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From anil gupta <anilgupt...@gmail.com>
Subject Re: Coprocessor Aggregation supposed to be ~20x slower than Scans?
Date Wed, 16 May 2012 00:30:42 GMT
Hi Ted,

I looked into hbase-0.92.0-cdh4b1-20120206.193413-23-sources.jar and it
also doesn't have it.

On Tue, May 15, 2012 at 5:07 PM, Ted Yu <yuzhihong@gmail.com> wrote:

> Why did you need to decompile ?
> Here is the source code:
>
>
> https://repository.cloudera.com/artifactory/public/org/apache/hbase/hbase/0.92.0-cdh4b1-SNAPSHOT/
>
> On Tue, May 15, 2012 at 4:58 PM, anil gupta <anilgupta84@gmail.com> wrote:
>
> > Hi Ted,
> >
> > I decompiled the hbase-0.92.0-cdh4b1.jar using JD-GUI and in
> > validateParameter method i don't find that condition.
> >
> > Thanks,
> > Anil
> >
> > On Tue, May 15, 2012 at 1:37 PM, Ted Yu <yuzhihong@gmail.com> wrote:
> >
> > > I checked the code in Apache HBase 0.92 and trunk. I see the following
> > line
> > > in validateParameters():
> > >            !Bytes.equals(scan.getStopRow(),
> HConstants.EMPTY_END_ROW))) {
> > >
> > > Can you confirm that the bug is in cdh4b1 only ?
> > >
> > > Sorry for not doing the validation earlier.
> > >
> > > On Tue, May 15, 2012 at 12:09 PM, anil gupta <anilgupta84@gmail.com>
> > > wrote:
> > >
> > > > Oh i c.. Now if i look closely at your gmail id then i can see your
> > > name. I
> > > > was totally confused.
> > > >
> > > > So, you want to force the user to specify stopRow if the filter is
> not
> > > > used? What if the user just wants to scan the table from startRow
> till
> > > the
> > > > end of table? In your solution user will have explicitly set the
> > stopRow
> > > as
> > > > HConstants.EMPTY_END_ROW. Do we really want to force this?
> > > >
> > > > As per your solution the code would look like this:
> > > >      if(scan.hasFilter())
> > > >      {  if (scan == null || (Bytes.equals(scan.getStartRow(),
> > > > scan.getStopRow()) && !Bytes.equals(scan.getStartRow(),
> > > > HConstants.EMPTY_START_ROW)) || (Bytes.compareTo(scan.getStartRow(),
> > > > scan.getStopRow()) > 0 &&
> > > >             !Bytes.equals(scan.getStopRow(),
> HConstants.EMPTY_END_ROW)
> > > )) {
> > > >      throw new IOException(
> > > >          "Agg client Exception: Startrow should be smaller than
> > > Stoprow");
> > > >    } else if (scan.getFamilyMap().size() != 1) {
> > > >      throw new IOException("There must be only one family.");
> > > >    }
> > > >      }
> > > >      else
> > > >      {  if (scan == null || (Bytes.equals(scan.getStartRow(),
> > > > scan.getStopRow()) && !Bytes.equals(scan.getStartRow(),
> > > > HConstants.EMPTY_START_ROW)) || Bytes.compareTo(scan.getStartRow(),
> > > > scan.getStopRow()) > 0) {
> > > >          throw new IOException(
> > > >               "Agg client Exception: Startrow should be smaller than
> > > > Stoprow");
> > > >        } else if (scan.getFamilyMap().size() != 1) {
> > > >          throw new IOException("There must be only one family.");
> > > >        }
> > > >      }
> > > >
> > > > Let me know your thoughts.
> > > >
> > > > Thanks,
> > > > Anil
> > > >
> > > >
> > > > On Tue, May 15, 2012 at 11:46 AM, Ted Yu <yuzhihong@gmail.com>
> wrote:
> > > >
> > > > > Anil:
> > > > > I am having trouble accessing JIRA.
> > > > >
> > > > > Ted Yu and Zhihong Yu are the same person :-)
> > > > >
> > > > > I think it would be good to remind user of aggregation client to
> > narrow
> > > > > range of scan. That's why I proposed adding check of hasFilter().
> > > > >
> > > > > Cheers
> > > > >
> > > > > On Tue, May 15, 2012 at 10:47 AM, Ted Yu <yuzhihong@gmail.com>
> > wrote:
> > > > >
> > > > > > Take your time.
