Package io.camunda.zeebe.engine.processing.distribution

Class CommandDistributionBehavior

java.lang.Object

io.camunda.zeebe.engine.processing.distribution.CommandDistributionBehavior

public final class CommandDistributionBehavior
extends Object

The network communication between the partitions is unreliable. To allow communication between partitions in a reliable way, we've built command distribution: a way for partitions to send, receive, and acknowledge (or retry sending) commands between partitions.

This behavior allows distributing a command to other partitions, and for those receiving partitions to acknowledge the distributed commands back to the partition that started.

See Also:

• generalized_distribution.md

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	CommandDistributionBehavior.ContinuationRequestBuilder
static interface	CommandDistributionBehavior.DistributionRequestBuilder
static interface	CommandDistributionBehavior.RequestBuilder

Constructor Summary

Constructors

Constructor	Description
CommandDistributionBehavior(DistributionState distributionState, Writers writers, int currentPartition, RoutingInfo routingInfo, InterPartitionCommandSender partitionCommandSender)

Method Summary

Modifier and Type	Method	Description
<T extends UnifiedRecordValue> void	acknowledgeCommand(TypedRecord<T> command)	Acknowledges that a command was distributed to another partition successfully.
CommandDistributionBehavior.RequestBuilder	withKey(long distributionKey)	Starts a new command distribution request.

Methods inherited from class java.lang.Object

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

Constructor Details

CommandDistributionBehavior

public CommandDistributionBehavior(DistributionState distributionState,
 Writers writers,
 int currentPartition,
 RoutingInfo routingInfo,
 InterPartitionCommandSender partitionCommandSender)

Method Details

withKey

public CommandDistributionBehavior.RequestBuilder withKey(long distributionKey)

Starts a new command distribution request.

Parameters:

distributionKey - the key to identify this unique command distribution. The key is used to store the pending distribution, as the key of distributed command, to identify the distributing partition when processing the distributed command, and as the key to correlate the ACKNOWLEDGE command to the pending distribution. This can be a newly generated key, or the key identifying the entity that's being distributed. Please note that it must be unique for command distribution. Don't reuse the key to distribute another command. Don't reuse the key to distribute another command until the previous command distribution has been completed. Additionally, the key determines the order in which the commands are distributed if they are distributed ordered, i.e. a queue is specified.

acknowledgeCommand

public <T extends UnifiedRecordValue> void acknowledgeCommand(TypedRecord<T> command)

Acknowledges that a command was distributed to another partition successfully.

Parameters:

command - the command that was distributed