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Questions tagged [kafka-streams-scala]

10 questions
5
votes
1 answer

When to use GlobalKTable over KTable when 1 partition is used

I understand the differences between the 2, but still, it seems that i use KTable as a "default", not really know when to prefer a GlobalKTable. Please share your experience, when does a GlobalKTable is a must, why not to use it etc.
Aaron_ab
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5
votes
1 answer

Kafka Streams - Processor API - Forward to different topics

I have a Processor-API Processor, which internally forwards to several separate sinks (think of an event classifier, although it also has stateful logic between the events). I was thinking of having a join later between two of those topics. Once a…
xmar
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2
votes
3 answers

How to define Scala API for Kafka Streams as dependency in build.sbt?

I am trying to start a new SBT Scala project and have the following in build.sbt file: name := "ScalaKafkaStreamsDemo" version := "1.0" scalaVersion := "2.12.1" libraryDependencies += "javax.ws.rs" % "javax.ws.rs-api" % "2.1"…
sacha barber
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2
votes
2 answers

Using sbt Avrohugger plugin in gradle

I am using https://github.com/julianpeeters/avrohugger sbt plugin to generate Scala case classes for Avro .avsc files. How can I use the same plugin in a Gradle project?
Sumit Nekar
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1
vote
1 answer

kafka streams application only prints when application is killed

I created a kafka streams scala g8 template but I noticed it only prints when the application is killed. I also tried the print to file and noticed the file is only updated when the application is…
Ikenna Darlington Ogbajie
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1
vote
1 answer

What is difference between found and required in following errors

While working on Scala Kafka KeyValueMapper implementation I am getting following error. I am not sure what exactly is the difference. Thanks for your help. Code: I created a KTable from topic. val creducer: Reducer[java.lang.Long] = (v1, v2)…
bijaya media
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0
votes
1 answer

Random fail on KafkaStreams stateful application

Hi here is a problem I stumble upon since a few days and can't find the answer by myself. I am using the scala streams API v2.0.0. I have two incoming streams, branched over two handlers for segregation and both declaring a Transformer using a…
whisust
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0
votes
1 answer

Getting unspecified value parameter scala Kafka

Hi I am getting this compilation error - Unspecified Value parameters: aggregator: (String, String, NotInferedVR) => NotInferedVR But I clearly have an aggregator there already. Does anyone know what's going on? val stream = builder …
uh_big_mike_boi
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0
votes
1 answer

Why one Kafka streams block the other one from getting started?

I am working with the new Kafka-scala-streams api recently opensourced by lightbend. And I am trying to run two streams. But Whats happening is two of them don't run simultaneously and I am not getting the desired output. package…
Shivansh
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-1
votes
1 answer

Last car coordinates tracking

I have a kafka topic, where I'm storing car position data. I need to write a stream which show me only the last 4 coordinates for each car. How can I do this in kafka streams?
mi.mo
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