node-kafka-streams

// suggested Node.js version: v12.16.1
npm install --save kafka-streams

const {KafkaStreams} = require("kafka-streams");

const config = require("./config.json");
const factory = new KafkaStreams(config);

const kstream = factory.getKStream("input-topic");
const ktable = factory.getKTable(/* .. */);

kstream.merge(ktable).filter(/* .. */).map(/* .. */).reduce(/* .. */).to("output-topic");

CHANGES: The latest version brings a lot of changes, please check here before updating.

API Overview

• Quick Start
• Message 'to' and 'from' Apache Kafka
• API Info
• Documentation
• Operator descriptions
• Examples
• Native Client | SSL, SASL, Kerberos

You might also like

• node-kafka-connect
• node-schema-registry
• node-kafka-rest-ui

README Overview

• Prerequisites
• Aim of this Library
• Description
• Port Progress Overview
• Operator Implementations
• Additional Operators
• Stream Action Implementations
• Join Operators Status
• Window Operations
• FAQ - More

Prerequisites

• Kafka broker should be version >= 0.11.x
• Node.js should be version >= 8.x.x

A note on native mode

If you are using the native mode (config: { noptions: {} }). You will have to manually install node-rdkafka alongside kafka-streams. (This requires a Node.js version between 9 and 12 and will not work with Node.js >= 13, last tested with 12.16.1)

On Mac OS High Sierra / Mojave: CPPFLAGS=-I/usr/local/opt/openssl/include LDFLAGS=-L/usr/local/opt/openssl/lib yarn add --frozen-lockfile [email protected]

Otherwise: yarn add --frozen-lockfile [email protected]

(Please also note: Doing this with npm does not work, it will remove your deps, npm i -g yarn)

Aim of this Library

• this is not a 1:1 port of the official JAVA kafka-streams
• the goal of this project is to give at least the same options to a nodejs developer that kafka-streams provides for JVM developers
• stream-state processing, table representation, joins, aggregate etc. I am aiming for the easiest api access possible checkout the word count example

Description

kafka-streams :octopus: equivalent for nodejs :sparkles::turtle::rocket::sparkles: build on super fast :fire: observables using most.js :metal:

ships with sinek :pray: for backpressure

comes with js and native Kafka client, for more performance and SSL, SASL and Kerberos features

the lib also comes with a few window operations that are more similar to Apache Flink, yet they still feel natural in this api :squirrel:

overwriteable local-storage solution allows for any kind of datastore e.g. RocksDB, Redis, Postgres..

async (Promises) and sync stream operators e.g. stream$.map() or stream$.asyncMap()

super easy API :goberserk:

the lib is based on sinek, which is based on kafka-node's ConsumerGroups

Port Progress Overview

• [x] core structure
• [x] KStream base - stream as a changelog
• [x] KTable base - stream as a database
• [x] KStream & KTable cloning
• [x] complex stream join structure
• [ ] advanced joins see
• [ ] windows (for joins) see
• [ ] flink like window operations
• [x] word-count example
• [x] more examples
• [x] local-storage for etl actions
• [x] local-storage factory (one per action)
• [ ] KStorage example for any DB that supports atomic actions
• [ ] backing-up local-storage via kafka
• [x] kafka client implementation
• [x] KTable replay to Kafka (produce)
• [x] stream for topic message production only
• [x] sinek implementation
• [x] backpressure mode for KafkaClient
• [x] auto-json payloads (read-map/write-map)
• [x] auto producer partition and keyed-message handling
• [x] documentation
• [x] API description
• [ ] higher join & combine examples
• [x] embed native client librdkafka for more performance
• [x] SSL
• [x] SASL
• [x] Kerberos

Operator Implementations

• [x] map
• [x] asyncMap
• [x] constant
• [x] scan
• [x] timestamp
• [x] tap
• [x] filter
• [x] skipRepeats
• [x] skipRepeatsWith
• [x] slice
• [x] take
• [x] skip
• [x] takeWhile
• [x] skipWhile
• [x] until
• [x] since
• [x] reduce
• [x] chainReduce
• [x] forEach (observe)
• [x] chainForEach
• [x] drain
• [x] _zip
• [x] _merge
• [x] _join
• [x] _combine
• [x] _sample
• [x] throttle
• [x] debounce
• [x] delay
• [x] multicast
• A description of the operators can be found here
• Missing an operator? Feel free to open an issue :cop:

Additional Operators

• [x] mapStringToArray
• [x] mapArrayToKV
• [x] mapStringToKV
• [x] mapParse
• [x] mapStringify
• [x] atThroughput
• [x] mapWrapKafkaPayload
• [x] mapToFormat
• [x] mapFromFormat
• Want more? Feel free to open an issue :cop:

Stream Action Implementations

• [x] countByKey
• [x] sumByKey
• [x] min
• [x] max
• Want more? Feel free to open an issue :cop:

Join Operations

Operation description

KStream Status

• [x] merge
• [ ] outerJoin
• [x] innerJoin
• [ ] leftJoin
• [x] branch

KTable Status

• [x] merge
• [ ] outerJoin
• [ ] innerJoin
• [ ] leftJoin

KTable <-> KStream Status

• [x] merge
• [ ] outerJoin
• [ ] innerJoin
• [ ] leftJoin

Window Operations

KStream

• [x] window
• [ ] advanced window
• [ ] rolling window

More

Can I use this library yet?

Yes.

Are we ready for production yet?

Probably, yes. :smile:

Even More

Forks or Stars give motivation :bowtie: