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From Vinay Patil <vinay18.pa...@gmail.com>
Subject Re: [Discussion] Query regarding Join
Date Mon, 27 Jun 2016 18:01:41 GMT
Just an update, when I keep IngestionTime and remove the timestamp I am
generating, I am getting all the records, but for Event Time I am getting
one less record, I checked the Time Difference between two records, it is 3
min, I tried keeping the window time to 5 mins, but that even did not work.

Even when I try assigning timestamp for IngestionTime, I get one record
less, so should I safely use Ingestion Time or is it always advisable to
use EventTime ?

Regards,
Vinay Patil

On Mon, Jun 27, 2016 at 8:16 PM, Vinay Patil <vinay18.patil@gmail.com>
wrote:

> Hi ,
>
> Actually I am only publishing 5 messages each to two different kafka
> topics (using Junit), even if I keep the window to 500 seconds the result
> is same.
>
> I am not understanding why it is not sending the 5th element to co-group
> operator even when the keys are same.
>
> I actually cannot share the actual client code.
> But this is what the streams look like :
> sourceStream.coGroup(destStream)
> here the sourceStream and destStream is actually Tuple2<String,DTO> , and
> the ElementSelector returns tuple.f0 which is the key.
>
> I am generating the timestamp based on a field from the DTO which is
> guaranteed to be in order.
>
> Will using the triggers help here ?
>
>
> Regards,
> Vinay Patil
>
> *+91-800-728-4749*
>
> On Mon, Jun 27, 2016 at 7:05 PM, Aljoscha Krettek <aljoscha@apache.org>
> wrote:
>
>> Hi,
>> what timestamps are you assigning? Is it guaranteed that all of them would
>> fall into the same 30 second window?
>>
>> The issue with duplicate printing in the ElementSelector is strange? Could
>> you post a more complete code example so that I can reproduce the problem?
>>
>> Cheers,
>> Aljoscha
>>
>> On Mon, 27 Jun 2016 at 13:21 Vinay Patil <vinay18.patil@gmail.com> wrote:
>>
>> > Hi ,
>> >
>> > I am able to get the matching and non-matching elements.
>> >
>> > However when I am unit testing the code , I am getting one record less
>> > inside the overriden cogroup function.
>> > Testing the following way :
>> >
>> > 1) Insert 5 messages into local kafka topic (test1)
>> > 2) Insert different 5 messages into local kafka topic (test2)
>> > 3) Consume 1) and 2) and I have two different kafka  streams
>> > 4) Generate ascending timestamp(using Event Time) for both streams and
>> > create key(String)
>> >
>> > Now till 4) I am able to get all the records (checked by printing the
>> > stream in text file)
>> >
>> > However when I send the stream to co-group operator, I am receiving one
>> > less record, using the following syntax:
>> >
>> > sourceStream.coGroup(destStream)
>> > .where(new ElementSelector())
>> > .equalTo(new ElementSelector())
>> > .window(TumblingEventTimeWindows.of(Time.seconds(30)))
>> > .apply(new JoinStreams);
>> >
>> > Also in the Element Selector I have inserted a sysout, I am getting 20
>> > sysouts instead of 10 (10 sysouts for source and 10 for dest stream)
>> >
>> > Unable to understand why one record is coming less to co-group
>> >
>> >
>> >
>> > Regards,
>> > Vinay Patil
>> >
>> > On Wed, Jun 15, 2016 at 1:39 PM, Fabian Hueske <fhueske@gmail.com>
>> wrote:
>> >
