mridulm commented on a change in pull request #32140:
URL: https://github.com/apache/spark/pull/32140#discussion_r649690353
##########
File path:
core/src/main/scala/org/apache/spark/storage/ShuffleBlockFetcherIterator.scala
##########
@@ -347,20 +361,48 @@ final class ShuffleBlockFetcherIterator(
}
}
- private[this] def partitionBlocksByFetchMode(): ArrayBuffer[FetchRequest] = {
+ /**
+ * This is called from initialize and also from the fallback which is
triggered from
+ * [[PushBasedFetchHelper]].
+ */
+ private[this] def partitionBlocksByFetchMode(
+ blocksByAddress: Iterator[(BlockManagerId, Seq[(BlockId, Long, Int)])],
+ localBlocks: scala.collection.mutable.LinkedHashSet[(BlockId, Int)],
Review comment:
Looks like my comments overlapped with @Ngone51's comments a lot :-)
##########
File path:
core/src/main/scala/org/apache/spark/storage/PushBasedFetchHelper.scala
##########
@@ -0,0 +1,289 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.storage
+
+import java.util.concurrent.TimeUnit
+
+import scala.collection.mutable
+import scala.collection.mutable.ArrayBuffer
+import scala.util.{Failure, Success}
+
+import org.roaringbitmap.RoaringBitmap
+
+import org.apache.spark.MapOutputTracker
+import org.apache.spark.MapOutputTracker.SHUFFLE_PUSH_MAP_ID
+import org.apache.spark.internal.Logging
+import org.apache.spark.network.buffer.ManagedBuffer
+import org.apache.spark.network.shuffle.{BlockStoreClient, MergedBlockMeta,
MergedBlocksMetaListener}
+import org.apache.spark.storage.BlockManagerId.SHUFFLE_MERGER_IDENTIFIER
+import org.apache.spark.storage.ShuffleBlockFetcherIterator._
+
+/**
+ * Helper class for [[ShuffleBlockFetcherIterator]] that encapsulates all the
push-based
+ * functionality to fetch merged block meta and merged shuffle block chunks.
+ */
+private class PushBasedFetchHelper(
+ private val iterator: ShuffleBlockFetcherIterator,
+ private val shuffleClient: BlockStoreClient,
+ private val blockManager: BlockManager,
+ private val mapOutputTracker: MapOutputTracker) extends Logging {
+
+ private[this] val startTimeNs = System.nanoTime()
+
+ private[this] val localShuffleMergerBlockMgrId = BlockManagerId(
+ SHUFFLE_MERGER_IDENTIFIER, blockManager.blockManagerId.host,
+ blockManager.blockManagerId.port, blockManager.blockManagerId.topologyInfo)
+
+ /** A map for storing merged block shuffle chunk bitmap */
+ private[this] val chunksMetaMap = new mutable.HashMap[ShuffleBlockChunkId,
RoaringBitmap]()
+
+ /**
+ * Returns true if the address is for a push-merged block.
+ */
+ def isMergedShuffleBlockAddress(address: BlockManagerId): Boolean = {
+ SHUFFLE_MERGER_IDENTIFIER.equals(address.executorId)
+ }
+
+ /**
+ * Returns true if the address is not of executor local or merged local
block. false otherwise.
+ */
+ def isNotExecutorOrMergedLocal(address: BlockManagerId): Boolean = {
+ (isMergedShuffleBlockAddress(address) && address.host !=
blockManager.blockManagerId.host) ||
+ (!isMergedShuffleBlockAddress(address) && address !=
blockManager.blockManagerId)
+ }
+
+ /**
+ * Returns true if the address if of merged local block. false otherwise.
+ */
+ def isMergedLocal(address: BlockManagerId): Boolean = {
+ isMergedShuffleBlockAddress(address) && address.host ==
blockManager.blockManagerId.host
+ }
+
+ def getNumberOfBlocksInChunk(blockId : ShuffleBlockChunkId): Int = {
+ chunksMetaMap(blockId).getCardinality
+ }
+
+ def removeChunk(blockId: ShuffleBlockChunkId): Unit = {
+ chunksMetaMap.remove(blockId)
+ }
+
+ def createChunkBlockInfosFromMetaResponse(
+ shuffleId: Int,
+ reduceId: Int,
+ blockSize: Long,
+ numChunks: Int,
+ bitmaps: Array[RoaringBitmap]): ArrayBuffer[(BlockId, Long, Int)] = {
+ val approxChunkSize = blockSize / numChunks
+ val blocksToFetch = new ArrayBuffer[(BlockId, Long, Int)]()
+ for (i <- 0 until numChunks) {
+ val blockChunkId = ShuffleBlockChunkId(shuffleId, reduceId, i)
+ chunksMetaMap.put(blockChunkId, bitmaps(i))
+ logDebug(s"adding block chunk $blockChunkId of size $approxChunkSize")
+ blocksToFetch += ((blockChunkId, approxChunkSize, SHUFFLE_PUSH_MAP_ID))
+ }
+ blocksToFetch
+ }
+
+ def sendFetchMergedStatusRequest(req: FetchRequest): Unit = {
+ val sizeMap = req.blocks.map {
+ case FetchBlockInfo(blockId, size, _) =>
+ val shuffleBlockId = blockId.asInstanceOf[ShuffleBlockId]
+ ((shuffleBlockId.shuffleId, shuffleBlockId.reduceId), size)}.toMap
+ val address = req.address
+ val mergedBlocksMetaListener = new MergedBlocksMetaListener {
+ override def onSuccess(shuffleId: Int, reduceId: Int, meta:
MergedBlockMeta): Unit = {
+ logInfo(s"Received the meta of merged block for ($shuffleId,
$reduceId) " +
+ s"from ${req.address.host}:${req.address.port}")
+ try {
+ iterator.addToResultsQueue(MergedBlocksMetaFetchResult(shuffleId,
reduceId,
+ sizeMap((shuffleId, reduceId)), meta.getNumChunks,
meta.readChunkBitmaps(), address))
+ } catch {
+ case exception: Throwable =>
Review comment:
The problem with catching `Throwable` is it might suppress cases which
should not be handled - like ignoring some Error like OOM for example
(ofcourse, an OOM will typically result in other failures as well : but I am
simply illustrating the issue).
