You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@hbase.apache.org by Ted Yu <yu...@gmail.com> on 2012/01/10 16:19:44 UTC
more implementations of ColumnInterpreter Was: median aggregate
I plan to check in HBASE-5139 after some minor optimizations.
The rationale behind ColumnInterpreter is that you can extract a portion of
the value of cf:cq where the value might be serialized form of a structure
(I am thinking about Hive here).
Feel free to add sub-task to HBASE-5123 for more implementations of
ColumnInterpreter.
Cheers
On Tue, Jan 10, 2012 at 5:01 AM, Royston Sellman <
royston.sellman@googlemail.com> wrote:
> Hi Ted,
>
> Great! Thanks for your work. I see you posted another comment saying you
> now
> support weighted median. You're very fast!
>
> We have to spend time getting ready for a presentation this week but we
> will
> try to make time to test the patch.
>
> The code is quite hard for me to read due to the generics but it looks like
> you have made ColumnInterpreter more ready to take types other than Longs
> BUT you have not provided column interpreter implementations for types
> other
> than Longs. So there is more work to do for other types, am I correct? If
> so, should we start a new JIRA for more types? I am thinking the type we
> most need is double.
>
> Cheers,
> Royston
>
> -----Original Message-----
> From: Ted Yu [mailto:yuzhihong@gmail.com]
> Sent: 10 January 2012 04:04
> To: user@hbase.apache.org
> Subject: Re: median aggregate Was: AggregateProtocol Help
>
> Tom / Royston:
> I attached first version of patch to HBASE-5139.
> I need to handle weighted median and add more tests.
>
> javadoc is available for methods. More javadoc is needed inside median()
> method.
>
> It took longer than I expected due to the generic parameters.
>
> Comments are welcome.
>
> On Sat, Jan 7, 2012 at 3:45 AM, <yu...@gmail.com> wrote:
>
> > Tom:
> > Two pass algorithm is fine. See HBASE-5139.
> >
> > But we have to consider that there might be change in the underlying data
> > across the two passes.
> >
> > Feel free to log subtasks for hbase-5123 for each aggregate that you
> think
> > should be supported.
> >
> > Cheers
> >
> >
> >
> > On Jan 7, 2012, at 3:32 AM, Tom Wilcox <To...@cse.org.uk> wrote:
> >
> > > Forgive me if this is stating the obvious (I just want to understand
> > this better), but a naive approach to hist would surely just be a 2-pass
> > algorithm where the first pass gathers statistics such as the range.
> Those
> > statistics could be cached for subsequent requests that are also
> > "range-dependent" such as n-tiles.
> > >
> > > Are 2-pass algorithms out of the question or too inefficient to
> consider?
> > >
> > > Cheers,
> > > Tom
> > > ________________________________________
> > > From: Royston Sellman [royston.sellman@googlemail.com]
> > > Sent: 06 January 2012 22:00
> > > To: user@hbase.apache.org
> > > Subject: Re: median aggregate Was: AggregateProtocol Help
> > >
> > > I will have to think about this properly next week as I am travelling
> > this weekend but...
> > >
> > > I was using binning only as an example. I have worked with R in the
> past
> > and there is a neat R function called hist which generates histograms
> from
> > arrays of values and the number of "breaks" (=bins) is a parameter to
> hist.
> > The generated histogram is an object so you can examine it: hist()?counts
> > returns a vector containing the frequencies in each bin ("?" in R is like
> > "." in Java). The discussion is here:
> > http://www.stat.ucl.ac.be/ISdidactique/Rhelp/library/base/html/hist.html
> > >
> > > I am not trying to turn HBase into R ;) but binning is in my experience
> > a useful aggregation. I have no idea how to efficiently implement it
> across
> > the regionservers though. I think it is *me* who needs to brush up my
> > knowledge of HBase internal machinery. But I think it will be a similar
> > problem to crack for quantile/ntile. The start of the boundaries will be
> > the ntiles. Maybe if ntile is done first then it will help with binning,
> > maybe even make it trivial.
> > >
> > > HBASE-5139 looks good, thanks. I will get colleagues to look at it and
> > comment.
> > >
> > > Cheers,
> > > Royston
> > >
> > > On 6 Jan 2012, at 19:29, Ted Yu wrote:
> > >
> > >> Royston:
> > >> I need to brush up my math knowledge so bear with me for a few
> > questions.
> > >>
> > >> For binning, you gave 100 as the number of bins. If the computation is
> > >> initiated on each region server simultaneously, how would each region
> > know
> > >> where the bin boundaries are ? If the boundaries are naturally aligned
> > with
> > >> region boundaries, that would be easier.
> > >>
> > >> I logged HBASE-5139 for weighted median, please comment there.
> > >>
> > >> If you or other people feel there is plausible implementation for any
> > new
> > >> aggregate, please create subtask so that the original JIRA can host
> > general
> > >> discussions.
> > >>
> > >> Cheers
> > >>
> > >> On Fri, Jan 6, 2012 at 6:22 AM, Royston Sellman <
> > >> royston.sellman@googlemail.com> wrote:
> > >>
> > >>> Hi Ted,
> > >>>
> > >>> Yes, that is the use case I am thinking of.
> > >>>
> > >>> Re: 5123 I have also had some time to think about other aggregation
> > >>> functions (Please be aware that I am new to HBase, Coprocessors, and
> > the
> > >>> Aggregation Protocol and I have little knowledge of distributed
> > numerical
> > >>> algorithms!). It seems to me the pattern in AP is to return a SINGLE
> > value
> > >>> from a SINGLE column (CF:CQ) of a table. In future one might wish to
> > extend
> > >>> AP to return MULTIPLE values from MULTIPLE columns, so it is good to
> > keep
> > >>> this in mind for the SINGLE value/SINGLE column (SVSC) case.
> > >>>
> > >>> So, common SVSC aggregation functions (AP supported first):
> > >>> min
> > >>> max
> > >>> sum
> > >>> count
> > >>> avg (arithmetic mean)
> > >>> std
> > >>> median
> > >>> mode
> > >>> quantile/ntile
> > >>> mult/product
> > >>>
> > >>> for column values of all numeric types, returning values of that
> type.
> > >>>
> > >>> Some thoughts on the future possibilities:
> > >>> An example of a future SINGLE value MULTIPLE column use case could be
> > >>> weighted versions of the above functions i.e. a column of weights
> > applied
> > >>> to the column of values then the new aggregation derived.
> > >>> (note: there is a very good description of Weighted Median in the R
> > >>> language documentation:
> > >>>
> > >>>
> >
>
> http://www.stat.ucl.ac.be/ISdidactique/Rhelp/library/R.basic/html/weighted.m
> edian.html
> > >>> )
> > >>>
> > >>> An example of future MULTIPLE value SINGLE column could be range:
> > return
> > >>> all rows with a column value between two values. Maybe this is a bad
> > >>> example because there could be better HBase ways to do it with
> > >>> filters/scans at a higher level. Perhaps binning is a better example?
> > i.e.
> > >>> return an array containing values derived from applying one of the
> SVSC
> > >>> functions to a binned column e.g:
> > >>> int bins = 100;
> > >>> aClient.sum(table, ci, scan, bins); => {12.3, 14.5...}
> > >>> Another example (common in several programming languages) is to map
> an
> > >>> arbitrary function over a column and return the new vector. Of
> course,
> > >>> again this may be a bad example in the case of long HBase columns but
> > it
> > >>> seems like an appropriate thing to do with coprocessors.
> > >>>
> > >>> MULTIPLE value MULTIPLE column examples are common in spatial data
> > >>> processing but I see there has been a lot of spatial/GIS discussion
> > around
> > >>> HBase which I have not read yet. So I'll keep quiet for now.
> > >>>
> > >>> I hope these thoughts strike a balance between my (special interest)
> > use
> > >>> case of statistical/spatial functions on tables and general purpose
> > (but
> > >>> coprocessor enabled/regionserver distributed) HBase.
> > >>>
> > >>> Best regards,
> > >>> Royston
> > >>>
> > >>>
> > >>> On 6 Jan 2012, at 03:31, Ted Yu wrote:
> > >>>
> > >>>> Royston:
> > >>>> For the median aggregate, is the following what you're looking for ?
> > >>>> Find the median among the values of all the keyvalue for
> cf:qualifier
> > >>>> column.
> > >>>>
> > >>>> There is a well known distributed method of computing median that
> > >>> involves
> > >>>> multiple roundtrips (to the region servers).
> > >>>>
> > >>>> Just want to confirm the use case.
> > >>>>
> > >>>> Thanks
> > >>>>
> > >>>> On Wed, Jan 4, 2012 at 10:57 AM, Royston Sellman <
> > >>>> royston.sellman@googlemail.com> wrote:
> > >>>>
> > >>>>> Great ideas. Thanks.
> > >>>>>
> > >>>>> w.r.t. 5123: I'll think about it for a day or two then make some
> > >>> comments.
> > >>>>>
> > >>>>> 5122 is very desirable.
> > >>>>>
> > >>>>> Best Regards,
> > >>>>> Royston
> > >>>>>
> > >>>>> On 4 Jan 2012, at 15:01, Ted Yu wrote:
> > >>>>>
> > >>>>>> I can see room for improvement w.r.t. ColumnInterpreters
> > >>>>>> I logged two JIRAs:
> > >>>>>> https://issues.apache.org/jira/browse/HBASE-5122 is for loading
> > >>>>>> ColumnInterpreters dynamically
> > >>>>>>
> > >>>>>> https://issues.apache.org/jira/browse/HBASE-5123 is for adding
> more
> > >>>>>> aggregation functions.
