com.amazonaws.services.dynamodbv2.streamsadapter

Class StreamsDeterministicShuffleShardSyncLeaderDecider

java.lang.Object

com.amazonaws.services.dynamodbv2.streamsadapter.StreamsDeterministicShuffleShardSyncLeaderDecider

All Implemented Interfaces:

com.amazonaws.services.kinesis.clientlibrary.lib.worker.LeaderDecider

public class StreamsDeterministicShuffleShardSyncLeaderDecider
extends java.lang.Object
implements com.amazonaws.services.kinesis.clientlibrary.lib.worker.LeaderDecider

An implementation of the LeaderDecider to elect leader(s) based on workerId. Leases are shuffled using a predetermined constant seed so that lease ordering is preserved across workers. This reduces the probability of choosing the leader workers co-located on the same host in case workerId starts with a common string (e.g. IP Address). Hence if a host has 3 workers, IPADDRESS_Worker1, IPADDRESS_Worker2, and IPADDRESS_Worker3, we don't end up choosing all 3 for shard sync as a result of natural ordering of Strings. This ensures redundancy for shard-sync during host failures.

Constructor Summary

Constructors

Constructor and Description
StreamsDeterministicShuffleShardSyncLeaderDecider(com.amazonaws.services.kinesis.clientlibrary.lib.worker.KinesisClientLibConfiguration config, com.amazonaws.services.kinesis.leases.interfaces.ILeaseManager<com.amazonaws.services.kinesis.leases.impl.KinesisClientLease> leaseManager, int numPeriodicShardSyncWorkers) Create an instance overriding the default periodic shard sync worker count.

Method Summary

Modifier and Type	Method and Description
java.lang.Boolean	isLeader(java.lang.String workerId)
void	shutdown()

Methods inherited from class java.lang.Object

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

Constructor Detail

StreamsDeterministicShuffleShardSyncLeaderDecider

public StreamsDeterministicShuffleShardSyncLeaderDecider(com.amazonaws.services.kinesis.clientlibrary.lib.worker.KinesisClientLibConfiguration config,
                                                         com.amazonaws.services.kinesis.leases.interfaces.ILeaseManager<com.amazonaws.services.kinesis.leases.impl.KinesisClientLease> leaseManager,
                                                         int numPeriodicShardSyncWorkers)

Create an instance overriding the default periodic shard sync worker count. This is intentionally public for use by consumers to build KCL workers using KCL Worker Builder directly instead of using StreamsWorkerFactory.

Parameters:

config - KinesisClientLibConfiguration instance

leaseManager - LeaseManager instance.

numPeriodicShardSyncWorkers - Max number of periodic shard sync workers.

Method Detail

isLeader

public java.lang.Boolean isLeader(java.lang.String workerId)

Specified by:

isLeader in interface com.amazonaws.services.kinesis.clientlibrary.lib.worker.LeaderDecider

shutdown

public void shutdown()

Specified by:

shutdown in interface com.amazonaws.services.kinesis.clientlibrary.lib.worker.LeaderDecider