kafka-streams | Code examples for working with Kafka Streams | Stream Processing library

by bbejeck Java Version: Current License: Apache-2.0

X-Ray Key Features Code Snippets(2)Community Discussions(10)Vulnerabilities Install Support

kandi X-RAY | kafka-streams Summary

kafka-streams is a Java library typically used in Data Processing, Stream Processing, Nodejs, Kafka applications. kafka-streams 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.

Code examples for working with Kafka Streams

Support

Quality

Security

License

Reuse

Support

kafka-streams has a low active ecosystem.

It has 231 star(s) with 100 fork(s). There are 21 watchers for this library.

It had no major release in the last 6 months.

There are 2 open issues and 0 have been closed. On average issues are closed in 589 days. There are no pull requests.

It has a neutral sentiment in the developer community.

The latest version of kafka-streams is current.

Quality

kafka-streams has 0 bugs and 0 code smells.

Security

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

kafka-streams code analysis shows 0 unresolved vulnerabilities.

There are 0 security hotspots that need review.

License

kafka-streams 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.

Reuse

kafka-streams 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.

kafka-streams saves you 463 person hours of effort in developing the same functionality from scratch.

It has 1093 lines of code, 109 functions and 25 files.

It has low code complexity. Code complexity directly impacts maintainability of the code.

Top functions reviewed by kandi - BETA

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

Process a stock transaction
Creates a stockTransactionSummary from a transaction transaction
Updates the stock information from a transaction
Entry point to the purchase stream
Returns the Kafka properties
Main method for testing
Stops the Kafka consumer
Process a purchase
Creates a builder for a new purchase
Main method for testing
Adds a transaction to the collector
Initializes this processor
Cancel all pending transactions

Get all kandi verified functions for this library.

kafka-streams Key Features

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

kafka-streams Examples and Code Snippets

Default configuration for Kafka streams .

java

Lines of Code : 12

License : Permissive (MIT License)

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@Bean(name = KafkaStreamsDefaultConfiguration.DEFAULT_STREAMS_CONFIG_BEAN_NAME)
    KafkaStreamsConfiguration kStreamsConfig() {
        Map props = new HashMap<>();
        props.put(APPLICATION_ID_CONFIG, "streams-app");
        props.put(BOO

Start the Kafka streams application .

java

Lines of Code : 3

License : Permissive (MIT License)

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public static void main(String[] args) {
        SpringApplication.run(KafkaStreamsApplication.class, args);
    }

Community Discussions

Trending Discussions on kafka-streams

Quarkus - Kafka Streams - How to pass through config options to underlying producer and consumer

Metadata for key is wrong even if the key is present in local Ktable in kafka streams when running two instances

How to create an output stream (changelog) based on a table in KSQL correctly?

AccessDeniedException for Kafka 3 default state.dir

Spring Kafka - Added Store cannot access from stream process

Binding GlobalStateStore into Processor with spring-cloud-stream-binder-kafka

The Kafka topic is here, a Java consumer program finds it, but lists none of its content, while a kafka-console-consumer is able to

My Kafka streaming application just exit with code 0 doing nothing

Access record's partition numebr in kafka streams

Overwrite of Kafka Version in Spring Boot fails for some dependencies

QUESTION

Quarkus - Kafka Streams - How to pass through config options to underlying producer and consumer

Asked 2022-Apr-11 at 14:58

Quarkus' Kafka-Streams extension provides a convenient way to start a pipeline. Necessary configuration options for the stream application, e.g., quarkus.kafka-streams.bootstrap-servers=localhost:9092 must be inserted in the application.properties file for the encompassing project.

Quarkus also provides a pass-through option for a finer configuration. The documentation states:

All the properties within the kafka-streams namespace are passed through as-is to the Kafka Streams engine. Changing their values requires a rebuild of the application.

With that, we can for example pass-through a custom timestamp extractor (or any other configuration property that related to the streams configuration)

...