> > >>>>>>
> > >>>>>> Royston:
> > >>>>>> Feel free to elaborate on 5213 and explain what Mult aggregate
> > should
> > >>> do.
> > >>>>>>
> > >>>>>> Cheers
> > >>>>>>
> > >>>>>> On Wed, Jan 4, 2012 at 3:43 AM, Royston Sellman <
> > >>>>>> royston.sellman@googlemail.com> wrote:
> > >>>>>>
> > >>>>>>> Ted, Himanshu and Gary,
> > >>>>>>>
> > >>>>>>> It works now! I re-created my HBase table to contain
> > >>> Bytes.toBytes(Long)
> > >>>>>>> values and that fixed it.
> > >>>>>>>
> > >>>>>>> For the time being we can convert everything to Longs and work
> with
> > >>>>> that,
> > >>>>>>> but we will probably write our own ColumnInterpreters soon for
> our
> > >>> data
> > >>>>>>> types, so thanks for the pointer to HBASE-4946. There are also
> > >>>>> Functions we
> > >>>>>>> need (e.g. Median, Weighted Median, Mult) which might best be
> > placed
> > >>> in
> > >>>>> the
> > >>>>>>> Aggregations Protocol. We'll be sure to discuss this with you
> when
> > we
> > >>>>> start.
> > >>>>>>>
> > >>>>>>> Meanwhile, thanks again for all your help!
> > >>>>>>>
> > >>>>>>> Royston
> > >>>>>>>
> > >>>>>>>
> > >>>>>>> On 3 Jan 2012, at 18:58, Ted Yu wrote:
> > >>>>>>>
> > >>>>>>>> I like long messages :-) because they provide more clues.
> > >>>>>>>>
> > >>>>>>>> For part 1, you don't have to call Bytes.toxxx as long as the
> > >>>>> interpreter
> > >>>>>>>> uses method consistent with the way you write values into HBase
> > >>> tables.
> > >>>>>>>>
> > >>>>>>>> For part 2, HBASE-4946 is related.
> > >>>>>>>> Basically you need to place the jar containing your coprocessor
> > and
> > >>>>>>>> interpreter code on hdfs so that you can load it into your HBase
> > >>> table.
> > >>>>>>>> Look at this for details:
> > >>>>>>>> https://issues.apache.org/jira/browse/HBASE-4554
> > >>>>>>>>
> > >>>>>>>> Cheers
> > >>>>>>>>
> > >>>>>>>> On Tue, Jan 3, 2012 at 10:42 AM, Royston Sellman <
> > >>>>>>>> royston.sellman@googlemail.com> wrote:
> > >>>>>>>>
> > >>>>>>>>> Hi Ted,
> > >>>>>>>>>
> > >>>>>>>>> PART 1
> > >>>>>>>>> =====
> > >>>>>>>>> Thanks for the hint. I think maybe you have given me some
> > >>> inspiration!
> > >>>>>>>>>
> > >>>>>>>>> It looks like getValue will return null if the table value is
> not
> > >>> the
> > >>>>>>>>> length
> > >>>>>>>>> of a long. When we created our table (batch loading CSVs using
> > the
> > >>>>>>>>> SampleUploader example) we simply have this as our put():
> > >>>>>>>>> put.add(family, Bytes.toBytes("advanceKWh"), advanceKWh);
> > >>>>>>>>> [note we do no Bytes.toxxx casts to the advanceKWh value. The
> > values
> > >>>>>>> look
> > >>>>>>>>> OK
> > >>>>>>>>> from HBase shell though :-)]
> > >>>>>>>>>
> > >>>>>>>>> but I looked at TestAggregateProtocol.java again and I see
> there
> > >>> puts
> > >>>>>>> like:
> > >>>>>>>>> p2.add(TEST_FAMILY, Bytes.add(TEST_MULTI_CQ, Bytes.toBytes(l)),
> > >>>>>>>>> Bytes.toBytes(l * 10));
> > >>>>>>>>>
> > >>>>>>>>> So my hypothesis is that we need to do something like:
> > >>>>>>>>> Long l = new Long(1);
> > >>>>>>>>> put.add(family, Bytes.toBytes("advanceKWh"), Bytes.toBytes(l *
> > >>>>>>>>> advanceKWh));
> > >>>>>>>>> when we create the table.
> > >>>>>>>>>
> > >>>>>>>>> Do you think my hypothesis is correct? Did we build our table
> > >>>>>>> incorrectly
> > >>>>>>>>> for reading longs from it?
> > >>>>>>>>>
> > >>>>>>>>> PART 2
> > >>>>>>>>> =====
> > >>>>>>>>> Anyway we will obviously need to make our own interpreters. but
> > we
> > >>>>>>> failed
> > >>>>>>>>> at
> > >>>>>>>>> this task so far:
> > >>>>>>>>> In order to implement our own ColumnInterpretter, we first
> > attempted
> > >>>>>>> simply
> > >>>>>>>>> extending the LongColumnInterpreter and passing that as a
> > parameter
> > >>> to
> > >>>>>>>>> aClient.sum().
> > >>>>>>>>> import
> > >>>>> org.apache.hadoop.hbase.client.coprocessor.LongColumnInterpreter;
> > >>>>>>>>>
> > >>>>>>>>> public class LCI extends LongColumnInterpreter {
> > >>>>>>>>> public Long add(Long a, Long b) {
> > >>>>>>>>> System.out.print("LCI.add("+a+","+b+")");
> > >>>>>>>>> Long c = super.add(a,b);
> > >>>>>>>>> System.out.println(" -> "+c);
> > >>>>>>>>> return c;
> > >>>>>>>>> }
> > >>>>>>>>> };
> > >>>>>>>>> ....
> > >>>>>>>>> final ColumnInterpreter<Long, Long> ci = new LCI();
> > >>>>>>>>> long sum=-1;
> > >>>>>>>>> try {
> > >>>>>>>>> sum = aClient.sum(EDRP_TABLE, ci, scan);
> > >>>>>>>>> ...
> > >>>>>>>>> However, we received class not found errors in our regionserver
> > log
> > >>>>>>> when we
> > >>>>>>>>> ran this code
> > >>>>>>>>> Clearly we are missing something
> > >>>>>>>>> We've started looking at modifying the HBase source and
> > rebuilding
> > >>>>> that
> > >>>>>>>>> But I think this is not the way we should be working
> > >>>>>>>>> It seems that we should be implementing the ColumnInterpreter
> > >>>>> interface
> > >>>>>>> and
> > >>>>>>>>> passing an instance of that implementation class too as a
> > parameter.
> > >>>>> Is
> > >>>>>>>>> this correct? Could you provide us with an example? Any ideas
> > why
> > >>> we
> > >>>>>>>>> might
> > >>>>>>>>> be getting class not found exception from the regionserver?
> > >>>>>>>>>
> > >>>>>>>>> Sorry for the long message!
> > >>>>>>>>>
> > >>>>>>>>> Royston (and Tom)
> > >>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>>> -----Original Message-----
> > >>>>>>>>> From: Ted Yu [mailto:yuzhihong@gmail.com]
> > >>>>>>>>> Sent: 03 January 2012 18:00
> > >>>>>>>>> To: user@hbase.apache.org
> > >>>>>>>>> Subject: Re: AggregateProtocol Help
> > >>>>>>>>>
> > >>>>>>>>> My previous email might not be hitting the root cause.
> > >>>>>>>>> I think the following method in LCI may be giving you the null:
> > >>>>>>>>>
> > >>>>>>>>> public Long getValue(byte[] colFamily, byte[] colQualifier,
> > KeyValue
> > >>>>> kv)
> > >>>>>>>>> throws IOException {
> > >>>>>>>>> if (kv == null || kv.getValueLength() != Bytes.SIZEOF_LONG)
> > >>>>>>>>> return null;
> > >>>>>>>>> return Bytes.toLong(kv.getBuffer(), kv.getValueOffset());
> > >>>>>>>>>
> > >>>>>>>>> Look at the if statement above carefully.
> > >>>>>>>>> If it doesn't match how you store values in HBase, feel free to
> > >>>>> subclass
> > >>>>>>>>> LongColumnInterpreter and provide the correct interpretation.
> > >>>>>>>>>
> > >>>>>>>>> BTW you don't need to restart cluster just because you need to
> > use
> > >>>>> your
> > >>>>>>> own
> > >>>>>>>>> interpreter :-)
> > >>>>>>>>>
> > >>>>>>>>> On Tue, Jan 3, 2012 at 9:48 AM, Royston Sellman <
> > >>>>>>>>> royston.sellman@googlemail.com> wrote:
> > >>>>>>>>>
> > >>>>>>>>>> Hi Ted,
> > >>>>>>>>>>
> > >>>>>>>>>> Here is the output. As you can see aClient is not nul:
> > >>>>>>>>>>
> > >>>>>>>>>> AggregationClient aClient = new AggregationClient(conf);
> > >>>>>>>>>> System.err.println("aClient: "+aClient);
> > >>>>>>>>>>
> > >>>>>>>>>> <<< aClient:
> > >>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.coprocessor.AggregationClient@28787c16
> > >>>>>>>>>>
> > >>>>>>>>>> It will take us a little while to add log code to LCI... we
> > have to
> > >>>>>>>>>> edit the source, rebuild 0.92, redistribute round our cluster,
> > >>>>> restart
> > >>>>>>>>>> ;) We'll get back to you when this is done.
