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From ramkrishna vasudevan <ramkrishna.s.vasude...@gmail.com>
Subject Re: Hbase Count Aggregate Function
Date Wed, 26 Dec 2012 15:41:32 GMT
Dalia,

I tried out this eg,

{code}
  private static final byte[] TEST_TABLE = Bytes.toBytes("TestTable");
  private static final byte[] TEST_FAMILY = Bytes.toBytes("TestFamily");
  private static final byte[] TEST_QUALIFIER =
Bytes.toBytes("TestQualifier");
  private static final byte[] TEST_MULTI_CQ = Bytes.toBytes("TestMultiCQ");

  private static byte[] ROW = Bytes.toBytes("testRow");
  private static final int ROWSIZE = 20;
  private static final int rowSeperator1 = 5;
  private static final int rowSeperator2 = 12;
  private static byte[][] ROWS = makeN(ROW, ROWSIZE);
for (int i = 0; i < ROWSIZE; i++) {
      Put put = new Put(ROWS[i]);
      put.setWriteToWAL(false);
      Long l = new Long(i);
      put.add(TEST_FAMILY, TEST_QUALIFIER, Bytes.toBytes(l));
      table.put(put);
      Put p2 = new Put(ROWS[i]);
      put.setWriteToWAL(false);
      p2.add(TEST_FAMILY, Bytes.add(TEST_MULTI_CQ, Bytes.toBytes(l)), Bytes
          .toBytes(l * 10));
      table.put(p2);

   AggregationClient aClient = new AggregationClient(conf);
    Scan scan = new Scan();
    scan.addColumn(TEST_FAMILY, TEST_QUALIFIER);
    final ColumnInterpreter<Long, Long> ci = new LongColumnInterpreter();
    SingleColumnValueFilter scvf = new SingleColumnValueFilter(TEST_FAMILY,
TEST_QUALIFIER, CompareOp.EQUAL,
          Bytes.toBytes(4l));
    scan.setFilter(scvf);
    long rowCount = aClient.rowCount(TEST_TABLE, ci,
        scan);
    assertEquals(ROWSIZE, rowCount);
    }
{code}

So this assertion is failing and it is working as expected.  If you want to
try out check out the testcase
in TestAggregateProtocol.testRowCountAllTable().
Just modify the testcase so that you pass a SingleColumnValueFilter.  It is
working fine.

Please check and let me know.  May be am doing some mistake.

Regards
Ram

On Tue, Dec 25, 2012 at 11:25 PM, Dalia Sobhy <dalia.mohsobhy@hotmail.com>wrote:

