to trigger this problem? Set blockingStoreFiles to 200
> or
> > more. Tune down the region size to 128K or similar. If
> > it's reproducible like that please open a JIRA.
> >
> > On Wed, Dec 3, 2014 at 9:07 AM, Vladimir Rodionov <
> [email protected]>
> > wrote:
> >
> > > Kevin,
> > >
> > > Thank you for your response. This is not a question on how to configure
> > > correctly HBase cluster for write heavy workloads. This is internal
> HBase
> > > issue - something is wrong in a default logic of compaction selection
> > > algorithm in 0.94-0.98. It seems that nobody has ever tested importing
> > data
> > > with very high hbase.hstore.blockingStoreFiles value (200 in our case).
> > >
> > > -Vladimir Rodionov
> > >
> > > On Wed, Dec 3, 2014 at 6:38 AM, Kevin O'dell <[email protected]
> >
> > > wrote:
> > >
> > > > Vladimir,
> > > >
> > > >   I know you said, "do not ask me why", but I am going to have to ask
> > you
> > > > why.  The fact you are doing this(this being blocking store files >
> > 200)
> > > > tells me there is something or multiple somethings wrong with your
> > > cluster
> > > > setup.  A couple things come to mind:
> > > >
> > > > * During this heavy write period, could we use bulk loads?  If so,
> this
> > > > should solve almost all of your problems
> > > >
> > > > * 1GB region size is WAY too small, and if you are pushing the volume
> > of
> > > > data you are talking about I would recommend 10 - 20GB region sizes
> > this
> > > > should help keep your region count smaller as well which will result
> in
> > > > more optimal writes
> > > >
> > > > * Your cluster may be undersized, if you are setting the blocking to
> be
> > > > that high, you may be pushing too much data for your cluster overall.
> > > >
> > > > Would you be so kind as to pass me a few pieces of information?
> > > >
> > > > 1.) Cluster size
> > > > 2.) Average region count per RS
> > > > 3.) Heap size, Memstore global settings, and block cache settings
> > > > 4.) a RS log to pastebin and a time frame of "high writes"
> > > >
> > > > I can probably make some solid suggestions for you based on the above
> > > data.
> > > >
> > > > On Wed, Dec 3, 2014 at 1:04 AM, Vladimir Rodionov <
> > > [email protected]>
> > > > wrote:
> > > >
> > > > > This is what we observed in our environment(s)
> > > > >
> > > > > The issue exists in CDH4.5, 5.1, HDP2.1, Mapr4
> > > > >
> > > > > If some one sets # of blocking stores way above default value, say
> -
> > > 200
> > > > to
> > > > > avoid write stalls during intensive data loading (do not ask me ,
> why
> > > we
> > > > do
> > > > > this), then
> > > > > one of the regions grows indefinitely and takes more 99% of overall
> > > > table.
> > > > >
> > > > > It can't be split because it still has orphaned reference files.
> Some
> > > of
> > > > a
> > > > > reference files are able to avoid compactions for a long time,
> > > obviously.
> > > > >
> > > > > The split policy is IncreasingToUpperBound, max region size is 1G.
> I
> > do
> > > > my
> > > > > tests on CDH4.5 mostly but all other distros seem have the same
> > issue.
> > > > >
> > > > > My attempt to add reference files forcefully to compaction list in
> > > > > Store.requetsCompaction() when region exceeds recommended maximum
> > size
> > > > did
> > > > > not work out well - some weird results in our test cases (but HBase
> > > tests
> > > > > are OK: small, medium and large).
> > > > >
> > > > > What is so special with these reference files? Any ideas, what can
> be
> > > > done
> > > > > here to fix the issue?
> > > > >
> > > > > -Vladimir Rodionov
> > > > >
> > > >
> > > >
> > > >
> > > > --
> > > > Kevin O'Dell
> > > > Systems Engineer, Cloudera
> > > >
> > >
> >
> >
> >
> > --
> > Best regards,
> >
> >    - Andy
> >
> > Problems worthy of attack prove their worth by hitting back. - Piet Hein
> > (via Tom White)
> >
>



-- 
Best regards,

   - Andy

Problems worthy of attack prove their worth by hitting back. - Piet Hein
(via Tom White)

Reply via email to