> > >>>>>>>>>>
> > >>>>>>>>>> Royston
> > >>>>>>>>>>
> > >>>>>>>>>> -----Original Message-----
> > >>>>>>>>>> From: Ted Yu [mailto:yuzhihong@gmail.com]
> > >>>>>>>>>> Sent: 03 January 2012 17:10
> > >>>>>>>>>> To: user@hbase.apache.org
> > >>>>>>>>>> Subject: Re: AggregateProtocol Help
> > >>>>>>>>>>
> > >>>>>>>>>> Royston:
> > >>>>>>>>>> Thanks for your effort trying to hunt down the problem.
> > >>>>>>>>>>
> > >>>>>>>>>> Can you add a log after this line to see if aClient is null ?
> > >>>>>>>>>> AggregationClient aClient = new
> > AggregationClient(conf);
> > >>>>>>>>>>
> > >>>>>>>>>> I was looking at LongColumnInterpreter.add() which is called
> by
> > >>>>>>>>>> aClient.sum()
> > >>>>>>>>>> Can you add a few log statements in
> LongColumnInterpreter.add()
> > to
> > >>>>> see
> > >>>>>>>>>> what parameters are passed to it ?
> > >>>>>>>>>>
> > >>>>>>>>>> Cheers
> > >>>>>>>>>>
> > >>>>>>>>>> On Tue, Jan 3, 2012 at 8:32 AM, Royston Sellman <
> > >>>>>>>>>> royston.sellman@googlemail.com> wrote:
> > >>>>>>>>>>
> > >>>>>>>>>>> Hi Ted, Himanshu, Gary,
> > >>>>>>>>>>>
> > >>>>>>>>>>> Thanks again for your attention. I experimented with a
> shorter
> > >>> table
> > >>>>>>>>>>> and it looks like the timeout error was spurious...
> > >>>>>>>>>>>
> > >>>>>>>>>>> With the shorter table I now get an NPE when I call
> > >>>>>>>>>>> AggregationClient.sum().
> > >>>>>>>>>>> Here's the code snippet:
> > >>>>>>>>>>>
> > >>>>>>>>>>> // Test the table
> > >>>>>>>>>>> HTable table = new HTable(EDRP_TABLE);
> > >>>>>>>>>>> Get get = new Get(Bytes.toBytes("row-aa"));
> > >>>>>>>>>>> get.addColumn(Bytes.toBytes("EDRP"),
> > >>>>>>>>>>> Bytes.toBytes("advanceKWh"));
> > >>>>>>>>>>> Result result = table.get(get);
> > >>>>>>>>>>> byte [] val =
> result.getValue(Bytes.toBytes("EDRP"),
> > >>>>>>>>>>> Bytes.toBytes("advanceKWh"));
> > >>>>>>>>>>> System.out.println("Row aa = " +
> > >>>>>>>>>>> Bytes.toString(val));
> > >>>>>>>>>>>
> > >>>>>>>>>>> AggregationClient aClient = new
> > >>>>> AggregationClient(conf);
> > >>>>>>>>>>> Scan scan = new Scan();
> > >>>>>>>>>>> scan.addColumn(EDRP_FAMILY, EDRP_QUALIFIER);
> > >>>>>>>>>>> scan.setStartRow(Bytes.toBytes("row-ab"));
> > >>>>>>>>>>> scan.setStopRow(Bytes.toBytes("row-az"));
> > >>>>>>>>>>> System.out.println(Bytes.toString(EDRP_FAMILY) +
> ":"
> > >>>>>>>>>>> + Bytes.toString(EDRP_QUALIFIER));
> > >>>>>>>>>>> final ColumnInterpreter<Long, Long> ci = new
> > >>>>>>>>>>> LongColumnInterpreter();
> > >>>>>>>>>>> long sum=-1;
> > >>>>>>>>>>> try {
> > >>>>>>>>>>> sum = aClient.sum(EDRP_TABLE, ci, scan);
> > >>>>>>>>>>> } catch (Throwable e) {
> > >>>>>>>>>>> // TODO Auto-generated catch block
> > >>>>>>>>>>> e.printStackTrace();
> > >>>>>>>>>>> }
> > >>>>>>>>>>> System.out.println(sum);
> > >>>>>>>>>>>
> > >>>>>>>>>>> The first part is just to check that my table is OK. It
> prints
> > the
> > >>>>>>>>>>> correct value for row aa. Then I check CF:CQ is correct. Then
> I
> > >>> get
> > >>>>>>>>>>> the -1 that sum was defined as. Then the NPE. Here is the run
> > >>>>> output:
> > >>>>>>>>>>>
> > >>>>>>>>>>> Row aa = 3.0
> > >>>>>>>>>>> EDRP:advanceKWh
> > >>>>>>>>>>> -1
> > >>>>>>>>>>> java.lang.NullPointerException
> > >>>>>>>>>>> at
> EDRPAggregator.testSumWithValidRange(EDRPAggregator.java:66)
> > >>>>>>>>>>> at EDRPAggregator.main(EDRPAggregator.java:96)
> > >>>>>>>>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
> Method)
> > at
> > >>>>>>>>>>>
> > >>>>>>>>>>>
> > >>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl
> > >>>>>>>>>>> .j
> > >>>>>>>>>>> ava:39
> > >>>>>>>>>>> )
> > >>>>>>>>>>> at
> > >>>>>>>>>>>
> > >>>>>>>>>>>
> > >>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcce
> > >>>>>>>>>>> ss
> > >>>>>>>>>>> orImpl
> > >>>>>>>>>>> .java:25)
> > >>>>>>>>>>> at java.lang.reflect.Method.invoke(Method.java:597)
> > >>>>>>>>>>> at org.apache.hadoop.util.RunJar.main(RunJar.java:156)
> > >>>>>>>>>>>
> > >>>>>>>>>>> Line 66 is the line:
> > >>>>>>>>>>> sum = aClient.sum(EDRP_TABLE, ci, scan);
> > >>>>>>>>>>>
> > >>>>>>>>>>> But I'm not sure that is really the line generating the NPE
> > >>> because
> > >>>>>>>>>>> I get the -1 output (same result when line 66 is not wrapped
> in
> > >>>>>>>>>>> try-catch
> > >>>>>>>>>> BTW).
> > >>>>>>>>>>> Anyway, -1 is clearly not the correct value for the sum.
> > >>>>>>>>>>>
> > >>>>>>>>>>> [Note: I'm setting a start and end row on the scan because I
> > saw a
> > >>>>>>>>>>> comment in AggregationClient.java saying they must be set.
> > >>> However,
> > >>>>>>>>>>> I think this comment is obsolete as the test code in
> > >>>>>>>>>>> TestAggregateProtocol.java sometimes does not include start &
> > end
> > >>>>>>>>>>> rows. The run is exactly the same without the start & stop
> > rows ]
> > >>>>>>>>>>>
> > >>>>>>>>>>> We are struggling with Aggregations not least because
> > >>>>>>>>>>> TestAggregateProtocol.java is the only source of example code
> > we
> > >>>>>>>>>>> could find and it is not ideal because it is designed to work
> > with
> > >>>>>>>>>>> MiniCluster rather than a real cluster like ours. Is there
> any
> > >>> other
> > >>>>>>>>>>> example code in existence?
> > >>>>>>>>>>> I think that would really help us.
> > >>>>>>>>>>>
> > >>>>>>>>>>> Meanwhile, thanks for your patience with our questions. We
> are
> > >>>>>>>>>>> really impressed with the AggregationProtocol
> > >>>>>>>>>>> architecture/functionality and very keen to use it.
> > >>>>>>>>>>>
> > >>>>>>>>>>> Royston (and Tom)
> > >>>>>>>>>>>
> > >>>>>>>>>>> -----Original Message-----
> > >>>>>>>>>>> From: Gary Helmling [mailto:ghelmling@gmail.com]
> > >>>>>>>>>>> Sent: 02 January 2012 06:23
> > >>>>>>>>>>> To: user@hbase.apache.org
> > >>>>>>>>>>> Subject: Re: AggregateProtocol Help
> > >>>>>>>>>>>
> > >>>>>>>>>>> Hi Royston,
> > >>>>>>>>>>>
> > >>>>>>>>>>> Try increasing the value set for hbase.rpc.timeout (by
> default
> > 60
> > >>>>>>>>>> seconds).
> > >>>>>>>>>>> Add something like this to hbase-site.xml:
> > >>>>>>>>>>>
> > >>>>>>>>>>> <property>
> > >>>>>>>>>>> <name>hbase.rpc.timeout</name>
> > >>>>>>>>>>> <value>180000</value>
> > >>>>>>>>>>> </property>
> > >>>>>>>>>>>
> > >>>>>>>>>>> This would increase the timeout value to 3 minutes, for
> > example.
> > >>>>>>>>>>>
> > >>>>>>>>>>> But as Ted and Himanshu mention, 557k rows is not a large
> table
> > >>> and
> > >>>>>>>>>>> should not be taking very long to process, unless these
> happen
> > to
> > >>> be
> > >>>>>>>>>>> very, very wide rows. It sounds like there could be
> something
> > >>> else
> > >>>>>>>>>>> going on. Does debug level logging show anything else in the
> > >>> region
> > >>>>>>>>>> server log?