Catching Exception should suffice here.
There are indeed some cases which have slipped through (catching Throwable),
but those are not common.
##########
File path:
core/src/main/scala/org/apache/spark/storage/PushBasedFetchHelper.scala
##########
@@ -0,0 +1,289 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.storage
+
+import java.util.concurrent.TimeUnit
+
+import scala.collection.mutable
+import scala.collection.mutable.ArrayBuffer
+import scala.util.{Failure, Success}
+
+import org.roaringbitmap.RoaringBitmap
+
+import org.apache.spark.MapOutputTracker
+import org.apache.spark.MapOutputTracker.SHUFFLE_PUSH_MAP_ID
+import org.apache.spark.internal.Logging
+import org.apache.spark.network.buffer.ManagedBuffer
+import org.apache.spark.network.shuffle.{BlockStoreClient, MergedBlockMeta,
MergedBlocksMetaListener}
+import org.apache.spark.storage.BlockManagerId.SHUFFLE_MERGER_IDENTIFIER
+import org.apache.spark.storage.ShuffleBlockFetcherIterator._
+
+/**
+ * Helper class for [[ShuffleBlockFetcherIterator]] that encapsulates all the
push-based
+ * functionality to fetch merged block meta and merged shuffle block chunks.
+ */
+private class PushBasedFetchHelper(
+ private val iterator: ShuffleBlockFetcherIterator,
+ private val shuffleClient: BlockStoreClient,
+ private val blockManager: BlockManager,
+ private val mapOutputTracker: MapOutputTracker) extends Logging {
+
+ private[this] val startTimeNs = System.nanoTime()
+
+ private[this] val localShuffleMergerBlockMgrId = BlockManagerId(
+ SHUFFLE_MERGER_IDENTIFIER, blockManager.blockManagerId.host,
+ blockManager.blockManagerId.port, blockManager.blockManagerId.topologyInfo)
+
+ /** A map for storing merged block shuffle chunk bitmap */
+ private[this] val chunksMetaMap = new mutable.HashMap[ShuffleBlockChunkId,
RoaringBitmap]()
+
+ /**
+ * Returns true if the address is for a push-merged block.
+ */
+ def isMergedShuffleBlockAddress(address: BlockManagerId): Boolean = {
+ SHUFFLE_MERGER_IDENTIFIER.equals(address.executorId)
+ }
+
+ /**
+ * Returns true if the address is not of executor local or merged local
block. false otherwise.
+ */
+ def isNotExecutorOrMergedLocal(address: BlockManagerId): Boolean = {
+ (isMergedShuffleBlockAddress(address) && address.host !=
blockManager.blockManagerId.host) ||
+ (!isMergedShuffleBlockAddress(address) && address !=
blockManager.blockManagerId)
+ }
+
+ /**
+ * Returns true if the address if of merged local block. false otherwise.
