kafka-tutorials | Tutorials and Recipes for Apache Kafka | Pub Sub library

by confluentinc Java Version: Current License: Apache-2.0

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kandi X-RAY | kafka-tutorials Summary

kafka-tutorials is a Java library typically used in Messaging, Pub Sub, Spring Boot, Kafka applications. kafka-tutorials has no bugs, it has no vulnerabilities, it has build file available, it has a Permissive License and it has low support. You can download it from GitHub.

This GitHub repo has the source code for Kafka Tutorials. Read about it in our blog post.

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kafka-tutorials has a low active ecosystem.

It has 268 star(s) with 92 fork(s). There are 150 watchers for this library.

It had no major release in the last 6 months.

There are 242 open issues and 251 have been closed. On average issues are closed in 25 days. There are 12 open pull requests and 0 closed requests.

It has a neutral sentiment in the developer community.

The latest version of kafka-tutorials is current.

Quality

kafka-tutorials has no bugs reported.

Security

kafka-tutorials has no vulnerabilities reported, and its dependent libraries have no vulnerabilities reported.

License

kafka-tutorials is licensed under the Apache-2.0 License. This license is Permissive.

Permissive licenses have the least restrictions, and you can use them in most projects.

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kafka-tutorials releases are not available. You will need to build from source code and install.

Build file is available. You can build the component from source.

Installation instructions, examples and code snippets are available.

Top functions reviewed by kandi - BETA

kandi has reviewed kafka-tutorials and discovered the below as its top functions. This is intended to give you an instant insight into kafka-tutorials implemented functionality, and help decide if they suit your requirements.

Builds a topology .
Creates a transformer supplier for the given store .
Initializes the processor .
Run a recipe .
Runs the tutorial .
Run the Kafka .
Print the windowed key value .
Handles a throwable exception .
Delete Kafka topics
Prints metadata to stdout .

Get all kandi verified functions for this library.

kafka-tutorials Key Features

No Key Features are available at this moment for kafka-tutorials.

kafka-tutorials Examples and Code Snippets

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Community Discussions

Trending Discussions on kafka-tutorials

kafka stream windowedBy not producing results when expected

Kafka Streams: Should we advance stream time per key to test Windowed suppression?

How can I reduce the 1s consumer lag in the Kafka Tutorial?

Unable to read kafka using spark sql

QUESTION

kafka stream windowedBy not producing results when expected

Asked 2021-Jan-06 at 11:13

I'm doing this simple windowed aggregation in kafka streams:

...

ANSWER

Answered 2021-Jan-06 at 11:13

Based on this post https://www.nerd.vision/post/suppress-surprise-kafka-streams-and-the-suppress-operator

The suppress operator is based on event-time and as long as no new records arrive the stream is basically frozen.

This post explains how to test this.

For the tests to work you need:

produce test data
produce a dummy event with future timestamp to release the window result assert.

Note that each test needs to be isolated (e.g bring Kafka broker and the stream up before and turn off after each individual test or close the test driver).

Source https://stackoverflow.com/questions/65519575

QUESTION

Kafka Streams: Should we advance stream time per key to test Windowed suppression?

Asked 2020-Jul-13 at 14:40

I learnt from This blog and this tutorial that in order to test suppression with event time semantics, one should send dummy records to advance stream time. I've tried to advance time by doing just that. But this does not seem to work unless time is advanced for a particular key.

I have a custom TimestampExtractor which associates my preferred "stream-time" with the records. My stream topology pseudocode is as follows (I use the Kafka Streams DSL API):

...

ANSWER

Answered 2020-Jul-13 at 14:40

I’m sorry for the trouble. This is indeed a tricky problem. I have some ideas for adding some operations to support this kind of integration testing, but it’s hard to do without breaking basic stream processing time semantics.

It sounds like you’re testing a “real” KafkaStreams application, as opposed to testing with TopologyTestDriver. My first suggestion is that you’ll have a much better time validating your application semantics with TopologyTestDriver, if it meets your needs.

It sounds to me like you might have more than one partition in your input topic (and therefore your application). In the event that key 1 goes to one partition, and key 3 goes to another, you would see what you’ve observed. Each partition of your application tracks stream time independently. TopologyTestDriver works nicely because it only uses one partition, and also because it processes data synchronously. Otherwise, you’ll have to craft your “dummy” time advancement messages to go to the same partition as the key you’re trying to flush out.

This is going to be especially tricky because your “flatMap().groupByKey()” is going to repartition the data. You’ll have to craft the dummy message so that it goes into the right partition after the repartition. Or you could experiment with writing your dummy messages directly into the repartition topic.

If you do need to test with KafkaStreams instead of TopologyTestDriver, I guess the easiest thing is just to write a “time advancement” message per key, as you were suggesting in your question. Not because it’s strictly necessary, but because it’s the easiest way to meet all these caveats. I’ll also mention that we are working on some general improvements to stream time handling in Kafka Streams that should simplify the situation significantly, but that doesn’t help you right now, of course.

Source https://stackoverflow.com/questions/62805247

QUESTION

How can I reduce the 1s consumer lag in the Kafka Tutorial?

Asked 2020-Jul-13 at 13:23

I'm working through the very first section of the Confluent Tutorials: https://kafka-tutorials.confluent.io/kafka-console-consumer-producer-basics/kafka.html. Everything works as described, but I notice there's about 1 second of lag between when I press enter in the producer terminal and when a message is displayed in the consumer terminal. Is it the producer or the consumer who's responsible for this lag/batching? Is there a way to configure things to be more responsive? A quick search turned up the linger.ms setting, but it seems like recent versions of Kafka default this setting to zero, and it doesn't appear to be overridden in these containers.

...

ANSWER

Answered 2020-Jul-12 at 20:34

Ok, it looks like setting --timeout=0 in the producer makes the lag disappear. Looking at the kafka-console-producer source code, --timeout defaults to 1000 and gets merged into LINGER_MS_CONFIG. So even though linger defaults to zero in Kafka generally, it effectively defaults to 1 sec in this command line producer.

Source https://stackoverflow.com/questions/62862798

QUESTION

Unable to read kafka using spark sql

Asked 2019-Jun-21 at 15:00

I am trying to read kafka using spark but facing some library related issue I guess .

I am pushing some event to kafka topics which I am able to read through kafka console consumer but unable to read through spark. I am using spark-sql-kafka library and the project is written in maven. Scala version is 2.11.12 and spark version is 2.4.3.

...

ANSWER

Answered 2019-Jun-21 at 13:21

This:

Source https://stackoverflow.com/questions/56704113

Community Discussions, Code Snippets contain sources that include Stack Exchange Network

Vulnerabilities

No vulnerabilities reported

Install kafka-tutorials

If you want to hack on this site to add a new tutorial or make a change, follow these instructions.
If you have pip3 installed locally:.
Check out the kafka-tutorials GitHub repo:
Install the packages for the harness runner.
Install gradle for tutorials that compile any code.
Install Docker Compose

Support

For any new features, suggestions and bugs create an issue on GitHub. If you have any questions check and ask questions on community page Stack Overflow .

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