> > >>>>>>>>>>>
> > >>>>>>>>>>> --gh
> > >>>>>>>>>>>
> > >>>>>>>>>>> On Sun, Jan 1, 2012 at 5:53 PM, Ted Yu <yu...@gmail.com>
> > >>> wrote:
> > >>>>>>>>>>>> Thanks for the reminder Himanshu.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> Royston:
> > >>>>>>>>>>>> From this blog you can get some history on this subject:
> > >>>>>>>>>>>>
> > >>> http://zhihongyu.blogspot.com/2011/03/genericizing-endpointcoproce
> > >>>>>>>>>>>> ss
> > >>>>>>>>>>>> or
> > >>>>>>>>>>>> .html
> > >>>>>>>>>>>>
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> On Sun, Jan 1, 2012 at 5:18 PM, Himanshu Vashishtha
> > >>>>>>>>>>>> <hvashish@cs.ualberta.ca
> > >>>>>>>>>>>>> wrote:
> > >>>>>>>>>>>>
> > >>>>>>>>>>>>> Hello Royston,
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> Sorry to hear that you are getting trouble while using
> > >>>>>>>>>>>>> Aggregation functionalities.
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> 557k rows seems to be a small table and a SocketTimeout
> does
> > not
> > >>>>>>>>>>>>> seem to be an ok response.
> > >>>>>>>>>>>>> It will be good to know the region distribution as such.
> (how
> > >>>>>>>>>>>>> many
> > >>>>>>>>>>> regions?
> > >>>>>>>>>>>>> Is it a full table scan?)
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> You are using the sum function; how are you using the
> > >>>>>>>>>> ColumnInterpreter.
> > >>>>>>>>>>>>> Can you enable the log level to debug to see why the RS is
> > >>> taking
> > >>>>>>>>>>>>> that long to respond (more than 113 sec).
> > >>>>>>>>>>>>> The 0 return value is the default result.
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> Thanks for trying this out.
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> Thanks,
> > >>>>>>>>>>>>> Himanshu
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> On Sun, Jan 1, 2012 at 12:26 PM, Royston Sellman <
> > >>>>>>>>>>>>> royston.sellman@googlemail.com> wrote:
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>>> Hi Ted,
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>> I think 0 is the only value we ever see (I'll check
> > tomorrow:
> > >>>>>>>>>>>>>> the server is down right now). Our table has 557,000 rows.
> > I'll
> > >>>>>>>>>>>>>> try a much shorter table tomorrow.
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>> Yes, we have RS running on the NN, but it's a test cluster
> > and
> > >>>>>>>>>>>>>> we are
> > >>>>>>>>>>>>> used
> > >>>>>>>>>>>>>> to it :)
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>> Do you think using AggregationProtocol is the best
> strategy
> > for
> > >>>>>>>>>>>>>> the case where we want to use basic SQL-style functions
> like
> > >>>>>>>>>>>>>> SUM, AVG, STD, MIN, MAX? Do you think there is a better
> > >>> strategy?
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>> Many thanks,
> > >>>>>>>>>>>>>> Royston
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>> On 1 Jan 2012, at 17:58, Ted Yu wrote:
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>> Royston:
> > >>>>>>>>>>>>>>> Happy New Year to you too.
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>> java.net.SocketTimeoutException: Call to
> > >>>>>>>>>>>>>>>>> namenode/10.0.0.235:60020
> > >>>>>>>>>>>>> failed
> > >>>>>>>>>>>>>> on
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>> It seems the namenode above actually refers to a region
> > >>> server.
> > >>>>>>>>>>>>>>> This
> > >>>>>>>>>>>>> is a
> > >>>>>>>>>>>>>>> little bit confusing :-)
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>> The sum value below is 0.
> > >>>>>>>>>>>>>>> Have you ever seen a value greater than 0 ?
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>> How many rows are there in this CF:CQ ?
> > >>>>>>>>>>>>>>> The timeout was reported earlier by other people where
> > >>>>>>>>>>>>>>> there're many
> > >>>>>>>>>>>>> rows
> > >>>>>>>>>>>>>>> in the table.
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>> There is a JIRA to provide streaming support for
> > coprocessor
> > >>>>>>>>>>>>>>> but the development there has stalled.
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>> Cheers
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>> On Sun, Jan 1, 2012 at 9:35 AM, Royston Sellman <
> > >>>>>>>>>>>>>>> royston.sellman@googlemail.com> wrote:
> > >>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Hi Gary and Ted,
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Royston (Tom's colleague) here. Back onto this after the
> > >>>>>>>>>>>>>>>> Christmas/New
> > >>>>>>>>>>>>>> Year
> > >>>>>>>>>>>>>>>> break.
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Many thanks for your help so far. We enabled our
> database
> > >>>>>>>>>>>>>>>> via your hbase-site.xml mod and were able to move on. to
> > >>>>>>>>>>>>>>>> other errors. But I
> > >>>>>>>>>>>>>> think
> > >>>>>>>>>>>>>>>> we
> > >>>>>>>>>>>>>>>> are now actually getting an aggregation partially
> > calculated
> > >>>>>>>>>>>>>>>> on our
> > >>>>>>>>>>>>>> table
> > >>>>>>>>>>>>>>>> (this feels like progress). The details:
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> On running our client we now get this exception:
> > >>>>>>>>>>>>>>>> 11/12/31 17:51:09 WARN
> > >>>>>>>>>>>>>>>> client.HConnectionManager$HConnectionImplementation:
> Error
> > >>>>>>>>>>>>>>>> executing
> > >>>>>>>>>>>>> for
> > >>>>>>>>>>>>>>>> row
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> java.util.concurrent.ExecutionException:
> > >>>>>>>>>>>>>>>>
> org.apache.hadoop.hbase.client.RetriesExhaustedException:
> > >>>>>>>>>>>>>>>> Failed after attempts=10, exceptions:
> > >>>>>>>>>>>>>>>> Sat Dec 31 17:41:30 GMT 2011,
> > >>>>>>>>>>>>>>>> org.apache.hadoop.hbase.ipc.ExecRPCInvoker$1@1fc4f0f8,
> > >>>>>>>>>>>>>>>> java.net.SocketTimeoutException: Call to
> > >>>>>>>>>>>>>>>> namenode/10.0.0.235:60020
> > >>>>>>>>>>>>> failed
> > >>>>>>>>>>>>>>>> on
> > >>>>>>>>>>>>>>>> socket timeout exception:
> java.net.SocketTimeoutException:
> > >>>>>>>>>>>>>>>> 60000
> > >>>>>>>>>>>>> millis
> > >>>>>>>>>>>>>>>> timeout while waiting for channel to be ready for read.
> > ch :
> > >>>>>>>>>>>>>>>> java.nio.channels.SocketChannel[connected
> > >>>>>>>>>>>>>>>> local=/10.0.0.235:59999 remote=namenode/
> 10.0.0.235:60020]
> > >>>>>>>>>>>>>>>> (8 more of these, making for 10 tries) Sat Dec 31
> 17:51:09
> > >>>>>>>>>>>>>>>> GMT 2011,
> > >>>>>>>>>>>>>>>> org.apache.hadoop.hbase.ipc.ExecRPCInvoker$1@1fc4f0f8,
> > >>>>>>>>>>>>>>>> java.net.SocketTimeoutException: Call to
> > >>>>>>>>>>>>>>>> namenode/10.0.0.235:60020
> > >>>>>>>>>>>>> failed
> > >>>>>>>>>>>>>>>> on
> > >>>>>>>>>>>>>>>> socket timeout exception:
> java.net.SocketTimeoutException:
> > >>>>>>>>>>>>>>>> 60000
> > >>>>>>>>>>>>> millis
> > >>>>>>>>>>>>>>>> timeout while waiting for channel to be ready for read.
> > ch :
> > >>>>>>>>>>>>>>>> java.nio.channels.SocketChannel[connected
> > >>>>>>>>>>>>>>>> local=/10.0.0.235:59364 remote=namenode/
> 10.0.0.235:60020]
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>> java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.java:
> > >>>>>>>>>>>>>>>> 22
> > >>>>>>>>>>>>>>>> 2)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>> java.util.concurrent.FutureTask.get(FutureTask.java:83)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>>>>>>
> > >>>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>
> > >>>>>
> > >>>
> >
>
> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImplementation.
