think your anwser.
but i can not get your ideal."If all elements of "words2" have been processed,
the right side of your coGroup will always be empty no matter what is incoming
in your socketTextStream.",the mean i can not get.
the following is the ideal from me(it maybe error):
the coGroup will create new dataStream,T1 and T2,this must use
GlobalWindows to store all elements from T2,if use timeWindow or others,the
T2's element will not all store.
------------------
T1, T2
------------------
and into apply function,get result,
when input first element,the T1 will add one element,
---------------------------------
T1(+first), T2
---------------------------------
and into apply function,get result.
when input second element,the T1 will add one element,
---------------------------------------
T1(+first+second), T2
-----------------------------------------
and into apply function,get result.
***************************************************
but,in fact ,i want to get the datastream like this,
-------------------------------
T1, T2
--------------------------------
when input first ,is follow:
--------------------------------
T1(+first), T2
---------------------------------
when input second, is follow:
--------------------------------
T1(+second), T2
--------------------------------
so the first must fired,this is my intention.
and i try to cut socket input datastream,use countWindow or timewindow,it is
not work,when use coGroup,the datastream is T1 and T2,they are a whole ，so i
think must window the coGroup.
----- 原始邮件 -----
发件人：Timo Walther <twal...@apache.org>
收件人：user@flink.apache.org
主题：Re: 回复：Re: modify coGroup GlobalWindows_GlobalWindow
日期：2016年09月06日 20点52分
I think you have to rethink your
approach. In your example "words2" is a stream but only with a
fixed set of elements. If all elements of "words2" have been
processed, the right side of your coGroup will always be empty no
matter what is incoming in your socketTextStream.
It is not read in over and over again. Is that your intention?
Am 06/09/16 um 13:15 schrieb rimin...@sina.cn:
i try read data into a list or List[Map] to store the
T2,but i think if use list or List[Map],there is not
parallelization,so i want to use coGroup.
other hand,the coGroup function is join the T1 and T2,and must
have window and trigger method,the window is cut the T1 and T2,
the trigger is trigger the apply function when input to the
trigger threshold.
from the result,in apply(), i use my InnerJoinFunction,and output
the T1 and T2,we can see when input data,and trigger the
apply,into the InnerJoinFunction,the T1 and T2 will output,
the T1 is increase,and T2 is not change, so the window cut the T1
and T2 do not achieve mine goal,so i want to write my
"GlobalWindows.create()".
and Flink's operator state i have no ideal for it,and really do
not know how to use it.can you give me a example.
----- 原始邮件 -----
发件人：Timo Walther <twal...@apache.org>
收件人：user@flink.apache.org
主题：Re: modify coGroup GlobalWindows GlobalWindow
日期：2016年09月06日 17点52分
Hi,
will words2 always remain constant? If yes, you don't have to
create a stream out of it and coGroup it, but you could simply
pass the collection to Map/FlatMap function and do the joining
there without the need of a window. Btw. you know that
non-keyed global windows do not scale?
If I understand your code correctly, you just want to get a
stream with the last T2, right? I don't think you have to
implement your own "GlobalWindow" for that. Have you tried to
use Flink's operator state for that? So that if the state is
growing it can be written to disk.
Hope that helps.
Timo
Am 06/09/16 um 10:05 schrieb rimin...@sina.cn:
Hi,
the follow code:
val text =
env.socketTextStream(hostName, port)
val words1 = text.map { x =>
val res = x.split(",")
(res.apply(0)->res.apply(1))
}
val words2 =
env.fromElements(("a","w1"),("a","w2"),("c","w3"),("d","w4"))
val joinedStream = words1
.coGroup(words2)
.where(_._1)
.equalTo(_._1)
.window(GlobalWindows.create())
.trigger(CountTrigger.of(1))
val res =
joinedStream.apply(new InnerJoinFunction).print()
env.execute()
class InnerJoinFunction extends
CoGroupFunction[(String,String),(String,String),(String,String)]{
override def coGroup(T1:
java.lang.Iterable[(String,String)],
T2: java.lang.Iterable[(String,String)],
out: Collector[(String, String)]): Unit = {
println("****************************")
println("T1="+T1+"T2="+T2)
import scala.collection.JavaConverters._
val scalaT2 = T2.asScala.toList
if(!T1.asScala.isEmpty &&
scalaT2.nonEmpty){
val transaction = T1.asScala.last
println("T2 last="+transaction)
for(snapshot <- scalaT2){
out.collect(transaction._1,transaction._2+snapshot._2)
}
}
}
}
--------------------------------
the code have no proplem,and can
run,the follow is the result:(input "a,1" then input
"a,2")
****************************
T1=[(a,1)]T2=[(a,w2), (a,w1)]
T2 last=(a,1)
2> (a,1w2)
2> (a,1w1)
****************************
T1=[(a,1), (a,2)]T2=[(a,w2),
(a,w1)]
T2 last=(a,2)
2> (a,2w2)
2> (a,2w1)
--------------------------------------------------
the T1 is increase,and T2 is not
change.i worry,when input so many,the T1 will out of
storage.
so i want to write my
"GlobalWindows.create()", to achieve T1 will store the
only one,from input(or read from kafka),and the history
of T1 will clear(input a,1 T1 is [(a,1)],then input
a,2,T1 is [(a,2)],not T1=[(a,1), (a,2)]),but T2 will not
change.
i rewrite the "GlobalWindows",but it
do not work,i read the code,find must rewrite the
"GlobalWindow",and must modify "the class Serializer
extends TypeSerializer<MyGlobalWindow>",but when i
run,it can not into there,why? some can tell me?
--
Freundliche Grüße / Kind Regards
Timo Walther
Follow me: @twalthr
https://www.linkedin.com/in/twalthr
--
Freundliche Grüße / Kind Regards
Timo Walther
Follow me: @twalthr
https://www.linkedin.com/in/twalthr
