org.apache.flink.runtime.checkpoint

类 DefaultCompletedCheckpointStore<R extends ResourceVersion<R>>

java.lang.Object

org.apache.flink.runtime.checkpoint.AbstractCompleteCheckpointStore

org.apache.flink.runtime.checkpoint.DefaultCompletedCheckpointStore<R>

所有已实现的接口:

CompletedCheckpointStore

public class DefaultCompletedCheckpointStore<R extends ResourceVersion<R>>
extends AbstractCompleteCheckpointStore

Default implementation of CompletedCheckpointStore. Combined with different StateHandleStore, we could persist the completed checkpoints to various storage.

During recovery, the latest checkpoint is read from StateHandleStore. If there is more than one, only the latest one is used and older ones are discarded (even if the maximum number of retained checkpoints is greater than one).

If there is a network partition and multiple JobManagers run concurrent checkpoints for the same program, it is OK to take any valid successful checkpoint as long as the "history" of checkpoints is consistent. Currently, after recovery we start out with only a single checkpoint to circumvent those situations.

构造器概要

构造器

构造器和说明
DefaultCompletedCheckpointStore(int maxNumberOfCheckpointsToRetain, StateHandleStore<CompletedCheckpoint,R> stateHandleStore, CheckpointStoreUtil completedCheckpointStoreUtil, Collection<CompletedCheckpoint> completedCheckpoints, SharedStateRegistry sharedStateRegistry, Executor executor) Creates a DefaultCompletedCheckpointStore instance.

方法概要

限定符和类型	方法和说明
CompletedCheckpoint	addCheckpointAndSubsumeOldestOne(CompletedCheckpoint checkpoint, CheckpointsCleaner checkpointsCleaner, Runnable postCleanup) Synchronously writes the new checkpoints to state handle store and asynchronously removes older ones.
List<CompletedCheckpoint>	getAllCheckpoints() Returns all CompletedCheckpoint instances.
int	getMaxNumberOfRetainedCheckpoints() Returns the max number of retained checkpoints.
int	getNumberOfRetainedCheckpoints() Returns the current number of retained checkpoints.
boolean	requiresExternalizedCheckpoints() This method returns whether the completed checkpoint store requires checkpoints to be externalized.
void	shutdown(org.apache.flink.api.common.JobStatus jobStatus, CheckpointsCleaner checkpointsCleaner) Shuts down the store.

从类继承的方法 org.apache.flink.runtime.checkpoint.AbstractCompleteCheckpointStore

findLowest, getSharedStateRegistry, unregisterUnusedState

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.apache.flink.runtime.checkpoint.CompletedCheckpointStore

getLatestCheckpoint, getLatestCheckpointId

构造器详细资料

DefaultCompletedCheckpointStore

public DefaultCompletedCheckpointStore(int maxNumberOfCheckpointsToRetain,
                                       StateHandleStore<CompletedCheckpoint,R> stateHandleStore,
                                       CheckpointStoreUtil completedCheckpointStoreUtil,
                                       Collection<CompletedCheckpoint> completedCheckpoints,
                                       SharedStateRegistry sharedStateRegistry,
                                       Executor executor)

Creates a DefaultCompletedCheckpointStore instance.

参数:

maxNumberOfCheckpointsToRetain - The maximum number of checkpoints to retain (at least 1). Adding more checkpoints than this results in older checkpoints being discarded. On recovery, we will only start with a single checkpoint.

stateHandleStore - Completed checkpoints in external store

completedCheckpointStoreUtil - utilities for completed checkpoint store

executor - to execute blocking calls

方法详细资料

requiresExternalizedCheckpoints

public boolean requiresExternalizedCheckpoints()

从接口复制的说明: CompletedCheckpointStore

This method returns whether the completed checkpoint store requires checkpoints to be externalized. Externalized checkpoints have their meta data persisted, which the checkpoint store can exploit (for example by simply pointing the persisted metadata).

返回:

True, if the store requires that checkpoints are externalized before being added, false if the store stores the metadata itself.

addCheckpointAndSubsumeOldestOne

public CompletedCheckpoint addCheckpointAndSubsumeOldestOne(CompletedCheckpoint checkpoint,
                                                            CheckpointsCleaner checkpointsCleaner,
                                                            Runnable postCleanup)
                                                     throws Exception

Synchronously writes the new checkpoints to state handle store and asynchronously removes older ones.

参数:

checkpoint - Completed checkpoint to add.

返回:

the subsumed oldest completed checkpoint if possible, return null if no checkpoint needs to be discarded on subsume.

抛出:

PossibleInconsistentStateException - if adding the checkpoint failed and leaving the system in a possibly inconsistent state, i.e. it's uncertain whether the checkpoint metadata was fully written to the underlying systems or not.

Exception

getAllCheckpoints

public List<CompletedCheckpoint> getAllCheckpoints()

从接口复制的说明: CompletedCheckpointStore

Returns all CompletedCheckpoint instances.

Returns an empty list if no checkpoint has been added yet.

getNumberOfRetainedCheckpoints

public int getNumberOfRetainedCheckpoints()

从接口复制的说明: CompletedCheckpointStore

Returns the current number of retained checkpoints.

getMaxNumberOfRetainedCheckpoints

public int getMaxNumberOfRetainedCheckpoints()

从接口复制的说明: CompletedCheckpointStore

Returns the max number of retained checkpoints.

shutdown

public void shutdown(org.apache.flink.api.common.JobStatus jobStatus,
                     CheckpointsCleaner checkpointsCleaner)
              throws Exception

从接口复制的说明: CompletedCheckpointStore

Shuts down the store.

The job status is forwarded and used to decide whether state should actually be discarded or kept.

指定者:

shutdown 在接口中 CompletedCheckpointStore

覆盖:

shutdown 在类中 AbstractCompleteCheckpointStore

参数:

jobStatus - Job state on shut down

checkpointsCleaner - that will cleanup completed checkpoints if needed

抛出:

Exception