otterc commented on a change in pull request #32140: URL: https://github.com/apache/spark/pull/32140#discussion_r648685526
########## File path: core/src/main/scala/org/apache/spark/storage/ShuffleBlockFetcherIterator.scala ########## @@ -1124,4 +1392,298 @@ object ShuffleBlockFetcherIterator { */ private[storage] case class DeferFetchRequestResult(fetchRequest: FetchRequest) extends FetchResult + + /** + * Result of a fetch from a remote merged block unsuccessfully. + * 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, + address: BlockManagerId, + size: Long, + isNetworkReqDone: Boolean) extends FetchResult + + /** + * Result of a successful fetch of meta information for a merged block. + * + * @param shuffleId shuffle id. + * @param reduceId reduce id. + * @param blockSize size of each merged block. + * @param numChunks number of chunks in the merged block. + * @param bitmaps bitmaps for every chunk. + * @param address BlockManager that the merged status was fetched from. + */ + private[storage] case class MergedBlocksMetaFetchResult( + shuffleId: Int, + reduceId: Int, + blockSize: Long, + numChunks: Int, + bitmaps: Array[RoaringBitmap], + address: BlockManagerId, + blockId: BlockId = DUMMY_SHUFFLE_BLOCK_ID) extends FetchResult + + /** + * Result of a failure while fetching the meta information for a merged block. + * + * @param shuffleId shuffle id. + * @param reduceId reduce id. + * @param address BlockManager that the merged status was fetched from. + */ + private[storage] case class MergedBlocksMetaFailedFetchResult( + shuffleId: Int, + reduceId: Int, + address: BlockManagerId, + blockId: BlockId = DUMMY_SHUFFLE_BLOCK_ID) extends FetchResult +} + +/** + * Helper class 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 blocksToRequest: ArrayBuffer[(BlockId, Long, Int)] = + 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 $approxChunkSize") + blocksToRequest += ((blockChunkId, approxChunkSize, SHUFFLE_PUSH_MAP_ID)) + } + blocksToRequest + } + + def sendFetchMergedStatusRequest(req: FetchRequest): Unit = { + val sizeMap = req.blocks.map { + case FetchBlockInfo(blockId, size, _) => + val shuffleBlockId = blockId.asInstanceOf[ShuffleBlockId] + ((shuffleBlockId.shuffleId, shuffleBlockId.reduceId), size)}.toMap + val address = req.address + val mergedBlocksMetaListener = new MergedBlocksMetaListener { + override def onSuccess(shuffleId: Int, reduceId: Int, meta: MergedBlockMeta): Unit = { + logInfo(s"Received the meta of merged block for ($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 _: Throwable => + 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 blocks 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 + if (isNotExecutorOrMergedLocal(address)) { Review comment: Added comments. PTAL. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org