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Posted to user@hbase.apache.org by Upendra Yadav <up...@gmail.com> on 2014/02/25 20:03:27 UTC
HBase read operation document/help...
I have go through no. of documents/slides about HBase read/get operation...
But I have lot of broken links and question to clear view about how hbase
read operation happen...
Like....
Client Communicate to zookeeper and get region server where -ROOT- table
region reside...(And this is in memory)
Then getting region server location for .META table region (And this is in
memory)
Then location of region server where region of user table reside by
checking start and end rowkey with given GET operation rowkey...
then will search 1st in memstore.... if found then return data
else
BlockCache.... if not then BloomFilter if negative then return not
found.... else
read from hfile....(how i don't know.. please help me)
Bloomfilter and BlockCache update and return data...
Is this correct... Please suggest me some good document...
Still i have doubt ... how BlockCache LRU works...
Re: HBase read operation document/help...
Posted by Upendra Yadav <up...@gmail.com>.
Thanks Ted Yu...
I will go through these document...
On Wed, Feb 26, 2014 at 12:54 AM, Ted Yu <yu...@gmail.com> wrote:
> You may have read http://hbase.apache.org/book.html#perf.reading
>
> For BlockCache, see this blog:
> http://www.n10k.com/blog/blockcache-101/
>
> Cheers
>
>
> On Tue, Feb 25, 2014 at 11:03 AM, Upendra Yadav <upendra1024@gmail.com
> >wrote:
>
> > I have go through no. of documents/slides about HBase read/get
> operation...
> > But I have lot of broken links and question to clear view about how hbase
> > read operation happen...
> >
> > Like....
> > Client Communicate to zookeeper and get region server where -ROOT- table
> > region reside...(And this is in memory)
> >
> > Then getting region server location for .META table region (And this is
> in
> > memory)
> >
> > Then location of region server where region of user table reside by
> > checking start and end rowkey with given GET operation rowkey...
> >
> > then will search 1st in memstore.... if found then return data
> > else
> > BlockCache.... if not then BloomFilter if negative then return not
> > found.... else
> >
> > read from hfile....(how i don't know.. please help me)
> >
> > Bloomfilter and BlockCache update and return data...
> >
> > Is this correct... Please suggest me some good document...
> >
> > Still i have doubt ... how BlockCache LRU works...
> >
>
Re: HBase read operation document/help...
Posted by Upendra Yadav <up...@gmail.com>.
I didn't know such changes... Thanks Tariq...
On Wed, Feb 26, 2014 at 1:03 AM, Mohammad Tariq <do...@gmail.com> wrote:
> Just to add on to Ted's comment, ROOT has been dropped. META locations are
> now directly stored in ZK. See this
> ticket<https://issues.apache.org/jira/browse/HBASE-3171>for more.
>
> Warm Regards,
> Tariq
> cloudfront.blogspot.com
>
>
> On Wed, Feb 26, 2014 at 12:54 AM, Ted Yu <yu...@gmail.com> wrote:
>
> > You may have read http://hbase.apache.org/book.html#perf.reading
> >
> > For BlockCache, see this blog:
> > http://www.n10k.com/blog/blockcache-101/
> >
> > Cheers
> >
> >
> > On Tue, Feb 25, 2014 at 11:03 AM, Upendra Yadav <upendra1024@gmail.com
> > >wrote:
> >
> > > I have go through no. of documents/slides about HBase read/get
> > operation...
> > > But I have lot of broken links and question to clear view about how
> hbase
> > > read operation happen...
> > >
> > > Like....
> > > Client Communicate to zookeeper and get region server where -ROOT-
> table
> > > region reside...(And this is in memory)
> > >
> > > Then getting region server location for .META table region (And this is
> > in
> > > memory)
> > >
> > > Then location of region server where region of user table reside by
> > > checking start and end rowkey with given GET operation rowkey...
> > >
> > > then will search 1st in memstore.... if found then return data
> > > else
> > > BlockCache.... if not then BloomFilter if negative then return not
> > > found.... else
> > >
> > > read from hfile....(how i don't know.. please help me)
> > >
> > > Bloomfilter and BlockCache update and return data...
> > >
> > > Is this correct... Please suggest me some good document...
> > >
> > > Still i have doubt ... how BlockCache LRU works...
> > >
> >
>
Re: HBase read operation document/help...
Posted by Mohammad Tariq <do...@gmail.com>.
Just to add on to Ted's comment, ROOT has been dropped. META locations are
now directly stored in ZK. See this
ticket<https://issues.apache.org/jira/browse/HBASE-3171>for more.
Warm Regards,
Tariq
cloudfront.blogspot.com
On Wed, Feb 26, 2014 at 12:54 AM, Ted Yu <yu...@gmail.com> wrote:
> You may have read http://hbase.apache.org/book.html#perf.reading
>
> For BlockCache, see this blog:
> http://www.n10k.com/blog/blockcache-101/
>
> Cheers
>
>
> On Tue, Feb 25, 2014 at 11:03 AM, Upendra Yadav <upendra1024@gmail.com
> >wrote:
>
> > I have go through no. of documents/slides about HBase read/get
> operation...
> > But I have lot of broken links and question to clear view about how hbase
> > read operation happen...
> >
> > Like....
> > Client Communicate to zookeeper and get region server where -ROOT- table
> > region reside...(And this is in memory)
> >
> > Then getting region server location for .META table region (And this is
> in
> > memory)
> >
> > Then location of region server where region of user table reside by
> > checking start and end rowkey with given GET operation rowkey...
> >
> > then will search 1st in memstore.... if found then return data
> > else
> > BlockCache.... if not then BloomFilter if negative then return not
> > found.... else
> >
> > read from hfile....(how i don't know.. please help me)
> >
> > Bloomfilter and BlockCache update and return data...
> >
> > Is this correct... Please suggest me some good document...
> >
> > Still i have doubt ... how BlockCache LRU works...
> >
>
Re: HBase read operation document/help...
Posted by Ted Yu <yu...@gmail.com>.
You may have read http://hbase.apache.org/book.html#perf.reading
For BlockCache, see this blog:
http://www.n10k.com/blog/blockcache-101/
Cheers
On Tue, Feb 25, 2014 at 11:03 AM, Upendra Yadav <up...@gmail.com>wrote:
> I have go through no. of documents/slides about HBase read/get operation...
> But I have lot of broken links and question to clear view about how hbase
> read operation happen...
>
> Like....
> Client Communicate to zookeeper and get region server where -ROOT- table
> region reside...(And this is in memory)
>
> Then getting region server location for .META table region (And this is in
> memory)
>
> Then location of region server where region of user table reside by
> checking start and end rowkey with given GET operation rowkey...
>
> then will search 1st in memstore.... if found then return data
> else
> BlockCache.... if not then BloomFilter if negative then return not
> found.... else
>
> read from hfile....(how i don't know.. please help me)
>
> Bloomfilter and BlockCache update and return data...
>
> Is this correct... Please suggest me some good document...
>
> Still i have doubt ... how BlockCache LRU works...
>