> > > > > > Once you complete your first submission, subsequent contributions
> > > would
> > > > > be
> > > > > > easier.
> > > > > >
> > > > > >
> > > > > > On Tue, May 15, 2012 at 10:34 AM, anil gupta <
> > anilgupta84@gmail.com
> > > > > >wrote:
> > > > > >
> > > > > >> Hi Ted,
> > > > > >>
> > > > > >> I created the jira:
> > > https://issues.apache.org/jira/browse/HBASE-5999for
> > > > > >> fixing this.
> > > > > >>
> > > > > >> Creating the patch might take me sometime(due to learning
curve)
> > as
> > > > this
> > > > > >> is
> > > > > >> the first time i would be creating a patch.
> > > > > >>
> > > > > >> Thanks,
> > > > > >> Anil Gupta
> > > > > >>
> > > > > >>
> > > > > >> On Mon, May 14, 2012 at 4:00 PM, Ted Yu <yuzhihong@gmail.com>
> > > wrote:
> > > > > >>
> > > > > >> > I was aware of the following change.
> > > > > >> >
> > > > > >> > Can you log a JIRA and attach the patch to it ?
> > > > > >> >
> > > > > >> > Thanks for trying out and improving aggregation client.
> > > > > >> >
> > > > > >> > On Mon, May 14, 2012 at 3:31 PM, anil gupta <
> > > anilgupta84@gmail.com>
> > > > > >> wrote:
> > > > > >> >
> > > > > >> > > Hi Ted,
> > > > > >> > >
> > > > > >> > > If we change the if statement condition in
> validateParameters
> > > > method
> > > > > >> in
> > > > > >> > > AggregationClient.java to:
> > > > > >> > > if (scan == null || (Bytes.equals(scan.getStartRow(),
> > > > > >> scan.getStopRow())
> > > > > >> > &&
> > > > > >> > > !Bytes.equals(scan.getStartRow(),
> HConstants.EMPTY_START_ROW))
> > > ||
> > > > > >> > > (Bytes.compareTo(scan.getStartRow(), scan.getStopRow())
> 0
> &&
> > > > > >> > > *!Bytes.equals(scan.getStopRow(),
> > > > > >> > > HConstants.EMPTY_END_ROW)* ))
> > > > > >> > >
> > > > > >> > > Condition specified in the bold and Italic will
handle the
> > case
> > > > when
> > > > > >> the
> > > > > >> > > stopRow is not specified. IMHO, it's not an error
if we are
> > not
> > > > > >> > specifying
> > > > > >> > > the stopRow. This is what is was looking for because
in my
> > case
> > > i
> > > > > >> didnt
> > > > > >> > > wanted to set the stop row as I am using a prefix
filter. I
> > have
> > > > > >> tested
> > > > > >> > the
> > > > > >> > > above specified code and it works fine when i
only specify
> the
> > > > > >> startRow.
> > > > > >> > Is
> > > > > >> > > this a desirable functionality? If yes, should
this be added
> > to
> > > > > trunk?
> > > > > >> > >
> > > > > >> > > Here is the link for source of AggregationClient:
> > > > > >> > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> > >
> >
> http://grepcode.com/file_/repo1.maven.org/maven2/org.apache.hbase/hbase/0.92.0/org/apache/hadoop/hbase/client/coprocessor/AggregationClient.java/?v=source
> > > > > >> > >
> > > > > >> > > Thanks,
> > > > > >> > > Anil Gupta
> > > > > >> > >
> > > > > >> > >
> > > > > >> > > On Mon, May 14, 2012 at 1:58 PM, Ted Yu <
> yuzhihong@gmail.com>
> > > > wrote
> > > > > >> > >
> > > > > >> > > > Anil:
> > > > > >> > > > As code #3 shows, having stopRow helps narrow
the range of
> > > rows
> > > > > >> > > > participating in aggregation.
> > > > > >> > > >
> > > > > >> > > > Do you have suggestion on how this process
can be made
> more
> > > > > >> > > user-friendly ?