>
> Is there a problem in letting ID (rowkey) "int" value??
>
> > Date: Tue, 25 Dec 2012 22:44:00 +0530
> > Subject: Re: Hbase Count Aggregate Function
> > From: ramkrishna.s.vasudevan@gmail.com
> > To: user@hbase.apache.org
> >
> > @Dalia
> >
> > I think the aggregation client should work with what you have passed.
>  What
> > i meant in the previous mail was with table.count() and now with
> > AggregationClient.
> > {code}
> > if (scan.getFilter() == null && qualifier == null)
> >       scan.setFilter(new FirstKeyOnlyFilter());
> > {code}
> >
> > So as you have passed the filter then it should work as how the SCVF
> should
> > work.  I can check this out during free time (may be tomorrow).
> > If not you can raise a bug.  If it turns to be fine then we can close it
> > out otherwise its better we fix it.
> > I can understand your urgency in this.
> >
> > Regards
> > Ram
> >
> >
> >
> >
> >
> > On Tue, Dec 25, 2012 at 10:27 PM, <yuzhihong@gmail.com> wrote:
> >
> > > RowCount method accepts scan object where you can attach your custom
> > > filter.
> > >
> > > Cheers
> > >
> > >
> > >
> > > On Dec 25, 2012, at 8:42 AM, Dalia Sobhy <dalia.mohsobhy@hotmail.com>
> > > wrote:
> > >
> > > >
> > > > Do you mean I implement a new rowCount method in Aggregation Client
> > > Class.
> > > >
> > > > I cannot understand, could u illustrate with a code sample Ram?
> > > >
> > > >>> Date: Tue, 25 Dec 2012 00:21:14 +0530
> > > >>> Subject: Re: Hbase Count Aggregate Function
> > > >>> From: ramkrishna.s.vasudevan@gmail.com
> > > >>> To: user@hbase.apache.org
> > > >>>
> > > >>> Hi
> > > >>> You could have custom filter implemented which is similar to
> > > >>> FirstKeyOnlyfilter.
> > > >>> Implement the filterKeyValue method such that it should match
your
> > > keyvalue
> > > >>> (the specific qualifier that you are looking for).
> > > >>>
> > > >>> Deploy it in your cluster.  It should work.
> > > >>>
> > > >>> Regards
> > > >>> Ram
> > > >>>
> > > >>> On Mon, Dec 24, 2012 at 10:35 PM, Dalia Sobhy <
> > > dalia.mohsobhy@hotmail.com>wrote:
> > > >>>
> > > >>>>
> > > >>>> So do you have a suggestion how to enable/work the filter?
> > > >>>>
> > > >>>>> Date: Mon, 24 Dec 2012 22:22:49 +0530
> > > >>>>> Subject: Re: Hbase Count Aggregate Function
> > > >>>>> From: ramkrishna.s.vasudevan@gmail.com
> > > >>>>> To: user@hbase.apache.org
> > > >>>>>
> > > >>>>> Okie, seeing the shell script and the code I feel that
while you
> use
> > > this
> > > >>>>> counter, the user's filter is not taken into account.
> > > >>>>> It adds a FirstKeyOnlyFilter and proceeds with the scan.
:(.
> > > >>>>>
> > > >>>>> Regards
> > > >>>>> Ram
> > > >>>>>
> > > >>>>> On Mon, Dec 24, 2012 at 10:11 PM, Dalia Sobhy <
> > > >>>> dalia.mohsobhy@hotmail.com>wrote:
> > > >>>>>
> > > >>>>>>
> > > >>>>>> yeah scan gives the correct number of rows, while
count returns
> the
> > > >>>> total
> > > >>>>>> number of rows.
> > > >>>>>>
> > > >>>>>> Both are using the same filter, I even tried it using
Java API,
> > > using
> > > >>>> row
> > > >>>>>> count method.
> > > >>>>>>
> > > >>>>>> rowCount = aggregationClient.rowCount(TABLE_NAME,
null, scan);
> > > >>>>>>
> > > >>>>>> I get the total number of rows not the number of rows
filtered.
> > > >>>>>>
> > > >>>>>> So any idea ??
> > > >>>>>>
> > > >>>>>> Thanks Ram :)
> > > >>>>>>
> > > >>>>>>> Date: Mon, 24 Dec 2012 21:57:54 +0530
> > > >>>>>>> Subject: Re: Hbase Count Aggregate Function
> > > >>>>>>> From: ramkrishna.s.vasudevan@gmail.com
> > > >>>>>>> To: user@hbase.apache.org
> > > >>>>>>>
> > > >>>>>>> So you find that scan with a filter and count
with the same
> filter
> > > is
> > > >>>>>>> giving you different results?
> > > >>>>>>>
> > > >>>>>>> Regards
> > > >>>>>>> Ram
> > > >>>>>>>
> > > >>>>>>> On Mon, Dec 24, 2012 at 8:33 PM, Dalia Sobhy <
> > > >>>> dalia.mohsobhy@hotmail.com
> > > >>>>>>> wrote:
> > > >>>>>>>
> > > >>>>>>>>
> > > >>>>>>>> Dear all,
> > > >>>>>>>>
> > > >>>>>>>> I have 50,000 row with diagnosis qualifier
= "cardiac", and
> > > another
> > > >>>>>> 50,000
> > > >>>>>>>> rows with "renal".
> > > >>>>>>>>
> > > >>>>>>>> When I type this in Hbase shell,
> > > >>>>>>>>
> > > >>>>>>>> import org.apache.hadoop.hbase.filter.CompareFilter
> > > >>>>>>>> import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
> > > >>>>>>>> import org.apache.hadoop.hbase.filter.SubstringComparator
> > > >>>>>>>> import org.apache.hadoop.hbase.util.Bytes
> > > >>>>>>>>
> > > >>>>>>>> scan 'patient', { COLUMNS => "info:diagnosis",
FILTER =>
> > > >>>>>>>>    SingleColumnValueFilter.new(Bytes.toBytes('info'),
> > > >>>>>>>>         Bytes.toBytes('diagnosis'),
> > > >>>>>>>>         CompareFilter::CompareOp.valueOf('EQUAL'),
> > > >>>>>>>>         SubstringComparator.new('cardiac'))}
> > > >>>>>>>>
> > > >>>>>>>> Output = 50,000 row
> > > >>>>>>>>
> > > >>>>>>>> import org.apache.hadoop.hbase.filter.CompareFilter
> > > >>>>>>>> import org.apache.hadoop.hbase.filter.SingleColumnValueFilter
> > > >>>>>>>> import org.apache.hadoop.hbase.filter.SubstringComparator
> > > >>>>>>>> import org.apache.hadoop.hbase.util.Bytes
> > > >>>>>>>>
> > > >>>>>>>> count 'patient', { COLUMNS => "info:diagnosis",
FILTER =>
> > > >>>>>>>>    SingleColumnValueFilter.new(Bytes.toBytes('info'),
> > > >>>>>>>>         Bytes.toBytes('diagnosis'),
> > > >>>>>>>>         CompareFilter::CompareOp.valueOf('EQUAL'),
> > > >>>>>>>>         SubstringComparator.new('cardiac'))}
> > > >>>>>>>> Output = 100,000 row
> > > >>>>>>>>
> > > >>>>>>>> Even though I tried it using Hbase Java API,
Aggregation
> Client
> > > >>>>>> Instance,
> > > >>>>>>>> and I enabled the Coprocessor aggregation
for the table.
> > > >>>>>>>> rowCount = aggregationClient.rowCount(TABLE_NAME,
null, scan)
> > > >>>>>>>>
> > > >>>>>>>> Also when measuring the improved performance
on case of adding
> > > more
> > > >>>>>> nodes
> > > >>>>>>>> the operation takes the same time.
> > > >>>>>>>>
> > > >>>>>>>> So any advice please?
> > > >>>>>>>>
> > > >>>>>>>> I have been throughout all this mess from
a couple of weeks
> > > >>>>>>>>
> > > >>>>>>>> Thanks,
> > > >>>>>>
> > > >>>>>>
> > > >>>>
> > > >>>>
> > > >>
> > > >
> > >
>
>

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