org.apache.beam.sdk.io.kinesis

Class KinesisIO

java.lang.Object

org.apache.beam.sdk.io.kinesis.KinesisIO

@Experimental(value=SOURCE_SINK)
public final class KinesisIO
extends java.lang.Object

PTransforms for reading from and writing to Kinesis streams.

Reading from Kinesis

Example usage:

 p.apply(KinesisIO.read()
     .withStreamName("streamName")
     .withInitialPositionInStream(InitialPositionInStream.LATEST)
     .withAWSClientsProvider("AWS_KEY", _"AWS_SECRET", STREAM_REGION)
  .apply( ... ) // other transformations
 

As you can see you need to provide 3 things:

• name of the stream you're going to read
• position in the stream where reading should start. There are two options:
  • InitialPositionInStream.LATEST - reading will begin from end of the stream
  • InitialPositionInStream.TRIM_HORIZON - reading will begin at the very beginning of the stream
• data used to initialize AmazonKinesis and AmazonCloudWatch clients:
  • credentials (aws key, aws secret)
  • region where the stream is located

In case when you want to set up AmazonKinesis or AmazonCloudWatch client by your own (for example if you're using more sophisticated authorization methods like Amazon STS, etc.) you can do it by implementing AWSClientsProvider class:

 public class MyCustomKinesisClientProvider implements AWSClientsProvider {
   {@literal @}Override
   public AmazonKinesis getKinesisClient() {
     // set up your client here
   }

   public AmazonCloudWatch getCloudWatchClient() {
     // set up your client here
   }

 }
 

Usage is pretty straightforward:

 p.apply(KinesisIO.read()
    .withStreamName("streamName")
    .withInitialPositionInStream(InitialPositionInStream.LATEST)
    .withAWSClientsProvider(new MyCustomKinesisClientProvider())
  .apply( ... ) // other transformations
 

There’s also possibility to start reading using arbitrary point in time - in this case you need to provide Instant object:

 p.apply(KinesisIO.read()
     .withStreamName("streamName")
     .withInitialTimestampInStream(instant)
     .withAWSClientsProvider(new MyCustomKinesisClientProvider())
  .apply( ... ) // other transformations
 

Kinesis IO uses ArrivalTimeWatermarkPolicy by default. To use Processing time as event time:

 p.apply(KinesisIO.read()
    .withStreamName("streamName")
    .withInitialPositionInStream(InitialPositionInStream.LATEST)
    .withProcessingTimeWatermarkPolicy())
 

It is also possible to specify a custom watermark policy to control watermark computation. Below is an example

 // custom policy
 class MyCustomPolicy implements WatermarkPolicy {
     private WatermarkPolicyFactory.CustomWatermarkPolicy customWatermarkPolicy;

     MyCustomPolicy() {
       this.customWatermarkPolicy = new WatermarkPolicyFactory.CustomWatermarkPolicy(WatermarkParameters.create());
     }

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	KinesisIO.Read Implementation of read().
static class	KinesisIO.Write Implementation of write().

Constructor Summary

Constructors

Constructor and Description
KinesisIO()

Method Summary

Modifier and Type	Method and Description
static KinesisIO.Read	read() Returns a new KinesisIO.Read transform for reading from Kinesis.
static KinesisIO.Write	write() A PTransform writing data to Kinesis.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

KinesisIO

public KinesisIO()

Method Detail

read

public static KinesisIO.Read read()

Returns a new KinesisIO.Read transform for reading from Kinesis.

write

public static KinesisIO.Write write()

A PTransform writing data to Kinesis.