> > > > > >> > > >
> > > > > >> > > > Thanks
> > > > > >> > > >
> > > > > >> > > > On Mon, May 14, 2012 at 1:47 PM, anil gupta
<
> > > > > anilgupta84@gmail.com>
> > > > > >> > > wrote:
> > > > > >> > > >
> > > > > >> > > > > HI Ted,
> > > > > >> > > > >
> > > > > >> > > > > My bad, i missed out a big difference
between the Scan
> > > object
> > > > i
> > > > > am
> > > > > >> > > using
> > > > > >> > > > in
> > > > > >> > > > > my filter and Scan object used in coprocessors.
So, scan
> > > > object
> > > > > is
> > > > > >> > not
> > > > > >> > > > > same.
> > > > > >> > > > > Basically, i am doing filtering on the
basis of a prefix
> > of
> > > > > >> RowKey.
> > > > > >> > > > >
> > > > > >> > > > > So, in my filter i do this to build
scanner:
> > > > > >> > > > > Code 1:
> > > > > >> > > > >  Filter filter = new
> > PrefixFilter(Bytes.toBytes(strPrefix));
> > > > > >> > > > >            Scan scan = new Scan();
> > > > > >> > > > >            scan.setFilter(filter);
> > > > > >> > > > >            scan.setStartRow(Bytes.toBytes(strPrefix));
> //
> > I
> > > > dont
> > > > > >> set
> > > > > >> > > any
> > > > > >> > > > > stopRow in this scanner.
> > > > > >> > > > >
> > > > > >> > > > > In coprocessor, i do the following for
scanner:
> > > > > >> > > > > Code 2:
> > > > > >> > > > >  Scan scan = new Scan();
> > > > > >> > > > > scan.setFilter(new PrefixFilter(Bytes.toBytes(prefix)));
> > > > > >> > > > >
> > > > > >> > > > >  I dont have startRow in above code
because if i only
> use
> > > only
> > > > > the
> > > > > >> > > > startRow
> > > > > >> > > > > in coprocessor scanner then i get the
following
> > > exception(due
> > > > to
> > > > > >> > this I
> > > > > >> > > > > removed the startRow from CP scan object
code):
> > > > > >> > > > > java.io.IOException: Agg client Exception:
Startrow
> should
> > > be
> > > > > >> smaller
> > > > > >> > > > than
> > > > > >> > > > > Stoprow
> > > > > >> > > > >    at
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> > >
> >
> org.apache.hadoop.hbase.client.coprocessor.AggregationClient.validateParameters(AggregationClient.java:116)
> > > > > >> > > > >    at
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> > >
> >
> org.apache.hadoop.hbase.client.coprocessor.AggregationClient.max(AggregationClient.java:85)
> > > > > >> > > > >    at
> > > > > >> > > > >
> > > > > >> >
> > > >
> com.intuit.ihub.hbase.poc.DummyClass.doAggregation(DummyClass.java:81)
> > > > > >> > > > >    at
> sun.reflect.NativeMethodAccessorImpl.invoke0(Native
> > > > > Method)
> > > > > >> > > > >    at
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> > >
> >
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > > > > I modified the above code#2 to add the
stopRow also:
> > > > > >> > > > > Code 3:
> > > > > >> > > > > Scan scan = new Scan();
> > > > > >> > > > >        scan.setStartRow(Bytes.toBytes(prefix));
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > >
> > > > > >>
> > > > >
> > >
> scan.setStopRow(Bytes.toBytes(String.valueOf(Long.parseLong(prefix)+1)));
> > > > > >> > > > >        scan.setFilter(new
> > > > PrefixFilter(Bytes.toBytes(prefix)));
> > > > > >> > > > >
> > > > > >> > > > > When, i run the coprocessor with Code
#3, its blazing
> > fast.
> > > I
> > > > > >> gives
> > > > > >> > the
> > > > > >> > > > > result in around 200 millisecond. :)
> > > > > >> > > > > Since, this was just testing a coprocessors
i added the
> > > logic
> > > > to
> > > > > >> add
> > > > > >> > > the
> > > > > >> > > > > stopRow manually. What is the reason
that Scan object in
> > > > > >> coprocessor
> > > > > >> > > > always
> > > > > >> > > > > requires stopRow along with startRow?(code
#1 works fine
> > > even
> > > > > >> when i
> > > > > >> > > dont
> > > > > >> > > > > use stopRow)  Can this restriction be
relaxed?
