gaborgsomogyi commented on a change in pull request #24922: [SPARK-28120][SS] Rocksdb state storage implementation URL: https://github.com/apache/spark/pull/24922#discussion_r316203629
########## File path: sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/state/RocksDbStateStoreProvider.scala ########## @@ -0,0 +1,642 @@ +/* + * 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.sql.execution.streaming.state; + +import java.io._ +import java.util +import java.util.Locale + +import scala.collection.JavaConverters._ +import scala.util.control.NonFatal + +import org.apache.commons.io.FileUtils +import org.apache.hadoop.conf.Configuration +import org.apache.hadoop.fs._ + +import org.apache.spark.{SparkConf, SparkEnv} +import org.apache.spark.internal.Logging +import org.apache.spark.io.FileUtility +import org.apache.spark.sql.catalyst.expressions.UnsafeRow +import org.apache.spark.sql.execution.streaming.CheckpointFileManager +import org.apache.spark.sql.types.StructType +import org.apache.spark.util.Utils + +private[sql] class RocksDbStateStoreProvider extends StateStoreProvider with Logging { + + /* Internal fields and methods */ + @volatile private var stateStoreId_ : StateStoreId = _ + @volatile private var keySchema: StructType = _ + @volatile private var valueSchema: StructType = _ + @volatile private var storeConf: StateStoreConf = _ + @volatile private var hadoopConf: Configuration = _ + @volatile private var numberOfVersionsToRetain: Int = _ + @volatile private var localDirectory: String = _ + + /* + * Additional configurations related to rocksDb. This will capture all configs in + * SQLConf that start with `spark.sql.streaming.stateStore.rocksDb` + */ + @volatile private var rocksDbConf: Map[String, String] = Map.empty[String, String] + + private lazy val baseDir: Path = stateStoreId.storeCheckpointLocation() + private lazy val fm = CheckpointFileManager.create(baseDir, hadoopConf) + private lazy val sparkConf = Option(SparkEnv.get).map(_.conf).getOrElse(new SparkConf) + + private case class StoreFile(version: Long, path: Path, isSnapshot: Boolean) + + import WALUtils._ + + /** Implementation of [[StateStore]] API which is backed by RocksDB and HDFS */ + class RocksDbStateStore(val version: Long) extends StateStore with Logging { + + /** Trait and classes representing the internal state of the store */ + trait STATE + + case object LOADED extends STATE + + case object UPDATING extends STATE + + case object COMMITTED extends STATE + + case object ABORTED extends STATE + + private val newVersion = version + 1 + @volatile private var state: STATE = LOADED + private val finalDeltaFile: Path = deltaFile(baseDir, newVersion) + private lazy val deltaFileStream = fm.createAtomic(finalDeltaFile, overwriteIfPossible = true) + private lazy val compressedStream = compressStream(deltaFileStream, sparkConf) + + override def id: StateStoreId = RocksDbStateStoreProvider.this.stateStoreId + + var rocksDbWriteInstance: OptimisticTransactionDbInstance = null + + /* + * numEntriesInDb and bytesUsedByDb are estimated value + * due to the nature of RocksDB implementation. + * see https://github.com/facebook/rocksdb/wiki/RocksDB-FAQ for more details + */ + var numEntriesInDb: Long = 0L + var bytesUsedByDb: Long = 0L + + private def initTransaction(): Unit = { + if (state == LOADED && rocksDbWriteInstance == null) { + logDebug(s"Creating Transactional DB for batch $version") + rocksDbWriteInstance = new OptimisticTransactionDbInstance( + keySchema, + valueSchema, + newVersion.toString, + rocksDbConf) + rocksDbWriteInstance.open(rocksDbPath) + state = UPDATING + rocksDbWriteInstance.startTransactions() + } + } + + override def get(key: UnsafeRow): UnsafeRow = { + initTransaction() + rocksDbWriteInstance.get(key) + } + + override def put(key: UnsafeRow, value: UnsafeRow): Unit = { + initTransaction() + verify(state == UPDATING, s"Cannot put after already committed or aborted") + val keyCopy = key.copy() + val valueCopy = value.copy() + rocksDbWriteInstance.put(keyCopy, valueCopy) + writeUpdateToDeltaFile(compressedStream, keyCopy, valueCopy) + } + + override def remove(key: UnsafeRow): Unit = { + initTransaction() + verify(state == UPDATING, "Cannot remove after already committed or aborted") + rocksDbWriteInstance.remove(key) + writeRemoveToDeltaFile(compressedStream, key) + } + + override def getRange( + start: Option[UnsafeRow], + end: Option[UnsafeRow]): Iterator[UnsafeRowPair] = { + verify(state == UPDATING, "Cannot getRange after already committed or aborted") + iterator() + } + + /** Commit all the updates that have been made to the store, and return the new version. */ + override def commit(): Long = { + initTransaction() + verify(state == UPDATING, s"Cannot commit after already committed or aborted") + try { + synchronized { + rocksDbWriteInstance.commit(Some(getCheckpointPath(newVersion))) + finalizeDeltaFile(compressedStream) + } + state = COMMITTED + numEntriesInDb = rocksDbWriteInstance.getApproxEntriesInDb() + bytesUsedByDb = numEntriesInDb * (keySchema.defaultSize + valueSchema.defaultSize) + newVersion + } catch { + case NonFatal(e) => + throw new IllegalStateException(s"Error committing version $newVersion into $this", e) + } finally { + storeMap.remove(version) + close() + } + } + + /* + * Abort all the updates made on this store. This store will not be usable any more. + */ + override def abort(): Unit = { + // This if statement is to ensure that files are deleted only if there are changes to the + // StateStore. We have two StateStores for each task, one which is used only for reading, and + // the other used for read+write. We don't want the read-only to delete state files. + try { + if (state == UPDATING) { + state = ABORTED + synchronized { + rocksDbWriteInstance.abort() + cancelDeltaFile(compressedStream, deltaFileStream) + } + logInfo(s"Aborted version $newVersion for $this") + } else { + state = ABORTED + } + } catch { + case NonFatal(e) => + throw new IllegalStateException(s"Error aborting version $newVersion into $this", e) + } finally { + storeMap.remove(version) + close() + } + } + + def close(): Unit = { + if (rocksDbWriteInstance != null) { + rocksDbWriteInstance.close() + rocksDbWriteInstance = null + } + } + + /* + * Get an iterator of all the store data. + * This can be called only after committing all the updates made in the current thread. + */ + override def iterator(): Iterator[UnsafeRowPair] = { + state match { + case UPDATING => + logDebug("state = updating using transaction DB") + // We need to use current db to read uncommitted transactions + rocksDbWriteInstance.iterator(closeDbOnCompletion = false) + + case LOADED | ABORTED => + // use check-pointed db for previous version + logDebug(s"state = loaded/aborted using check-pointed DB with version $version") + if (version == 0) { + Iterator.empty + } else { + val path = getCheckpointPath(version) + val r: RocksDbInstance = + new RocksDbInstance(keySchema, valueSchema, version.toString, rocksDbConf) + r.open(path, readOnly = true) + r.iterator(closeDbOnCompletion = true) + } + case COMMITTED => + logDebug(s"state = committed using check-pointed DB with version $newVersion") + // use check-pointed db for current updated version + val path = getCheckpointPath(newVersion) + val r: RocksDbInstance = + new RocksDbInstance(keySchema, valueSchema, newVersion.toString, rocksDbConf) + r.open(path, readOnly = true) + r.iterator(closeDbOnCompletion = true) + + case _ => Iterator.empty + } + } + + override def metrics: StateStoreMetrics = { + val metricsFromProvider: Map[String, Long] = getMetricsForProvider() + val customMetrics = metricsFromProvider.flatMap { + case (name, value) => + // just allow searching from list cause the list is small enough + supportedCustomMetrics.find(_.name == name).map(_ -> value) + } + StateStoreMetrics(Math.max(numEntriesInDb, 0), Math.max(bytesUsedByDb, 0), customMetrics) + } + + /* + * Whether all updates have been committed + */ + override def hasCommitted: Boolean = { + state == COMMITTED + } + + override def toString(): String = { + s"RocksDbStateStore[id=(op=${id.operatorId},part=${id.partitionId}),dir=$baseDir]" + } + + } + + /* + * Initialize the provider with more contextual information from the SQL operator. + * This method will be called first after