org.apache.samza.checkpoint

Interface CheckpointManager

public interface CheckpointManager

CheckpointManagers read and write Checkpoint to some implementation-specific location.

Method Summary

Modifier and Type	Method and Description
java.util.Map<TaskName,java.lang.Integer>	readChangeLogPartitionMapping() Read the taskName to partition mapping that is being maintained by this CheckpointManager
Checkpoint	readLastCheckpoint(TaskName taskName) Returns the last recorded checkpoint for a specified taskName.
void	register(TaskName taskName) Registers this manager to write checkpoints of a specific Samza stream partition.
void	start()
void	stop()
void	writeChangeLogPartitionMapping(java.util.Map<TaskName,java.lang.Integer> mapping) Write the taskName to partition mapping that is being maintained by this CheckpointManager
void	writeCheckpoint(TaskName taskName, Checkpoint checkpoint) Writes a checkpoint based on the current state of a Samza stream partition.

Method Detail

start

void start()

register

void register(TaskName taskName)

Registers this manager to write checkpoints of a specific Samza stream partition.

Parameters:

taskName - Specific Samza taskName of which to write checkpoints for.

writeCheckpoint

void writeCheckpoint(TaskName taskName,
                     Checkpoint checkpoint)

Writes a checkpoint based on the current state of a Samza stream partition.

Parameters:

taskName - Specific Samza taskName of which to write a checkpoint of.

checkpoint - Reference to a Checkpoint object to store offset data in.

readLastCheckpoint

Checkpoint readLastCheckpoint(TaskName taskName)

Returns the last recorded checkpoint for a specified taskName.

Parameters:

taskName - Specific Samza taskName for which to get the last checkpoint of.

Returns:

A Checkpoint object with the recorded offset data of the specified partition.

readChangeLogPartitionMapping

java.util.Map<TaskName,java.lang.Integer> readChangeLogPartitionMapping()

Read the taskName to partition mapping that is being maintained by this CheckpointManager

Returns:

TaskName to task log partition mapping, or an empty map if there were no messages.

writeChangeLogPartitionMapping

void writeChangeLogPartitionMapping(java.util.Map<TaskName,java.lang.Integer> mapping)

Write the taskName to partition mapping that is being maintained by this CheckpointManager

Parameters:

mapping - Each TaskName's partition within the changelog

stop

void stop()