> > > > > >> > > > >
> > > > > >> > > > > Thanks,
> > > > > >> > > > > Anil Gupta
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > > > > On Mon, May 14, 2012 at 12:55 PM, Ted
Yu <
> > > yuzhihong@gmail.com
> > > > >
> > > > > >> > wrote:
> > > > > >> > > > >
> > > > > >> > > > > > Anil:
> > > > > >> > > > > > I think the performance was related
to your custom
> > filter.
> > > > > >> > > > > >
> > > > > >> > > > > > Please tell us more about the filter
next time.
> > > > > >> > > > > >
> > > > > >> > > > > > Thanks
> > > > > >> > > > > >
> > > > > >> > > > > > On Mon, May 14, 2012 at 12:31 PM,
anil gupta <
> > > > > >> > anilgupta84@gmail.com>
> > > > > >> > > > > > wrote:
> > > > > >> > > > > >
> > > > > >> > > > > > > HI Stack,
> > > > > >> > > > > > >
> > > > > >> > > > > > > I'll look into Gary Helming
post and try to do
> > profiling
> > > > of
> > > > > >> > > > coprocessor
> > > > > >> > > > > > and
> > > > > >> > > > > > > share the results.
> > > > > >> > > > > > >
> > > > > >> > > > > > > Thanks,
> > > > > >> > > > > > > Anil Gupta
> > > > > >> > > > > > >
> > > > > >> > > > > > > On Mon, May 14, 2012 at 12:08
PM, Stack <
> > > stack@duboce.net
> > > > >
> > > > > >> > wrote:
> > > > > >> > > > > > >
> > > > > >> > > > > > > > On Mon, May 14, 2012
at 12:02 PM, anil gupta <
> > > > > >> > > > anilgupta84@gmail.com>
> > > > > >> > > > > > > > wrote:
> > > > > >> > > > > > > > > I loaded around
70 thousand 1-2KB records in
> > HBase.
> > > > For
> > > > > >> > scans,
> > > > > >> > > > with
> > > > > >> > > > > > my
> > > > > >> > > > > > > > > custom filter i
am able to get 97 rows in 500
> > > > > milliseconds
> > > > > >> > and
> > > > > >> > > > for
> > > > > >> > > > > > > doing
> > > > > >> > > > > > > > > sum, max, min(in
built aggregations of HBase) on
> > the
> > > > > same
> > > > > >> > > custom
> > > > > >> > > > > > filter
> > > > > >> > > > > > > > its
> > > > > >> > > > > > > > > taking 11000 milliseconds.
Does this mean that
> > > > > >> coprocessors
> > > > > >> > > > > > aggregation
> > > > > >> > > > > > > > is
> > > > > >> > > > > > > > > supposed to be around
~20x slower than scans?
> Am i
> > > > > missing
> > > > > >> > any
> > > > > >> > > > > trick
> > > > > >> > > > > > > over
> > > > > >> > > > > > > > > here?
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > That seems like a high
tax to pay for running CPs.
> > >  Can
> > > > > you
> > > > > >> dig
> > > > > >> > > in
> > > > > >> > > > on
> > > > > >> > > > > > > > where the time is being
spent?  (See another
> recent
> > > note
> > > > > on
> > > > > >> > this
> > > > > >> > > > list
> > > > > >> > > > > > > > or on dev where Gary
Helmling talks about how he
> did
> > > > basic
> > > > > >> > > > profiling
> > > > > >> > > > > > > > of CPs).
> > > > > >> > > > > > > > St.Ack
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > > > --
> > > > > >> > > > > > > Thanks & Regards,
> > > > > >> > > > > > > Anil Gupta
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > > > >
> > > > > >> > > > > --
> > > > > >> > > > > Thanks & Regards,
> > > > > >> > > > > Anil Gupta
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> > >
> > > > > >> > >
> > > > > >> > > --
> > > > > >> > > Thanks & Regards,
> > > > > >> > > Anil Gupta
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > > >>
> > > > > >>
> > > > > >> --
> > > > > >> Thanks & Regards,
> > > > > >> Anil Gupta
> > > > > >>
> > > > > >
> > > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > --
> > > > Thanks & Regards,
> > > > Anil Gupta
> > > >
> > >
> >
> >
> >
> > --
> > Thanks & Regards,
> > Anil Gupta
> >
>



-- 
Thanks & Regards,
Anil Gupta

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