+ */
+ def isMergedLocal(address: BlockManagerId): Boolean = {
+ isMergedShuffleBlockAddress(address) && address.host ==
blockManager.blockManagerId.host
+ }
+
+ def getNumberOfBlocksInChunk(blockId : ShuffleBlockChunkId): Int = {
+ chunksMetaMap(blockId).getCardinality
+ }
+
+ def removeChunk(blockId: ShuffleBlockChunkId): Unit = {
+ chunksMetaMap.remove(blockId)
+ }
+
+ def createChunkBlockInfosFromMetaResponse(
+ shuffleId: Int,
+ reduceId: Int,
+ blockSize: Long,
+ numChunks: Int,
+ bitmaps: Array[RoaringBitmap]): ArrayBuffer[(BlockId, Long, Int)] = {
+ val approxChunkSize = blockSize / numChunks
+ val blocksToFetch = new ArrayBuffer[(BlockId, Long, Int)]()
+ for (i <- 0 until numChunks) {
+ val blockChunkId = ShuffleBlockChunkId(shuffleId, reduceId, i)
+ chunksMetaMap.put(blockChunkId, bitmaps(i))
+ logDebug(s"adding block chunk $blockChunkId of size $approxChunkSize")
+ blocksToFetch += ((blockChunkId, approxChunkSize, SHUFFLE_PUSH_MAP_ID))
+ }
+ blocksToFetch
+ }
+
+ def sendFetchMergedStatusRequest(req: FetchRequest): Unit = {
+ val sizeMap = req.blocks.map {
+ case FetchBlockInfo(blockId, size, _) =>
+ val shuffleBlockId = blockId.asInstanceOf[ShuffleBlockId]
+ ((shuffleBlockId.shuffleId, shuffleBlockId.reduceId), size)}.toMap
+ val address = req.address
+ val mergedBlocksMetaListener = new MergedBlocksMetaListener {
+ override def onSuccess(shuffleId: Int, reduceId: Int, meta:
MergedBlockMeta): Unit = {
+ logInfo(s"Received the meta of merged block for ($shuffleId,
$reduceId) " +
+ s"from ${req.address.host}:${req.address.port}")
+ try {
+ iterator.addToResultsQueue(MergedBlocksMetaFetchResult(shuffleId,
reduceId,
+ sizeMap((shuffleId, reduceId)), meta.getNumChunks,
meta.readChunkBitmaps(), address))
+ } catch {
+ case exception: Throwable =>
+ logError(s"Failed to parse the meta of merged block for
($shuffleId, $reduceId) " +
+ s"from ${req.address.host}:${req.address.port}", exception)
+ iterator.addToResultsQueue(
+ MergedBlocksMetaFailedFetchResult(shuffleId, reduceId, address))
+ }
+ }
+
+ override def onFailure(shuffleId: Int, reduceId: Int, exception:
Throwable): Unit = {
+ logError(s"Failed to get the meta of merged block for ($shuffleId,
$reduceId) " +
+ s"from ${req.address.host}:${req.address.port}", exception)
+
iterator.addToResultsQueue(MergedBlocksMetaFailedFetchResult(shuffleId,
reduceId, address))
+ }
+ }
+ req.blocks.foreach { block =>
+ val shuffleBlockId = block.blockId.asInstanceOf[ShuffleBlockId]
+ shuffleClient.getMergedBlockMeta(address.host, address.port,
shuffleBlockId.shuffleId,
+ shuffleBlockId.reduceId, mergedBlocksMetaListener)
+ }
+ }
+
+ // Fetch all outstanding merged local blocks
+ def fetchAllMergedLocalBlocks(
+ mergedLocalBlocks: mutable.LinkedHashSet[BlockId]): Unit = {
+ if (mergedLocalBlocks.nonEmpty) {
+ blockManager.hostLocalDirManager.foreach(fetchMergedLocalBlocks(_,
mergedLocalBlocks))
+ }
+ }
+
+ /**
+ * Fetch the merged blocks dirs if they are not in the cache and eventually
fetch merged local
+ * blocks.
+ */
+ private def fetchMergedLocalBlocks(
+ hostLocalDirManager: HostLocalDirManager,
+ mergedLocalBlocks: mutable.LinkedHashSet[BlockId]): Unit = {
+ val cachedMergerDirs = hostLocalDirManager.getCachedHostLocalDirs.get(
+ SHUFFLE_MERGER_IDENTIFIER)
+ if (cachedMergerDirs.isDefined) {
+ logDebug(s"Fetching local merged blocks with cached executors dir: " +
+ s"${cachedMergerDirs.get.mkString(", ")}")
+ mergedLocalBlocks.foreach(blockId =>
+ fetchMergedLocalBlock(blockId, cachedMergerDirs.get,
localShuffleMergerBlockMgrId))
+ } else {
+ logDebug(s"Asynchronous fetching local merged blocks without cached
executors dir")
+ hostLocalDirManager.getHostLocalDirs(localShuffleMergerBlockMgrId.host,
+ localShuffleMergerBlockMgrId.port, Array(SHUFFLE_MERGER_IDENTIFIER)) {
+ case Success(dirs) =>
+ mergedLocalBlocks.takeWhile {
+ blockId =>
+ logDebug(s"Successfully fetched local dirs: " +
+ s"${dirs.get(SHUFFLE_MERGER_IDENTIFIER).mkString(", ")}")
+ fetchMergedLocalBlock(blockId, dirs(SHUFFLE_MERGER_IDENTIFIER),
+ localShuffleMergerBlockMgrId)
+ }
+ logDebug(s"Got local merged blocks (without cached executors' dir)
in " +
+ s"${TimeUnit.NANOSECONDS.toMillis(System.nanoTime() -
startTimeNs)} ms")
+ case Failure(throwable) =>
+ // If we see an exception with getting the local dirs for local
merged blocks,
+ // we fallback to fetch the original unmerged blocks. We do not
report block fetch
+ // failure.