> > >>>>>>>>>>>>>>>> processExecs(HConnectionManager.java:1465)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.HTable.coprocessorExec(HTable.java
> > >>>>>>>>>>>>> :1
> > >>>>>>>>>>>>> 55
> > >>>>>>>>>>>>> 5)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.coprocessor.AggregationClient.sum(
> > >>>>>>>>>>>>> Ag
> > >>>>>>>>>>>>> gr
> > >>>>>>>>>>>>> egation
> > >>>>>>>>>>>>>>>> Client.java:229)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > EDRPAggregator.testSumWithValidRange(EDRPAggregator.java:51)
> > >>>>>>>>>>>>>>>> at EDRPAggregator.main(EDRPAggregator.java:77)
> > >>>>>>>>>>>>>>>> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
> > >>>>>>>>>>>>>>>> Method)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
> > >>>>>>>>>>>>> java:39
> > >>>>>>>>>>>>>>>> )
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodA
> > >>>>>>>>>>>>> cc
> > >>>>>>>>>>>>> es
> > >>>>>>>>>>>>> sorImpl
> > >>>>>>>>>>>>>>>> .java:25)
> > >>>>>>>>>>>>>>>> at java.lang.reflect.Method.invoke(Method.java:597)
> > >>>>>>>>>>>>>>>> at org.apache.hadoop.util.RunJar.main(RunJar.java:156)
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Looking at the log (.regionserver-namenode.log) I see
> this
> > >>>>>>>>>>>>>>>> debug
> > >>>>>>>>>>>>>> message:
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> 2011-12-31 17:42:23,472 DEBUG
> > >>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.coprocessor.AggregateImplementation:
> > >>>>>>>>>>>>>>>> Sum from
> > >>>>>>>>>>>>>> this
> > >>>>>>>>>>>>>>>> region is
> > >>>>>>>>>>>>>
> EDRPTestTbl,,1324485124322.7b9ee0d113db9b24ea9fdde90702d006.:
> > >>>>>>>>>>>>>> 0
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Where the sum value looks reasonable which makes me
> think
> > >>>>>>>>>>>>>>>> the sum of a CF:CQ worked. But I never see this value on
> > >>>>>>>>> stdout.
> > >>>>>>>>>>>>>>>> Then I see this warning:
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> 2011-12-31 17:42:23,476 WARN
> > >>> org.apache.hadoop.ipc.HBaseServer:
> > >>>>>>>>>>>>>>>> (responseTooSlow):
> > >>>>>>>>>>>>>>>> {"processingtimems":113146,"call":"execCoprocess$
> > >>>>>>>>>>>>>>>> 2011-12-31 17:42:23,511 WARN
> > >>> org.apache.hadoop.ipc.HBaseServer:
> > >>>>>>>>>>>>>>>> IPC
> > >>>>>>>>>>>>>> Server
> > >>>>>>>>>>>>>>>> Responder, call execCoprocessor([B@4b22fad6,
> getSum(org.$
> > >>>>>>>>>>>>>>>> 2011-12-31 17:42:23,515 WARN
> > >>> org.apache.hadoop.ipc.HBaseServer:
> > >>>>>>>>>>>>>>>> IPC
> > >>>>>>>>>>>>>> Server
> > >>>>>>>>>>>>>>>> handler 1 on 60020 caught:
> java.nio.channels.ClosedChann$
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.nio.ch.SocketChannelImpl.ensureWriteOpen(SocketChannelImpl.ja
> > >>>>>>>>>>>>> va
> > >>>>>>>>>>>>> :1
> > >>>>>>>>>>>>> 33)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>
> > sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:324)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.HBaseServer.channelWrite(HBaseServer.
> > >>>>>>>>>>>>> ja
> > >>>>>>>>>>>>> va
> > >>>>>>>>>>>>> :1651)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.HBaseServer$Responder.processResponse
> > >>>>>>>>>>>>> (H
> > >>>>>>>>>>>>> Ba
> > >>>>>>>>>>>>> seServe
> > >>>>>>>>>>>>>>>> r.java:924)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.HBaseServer$Responder.doRespond(HBase
> > >>>>>>>>>>>>> Se
> > >>>>>>>>>>>>> rv
> > >>>>>>>>>>>>> er.java
> > >>>>>>>>>>>>>>>> :1003)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.HBaseServer$Call.sendResponseIfReady(
> > >>>>>>>>>>>>> HB
> > >>>>>>>>>>>>> as
> > >>>>>>>>>>>>> eServer
> > >>>>>>>>>>>>>>>> .java:409)
> > >>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:
> > >>>>>>>>>>>>> 1345)
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Have we missed out some step in the
> > HBase/RegionServerconfig?
> > >>>>>>>>>>>>>>>> Or is
> > >>>>>>>>>>>>> our
> > >>>>>>>>>>>>>>>> client code still deficient?
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Can you offer any suggestions? Is there any example code
> > for
> > >>>>>>>>>>>>>>>> the new Aggregations stuff.
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Thanks and Happy New Year to you guys,
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Royston (and Tom).
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> (HBase 0.92, Hadoop 1.0)
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> -----Original Message-----
> > >>>>>>>>>>>>>>>> From: Gary Helmling [mailto:ghelmling@gmail.com]
> > >>>>>>>>>>>>>>>> Sent: 23 December 2011 18:06
> > >>>>>>>>>>>>>>>> To: user@hbase.apache.org
> > >>>>>>>>>>>>>>>> Subject: Re: AggregateProtocol Help
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Hi Tom,
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> The test code is not really the best guide for
> > configuration.
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> To enable the AggregateProtocol on all of your tables,
> add
> > >>>>>>>>>>>>>>>> this to the hbase-site.xml for the servers in your
> > cluster:
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> <property>
> > >>>>>>>>>>>>>>>> <name>hbase.coprocessor.user.region.classes</name>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> <value>org.apache.hadoop.hbase.coprocessor.AggregateImplementatio
> > >>>>>>>>>>>>> n<
> > >>>>>>>>>>>>> /v
> > >>>>>>>>>>>>> alue>
> > >>>>>>>>>>>>>>>> </property>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> If you only want to use the aggregate functions on a
> > >>>>>>>>>>>>>>>> specific table
> > >>>>>>>>>>>>> (or
> > >>>>>>>>>>>>>>>> tables), then you can enable that individually for the
> > table
> > >>>>>>>>>>>>>>>> from the
> > >>>>>>>>>>>>>>>> shell:
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> 1) disable the table
> > >>>>>>>>>>>>>>>> hbase> disable 'EDRP7'
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> 2) add the coprocessor
> > >>>>>>>>>>>>>>>> hbase> alter 'EDRP7', METHOD => 'table_att',
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> 'coprocessor'=>'|org.apache.hadoop.hbase.coprocessor.AggregateImp
> > >>>>>>>>>>>>> le
> > >>>>>>>>>>>>> me
> > >>>>>>>>>>>>> ntation
> > >>>>>>>>>>>>>>>> ||'
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> (Note that the pipes in the value string are required)
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> 3) re-enable the table
> > >>>>>>>>>>>>>>>> hbase> enable 'EDRP7'
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> Either way should work. With the second approach you
> will
> > >>>>>>>>>>>>>>>> see the coprocessor listed when you describe the table
> > from
> > >>>>>>>>>>>>>>>> the shell, as Ted mentioned. With the first approach
> you
> > >>>>>>>>>>>>>>>> will not, but it should be
> > >>>>>>>>>>>>>> loaded
> > >>>>>>>>>>>>>>>> all the same.
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> --gh
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>> On Fri, Dec 23, 2011 at 7:04 AM, Ted Yu
> > >>>>>>>>>>>>>>>> <yu...@gmail.com>
> > >>>>>>>>>>> wrote:
> > >>>>>>>>>>>>>>>>> I don't know why you chose HBaseTestingUtility to
> create
> > >>>>>>>>>>>>>>>>> the
> > >>>>>>>>>>> table.
> > >>>>>>>>>>>>>>>>> I guess you followed test code example.
> > >>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>> At least you should pass the conf to this ctor:
> > >>>>>>>>>>>>>>>>> public HBaseTestingUtility(Configuration conf) {
> > >>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>> If coprocessor was installed correctly, you should see
> > >>>>>>>>>>>>>>>>> something like(from
> > >>>>>>>>>>>>>>>>> HBASE-5070):
> > >>>>>>>>>>>>>>>>> coprocessor$1 =>
> > >>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>
> '|org.apache.hadoop.hbase.constraint.ConstraintProcessor|1073741823|'
> > >>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>> Cheers
> > >>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>> On Fri, Dec 23, 2011 at 3:02 AM, Tom Wilcox
> > >>>>>>>>>>>>>>>>> <To...@cse.org.uk>
> > >>>>>>>>>>>>>>>> wrote:
> > >>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> Hi,
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> I am not sure how we load the AggregateImplementation
> > into
> > >>>>>>>>>>>>>>>>>> the
> > >>>>>>>>>>>>> table.
> > >>>>>>>>>>>>>>>>>> When we are creating a table, we use the same
> functions
> > as
> > >>>>>>>>>>>>>>>>>> the test
> > >>>>>>>>>>>>> as
> > >>>>>>>>>>>>>>>> follows...
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> ...
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> conf.set(CoprocessorHost.REGION_COPROCESSOR_CONF_KEY,
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>> "org.apache.hadoop.hbase.coprocessor.AggregateImplementation"
> > >>>>>>>>>>>>>>>>>>> );
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> // Utility.CreateHBaseTable(conf,
> > >>>>>>>>>>>>>>>>>>> otherArgs[1],
> > >>>>>>>>>>>>>>>>>> otherArgs[2],
> > >>>>>>>>>>>>>>>>>>> true);
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> HBaseTestingUtility util = new
> > >>>>>>>>>>>>>>>>>>> HBaseTestingUtility();
> > >>>>>>>>>>>>>>>>>>> HTable table = util.createTable(EDRP_TABLE,
> > >>>>>>>>>>>>>>>>>>> EDRP_FAMILY);
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> AggregationClient aClient = new
> > >>>>>>>>>>>>>>>>>>> AggregationClient(conf);
> > >>>>>>>>>>>>>>>>>> ...