creating an instance of the StateStoreProvider by + * reflection. + * + * @param stateStoreId Id of the versioned StateStores that this provider will generate + * @param keySchema Schema of keys to be stored + * @param valueSchema Schema of value to be stored + * @param keyIndexOrdinal Optional column (represent as the ordinal of the field in keySchema) by + * which the StateStore implementation could index the data. + * @param storeConfs Configurations used by the StateStores + * @param hadoopConf Hadoop configuration that could be used by StateStore + * to save state data + */ + override def init( + stateStoreId: StateStoreId, + keySchema: StructType, + valueSchema: StructType, + keyIndexOrdinal: Option[Int], // for sorting the data by their keys + storeConfs: StateStoreConf, + hadoopConf: Configuration): Unit = { + this.stateStoreId_ = stateStoreId + this.keySchema = keySchema + this.valueSchema = valueSchema + this.storeConf = storeConfs + this.hadoopConf = hadoopConf + this.numberOfVersionsToRetain = storeConfs.maxVersionsToRetainInMemory + fm.mkdirs(baseDir) + this.rocksDbConf = storeConf.confs + .filter(_._1.startsWith("spark.sql.streaming.stateStore.rocksDb")) + .map { + case (k, v) => (k.toLowerCase(Locale.ROOT), v) + } + this.localDirectory = this.rocksDbConf + .getOrElse( + "spark.sql.streaming.stateStore.rocksDb.localDirectory".toLowerCase(Locale.ROOT), + Utils.createTempDir().getAbsoluteFile.toString) + } + + /* + * Return the id of the StateStores this provider will generate. + * Should be the same as the one passed in init(). + */ + override def stateStoreId: StateStoreId = stateStoreId_ + + /* + * Called when the provider instance is unloaded from the executor + */ + override def close(): Unit = { + storeMap.values.asScala.foreach(_.close) + storeMap.clear() + } + + private val storeMap = new util.HashMap[Long, RocksDbStateStore]() + + /* + * Optional custom metrics that the implementation may want to report. + * + * @note The StateStore objects created by this provider must report the same custom metrics + * (specifically, same names) through `StateStore.metrics`. + */ + // TODO + override def supportedCustomMetrics: Seq[StateStoreCustomMetric] = { + Nil + } + + override def toString(): String = { + s"RocksDbStateStoreProvider[" + + s"id = (op=${stateStoreId.operatorId},part=${stateStoreId.partitionId}),dir = $baseDir]" + } + + def getMetricsForProvider(): Map[String, Long] = synchronized { + Map.empty[String, Long] + } + + /* + * Return an instance of [[StateStore]] representing state data of the given version + */ + override def getStore(version: Long): StateStore = synchronized { + logInfo(s"get Store for version $version") + require(version >= 0, "Version cannot be less than 0") + if (storeMap.containsKey(version)) { + storeMap.get(version) + } else { + val store = createStore(version) + storeMap.put(version, store) + store + } + } + + private def createStore(version: Long): RocksDbStateStore = { + val newStore = new RocksDbStateStore(version) + if (version > 0) { + // load the data into the rocksDB + logInfo( + s"Loading state into the db for $version and partition ${stateStoreId_.partitionId}") + loadIntoRocksDB(version) + } + newStore + } + + private def loadIntoRocksDB(version: Long): Unit = { + /* + 1. Get last available/committed Rocksdb version in local folder + 2. If last committed version = version, we already have loaded rocksdb state. + 3. If last committed version = version - 1, + we have to apply delta for version in the existing rocksdb + 4. Otherwise we have to recreate a new rocksDB store by using Snapshots/Delta + */ + val (_, elapsedMs) = Utils.timeTakenMs { + var lastAvailableVersion = getLastCommittedVersion() + if (lastAvailableVersion == -1L || lastAvailableVersion <= version - 2) { + // Destroy existing DB so that we can reconstruct it using snapshot and delta files + RocksDbInstance.destroyDB(rocksDbPath) + var lastAvailableSnapShotVersion: Long = version + 1 + // load from snapshot + var found = false + while (!found && lastAvailableSnapShotVersion > 0) { + try { + lastAvailableSnapShotVersion = lastAvailableSnapShotVersion - 1 + found = loadSnapshotFile(lastAvailableSnapShotVersion) + logDebug( + s"Snapshot for version $lastAvailableSnapShotVersion " + + "and partition ${stateStoreId_.partitionId}: found = $found") + } catch { + case e: Exception => + logError(s"$e while reading snapshot file") + throw e + } + } + lastAvailableVersion = lastAvailableSnapShotVersion + } + if (lastAvailableVersion < version) { + applyDelta(version, lastAvailableVersion) + } + } + logInfo( + s"Loading state for $version and partition ${stateStoreId_.partitionId} took $elapsedMs ms.") + } + + private def getLastCommittedVersion(): Long = { + val f = new File(rocksDbPath, RocksDbInstance.COMMIT_FILE_NAME) + if (f.exists()) { + try { + val fileContents = scala.io.Source.fromFile(f.getAbsolutePath).getLines.mkString + return fileContents.toLong + } catch { + case e: Exception => + logWarning("Exception while reading committed file") + } + } + return -1L + } + + private def loadSnapshotFile(version: Long): Boolean = { + val fileToRead = snapshotFile(baseDir, version) + if (version == 0 || !fm.exists(fileToRead)) { + return false + } + val versionTempPath = getTempPath(version) + val tmpLocDir: File = new File(versionTempPath) + val tmpLocFile: File = new File(s"${versionTempPath}.tar") + try { + logInfo(s"Will download $fileToRead at location ${tmpLocFile.toString()}") + if (downloadFile(fm, fileToRead, new Path(tmpLocFile.getAbsolutePath), sparkConf)) { + FileUtility.extractTarFile(tmpLocFile.getAbsolutePath, versionTempPath) + if (!tmpLocDir.list().exists(_.endsWith(".sst"))) { + logWarning("Snapshot files are corrupted") + throw new IOException( + s"Error reading snapshot file $fileToRead of $this:" + + s" No SST files found") + } + FileUtils.moveDirectory(tmpLocDir, new File(rocksDbPath)) + true + } else { + false + } + } catch { + case e: Exception => + logError(s"Exception while loading snapshot file $e") + throw e + } finally { + if (tmpLocFile.exists()) { + tmpLocFile.delete() + } + FileUtils.deleteDirectory(tmpLocDir) + } + } + + private def applyDelta(version: Long, lastAvailableVersion: Long): Unit = { + var rocksDbWriteInstance: OptimisticTransactionDbInstance = null + try { + rocksDbWriteInstance = + new OptimisticTransactionDbInstance(keySchema, valueSchema, version.toString, rocksDbConf) + rocksDbWriteInstance.open(rocksDbPath) + rocksDbWriteInstance.startTransactions() + // Load all the deltas from the version after the last available + // one up to the target version. + // The last available version is the one with a full snapshot, so it doesn't need deltas. + for (deltaVersion <- (lastAvailableVersion + 1) to version) { + val fileToRead = deltaFile(baseDir, deltaVersion) + updateFromDeltaFile( + fm, + fileToRead, + keySchema, + valueSchema, + rocksDbWriteInstance, + sparkConf) + logInfo(s"Read delta file for version $version of $this from $fileToRead") + } + rocksDbWriteInstance.commit(Some(getCheckpointPath(version))) + } catch { + case e: Exception => + logError(s"Exception while loading state ${e.getMessage}") + if (rocksDbWriteInstance != null) { + rocksDbWriteInstance.abort() + } + throw e + } finally { + if (rocksDbWriteInstance != null) { + rocksDbWriteInstance.close() + } + } + } + + /** Optional method for providers to allow for background maintenance (e.g. compactions) */ + override def doMaintenance(): Unit = { + try { + val (files: Seq[WALUtils.StoreFile], e1) = Utils.timeTakenMs(fetchFiles(fm, baseDir)) + logDebug(s"fetchFiles() took $e1 ms.") + doSnapshot(files) + cleanup(files) + cleanRocksDBCheckpoints(files) + } catch { + case NonFatal(e) => + logWarning(s"Error performing snapshot and cleaning up $this") + } + } + + private def doSnapshot(files: Seq[WALUtils.StoreFile]): Unit = { + if (files.nonEmpty) { + val lastVersion = files.last.version + val deltaFilesForLastVersion = + filesForVersion(files, lastVersion).filter(_.isSnapshot == false) + if (deltaFilesForLastVersion.size > storeConf.minDeltasForSnapshot) { + val dbPath = getCheckpointPath(lastVersion) + val snapShotFileName = s"{getTempPath(lastVersion)}.snapshot" + val f = new File(snapShotFileName) + try { + val (_, t1) = Utils.timeTakenMs { + FileUtility.createTarFile(dbPath, snapShotFileName) + val targetFile = snapshotFile(baseDir, lastVersion) + uploadFile(fm, new Path(snapShotFileName), targetFile, sparkConf) + } + logInfo(s"Creating snapshot file for ${stateStoreId_.partitionId} took $t1 ms.") + } catch { + case e: Exception => + logError(s"Exception while creating snapshot $e") + throw e + } finally { + f.delete() // delete the tarball + } + } + } + } + + /* + * Clean up old snapshots and delta files that are not needed any more. It ensures that last + * few versions of the store can be recovered from the files, so re-executed RDD operations + * can re-apply updates on the past versions of the store. + */ + private[state] def cleanup(files: Seq[WALUtils.StoreFile]): Unit = { + try { + if (files.nonEmpty) { + val earliestVersionToRetain = files.last.version - storeConf.minVersionsToRetain + if (earliestVersionToRetain > 0) { + val earliestFileToRetain = filesForVersion(files, earliestVersionToRetain).head + val filesToDelete = files.filter(_.version < earliestFileToRetain.version) + val (_, e2) = Utils.timeTakenMs { + filesToDelete.foreach { f => + fm.delete(f.path) + val file = new File(rocksDbPath, f.version.toString) + if (file.exists()) { + file.delete() + } + } + } + logDebug(s"deleting files took $e2 ms.") + logInfo( + s"Deleted files older than ${earliestFileToRetain.version} for $this: " + + filesToDelete.mkString(", ")) + } + } + } catch { + case NonFatal(e) => + logWarning(s"Error cleaning up files for $this", e) + } + } + + private def cleanRocksDBCheckpoints(files: Seq[WALUtils.StoreFile]): Unit = { + try { + val (_, e2) = Utils.timeTakenMs { + if (files.nonEmpty) { + val earliestVersionToRetain = files.last.version - storeConf.minVersionsToRetain + if (earliestVersionToRetain > 0) { + new File(getCheckpointPath(earliestVersionToRetain)).getParentFile + .listFiles(new FileFilter { + def accept(f: File): Boolean = { + try { + f.getName.toLong < earliestVersionToRetain + } catch { + case _: NumberFormatException => false + } + } + }) + .foreach(p => RocksDbInstance.destroyDB(p.getAbsolutePath)) + logInfo( + s"Deleted rocksDB checkpoints older than ${earliestVersionToRetain} for $this: ") + } + } + } + logDebug(s"deleting rocksDB checkpoints took $e2 ms.") + } catch { + case NonFatal(e) => logWarning(s"Error cleaning up files for $this", e) + } + } + + // Used only for unit tests + private[sql] def latestIterator(): Iterator[UnsafeRowPair] = synchronized { + val versionsInFiles = fetchFiles(fm, baseDir).map(_.version).toSet + if (versionsInFiles.nonEmpty) { + val maxVersion = versionsInFiles.max + if (maxVersion > 0) { + loadIntoRocksDB(maxVersion) + val r: RocksDbInstance = + new RocksDbInstance(keySchema, valueSchema, maxVersion.toString, rocksDbConf) + try { + r.open(rocksDbPath, readOnly = true) + return r.iterator(false) + } catch { + case e: Exception => + logWarning(s"Exception ${e.getMessage} while getting latest Iterator") + } + } + } + Iterator.empty + } + + private[sql] def getLocalDirectory: String = localDirectory + + private[sql] lazy val rocksDbPath: String = { + getPath("db") + } + + private def getCheckpointPath(version: Long): String = { + getPath("checkpoint", version.toString) + } + + private def getTempPath(version: Long): String = { + getPath("tmp", version.toString) + } + + private def getPath(parentFolderName: String, version: String = null): String = { + val checkpointRootLocationPath = new Path(stateStoreId.checkpointRootLocation) + + val basePath = new Path( + localDirectory, + new Path( + parentFolderName, + checkpointRootLocationPath.getName + "_" + checkpointRootLocationPath.hashCode())) + + val dirPath = new Path( + basePath, + new Path(stateStoreId_.operatorId.toString, stateStoreId_.partitionId.toString)) + + val f: File = new File(dirPath.toString) + if (!f.exists()) { + logInfo(s"creating rocksDb directory at : ${dirPath.toString}") + f.mkdirs() + } + + val path = if (version != null) { Review comment: No need to create temp val `path` just return the result of the if condition. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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