+ logWarning(s"Error occurred while getting the local dirs for local
merged " +
+ s"blocks: ${mergedLocalBlocks.mkString(", ")}. Fetch the original
blocks instead",
+ throwable)
+ mergedLocalBlocks.foreach(
+ blockId => iterator.addToResultsQueue(
+ IgnoreFetchResult(blockId, localShuffleMergerBlockMgrId, 0,
isNetworkReqDone = false))
+ )
+ }
+ }
+ }
+
+ /**
+ * Fetch a single local merged block generated.
+ * @param blockId ShuffleBlockId to be fetched
+ * @param localDirs Local directories where the merged shuffle files are
stored
+ * @param blockManagerId BlockManagerId
+ * @return Boolean represents successful or failed fetch
+ */
+ private[this] def fetchMergedLocalBlock(
+ blockId: BlockId,
+ localDirs: Array[String],
+ blockManagerId: BlockManagerId): Boolean = {
+ try {
+ val shuffleBlockId = blockId.asInstanceOf[ShuffleBlockId]
+ val chunksMeta = blockManager.getMergedBlockMeta(shuffleBlockId,
localDirs)
+ .readChunkBitmaps()
+ // Fetch local merged shuffle block data as multiple chunks
+ val bufs: Seq[ManagedBuffer] =
blockManager.getMergedBlockData(shuffleBlockId, localDirs)
+ // Update total number of blocks to fetch, reflecting the multiple local
chunks
+ iterator.foundMoreBlocksToFetch(bufs.size - 1)
+ for (chunkId <- bufs.indices) {
+ val buf = bufs(chunkId)
+ buf.retain()
+ val shuffleChunkId = ShuffleBlockChunkId(shuffleBlockId.shuffleId,
+ shuffleBlockId.reduceId, chunkId)
+ iterator.addToResultsQueue(
+ SuccessFetchResult(shuffleChunkId, SHUFFLE_PUSH_MAP_ID,
blockManagerId, buf.size(), buf,
+ isNetworkReqDone = false))
+ chunksMetaMap.put(shuffleChunkId, chunksMeta(chunkId))
+ }
+ true
+ } catch {
+ case e: Exception =>
+ // If we see an exception with reading a local merged block, we
fallback to
+ // fetch the original unmerged blocks. We do not report block fetch
failure
+ // and will continue with the remaining local block read.
+ logWarning(s"Error occurred while fetching local merged block, " +
+ s"prepare to fetch the original blocks", e)
+ iterator.addToResultsQueue(
+ IgnoreFetchResult(blockId, blockManagerId, 0, isNetworkReqDone =
false))
+ false
+ }
+ }
+
+ /**
+ * Initiate fetching fallback blocks for a merged block (or a merged block
chunk) that's failed
+ * to fetch.
+ * It calls out to map output tracker to get the list of original blocks for
the
+ * given merged blocks, split them into remote and local blocks, and process
them
+ * accordingly.
+ * The fallback happens when:
+ * 1. There is an exception while creating shuffle block chunk from local
merged shuffle block.
+ * See fetchLocalBlock.
+ * 2. There is a failure when fetching remote shuffle block chunks.
+ * 3. There is a failure when processing SuccessFetchResult which is for a
shuffle chunk
+ * (local or remote).
+ *
+ * @return number of blocks processed
+ */
+ def initiateFallbackBlockFetchForMergedBlock(
+ blockId: BlockId,
+ address: BlockManagerId): Int = {
+ logWarning(s"Falling back to fetch the original unmerged blocks for merged
block $blockId")
+ // Increase the blocks processed since we will process another block in
the next iteration of
+ // the while loop in ShuffleBlockFetcherIterator.next().
+ var blocksProcessed = 1
+ val fallbackBlocksByAddr: Iterator[(BlockManagerId, Seq[(BlockId, Long,
Int)])] =
+ if (blockId.isShuffle) {
+ val shuffleBlockId = blockId.asInstanceOf[ShuffleBlockId]
+ mapOutputTracker.getMapSizesForMergeResult(
+ shuffleBlockId.shuffleId, shuffleBlockId.reduceId)
+ } else {
+ val shuffleChunkId = blockId.asInstanceOf[ShuffleBlockChunkId]
+ val chunkBitmap: RoaringBitmap =
chunksMetaMap.remove(shuffleChunkId).orNull
+ // When there is a failure to fetch a remote merged shuffle block
chunk, then we try to
+ // fallback not only for that particular remote shuffle block chunk
but also for all the
+ // pending block chunks that belong to the same host. The reason for
doing so is that it is
+ // very likely that the subsequent requests for merged block chunks
from this host will fail
+ // as well. Since, push-based shuffle is best effort and we try not to
increase the delay
+ // of the fetches, we immediately fallback for all the pending shuffle
chunks in the
+ // fetchRequests queue.
