Client library for Amazon Kinesis

README.md

Amazon Kinesis Client Library for Java

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The Amazon Kinesis Client Library for Java (Amazon KCL) enables Java developers to easily consume and process data from Amazon Kinesis.

Recommended Upgrade for All Users of the 2.x Amazon Kinesis Client

⚠️ It's highly recommended for users of version 2.0 of the Amazon Kinesis Client to upgrade to version 2.0.3 or later. A bug has been identified in versions prior to 2.0.3 that could cause records to be delivered to the wrong record processor.

ℹ️ Amazon Kinesis Client versions 1.x are not impacted.

Please open an issue if you have any questions.

Features

  • Provides an easy-to-use programming model for processing data using Amazon Kinesis
  • Helps with scale-out and fault-tolerant processing

Getting Started

  1. Sign up for AWS — Before you begin, you need an AWS account. For more information about creating an AWS account and retrieving your AWS credentials, see AWS Account and Credentials in the AWS SDK for Java Developer Guide.
  2. Sign up for Amazon Kinesis — Go to the Amazon Kinesis console to sign up for the service and create an Amazon Kinesis stream. For more information, see Create an Amazon Kinesis Stream in the Amazon Kinesis Developer Guide.
  3. Minimum requirements — To use the Amazon Kinesis Client Library, you'll need Java 1.8+. For more information about Amazon Kinesis Client Library requirements, see Before You Begin in the Amazon Kinesis Developer Guide.
  4. Using the Amazon Kinesis Client Library — The best way to get familiar with the Amazon Kinesis Client Library is to read Developing Record Consumer Applications in the Amazon Kinesis Developer Guide.

Building from Source

After you've downloaded the code from GitHub, you can build it using Maven. To disable GPG signing in the build, use this command: mvn clean install -Dgpg.skip=true

Integration with the Kinesis Producer Library

For producer-side developers using the Kinesis Producer Library (KPL), the KCL integrates without additional effort. When the KCL retrieves an aggregated Amazon Kinesis record consisting of multiple KPL user records, it will automatically invoke the KPL to extract the individual user records before returning them to the user.

Amazon KCL support for other languages

To make it easier for developers to write record processors in other languages, we have implemented a Java based daemon, called MultiLangDaemon that does all the heavy lifting. Our approach has the daemon spawn a sub-process, which in turn runs the record processor, which can be written in any language. The MultiLangDaemon process and the record processor sub-process communicate with each other over STDIN and STDOUT using a defined protocol. There will be a one to one correspondence amongst record processors, child processes, and shards. For Python developers specifically, we have abstracted these implementation details away and expose an interface that enables you to focus on writing record processing logic in Python. This approach enables KCL to be language agnostic, while providing identical features and similar parallel processing model across all languages.

Using the KCL

The recommended way to use the KCL for Java is to consume it from Maven.

Version 2.x

<dependency>
    <groupId>software.amazon.kinesis</groupId>
    <artifactId>amazon-kinesis-client</artifactId>
    <version>2.0.4</version>
</dependency>

Version 1.x

Version 1.x tracking branch

<dependency>
    <groupId>com.amazonaws</groupId>
    <artifactId>amazon-kinesis-client</artifactId>
    <version>1.9.2</version>
</dependency>

Release Notes

Latest Release (2.0.5 - November 12, 2018)

Milestone #26

  • Fixed a deadlock condition that could occur when using the polling model.
    It was possible to hit a deadlock in the retrieval of records When using the PollingConfig and a slow running record processor.
  • Adjusted RetrievalConfig, and FanOutConfig to use accessors instead of direct member access.

For remaining release notes check CHANGELOG.md.