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> Running DESCRIBE on a table produced shows the
> following
> > >>>>>>>>>> output:
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> hbase(main):002:0> describe 'EDRP7'
> > >>>>>>>>>>>>>>>>>> DESCRIPTION
> > >>>>>>>>>>>>>>>>>> ENABLED {NAME =>
> > >>>>>>>>>>>>>>>>>> 'EDRP7', FAMILIES => [{NAME => 'advanceKWh',
> BLOOMFILTER
> > >>>>>>>>>>>>>>>>>> => 'NONE', REPLICATION_SCOPE => '0', VERSIONS => true
> > >>>>>>>>>>>>>>>>>> '3', COMPRESSION => 'NONE', MIN_VERSIONS => '0', TTL
> =>
> > >>>>>>>>>>>>>>>>>> '2147483647', BLOCKSIZE => '65536', IN_MEMORY =>
> > 'false',
> > >>>>>>>>>>>>>>>>>> B LOCKCACHE => 'true'}]}
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> We are using the tip of 0.92 (cloned from the Git
> repo).
> > >>>>>>>>>>>>>>>>>> See the version string below:
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> hbase(main):005:0> version 0.92.0, r1208286, Thu Dec
> 15
> > >>>>>>>>>>>>>>>>>> 13:16:03 GMT 2011
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> We would really appreciate an example of how to create
> a
> > >>>>>>>>>>>>>>>>>> table that is enabled to handle Aggregation).
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> Thanks
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> ________________________________________
> > >>>>>>>>>>>>>>>>>> From: Ted Yu [yuzhihong@gmail.com]
> > >>>>>>>>>>>>>>>>>> Sent: 22 December 2011 17:03
> > >>>>>>>>>>>>>>>>>> To: user@hbase.apache.org
> > >>>>>>>>>>>>>>>>>> Subject: Re: AggregateProtocol Help
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> Have you loaded AggregateImplementation into your
> table
> > ?
> > >>>>>>>>>>>>>>>>>> Can you show us the contents of the following command
> in
> > >>>>>>>>>>>>>>>>>> hbase
> > >>>>>>>>>>>>> shell:
> > >>>>>>>>>>>>>>>>>> describe 'your-table'
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> BTW are you using the tip of 0.92 ?
> > >>>>>>>>>>>>>>>>>> HBASE-4946 would be of help for dynamically loaded
> > >>>>>>>>>>>>>>>>>> coprocessors
> > >>>>>>>>>>>>> which
> > >>>>>>>>>>>>>>>>>> you might use in the future.
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> Cheers
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>> On Thu, Dec 22, 2011 at 8:09 AM, Tom Wilcox
> > >>>>>>>>>>>>>>>>>> <To...@cse.org.uk>
> > >>>>>>>>>>>>>>>> wrote:
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> Hi,
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> We are trying to use the aggregation functionality in
> > >>>>>>>>>>>>>>>>>>> HBase
> > >>>>>>>>>>>>>>>>>>> 0.92 and we have managed to get the test code working
> > >>>>>>>>>>>>>>>>>>> using the
> > >>>>>>>>>>>>> following
> > >>>>>>>>>>>>>>>> command:
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> java -classpath junit-4.10.jar:build/*:$HBASELIBS/*
> > >>>>>>>>>>>>>>>>>>> org.junit.runner.JUnitCore
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.coprocessor.TestAggregateProtocol
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> Closer inspection of this test class has revealed
> that
> > it
> > >>>>>>>>>>>>>>>>>>> uses a mini DFS cluster to populate and run the
> tests.
> > >>>>>>>>>>>>>>>>>>> These tests return
> > >>>>>>>>>>>>>>>> successfully.
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> However, when we attempt to run similar code on our
> > >>>>>>>>>>>>>>>>>>> development HDFS cluster we experience the following
> > >>> error:
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> 11/12/22 15:46:28 WARN
> > >>>>>>>>>>>>>>>>>>> client.HConnectionManager$HConnectionImplementation:
> > >>>>>>>>>>>>>>>>>>> Error executing for
> > >>>>>>>>>>>>>>>>>> row
> > >>>>>>>>>>>>>>>>>>> java.util.concurrent.ExecutionException:
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>> org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException:
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolExcep
> > >>>>>>>>>>>>>>>>>>> ti
> > >>>>>>>>>>>>>>>>>>> on
> > >>>>>>>>>>>>>>>>>>> : No
> > >>>>>>>>>>>>>>>>>> matching
> > >>>>>>>>>>>>>>>>>>> handler for protocol
> > >>>>>>>>>>>>>>>>>> org.apache.hadoop.hbase.coprocessor.AggregateProtocol
> > >>>>>>>>>>>>>>>>>>> in region
> > >>>>>>>>>>>>>>
> EDRPTestTbl,,1324485124322.7b9ee0d113db9b24ea9fdde90702d006.
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.regionserver.HRegion.exec(HRegion
> > >>>>>>>>>>>>>>>>>>> .j
> > >>>>>>>>>>>>>>>>>>> av
> > >>>>>>>>>>>>>>>>>>> a:4010
> > >>>>>>>>>>>>>>>>>>> )
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.regionserver.HRegionServer.execCoprocesso
> > >>>>>>>>>>>>> r(
> > >>>>>>>>>>>>> HR
> > >>>>>>>>>>>>>>>>>> egionServer.java:3040)
> > >>>>>>>>>>>>>>>>>>> at
> sun.reflect.NativeMethodAccessorImpl.invoke0(Native
> > >>>>>>>>>>>>>>>>>> Method)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
> > >>>>>>>>>>>>>>>>>> java:39)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodA
> > >>>>>>>>>>>>> cc
> > >>>>>>>>>>>>> es
> > >>>>>>>>>>>>>>>>>> sorImpl.java:25)
> > >>>>>>>>>>>>>>>>>>> at java.lang.reflect.Method.invoke(Method.java:597)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.WritableRpcEngine$Server.call(Writabl
> > >>>>>>>>>>>>> eR
> > >>>>>>>>>>>>> pc
> > >>>>>>>>>>>>>>>>>> Engine.java:364)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:
> > >>>>>>>>>>>>>>>>>> 1325)
> > >>>>>>>>>>>>>>>>>>> [sshexec]
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > java.util.concurrent.FutureTask$Sync.innerGet(FutureTask.
> > >>>>>>>>>>>>>>>>>>> ja
> > >>>>>>>>>>>>>>>>>>> va
> > >>>>>>>>>>>>>>>>>>> :222)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> java.util.concurrent.FutureTask.get(FutureTask.java:83)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImpl
> > >>>>>>>>>>>>> em
> > >>>>>>>>>>>>> en
> > >>>>>>>>>>>>>>>>>> tation.processExecs(HConnectionManager.java:1465)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>> org.apache.hadoop.hbase.client.HTable.coprocessorExec(HTable.
> > >>>>>>>>>>>>>>>>>>> java:1
> > >>>>>>>>>>>>>>>>>>> 555)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.coprocessor.AggregationClient.sum(
> > >>>>>>>>>>>>> Ag
> > >>>>>>>>>>>>> gr
> > >>>>>>>>>>>>>>>>>> egationClient.java:229)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>> EDRPAggregator.testSumWithValidRange(EDRPAggregator.java:51)
> > >>>>>>>>>>>>>>>>>>> at EDRPAggregator.main(EDRPAggregator.java:77)
> > >>>>>>>>>>>>>>>>>>> at
> sun.reflect.NativeMethodAccessorImpl.invoke0(Native
> > >>>>>>>>>>>>>>>>>> Method)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
> > >>>>>>>>>>>>>>>>>> java:39)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodA
> > >>>>>>>>>>>>> cc
> > >>>>>>>>>>>>> es
> > >>>>>>>>>>>>>>>>>> sorImpl.java:25)
> > >>>>>>>>>>>>>>>>>>> at java.lang.reflect.Method.invoke(Method.java:597)
> > >>>>>>>>>>>>>>>>>>> at
> org.apache.hadoop.util.RunJar.main(RunJar.java:156)
> > >>>>>>>>>>>>>>>>>>> Caused by:
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>> org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException:
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolExcep
> > >>>>>>>>>>>>>>>>>>> ti
> > >>>>>>>>>>>>>>>>>>> on
> > >>>>>>>>>>>>>>>>>>> : No
> > >>>>>>>>>>>>>>>>>> matching
> > >>>>>>>>>>>>>>>>>>> handler for protocol
> > >>>>>>>>>>>>>>>>>> org.apache.hadoop.hbase.coprocessor.AggregateProtocol
> > >>>>>>>>>>>>>>>>>>> in region
> > >>>>>>>>>>>>>>
> EDRPTestTbl,,1324485124322.7b9ee0d113db9b24ea9fdde90702d006.
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.regionserver.HRegion.exec(HRegion
> > >>>>>>>>>>>>>>>>>>> .j
> > >>>>>>>>>>>>>>>>>>> av
> > >>>>>>>>>>>>>>>>>>> a:4010
> > >>>>>>>>>>>>>>>>>>> )
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.regionserver.HRegionServer.execCoprocesso
> > >>>>>>>>>>>>> r(
> > >>>>>>>>>>>>> HR
> > >>>>>>>>>>>>>>>>>> egionServer.java:3040)
> > >>>>>>>>>>>>>>>>>>> at
> sun.reflect.NativeMethodAccessorImpl.invoke0(Native
> > >>>>>>>>>>>>>>>>>> Method)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
> > >>>>>>>>>>>>>>>>>> java:39)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodA
> > >>>>>>>>>>>>> cc
> > >>>>>>>>>>>>> es
> > >>>>>>>>>>>>>>>>>> sorImpl.java:25)
> > >>>>>>>>>>>>>>>>>>> at java.lang.reflect.Method.invoke(Method.java:597)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.WritableRpcEngine$Server.call(Writabl
> > >>>>>>>>>>>>> eR
> > >>>>>>>>>>>>> pc
> > >>>>>>>>>>>>>>>>>> Engine.java:364)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:
> > >>>>>>>>>>>>>>>>>> 1325)
> > >>>>>>>>>>>>>>>>>>> [sshexec]
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > sun.reflect.NativeConstructorAccessorImpl.newInstance0(Na
> > >>>>>>>>>>>>>>>>>>> ti
> > >>>>>>>>>>>>>>>>>>> ve
> > >>>>>>>>>>>>>>>>>>> Method)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConst
> > >>>>>>>>>>>>> ru
> > >>>>>>>>>>>>> ct
> > >>>>>>>>>>>>>>>>>> orAccessorImpl.java:39)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Delegat
> > >>>>>>>>>>>>> in
> > >>>>>>>>>>>>> gC
> > >>>>>>>>>>>>>>>>>> onstructorAccessorImpl.java:27)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>> java.lang.reflect.Constructor.newInstance(Constructor.java:
> > >>>>>>>>>>>>>>>>>>> 51
> > >>>>>>>>>>>>>>>>>>> 3)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.RemoteExceptionHandler.decodeRemoteExcept
> > >>>>>>>>>>>>> io
> > >>>>>>>>>>>>> n(
> > >>>>>>>>>>>>>>>>>> RemoteExceptionHandler.java:96)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImpl
> > >>>>>>>>>>>>> em
> > >>>>>>>>>>>>> en
> > >>>>>>>>>>>>>>>>>>
> tation.translateException(HConnectionManager.java:1651)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImpl
> > >>>>>>>>>>>>> em
> > >>>>>>>>>>>>> en
> > >>>>>>>>>>>>>>>>>>
> > tation.getRegionServerWithRetries(HConnectionManager.java:
> > >>>>>>>>>>>>>>>>>> 13
> > >>>>>>>>>>>>>>>>>> 27
> > >>>>>>>>>>>>>>>>>> )
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.ipc.ExecRPCInvoker.invoke(ExecRPC
> > >>>>>>>>>>>>>>>>>>> In
> > >>>>>>>>>>>>>>>>>>> vo
> > >>>>>>>>>>>>>>>>>>> ker.ja
> > >>>>>>>>>>>>>>>>>>> va:79)
> > >>>>>>>>>>>>>>>>>>> at $Proxy3.getSum(Unknown Source)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> org.apache.hadoop.hbase.client.coprocessor.AggregationClient$
> > >>> 4.ca
> > >>>>>>>>>>>>> ll
> > >>>>>>>>>>>>> (A
> > >>>>>>>>>>>>>>>>>> ggregationClient.java:233)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> org.apache.hadoop.hbase.client.coprocessor.AggregationClient$
> > >>> 4.ca
> > >>>>>>>>>>>>> ll
> > >>>>>>>>>>>>> (A
> > >>>>>>>>>>>>>>>>>> ggregationClient.java:230)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImpl
> > >>>>>>>>>>>>> em
> > >>>>>>>>>>>>> en
> > >>>>>>>>>>>>>>>>>> tation$4.call(HConnectionManager.java:1453)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.
> > >>>>>>>>>>>>>>>>>>> ja
> > >>>>>>>>>>>>>>>>>>> va
> > >>>>>>>>>>>>>>>>>>> :303)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > java.util.concurrent.FutureTask.run(FutureTask.java:138)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPool
> > >>>>>>>>>>>>> Ex
> > >>>>>>>>>>>>> ec
> > >>>>>>>>>>>>>>>>>> utor.java:886)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExec
> > >>>>>>>>>>>>> ut
> > >>>>>>>>>>>>> or
> > >>>>>>>>>>>>>>>>>> .java:908)
> > >>>>>>>>>>>>>>>>>>> at java.lang.Thread.run(Thread.java:662)
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>> org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolException:
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.ipc.HBaseRPC$UnknownProtocolExcep
> > >>>>>>>>>>>>>>>>>>> ti
> > >>>>>>>>>>>>>>>>>>> on
> > >>>>>>>>>>>>>>>>>>> : No
> > >>>>>>>>>>>>>>>>>> matching
> > >>>>>>>>>>>>>>>>>>> handler for protocol
> > >>>>>>>>>>>>>>>>>> org.apache.hadoop.hbase.coprocessor.AggregateProtocol
> > >>>>>>>>>>>>>>>>>>> in region
> > >>>>>>>>>>>>>>
> EDRPTestTbl,,1324485124322.7b9ee0d113db9b24ea9fdde90702d006.
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.regionserver.HRegion.exec(HRegion
> > >>>>>>>>>>>>>>>>>>> .j
> > >>>>>>>>>>>>>>>>>>> av
> > >>>>>>>>>>>>>>>>>>> a:4010
> > >>>>>>>>>>>>>>>>>>> )
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.regionserver.HRegionServer.execCoprocesso
> > >>>>>>>>>>>>> r(
> > >>>>>>>>>>>>> HR
> > >>>>>>>>>>>>>>>>>> egionServer.java:3040)
> > >>>>>>>>>>>>>>>>>>> at
> sun.reflect.NativeMethodAccessorImpl.invoke0(Native
> > >>>>>>>>>>>>>>>>>> Method)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
> > >>>>>>>>>>>>>>>>>> java:39)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodA
> > >>>>>>>>>>>>> cc
> > >>>>>>>>>>>>> es
> > >>>>>>>>>>>>>>>>>> sorImpl.java:25)
> > >>>>>>>>>>>>>>>>>>> at java.lang.reflect.Method.invoke(Method.java:597)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.WritableRpcEngine$Server.call(Writabl
> > >>>>>>>>>>>>> eR
> > >>>>>>>>>>>>> pc
> > >>>>>>>>>>>>>>>>>> Engine.java:364)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>
> > >>> org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:
> > >>>>>>>>>>>>>>>>>> 1325)
> > >>>>>>>>>>>>>>>>>>> [sshexec]
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > sun.reflect.NativeConstructorAccessorImpl.newInstance0(Na
> > >>>>>>>>>>>>>>>>>>> ti
> > >>>>>>>>>>>>>>>>>>> ve
> > >>>>>>>>>>>>>>>>>>> Method)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConst
> > >>>>>>>>>>>>> ru
> > >>>>>>>>>>>>> ct
> > >>>>>>>>>>>>>>>>>> orAccessorImpl.java:39)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Delegat
> > >>>>>>>>>>>>> in
> > >>>>>>>>>>>>> gC
> > >>>>>>>>>>>>>>>>>> onstructorAccessorImpl.java:27)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>> java.lang.reflect.Constructor.newInstance(Constructor.java:
> > >>>>>>>>>>>>>>>>>>> 51
> > >>>>>>>>>>>>>>>>>>> 3)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.RemoteExceptionHandler.decodeRemoteExcept
> > >>>>>>>>>>>>> io
> > >>>>>>>>>>>>> n(
> > >>>>>>>>>>>>>>>>>> RemoteExceptionHandler.java:96)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImpl
> > >>>>>>>>>>>>> em
> > >>>>>>>>>>>>> en
> > >>>>>>>>>>>>>>>>>>
> tation.translateException(HConnectionManager.java:1651)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImpl
> > >>>>>>>>>>>>> em
> > >>>>>>>>>>>>> en
> > >>>>>>>>>>>>>>>>>>
> > tation.getRegionServerWithRetries(HConnectionManager.java:
> > >>>>>>>>>>>>>>>>>> 13
> > >>>>>>>>>>>>>>>>>> 27
> > >>>>>>>>>>>>>>>>>> )
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.ipc.ExecRPCInvoker.invoke(ExecRPC
> > >>>>>>>>>>>>>>>>>>> In
> > >>>>>>>>>>>>>>>>>>> vo
> > >>>>>>>>>>>>>>>>>>> ker.ja
> > >>>>>>>>>>>>>>>>>>> va:79)
> > >>>>>>>>>>>>>>>>>>> at $Proxy3.getSum(Unknown Source)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> org.apache.hadoop.hbase.client.coprocessor.AggregationClient$
> > >>> 4.ca
> > >>>>>>>>>>>>> ll
> > >>>>>>>>>>>>> (A
> > >>>>>>>>>>>>>>>>>> ggregationClient.java:233)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> org.apache.hadoop.hbase.client.coprocessor.AggregationClient$
> > >>> 4.ca
> > >>>>>>>>>>>>> ll
> > >>>>>>>>>>>>> (A
> > >>>>>>>>>>>>>>>>>> ggregationClient.java:230)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> org.apache.hadoop.hbase.client.HConnectionManager$HConnectionImpl
> > >>>>>>>>>>>>> em
> > >>>>>>>>>>>>> en
> > >>>>>>>>>>>>>>>>>> tation$4.call(HConnectionManager.java:1453)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.