+ if (isNotExecutorOrMergedLocal(address)) {
+ // Fallback for all the pending fetch requests
+ val pendingShuffleChunks =
iterator.removePendingChunks(shuffleChunkId, address)
+ if (pendingShuffleChunks.nonEmpty) {
+ pendingShuffleChunks.foreach { pendingBlockId =>
+ logWarning(s"Falling back immediately for merged block
$pendingBlockId")
+ val bitmapOfPendingChunk: RoaringBitmap =
+ chunksMetaMap.remove(pendingBlockId).orNull
+ assert(bitmapOfPendingChunk != null)
+ chunkBitmap.or(bitmapOfPendingChunk)
Review comment:
If we are sure it cant be null, replace `orNull` with `get` instead ? It
makes the semantics clearer.
I am fine with leaving it with `assert` check as well.
##########
File path:
core/src/main/scala/org/apache/spark/storage/PushBasedFetchHelper.scala
##########
@@ -0,0 +1,289 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.storage
+
+import java.util.concurrent.TimeUnit
+
+import scala.collection.mutable
+import scala.collection.mutable.ArrayBuffer
+import scala.util.{Failure, Success}
+
+import org.roaringbitmap.RoaringBitmap
+
+import org.apache.spark.MapOutputTracker
+import org.apache.spark.MapOutputTracker.SHUFFLE_PUSH_MAP_ID
+import org.apache.spark.internal.Logging
+import org.apache.spark.network.buffer.ManagedBuffer
+import org.apache.spark.network.shuffle.{BlockStoreClient, MergedBlockMeta,
MergedBlocksMetaListener}
+import org.apache.spark.storage.BlockManagerId.SHUFFLE_MERGER_IDENTIFIER
+import org.apache.spark.storage.ShuffleBlockFetcherIterator._
+
+/**
+ * Helper class for [[ShuffleBlockFetcherIterator]] that encapsulates all the
push-based
+ * functionality to fetch merged block meta and merged shuffle block chunks.
+ */
+private class PushBasedFetchHelper(
+ private val iterator: ShuffleBlockFetcherIterator,
+ private val shuffleClient: BlockStoreClient,
+ private val blockManager: BlockManager,
+ private val mapOutputTracker: MapOutputTracker) extends Logging {
+
+ private[this] val startTimeNs = System.nanoTime()
+
+ private[this] val localShuffleMergerBlockMgrId = BlockManagerId(
+ SHUFFLE_MERGER_IDENTIFIER, blockManager.blockManagerId.host,
+ blockManager.blockManagerId.port, blockManager.blockManagerId.topologyInfo)
+
+ /** A map for storing merged block shuffle chunk bitmap */
+ private[this] val chunksMetaMap = new mutable.HashMap[ShuffleBlockChunkId,
RoaringBitmap]()
+
+ /**
+ * Returns true if the address is for a push-merged block.
+ */
+ def isMergedShuffleBlockAddress(address: BlockManagerId): Boolean = {
+ SHUFFLE_MERGER_IDENTIFIER.equals(address.executorId)
+ }
+
+ /**
+ * Returns true if the address is not of executor local or merged local
block. false otherwise.
+ */
+ def isNotExecutorOrMergedLocal(address: BlockManagerId): Boolean = {
+ (isMergedShuffleBlockAddress(address) && address.host !=
blockManager.blockManagerId.host) ||
+ (!isMergedShuffleBlockAddress(address) && address !=
blockManager.blockManagerId)
+ }
+
+ /**
+ * Returns true if the address if of merged local block. false otherwise.
+ */
+ def isMergedLocal(address: BlockManagerId): Boolean = {
+ isMergedShuffleBlockAddress(address) && address.host ==
blockManager.blockManagerId.host
+ }
+
+ def getNumberOfBlocksInChunk(blockId : ShuffleBlockChunkId): Int = {
+ chunksMetaMap(blockId).getCardinality
+ }
+
+ def removeChunk(blockId: ShuffleBlockChunkId): Unit = {
+ chunksMetaMap.remove(blockId)
+ }
+
+ def createChunkBlockInfosFromMetaResponse(
+ shuffleId: Int,
+ reduceId: Int,
+ blockSize: Long,
+ numChunks: Int,
+ bitmaps: Array[RoaringBitmap]): ArrayBuffer[(BlockId, Long, Int)] = {
+ val approxChunkSize = blockSize / numChunks
+ val blocksToFetch = new ArrayBuffer[(BlockId, Long, Int)]()
+ for (i <- 0 until numChunks) {
+ val blockChunkId = ShuffleBlockChunkId(shuffleId, reduceId, i)
+ chunksMetaMap.put(blockChunkId, bitmaps(i))
+ logDebug(s"adding block chunk $blockChunkId of size $approxChunkSize")
