org.apache.spark

Class ShuffleStatus

Object

org.apache.spark.ShuffleStatus

All Implemented Interfaces:

org.apache.spark.internal.Logging

public class ShuffleStatus
extends Object
implements org.apache.spark.internal.Logging

Helper class used by the MapOutputTrackerMaster to perform bookkeeping for a single ShuffleMapStage.

This class maintains a mapping from map index to MapStatus. It also maintains a cache of serialized map statuses in order to speed up tasks' requests for map output statuses.

All public methods of this class are thread-safe.

Constructor Summary

Constructors

Constructor and Description
ShuffleStatus(int numPartitions, int numReducers)

Method Summary

Modifier and Type	Method and Description
void	addMapOutput(int mapIndex, MapStatus status) Register a map output.
void	addMergeResult(int reduceId, org.apache.spark.scheduler.MergeStatus status) Register a merge result.
scala.collection.Seq<Object>	findMissingPartitions() Returns the sequence of partition ids that are missing (i.e.
boolean	hasCachedSerializedBroadcast()
void	invalidateSerializedMapOutputStatusCache() Clears the cached serialized map output statuses.
void	invalidateSerializedMergeOutputStatusCache() Clears the cached serialized merge result statuses.
MapStatus[]	mapStatuses() MapStatus for each partition.
MapStatus[]	mapStatusesDeleted() Keep the previous deleted MapStatus for recovery.
org.apache.spark.scheduler.MergeStatus[]	mergeStatuses() MergeStatus for each shuffle partition when push-based shuffle is enabled.
int	numAvailableMapOutputs() Number of partitions that have shuffle map outputs.
int	numAvailableMergeResults() Number of shuffle partitions that have already been merge finalized when push-based is enabled.
void	removeMapOutput(int mapIndex, BlockManagerId bmAddress) Remove the map output which was served by the specified block manager.
void	removeMergeResult(int reduceId, BlockManagerId bmAddress) Remove the merge result which was served by the specified block manager.
void	removeMergeResultsByFilter(scala.Function1<BlockManagerId,Object> f) Removes all shuffle merge result which satisfies the filter.
void	removeOutputsByFilter(scala.Function1<BlockManagerId,Object> f) Removes all shuffle outputs which satisfies the filter.
void	removeOutputsOnExecutor(String execId) Removes all map outputs associated with the specified executor.
void	removeOutputsOnHost(String host) Removes all shuffle outputs associated with this host.
scala.Tuple2<byte[],byte[]>	serializedMapAndMergeStatus(org.apache.spark.broadcast.BroadcastManager broadcastManager, boolean isLocal, int minBroadcastSize, SparkConf conf) Serializes the mapStatuses and mergeStatuses array into an efficient compressed format.
byte[]	serializedMapStatus(org.apache.spark.broadcast.BroadcastManager broadcastManager, boolean isLocal, int minBroadcastSize, SparkConf conf) Serializes the mapStatuses array into an efficient compressed format.
void	updateMapOutput(long mapId, BlockManagerId bmAddress) Update the map output location (e.g.
<T> T	withMapStatuses(scala.Function1<MapStatus[],T> f) Helper function which provides thread-safe access to the mapStatuses array.
<T> T	withMergeStatuses(scala.Function1<org.apache.spark.scheduler.MergeStatus[],T> f)

Methods inherited from class Object

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

Methods inherited from interface org.apache.spark.internal.Logging

$init$, initializeForcefully, initializeLogIfNecessary, initializeLogIfNecessary, initializeLogIfNecessary$default$2, initLock, isTraceEnabled, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning, org$apache$spark$internal$Logging$$log__$eq, org$apache$spark$internal$Logging$$log_, uninitialize

Constructor Detail

ShuffleStatus

public ShuffleStatus(int numPartitions,
                     int numReducers)

Method Detail

mapStatuses

public MapStatus[] mapStatuses()

MapStatus for each partition. The index of the array is the map partition id. Each value in the array is the MapStatus for a partition, or null if the partition is not available. Even though in theory a task may run multiple times (due to speculation, stage retries, etc.), in practice the likelihood of a map output being available at multiple locations is so small that we choose to ignore that case and store only a single location for each output.

Returns:

(undocumented)

mapStatusesDeleted

public MapStatus[] mapStatusesDeleted()

Keep the previous deleted MapStatus for recovery.

Returns:

(undocumented)

mergeStatuses

public org.apache.spark.scheduler.MergeStatus[] mergeStatuses()

MergeStatus for each shuffle partition when push-based shuffle is enabled. The index of the array is the shuffle partition id (reduce id). Each value in the array is the MergeStatus for a shuffle partition, or null if not available. When push-based shuffle is enabled, this array provides a reducer oriented view of the shuffle status specifically for the results of merging shuffle partition blocks into per-partition merged shuffle files.

Returns:

(undocumented)

addMapOutput

public void addMapOutput(int mapIndex,
                         MapStatus status)

Register a map output. If there is already a registered location for the map output then it will be replaced by the new location.

