Hi

One small observation after giving +1 on the RC.
The WAL compression feature causes OOME and causes Full GC.

The problem is, if we have 1500 regions and I need to create recovered.edits
for each of the region (I don’t have much data in the regions (~300MB)).
Now when I try to build the dictionary there is a Node object getting
created.
Each node object occupies 32 bytes.
We have 5 such dictionaries.

Initially we create indexToNodes array and its size is 32767.

So now we have 32*5*32767 = ~5MB.

Now I have 1500 regions.

So 5MB*1500 = ~7GB.(Excluding actual data).  This seems to a very high
initial memory foot print and this never allows me to split the logs and I
am not able to make the cluster up at all.

Our configured heap size was 8GB, tested in 3 node cluster with 5000
regions, very less data( 1GB in hdfs cluster including replication), some
small data is spread evenly across all regions.

The formula is 32(Node object size)*5(No of dictionary)*32767(no of node
objects)*noofregions.

I think this initial memory needs to be documented (documentation should do
for now)or has to be fixed with some workarounds.

So pls give your thoughts on this.

Regards
Ram




> -----Original Message-----
> From: Ramkrishna.S.Vasudevan [mailto:ramkrishna.vasude...@huawei.com]
> Sent: Monday, May 14, 2012 11:48 AM
> To: dev@hbase.apache.org; 'lars hofhansl'
> Subject: RE: ANN: The third hbase 0.94.0 release candidate is available
> for download
> 
> Hi
> We (it includes the test team here) 0.94 RC and carried out various
> operations on it.
> Puts, Scans, and all the restart scenarios (using kill -9 also).  Even
> the
> encoding stuffs were tested and carried out our basic test scenarios.
> Seems
> to work fine.
> 
> Did not test rolling restart with 0.92. By this week we may try to do
> some
> performance comparison with 0.92.
> Also Lars and I agreed for a point release too.
> So I am +1 on the RC.
> 
> Regards
> Ram
> 
> > -----Original Message-----
> > From: lars hofhansl [mailto:lhofha...@yahoo.com]
> > Sent: Sunday, May 13, 2012 10:53 PM
> > To: dev@hbase.apache.org
> > Subject: Re: ANN: The third hbase 0.94.0 release candidate is
> available
> > for download
> >
> > OK, I'll change my tactic :)
> >
> > If there are no -1's by Wed, May 16th, I'll release RC4 as 0.94.0.
> >
> > -- Lars
> >
> >
> >
> > ----- Original Message -----
> > From: Stack <st...@duboce.net>
> > To: lars hofhansl <lhofha...@yahoo.com>
> > Cc: "dev@hbase.apache.org" <dev@hbase.apache.org>
> > Sent: Friday, May 11, 2012 10:39 PM
> > Subject: Re: ANN: The third hbase 0.94.0 release candidate is
> available
> > for download
> >
> > On Fri, May 11, 2012 at 10:26 PM, lars hofhansl <lhofha...@yahoo.com>
> > wrote:
> > > Thanks Stack.
> > >
> > > So that's two +1 (mine doesn't count I guess). And no -1.
> >
> > Why doesn't yours count?  Usually the RMs does, if they +1 it.  So,
> > that'd be 3x+1 + a non-binding +1.
> >
> > > I talked to Ram offline, and we'll fix HBase with Hadoop 2.0.0 in a
> > 0.94 point release.
> > >
> > > I would like to see a few more +1's before I declare this the
> > official 0.94.0 release.
> > >
> >
> > You might be waiting a while (smile).  Fellas seem to be busy...
> >
> > Good on you Lars,
> > St.Ack

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