ANSWER

Answered 2022-Apr-11 at 14:58

You can just pass it using standard configuration for consumers and producers, prefixed with kafka-streams:

Source https://stackoverflow.com/questions/71797639

QUESTION

Metadata for key is wrong even if the key is present in local Ktable in kafka streams when running two instances

Asked 2022-Apr-05 at 13:28

I am facing a weird issue with when aggregating records into a Ktable. I have a following scenario in my system.

There are two kafka streams application running on different nodes (having the same application id but having different application server config).
Both of these streams listen to the same topic pattern where the records are partitioned by a key (string value).
Whenever both the application is running , some partition are consumed by app-1 and some are consumed by app-2 which is normal. They then build their own respective local state store.
I have a grapql query system which lets you query the key and get its value if its in local table or in another remote instance.
The problem is that when I query for a key's metadata it is giving me the wrong hostInfo (even if the key is processed by instance one it shows it has hostInfo of instance two) But when if I query the key's value in instance-1's local state store I can see that the key is indeed present. (It just that the metadata for the key's is wrong)
And this behaviour is random for key in both instance (some keys point the correct metadata while some don't)
I have logged for a state listener which tells me if a rebalancing is happening or not. But while the records are streaming or when I am querying , I have make sure that no rebalancing is happening.
The issue I face is something similar to this. Method of metadataForKey in Kafka Streams gives wrong information for multiple instances of application connected to the same group
Also when I query for all keys in the local state store I can see the key is present.

Anyone have idea of what could be causing this issue? Please

...

ANSWER

Answered 2022-Apr-05 at 13:28

Hello so the problem here was I was sending Kafka topic through my own custom logic for partitioning of records and wasn't using the default implementation that kafka provides. And on the streams side , it was calculating the metadata for the key using its default partitioning logic which resulted in wrong metadata. So , all I had to do is implement my own custom partitioner with the same logic I use over at the kafka side and use that logic to compute the metadata.

Source https://stackoverflow.com/questions/71694920

QUESTION

How to create an output stream (changelog) based on a table in KSQL correctly?

Asked 2022-Apr-02 at 15:59

Step 1: Create table

I currently have a table in KSQL which created by

...

ANSWER

Answered 2022-Apr-02 at 15:59

In step 2, instead of using the topic cdc_window_table, I should use something like _confluent-ksql-xxx-ksqlquery_CTAS_CDC_WINDOW_TABLE_271-Aggregate-GroupBy-repartition.

This table's changelog topic is automatically created by KSQL when I created the previous table.

You can find this long changelog topic name by using

Source https://stackoverflow.com/questions/71712040

QUESTION

AccessDeniedException for Kafka 3 default state.dir

Asked 2022-Mar-03 at 09:52

The following error would appear every 5 seconds when we have Kafka running on Windows 10.

Failed to write offset checkpoint file to C:/tmp/kafka-streams/user/global/.checkpoint for global stores: {}. This may occur if OS cleaned the state.dir in case when it is located in the (default) ${java.io.tmpdir}/kafka-streams directory. Changing the location of state.dir may resolve the problem.

java.nio.file.AccessDeniedException: C:/tmp/kafka-streams/user/global

Here is our Gradle. At the time of writing, this will import the 3.0 version by default.

...

ANSWER

Answered 2022-Mar-03 at 09:52

The warnings disappeared immediately when I bumped the Kafka version to 3.1.0. I couldn't figure out what the cause was.

Source https://stackoverflow.com/questions/71335123

QUESTION

Spring Kafka - Added Store cannot access from stream process

Asked 2022-Feb-25 at 19:00

I'm facing an issue with Spring Kafka which is that it cannot access state store from process event I added that particular store into topology/streams.

method 1:

...

ANSWER

Answered 2022-Feb-25 at 19:00

Adding a state store to a Topology is just the first step but it does not make it available: in order to allow a Processor to use a state store, you must connect both.

