Package org.apache.pekko.cluster.sharding.typed

Class Murmur2MessageExtractor<M>

java.lang.Object

org.apache.pekko.cluster.sharding.typed.ShardingMessageExtractor<ShardingEnvelope<M>,M>

org.apache.pekko.cluster.sharding.typed.Murmur2MessageExtractor<M>

public final class Murmur2MessageExtractor<M>
extends ShardingMessageExtractor<ShardingEnvelope<M>,M>

The murmur2 message extractor uses the same algorithm as the default kafka partitioner allowing kafka partitions to be mapped to shards. This can be used with the pekko.cluster.sharding.external.ExternalShardAllocationStrategy to have messages processed locally.

Extend Murmur2NoEnvelopeMessageExtractor to not use a message envelope extractor.

Constructor Summary

Constructors

Constructor	Description
Murmur2MessageExtractor(int numberOfShards)

Method Summary

Modifier and Type	Method	Description
java.lang.String	entityId(ShardingEnvelope<M> envelope)	Extract the entity id from an incoming message.
int	numberOfShards()
java.lang.String	shardId(java.lang.String entityId)	The shard identifier for a given entity id.
M	unwrapMessage(ShardingEnvelope<M> envelope)	Extract the message to send to the entity from an incoming message.

Methods inherited from class org.apache.pekko.cluster.sharding.typed.ShardingMessageExtractor

apply, noEnvelope

Methods inherited from class java.lang.Object

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

Constructor Detail

Murmur2MessageExtractor

public Murmur2MessageExtractor(int numberOfShards)

Method Detail

entityId

public java.lang.String entityId(ShardingEnvelope<M> envelope)

Description copied from class: ShardingMessageExtractor

Extract the entity id from an incoming message. If null is returned the message will be unhandled, i.e. posted as Unhandled messages on the event stream

Specified by:

entityId in class ShardingMessageExtractor<ShardingEnvelope<M>,M>

numberOfShards

public int numberOfShards()

shardId

public java.lang.String shardId(java.lang.String entityId)

Description copied from class: ShardingMessageExtractor

The shard identifier for a given entity id. Only messages that passed the ShardingMessageExtractor.entityId(E) function will be used as input to this function.

Specified by:

shardId in class ShardingMessageExtractor<ShardingEnvelope<M>,M>

unwrapMessage

public M unwrapMessage(ShardingEnvelope<M> envelope)

Description copied from class: ShardingMessageExtractor

Extract the message to send to the entity from an incoming message. Note that the extracted message does not have to be the same as the incoming message to support wrapping in message envelope that is unwrapped before sending to the entity actor.

Specified by:

unwrapMessage in class ShardingMessageExtractor<ShardingEnvelope<M>,M>