+ blocksToFetch += ((blockChunkId, approxChunkSize, SHUFFLE_PUSH_MAP_ID))
+ }
+ blocksToFetch
+ }
+
+ def sendFetchMergedStatusRequest(req: FetchRequest): Unit = {
+ val sizeMap = req.blocks.map {
+ case FetchBlockInfo(blockId, size, _) =>
+ val shuffleBlockId = blockId.asInstanceOf[ShuffleBlockId]
+ ((shuffleBlockId.shuffleId, shuffleBlockId.reduceId), size)}.toMap
+ val address = req.address
+ val mergedBlocksMetaListener = new MergedBlocksMetaListener {
+ override def onSuccess(shuffleId: Int, reduceId: Int, meta:
MergedBlockMeta): Unit = {
+ logInfo(s"Received the meta of merged block for ($shuffleId,
$reduceId) " +
+ s"from ${req.address.host}:${req.address.port}")
+ try {
+ iterator.addToResultsQueue(MergedBlocksMetaFetchResult(shuffleId,
reduceId,
+ sizeMap((shuffleId, reduceId)), meta.getNumChunks,
meta.readChunkBitmaps(), address))
+ } catch {
+ case exception: Throwable =>
+ logError(s"Failed to parse the meta of merged block for
($shuffleId, $reduceId) " +
+ s"from ${req.address.host}:${req.address.port}", exception)
+ iterator.addToResultsQueue(
+ MergedBlocksMetaFailedFetchResult(shuffleId, reduceId, address))
+ }
+ }
+
+ override def onFailure(shuffleId: Int, reduceId: Int, exception:
Throwable): Unit = {
+ logError(s"Failed to get the meta of merged block for ($shuffleId,
$reduceId) " +
+ s"from ${req.address.host}:${req.address.port}", exception)
+
iterator.addToResultsQueue(MergedBlocksMetaFailedFetchResult(shuffleId,
reduceId, address))
+ }
+ }
+ req.blocks.foreach { block =>
+ val shuffleBlockId = block.blockId.asInstanceOf[ShuffleBlockId]
+ shuffleClient.getMergedBlockMeta(address.host, address.port,
shuffleBlockId.shuffleId,
+ shuffleBlockId.reduceId, mergedBlocksMetaListener)
+ }
+ }
+
+ // Fetch all outstanding merged local blocks
+ def fetchAllMergedLocalBlocks(
+ mergedLocalBlocks: mutable.LinkedHashSet[BlockId]): Unit = {
+ if (mergedLocalBlocks.nonEmpty) {
+ blockManager.hostLocalDirManager.foreach(fetchMergedLocalBlocks(_,
mergedLocalBlocks))
+ }
+ }
+
+ /**
+ * Fetch the merged blocks dirs if they are not in the cache and eventually
fetch merged local
+ * blocks.
+ */
+ private def fetchMergedLocalBlocks(
+ hostLocalDirManager: HostLocalDirManager,
+ mergedLocalBlocks: mutable.LinkedHashSet[BlockId]): Unit = {
+ val cachedMergerDirs = hostLocalDirManager.getCachedHostLocalDirs.get(
+ SHUFFLE_MERGER_IDENTIFIER)
+ if (cachedMergerDirs.isDefined) {
+ logDebug(s"Fetching local merged blocks with cached executors dir: " +
+ s"${cachedMergerDirs.get.mkString(", ")}")
+ mergedLocalBlocks.foreach(blockId =>
+ fetchMergedLocalBlock(blockId, cachedMergerDirs.get,
localShuffleMergerBlockMgrId))
+ } else {
+ logDebug(s"Asynchronous fetching local merged blocks without cached
executors dir")
+ hostLocalDirManager.getHostLocalDirs(localShuffleMergerBlockMgrId.host,
+ localShuffleMergerBlockMgrId.port, Array(SHUFFLE_MERGER_IDENTIFIER)) {
+ case Success(dirs) =>
+ mergedLocalBlocks.takeWhile {
+ blockId =>
+ logDebug(s"Successfully fetched local dirs: " +
+ s"${dirs.get(SHUFFLE_MERGER_IDENTIFIER).mkString(", ")}")
+ fetchMergedLocalBlock(blockId, dirs(SHUFFLE_MERGER_IDENTIFIER),
+ localShuffleMergerBlockMgrId)
+ }
+ logDebug(s"Got local merged blocks (without cached executors' dir)
in " +
+ s"${TimeUnit.NANOSECONDS.toMillis(System.nanoTime() -
startTimeNs)} ms")
+ case Failure(throwable) =>
+ // If we see an exception with getting the local dirs for local
merged blocks,
+ // we fallback to fetch the original unmerged blocks. We do not
report block fetch
+ // failure.
+ logWarning(s"Error occurred while getting the local dirs for local
merged " +
+ s"blocks: ${mergedLocalBlocks.mkString(", ")}. Fetch the original
blocks instead",
+ throwable)
+ mergedLocalBlocks.foreach(
+ blockId => iterator.addToResultsQueue(
+ IgnoreFetchResult(blockId, localShuffleMergerBlockMgrId, 0,
isNetworkReqDone = false))
+ )
+ }
+ }
+ }
+
+ /**
+ * Fetch a single local merged block generated.