>> > > Can you add a flag to each element emitted by the CoGroupFunction that
>> > > indicates whether it was joined or not?
>> > > Then you can use split to distinguish between both cases and handle
>> both
>> > > streams differently.
>> > >
>> > > Best, Fabian
>> > >
>> > > 2016-06-15 6:45 GMT+02:00 Vinay Patil <vinay18.patil@gmail.com>:
>> > >
>> > > > Hi Jark,
>> > > >
>> > > > I am able to get the non-matching elements in a stream :,
>> > > >
>> > > > Of-course we can collect the matching elements in the same stream
as
>> > > well,
>> > > > however I want to perform additional operations on the joined stream
>> > > before
>> > > > writing it to S3, so I would have to include a separate join
>> operator
>> > for
>> > > > the same two streams, right ?
>> > > > Correct me if I am wrong.
>> > > >
>> > > > I have pasted the dummy code which collects the non-matching
>> records (i
>> > > > have to perform this on the actual data, correct me if I am dong
>> > wrong).
>> > > >
>> > > > sourceStream.coGroup(destStream).where(new
>> > ElementSelector()).equalTo(new
>> > > > ElementSelector())
>> > > > .window(TumblingEventTimeWindows.of(Time.seconds(30)))
>> > > > .apply(new CoGroupFunction<Integer, Integer, Integer>() {
>> > > >
>> > > > private static final long serialVersionUID = 6408179761497497475L;
>> > > >
>> > > > @Override
>> > > > public void coGroup(Iterable<Integer> paramIterable,
>> Iterable<Integer>
>> > > > paramIterable1,
>> > > > Collector<Integer> paramCollector) throws Exception {
>> > > > long exactSizeIfKnown =
>> > > paramIterable.spliterator().getExactSizeIfKnown();
>> > > > long exactSizeIfKnown2 =
>> > > > paramIterable1.spliterator().getExactSizeIfKnown();
>> > > > if(exactSizeIfKnown == 0 ) {
>> > > > paramCollector.collect(paramIterable1.iterator().next());
>> > > > } else if (exactSizeIfKnown2 == 0) {
>> > > > paramCollector.collect(paramIterable.iterator().next());
>> > > > }
>> > > > }
>> > > > }).print();
>> > > >
>> > > > Regards,
>> > > > Vinay Patil
>> > > >
>> > > >
>> > > > On Tue, Jun 14, 2016 at 1:37 PM, Vinay Patil <
>> vinay18.patil@gmail.com>
>> > > > wrote:
>> > > >
>> > > > > You are right, debugged it for all elements , I can do that now.
>> > > > > Thanks a lot.
>> > > > >
>> > > > > Regards,
>> > > > > Vinay Patil
>> > > > >
>> > > > > On Tue, Jun 14, 2016 at 11:56 AM, Jark Wu <
>> > wuchong.wc@alibaba-inc.com>
>> > > > > wrote:
>> > > > >
>> > > > >> In `coGroup(Iterable<Integer> iter1, Iterable<Integer>
iter2,
>> > > > >> Collector<Integer> out)` ,   when both iter1 and iter2
are not
>> > empty,
>> > > it
>> > > > >> means they are matched elements from both stream.
>> > > > >> When one of iter1 and iter2 is empty , it means that they
are
>> > > unmatched.
>> > > > >>
>> > > > >>
>> > > > >> - Jark Wu (wuchong)
>> > > > >>
>> > > > >> > 在 2016年6月14日,下午12:46,Vinay Patil <vinay18.patil@gmail.com>
写道:
>> > > > >> >
>> > > > >> > Hi Matthias ,
>> > > > >> >
>> > > > >> > I did not get you, even if we use Co-Group we have to
apply it
>> on
>> > a
>> > > > key
>> > > > >> >
>> > > > >> > sourceStream.coGroup(destStream)
>> > > > >> > .where(new ElementSelector())
>> > > > >> > .equalTo(new ElementSelector())
>> > > > >> > .window(TumblingEventTimeWindows.of(Time.seconds(30)))