Parameters:

mapIndex - (undocumented)

status - (undocumented)

updateMapOutput

public void updateMapOutput(long mapId,
                            BlockManagerId bmAddress)

Update the map output location (e.g. during migration).

Parameters:

mapId - (undocumented)

bmAddress - (undocumented)

removeMapOutput

public void removeMapOutput(int mapIndex,
                            BlockManagerId bmAddress)

Remove the map output which was served by the specified block manager. This is a no-op if there is no registered map output or if the registered output is from a different block manager.

Parameters:

mapIndex - (undocumented)

bmAddress - (undocumented)

addMergeResult

public void addMergeResult(int reduceId,
                           org.apache.spark.scheduler.MergeStatus status)

Register a merge result.

Parameters:

reduceId - (undocumented)

status - (undocumented)

removeMergeResult

public void removeMergeResult(int reduceId,
                              BlockManagerId bmAddress)

Remove the merge result which was served by the specified block manager.

Parameters:

reduceId - (undocumented)

bmAddress - (undocumented)

removeOutputsOnHost

public void removeOutputsOnHost(String host)

Removes all shuffle outputs associated with this host. Note that this will also remove outputs which are served by an external shuffle server (if one exists).

Parameters:

host - (undocumented)

removeOutputsOnExecutor

public void removeOutputsOnExecutor(String execId)

Removes all map outputs associated with the specified executor. Note that this will also remove outputs which are served by an external shuffle server (if one exists), as they are still registered with that execId.

Parameters:

execId - (undocumented)

removeOutputsByFilter

public void removeOutputsByFilter(scala.Function1<BlockManagerId,Object> f)

Removes all shuffle outputs which satisfies the filter. Note that this will also remove outputs which are served by an external shuffle server (if one exists).

Parameters:

f - (undocumented)

removeMergeResultsByFilter

public void removeMergeResultsByFilter(scala.Function1<BlockManagerId,Object> f)

Removes all shuffle merge result which satisfies the filter.

Parameters:

f - (undocumented)

numAvailableMapOutputs

public int numAvailableMapOutputs()

Number of partitions that have shuffle map outputs.

Returns:

(undocumented)

numAvailableMergeResults

public int numAvailableMergeResults()

Number of shuffle partitions that have already been merge finalized when push-based is enabled.

Returns:

(undocumented)

findMissingPartitions

public scala.collection.Seq<Object> findMissingPartitions()

Returns the sequence of partition ids that are missing (i.e. needs to be computed).

Returns:

(undocumented)

serializedMapStatus

public byte[] serializedMapStatus(org.apache.spark.broadcast.BroadcastManager broadcastManager,
                                  boolean isLocal,
                                  int minBroadcastSize,
                                  SparkConf conf)

Serializes the mapStatuses array into an efficient compressed format. See the comments on MapOutputTracker.serializeOutputStatuses() for more details on the serialization format.

This method is designed to be called multiple times and implements caching in order to speed up subsequent requests. If the cache is empty and multiple threads concurrently attempt to serialize the map statuses then serialization will only be performed in a single thread and all other threads will block until the cache is populated.

Parameters:

broadcastManager - (undocumented)

isLocal - (undocumented)

minBroadcastSize - (undocumented)

conf - (undocumented)

Returns:

(undocumented)

serializedMapAndMergeStatus

public scala.Tuple2<byte[],byte[]> serializedMapAndMergeStatus(org.apache.spark.broadcast.BroadcastManager broadcastManager,
                                                               boolean isLocal,
                                                               int minBroadcastSize,
                                                               SparkConf conf)

Serializes the mapStatuses and mergeStatuses array into an efficient compressed format. See the comments on MapOutputTracker.serializeOutputStatuses() for more details on the serialization format.

This method is designed to be called multiple times and implements caching in order to speed up subsequent requests. If the cache is empty and multiple threads concurrently attempt to serialize the statuses array then serialization will only be performed in a single thread and all other threads will block until the cache is populated.

Parameters:

broadcastManager - (undocumented)

isLocal - (undocumented)

minBroadcastSize - (undocumented)

conf - (undocumented)

Returns:

(undocumented)

hasCachedSerializedBroadcast

public boolean hasCachedSerializedBroadcast()

withMapStatuses

public <T> T withMapStatuses(scala.Function1<MapStatus[],T> f)

Helper function which provides thread-safe access to the mapStatuses array. The function should NOT mutate the array.

Parameters:

f - (undocumented)

Returns:

(undocumented)

withMergeStatuses

public <T> T withMergeStatuses(scala.Function1<org.apache.spark.scheduler.MergeStatus[],T> f)

invalidateSerializedMapOutputStatusCache

public void invalidateSerializedMapOutputStatusCache()

Clears the cached serialized map output statuses.

invalidateSerializedMergeOutputStatusCache

public void invalidateSerializedMergeOutputStatusCache()

Clears the cached serialized merge result statuses.