> > >>>>>>>>>>>>>>>>>>> ja
> > >>>>>>>>>>>>>>>>>>> va
> > >>>>>>>>>>>>>>>>>>> :303)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > java.util.concurrent.FutureTask.run(FutureTask.java:138)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPool
> > >>>>>>>>>>>>> Ex
> > >>>>>>>>>>>>> ec
> > >>>>>>>>>>>>>>>>>> utor.java:886)
> > >>>>>>>>>>>>>>>>>>> at
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExec
> > >>>>>>>>>>>>> ut
> > >>>>>>>>>>>>> or
> > >>>>>>>>>>>>>>>>>> .java:908)
> > >>>>>>>>>>>>>>>>>>> at java.lang.Thread.run(Thread.java:662)
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> The source for our class is:
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> import static org.junit.Assert.assertEquals;
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> import java.io.IOException;
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.conf.Configuration;
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.hbase.HBaseConfiguration;
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.hbase.HBaseTestingUtility;
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.hbase.HConstants;
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.hbase.HTableDescriptor;
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.hbase.client.HTable;
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.hbase.client.Put;
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.hbase.client.Scan;
> > >>>>>>>>>>>>>>>>>>> import
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.client.coprocessor.AggregationCli
> > >>>>>>>>>>>>>>>>>>> en
> > >>>>>>>>>>>>>>>>>>> t;
> > >>>>>>>>>>>>>>>>>>> import
> > >>>>>>>>>>>>>>>>>>>
> > org.apache.hadoop.hbase.client.coprocessor.LongColumnInte
> > >>>>>>>>>>>>>>>>>>> rp re ter; import org.apache.hadoop.hbase.util.Bytes;
> > >>>>>>>>>>>>>>>>>>> import org.apache.hadoop.util.GenericOptionsParser;
> > >>>>>>>>>>>>>>>>>>> import
> > >>>>>>>>>>>>>>>>>>>
> org.apache.hadoop.hbase.coprocessor.ColumnInterpreter;
> > >>>>>>>>>>>>>>>>>>> import
> > >>>>>>>>>>>>>>>>>>> org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
> > >>>>>>>>>>>>>>>>>>> import org.junit.Test;
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> public class EDRPAggregator {
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> // private static final byte[] EDRP_FAMILY =
> > >>>>>>>>>>>>>>>>>>> Bytes.toBytes("EDRP");
> > >>>>>>>>>>>>>>>>>>> // private static final byte[] EDRP_QUALIFIER =
> > >>>>>>>>>>>>>>>>>>> Bytes.toBytes("advanceKWh");
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> private static byte[] ROW = Bytes.toBytes("testRow");
> > >>>>>>>>>>>>>>>>>>> private static final int ROWSIZE = 20;
> > >>>>>>>>>>>>>>>>>>> private static byte[][] ROWS = makeN(ROW, ROWSIZE);
> > >>>>>>>>>>>>>>>>>>> private static final byte[] TEST_QUALIFIER =
> > >>>>>>>>>>>>>>>>>>> Bytes.toBytes("TestQualifier");
> > >>>>>>>>>>>>>>>>>>> private static final byte[] TEST_MULTI_CQ =
> > >>>>>>>>>>>>>>>>>>> Bytes.toBytes("TestMultiCQ");
> > >>>>>>>>>>>>>>>>>>> private static final int rowSeperator1 = 5;
> > >>>>>>>>>>>>>>>>>>> private static final int rowSeperator2 = 12;
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> public static void
> > >>>>>>>>>>>>>>>>>>> testSumWithValidRange(Configuration
> > >>>>>>>>>>>>>>>>>>> conf,
> > >>>>>>>>>>>>>>>>>>> String[] otherArgs) throws Throwable {
> > >>>>>>>>>>>>>>>>>>> byte[] EDRP_TABLE =
> Bytes.toBytes(otherArgs[1]);
> > >>>>>>>>>>>>>>>>>>> byte[] EDRP_FAMILY =
> > >>>>>>>>>>>>>>>>>>> Bytes.toBytes(otherArgs[2]);
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> conf.set(CoprocessorHost.REGION_COPROCESSOR_CONF_KEY,
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>> "org.apache.hadoop.hbase.coprocessor.AggregateImplementation"
> > >>>>>>>>>>>>>>>>>>> );
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> // Utility.CreateHBaseTable(conf,
> > >>>>>>>>>>>>>>>>>>> otherArgs[1],
> > >>>>>>>>>>>>>>>>>> otherArgs[2],
> > >>>>>>>>>>>>>>>>>>> true);
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> HBaseTestingUtility util = new
> > >>>>>>>>>>>>>>>>>>> HBaseTestingUtility();
> > >>>>>>>>>>>>>>>>>>> HTable table = util.createTable(EDRP_TABLE,
> > >>>>>>>>>>>>>>>>>>> EDRP_FAMILY);
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> AggregationClient aClient = new
> > >>>>>>>>>>>>>>>>>>> AggregationClient(conf);
> > >>>>>>>>>>>>>>>>>>> Scan scan = new Scan();
> > >>>>>>>>>>>>>>>>>>> scan.addColumn(EDRP_TABLE, EDRP_FAMILY);
> > >>>>>>>>>>>>>>>>>>> final ColumnInterpreter<Long, Long> ci = new
> > >>>>>>>>>>>>>>>>>>> LongColumnInterpreter();
> > >>>>>>>>>>>>>>>>>>> long sum =
> > >>>>>>>>>>>>>>>>>>> aClient.sum(Bytes.toBytes(otherArgs[0]),
> > >>>>>>>>>>>>>>>>>>> ci,
> > >>>>>>>>>>>>>>>>>> scan);
> > >>>>>>>>>>>>>>>>>>> System.out.println(sum);
> > >>>>>>>>>>>>>>>>>>> }
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> /**
> > >>>>>>>>>>>>>>>>>>> * Main entry point.
> > >>>>>>>>>>>>>>>>>>> *
> > >>>>>>>>>>>>>>>>>>> * @param argsThe
> > >>>>>>>>>>>>>>>>>>> * command line parameters.
> > >>>>>>>>>>>>>>>>>>> * @throws Exception
> > >>>>>>>>>>>>>>>>>>> * When running the job fails.
> > >>>>>>>>>>>>>>>>>>> */
> > >>>>>>>>>>>>>>>>>>> public static void main(String[] args) throws
> > >>>>>>>>>>>>>>>>>>> Exception {
> > >>>>>>>>>>>>>>>>>>> Configuration conf =
> > >>>>>>>>>>>>>>>>>>> HBaseConfiguration.create();
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> String[] otherArgs = new
> > >>>>>>>>>>>>>>>>>>> GenericOptionsParser(conf,
> > >>>>>>>>>>>>>>>>>>> args)
> > >>>>>>>>>>>>>>>>>>> .getRemainingArgs();
> > >>>>>>>>>>>>>>>>>>> if (otherArgs.length != 3) {
> > >>>>>>>>>>>>>>>>>>> System.err
> > >>>>>>>>>>>>>>>>>>> .println("Wrong number of
> > >>>>>>>>>>>>>>>>>>> arguments: " + otherArgs.length);
> > >>>>>>>>>>>>>>>>>>> System.err.println("Usage: " +
> > >>>>>>>>>>>>>>>>>>> "<tablename> <colfam> <qualifier>");
> > >>>>>>>>>>>>>>>>>>> System.exit(-1);
> > >>>>>>>>>>>>>>>>>>> }
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> try {
> > >>>>>>>>>>>>>>>>>>> testSumWithValidRange(conf, otherArgs);
> > >>>>>>>>>>>>>>>>>>> } catch (Throwable e) {
> > >>>>>>>>>>>>>>>>>>> e.printStackTrace();
> > >>>>>>>>>>>>>>>>>>> }
> > >>>>>>>>>>>>>>>>>>> }
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> /**
> > >>>>>>>>>>>>>>>>>>> * an infrastructure method to prepare rows for the
> > >>>>>>>>>>> testtable.
> > >>>>>>>>>>>>>>>>>>> *
> > >>>>>>>>>>>>>>>>>>> * @param base
> > >>>>>>>>>>>>>>>>>>> * @param n
> > >>>>>>>>>>>>>>>>>>> * @return
> > >>>>>>>>>>>>>>>>>>> */
> > >>>>>>>>>>>>>>>>>>> private static byte[][] makeN(byte[] base, int n) {
> > >>>>>>>>>>>>>>>>>>> byte[][] ret = new byte[n][];
> > >>>>>>>>>>>>>>>>>>> for (int i = 0; i < n; i++) {
> > >>>>>>>>>>>>>>>>>>> ret[i] = Bytes.add(base,
> > >>>>>>>>>>>>>>>>>>> Bytes.toBytes(i));
> > >>>>>>>>>>>>>>>>>>> }
> > >>>>>>>>>>>>>>>>>>> return ret;
> > >>>>>>>>>>>>>>>>>>> }
> > >>>>>>>>>>>>>>>>>>> }
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> Please can you suggest what might be causing and/or
> how
> > >>>>>>>>>>>>>>>>>>> we might fix this UnknownProtocolException?
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> Also, does anyone have any working examples using the
> > >>>>>>>>>>>>>>>>>>> aggregation
> > >>>>>>>>>>>>>>>>>> protocol
> > >>>>>>>>>>>>>>>>>>> other than the test code?
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>> Thanks,
> > >>>>>>>>>>>>>>>>>>> Tom
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>>
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>>>>>>
> > >>>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>
> > >>>>>>>
> > >>>>>
> > >>>>>
> > >>>
> > >>>
> > >
> >
>
>