+ * @param blockId ShuffleBlockId to be fetched
+ * @param localDirs Local directories where the merged shuffle files are
stored
+ * @param blockManagerId BlockManagerId
+ * @return Boolean represents successful or failed fetch
+ */
+ private[this] def fetchMergedLocalBlock(
+ blockId: BlockId,
+ localDirs: Array[String],
+ blockManagerId: BlockManagerId): Boolean = {
+ try {
+ val shuffleBlockId = blockId.asInstanceOf[ShuffleBlockId]
+ val chunksMeta = blockManager.getMergedBlockMeta(shuffleBlockId,
localDirs)
+ .readChunkBitmaps()
+ // Fetch local merged shuffle block data as multiple chunks
+ val bufs: Seq[ManagedBuffer] =
blockManager.getMergedBlockData(shuffleBlockId, localDirs)
+ // Update total number of blocks to fetch, reflecting the multiple local
chunks
+ iterator.foundMoreBlocksToFetch(bufs.size - 1)
+ for (chunkId <- bufs.indices) {
+ val buf = bufs(chunkId)
+ buf.retain()
+ val shuffleChunkId = ShuffleBlockChunkId(shuffleBlockId.shuffleId,
+ shuffleBlockId.reduceId, chunkId)
+ iterator.addToResultsQueue(
+ SuccessFetchResult(shuffleChunkId, SHUFFLE_PUSH_MAP_ID,
blockManagerId, buf.size(), buf,
+ isNetworkReqDone = false))
+ chunksMetaMap.put(shuffleChunkId, chunksMeta(chunkId))
+ }
+ true
+ } catch {
+ case e: Exception =>
+ // If we see an exception with reading a local merged block, we
fallback to
+ // fetch the original unmerged blocks. We do not report block fetch
failure
+ // and will continue with the remaining local block read.
+ logWarning(s"Error occurred while fetching local merged block, " +
+ s"prepare to fetch the original blocks", e)
+ iterator.addToResultsQueue(
+ IgnoreFetchResult(blockId, blockManagerId, 0, isNetworkReqDone =
false))
+ false
+ }
+ }
+
+ /**
+ * Initiate fetching fallback blocks for a merged block (or a merged block
chunk) that's failed
+ * to fetch.
+ * It calls out to map output tracker to get the list of original blocks for
the
+ * given merged blocks, split them into remote and local blocks, and process
them
+ * accordingly.
+ * The fallback happens when:
+ * 1. There is an exception while creating shuffle block chunk from local
merged shuffle block.
+ * See fetchLocalBlock.
+ * 2. There is a failure when fetching remote shuffle block chunks.
+ * 3. There is a failure when processing SuccessFetchResult which is for a
shuffle chunk
+ * (local or remote).
+ *
+ * @return number of blocks processed
+ */
+ def initiateFallbackBlockFetchForMergedBlock(
+ blockId: BlockId,
+ address: BlockManagerId): Int = {
+ logWarning(s"Falling back to fetch the original unmerged blocks for merged
block $blockId")
+ // Increase the blocks processed since we will process another block in
the next iteration of
+ // the while loop in ShuffleBlockFetcherIterator.next().
+ var blocksProcessed = 1
+ val fallbackBlocksByAddr: Iterator[(BlockManagerId, Seq[(BlockId, Long,
Int)])] =
+ if (blockId.isShuffle) {
+ val shuffleBlockId = blockId.asInstanceOf[ShuffleBlockId]
+ mapOutputTracker.getMapSizesForMergeResult(
+ shuffleBlockId.shuffleId, shuffleBlockId.reduceId)
+ } else {
+ val shuffleChunkId = blockId.asInstanceOf[ShuffleBlockChunkId]
+ val chunkBitmap: RoaringBitmap =
chunksMetaMap.remove(shuffleChunkId).orNull
+ // When there is a failure to fetch a remote merged shuffle block
chunk, then we try to
+ // fallback not only for that particular remote shuffle block chunk
but also for all the
+ // pending block chunks that belong to the same host. The reason for
doing so is that it is
+ // very likely that the subsequent requests for merged block chunks
from this host will fail
+ // as well. Since, push-based shuffle is best effort and we try not to
increase the delay
+ // of the fetches, we immediately fallback for all the pending shuffle
chunks in the
+ // fetchRequests queue.
+ if (isNotExecutorOrMergedLocal(address)) {
+ // Fallback for all the pending fetch requests
+ val pendingShuffleChunks =
iterator.removePendingChunks(shuffleChunkId, address)
+ if (pendingShuffleChunks.nonEmpty) {
+ pendingShuffleChunks.foreach { pendingBlockId =>
+ logWarning(s"Falling back immediately for merged block
$pendingBlockId")
+ val bitmapOfPendingChunk: RoaringBitmap =
+ chunksMetaMap.remove(pendingBlockId).orNull
+ assert(bitmapOfPendingChunk != null)
+ chunkBitmap.or(bitmapOfPendingChunk)
Review comment:
If we are sure it cant be `null`, replace `orNull` with `get` instead ?
It makes the semantics clearer.
I am fine with leaving it with `assert` check as well.