The simplest way is to pass in the state store name when adding the Processor:

Source https://stackoverflow.com/questions/71250498

QUESTION

Binding GlobalStateStore into Processor with spring-cloud-stream-binder-kafka

Asked 2022-Feb-17 at 17:01

Initial Question: I have a question how I can bind my GlobalStateStore to a processor. My Application has a GlobalStateStore with an own processor ("GlobalConfigProcessor") to keep the Store up to date. Also, I have another Processor ("MyClassProcessor") which is called in my Consumer Function. Now I try to access the store from MyClassProcessor, but I get an exception saying : Invalid topology: StateStore config_statestore is not added yet.

Update on current situation: I setup a test repository to give a better overview over my situation. This can be found here: https://github.com/fx42/store-example

As you can see in the repo, I have two Consumers which both consume different topics. The Config-Topic provides an event which I want to write to a GlobalStateStore. Here are the StateStoreUpdateConsumer.java and the StateStoreProcessor.java involved. With the MyClassEventConsumer.java I process another Input-Topic and want to read values from the GlobalStateStore. As provided in this doc I can't initialize GlobalStateStores just as StateStoreBean but instead I have to add this actively with the StreamsBuilderFactoryBeanCustomizer Bean. This Code is currently commented out in the StreamConfig.java. Without this code I get the Exception

...

ANSWER

Answered 2022-Feb-17 at 17:01

I figured out my problem. For me it was the @EnableKafkaStreams annotation which I used. I assume this was the reason I had two different contexts running in parallel and they collided. Also I needed to use the StreamsBuilderFactoryBeanConfigurer instead of StreamsBuilderFactoryBeanCustomizer to get the GlobalStateStore registered correctly. Theses changes done in the linked test-repo which now can start the Application Context properly.

Source https://stackoverflow.com/questions/71145107

QUESTION

The Kafka topic is here, a Java consumer program finds it, but lists none of its content, while a kafka-console-consumer is able to

Asked 2022-Feb-16 at 13:23

It's my first Kafka program.

From a kafka_2.13-3.1.0 instance, I created a Kafka topic poids_garmin_brut and filled it with this csv:

...

ANSWER

Answered 2022-Feb-15 at 14:36

Following should work.

Source https://stackoverflow.com/questions/71122596

QUESTION

My Kafka streaming application just exit with code 0 doing nothing

Asked 2022-Feb-04 at 15:44

In order to try the Kafka stream I did this :

...

ANSWER

Answered 2022-Feb-03 at 13:14

Your code works for me(even with wrong values-at least doesn't terminate). Please use logback in your code and keep logger level to DEBUG. This way you will be able to observe carefully what is happening when your kafka streams is launching. Probably kafka thread is terminating due to some reason which we can't just guess like that.

PS: Sorry I don't have reputation to add a comment.

Source https://stackoverflow.com/questions/70971002

QUESTION

Access record's partition numebr in kafka streams

Asked 2022-Jan-28 at 22:45

I am using Kafka 2.6 with spring cloud stream kafka-streams binder. I want to access record headers, partition no etc in my Kafka streams application. I read about using Processor API, using ProcessorContext etc. But everytime ProcessorContext object is coming null.

Below is the code

...

ANSWER

Answered 2022-Jan-28 at 22:45

Please change

Source https://stackoverflow.com/questions/70877427

QUESTION

Overwrite of Kafka Version in Spring Boot fails for some dependencies

Asked 2022-Jan-28 at 20:46

I have a fresh Spring Boot 2.6.3 Java 11 application with a Spring Kafka Dependency (generated with start.spring.io).

By default Kafka 3.0.0 is is used. I want to change the Kafka version to 3.1.0 and added

...

ANSWER

Answered 2022-Jan-28 at 20:46

According to the docs section on overriding dependencies

You could manually add the one it's looking for

Source https://stackoverflow.com/questions/70891088

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

Vulnerabilities

No vulnerabilities reported

Install kafka-streams

Java 8
Gradle
Download the latest json-data-generator release and follow the install instructions here. Clone or fork the repo. Then copy the json config files to json generator conf directory. Create all the topics required by the examples.

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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