>> > > > >> > .apply(new CoGroupFunction<Integer, Integer, Integer>()
{
>> > > > >> > private static final long serialVersionUID =
>> 6408179761497497475L;
>> > > > >> >
>> > > > >> > @Override
>> > > > >> > public void coGroup(Iterable<Integer> paramIterable,
>> > > Iterable<Integer>
>> > > > >> > paramIterable1,
>> > > > >> > Collector<Integer> paramCollector) throws Exception
{
>> > > > >> > Iterator<Integer> iterator = paramIterable.iterator();
>> > > > >> > while(iterator.hasNext()) {
>> > > > >> > }
>> > > > >> > }
>> > > > >> > });
>> > > > >> >
>> > > > >> > when I debug this ,only the matched element from both
stream
>> will
>> > > come
>> > > > >> in
>> > > > >> > the coGroup function.
>> > > > >> >
>> > > > >> > What I want is how do I check for unmatched elements
from both
>> > > streams
>> > > > >> and
>> > > > >> > write it to sink.
>> > > > >> >
>> > > > >> > Regards,
>> > > > >> > Vinay Patil
>> > > > >> >
>> > > > >> > *+91-800-728-4749*
>> > > > >> >
>> > > > >> > On Tue, Jun 14, 2016 at 2:07 AM, Matthias J. Sax <
>> > mjsax@apache.org>
>> > > > >> wrote:
>> > > > >> >
>> > > > >> >> You need to do an outer-join. However, there is
no build-in
>> > support
>> > > > for
>> > > > >> >> outer-joins yet.
>> > > > >> >>
>> > > > >> >> You can use Window-CoGroup to implement the outer-join
as an
>> own
>> > > > >> operator.
>> > > > >> >>
>> > > > >> >>
>> > > > >> >> -Matthias
>> > > > >> >>
>> > > > >> >> On 06/13/2016 06:53 PM, Vinay Patil wrote:
>> > > > >> >>> Hi,
>> > > > >> >>>
>> > > > >> >>> I have a question regarding the join operation,
consider the
>> > > > following
>> > > > >> >>> dummy example:
>> > > > >> >>>
>> > > > >> >>> StreamExecutionEnvironment env =
>> > > > >> >>> StreamExecutionEnvironment.getExecutionEnvironment();
>> > > > >> >>>
>> > env.setStreamTimeCharacteristic(TimeCharacteristic.IngestionTime);
>> > > > >> >>> DataStreamSource<Integer> sourceStream
=
>> > > > >> >>> env.fromElements(10,20,23,25,30,33,102,18);
>> > > > >> >>> DataStreamSource<Integer> destStream =
>> > > > >> >> env.fromElements(20,30,40,50,60,10);
>> > > > >> >>>
>> > > > >> >>> sourceStream.join(destStream)
>> > > > >> >>> .where(new ElementSelector())
>> > > > >> >>> .equalTo(new ElementSelector())
>> > > > >> >>> .window(TumblingEventTimeWindows.of(Time.milliseconds(10)))
>> > > > >> >>> .apply(new JoinFunction<Integer, Integer,
Integer>() {
>> > > > >> >>>
>> > > > >> >>> private static final long serialVersionUID =
1L;
>> > > > >> >>>
>> > > > >> >>> @Override
>> > > > >> >>> public Integer join(Integer paramIN1, Integer
paramIN2)
>> throws
>> > > > >> Exception
>> > > > >> >> {
>> > > > >> >>> return paramIN1;
>> > > > >> >>> }
>> > > > >> >>> }).print();
>> > > > >> >>>
>> > > > >> >>> I perfectly get the elements that are matching
in both the
>> > > streams,
>> > > > >> >> however
>> > > > >> >>> my requirement is to write these matched elements
and also
>> the
>> > > > >> unmatched
>> > > > >> >>> elements to sink(S3)
>> > > > >> >>>
>> > > > >> >>> How do I get the unmatched elements from each
stream ?
>> > > > >> >>>
>> > > > >> >>> Regards,
>> > > > >> >>> Vinay Patil
>> > > > >> >>>
>> > > > >> >>
>> > > > >> >>
>> > > > >>
>> > > > >>
>> > > > >
>> > > >
>> > >
>> >
>>
>
>

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