##########
File path:
core/src/main/scala/org/apache/spark/storage/PushBasedFetchHelper.scala
##########
@@ -0,0 +1,289 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.storage
+
+import java.util.concurrent.TimeUnit
+
+import scala.collection.mutable
+import scala.collection.mutable.ArrayBuffer
+import scala.util.{Failure, Success}
+
+import org.roaringbitmap.RoaringBitmap
+
+import org.apache.spark.MapOutputTracker
+import org.apache.spark.MapOutputTracker.SHUFFLE_PUSH_MAP_ID
+import org.apache.spark.internal.Logging
+import org.apache.spark.network.buffer.ManagedBuffer
+import org.apache.spark.network.shuffle.{BlockStoreClient, MergedBlockMeta,
MergedBlocksMetaListener}
+import org.apache.spark.storage.BlockManagerId.SHUFFLE_MERGER_IDENTIFIER
+import org.apache.spark.storage.ShuffleBlockFetcherIterator._
+
+/**
+ * Helper class for [[ShuffleBlockFetcherIterator]] that encapsulates all the
push-based
+ * functionality to fetch merged block meta and merged shuffle block chunks.
+ */
+private class PushBasedFetchHelper(
+ private val iterator: ShuffleBlockFetcherIterator,
+ private val shuffleClient: BlockStoreClient,
+ private val blockManager: BlockManager,
+ private val mapOutputTracker: MapOutputTracker) extends Logging {
+
+ private[this] val startTimeNs = System.nanoTime()
+
+ private[this] val localShuffleMergerBlockMgrId = BlockManagerId(
+ SHUFFLE_MERGER_IDENTIFIER, blockManager.blockManagerId.host,
+ blockManager.blockManagerId.port, blockManager.blockManagerId.topologyInfo)
+
+ /** A map for storing merged block shuffle chunk bitmap */
+ private[this] val chunksMetaMap = new mutable.HashMap[ShuffleBlockChunkId,
RoaringBitmap]()
Review comment:
`fetchMergedLocalBlock` is not invoked from the task thread right (from
`fetchMergedLocalBlocks`) ?
That updates `chunksMetaMap` ?
##########
File path:
core/src/main/scala/org/apache/spark/storage/ShuffleBlockFetcherIterator.scala
##########
@@ -1124,4 +1394,54 @@ object ShuffleBlockFetcherIterator {
*/
private[storage]
case class DeferFetchRequestResult(fetchRequest: FetchRequest) extends
FetchResult
+
+ /**
+ * Result of an un-successful fetch of either of these:
+ * 1) Remote shuffle block chunk.
+ * 2) Local merged block data.
+ *
+ * Instead of treating this as a FailureFetchResult, we ignore this failure
+ * and fallback to fetch the original unmerged blocks.
+ * @param blockId block id
+ * @param address BlockManager that the merged block was attempted to be
fetched from
+ * @param size size of the block, used to update bytesInFlight.
+ * @param isNetworkReqDone Is this the last network request for this host in
this fetch
+ * request. Used to update reqsInFlight.
+ */
+ private[storage] case class IgnoreFetchResult(blockId: BlockId,
Review comment:
Stick Merge in the class name - just in case we have other forms of
Fallback in future which need specialized handling.
##########
File path:
core/src/test/scala/org/apache/spark/storage/ShuffleBlockFetcherIteratorSuite.scala
##########
@@ -22,31 +22,40 @@ import java.nio.ByteBuffer
import java.util.UUID
import java.util.concurrent.{CompletableFuture, Semaphore}
+import scala.collection.mutable
import scala.concurrent.ExecutionContext.Implicits.global
import scala.concurrent.Future
import io.netty.util.internal.OutOfDirectMemoryError
import org.mockito.ArgumentMatchers.{any, eq => meq}
-import org.mockito.Mockito.{mock, times, verify, when}
+import org.mockito.Mockito.{doThrow, mock, times, verify, when}
+import org.mockito.invocation.InvocationOnMock
import org.mockito.stubbing.Answer
+import org.roaringbitmap.RoaringBitmap
import org.scalatest.PrivateMethodTester
-import org.apache.spark.{SparkFunSuite, TaskContext}
+import org.apache.spark.{MapOutputTracker, SparkFunSuite, TaskContext}
+import org.apache.spark.MapOutputTracker.SHUFFLE_PUSH_MAP_ID
import org.apache.spark.network._
import org.apache.spark.network.buffer.{FileSegmentManagedBuffer,
ManagedBuffer}
-import org.apache.spark.network.shuffle.{BlockFetchingListener,
DownloadFileManager, ExternalBlockStoreClient}
+import org.apache.spark.network.shuffle.{BlockFetchingListener,
DownloadFileManager, ExternalBlockStoreClient, MergedBlockMeta,
MergedBlocksMetaListener}
import org.apache.spark.network.util.LimitedInputStream
import org.apache.spark.shuffle.{FetchFailedException,
ShuffleReadMetricsReporter}
-import org.apache.spark.storage.ShuffleBlockFetcherIterator.FetchBlockInfo
+import org.apache.spark.storage.BlockManagerId.SHUFFLE_MERGER_IDENTIFIER
+import org.apache.spark.storage.ShuffleBlockFetcherIterator._
import org.apache.spark.util.Utils
class ShuffleBlockFetcherIteratorSuite extends SparkFunSuite with
PrivateMethodTester {
Review comment:
To clarify, what I meant was that on both failing, driver should see it
as a fetch failure (wont see the merge part - but will see a fetch failure).
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