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/*
* 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.streaming.kinesis
import java.util.concurrent._
import scala.util.control.NonFatal
import com.amazonaws.services.kinesis.clientlibrary.interfaces.IRecordProcessorCheckpointer
import com.amazonaws.services.kinesis.clientlibrary.types.ShutdownReason
import org.apache.spark.Logging
import org.apache.spark.streaming.Duration
import org.apache.spark.streaming.util.RecurringTimer
import org.apache.spark.util.{Clock, SystemClock, ThreadUtils}
/**
* This is a helper class for managing Kinesis checkpointing.
*
* @param receiver The receiver that keeps track of which sequence numbers we can checkpoint
* @param checkpointInterval How frequently we will checkpoint to DynamoDB
* @param workerId Worker Id of KCL worker for logging purposes
* @param clock In order to use ManualClocks for the purpose of testing
*/
private[kinesis] class KinesisCheckpointer(
receiver: KinesisReceiver[_],
checkpointInterval: Duration,
workerId: String,
clock: Clock = new SystemClock) extends Logging {
// a map from shardId's to checkpointers
private val checkpointers = new ConcurrentHashMap[String, IRecordProcessorCheckpointer]()
private val lastCheckpointedSeqNums = new ConcurrentHashMap[String, String]()
private val checkpointerThread: RecurringTimer = startCheckpointerThread()
/** Update the checkpointer instance to the most recent one for the given shardId. */
def setCheckpointer(shardId: String, checkpointer: IRecordProcessorCheckpointer): Unit = {
checkpointers.put(shardId, checkpointer)
}
/**
* Stop tracking the specified shardId.
*
* If a checkpointer is provided, e.g. on IRecordProcessor.shutdown [[ShutdownReason.TERMINATE]],
* we will use that to make the final checkpoint. If `null` is provided, we will not make the
* checkpoint, e.g. in case of [[ShutdownReason.ZOMBIE]].
*/
def removeCheckpointer(shardId: String, checkpointer: IRecordProcessorCheckpointer): Unit = {
synchronized {
checkpointers.remove(shardId)
checkpoint(shardId, checkpointer)
}
}
/** Perform the checkpoint. */
private def checkpoint(shardId: String, checkpointer: IRecordProcessorCheckpointer): Unit = {
try {
if (checkpointer != null) {
receiver.getLatestSeqNumToCheckpoint(shardId).foreach { latestSeqNum =>
val lastSeqNum = lastCheckpointedSeqNums.get(shardId)
// Kinesis sequence numbers are monotonically increasing strings, therefore we can do
// safely do the string comparison
if (lastSeqNum == null || latestSeqNum > lastSeqNum) {
/* Perform the checkpoint */
KinesisRecordProcessor.retryRandom(checkpointer.checkpoint(latestSeqNum), 4, 100)
logDebug(s"Checkpoint: WorkerId $workerId completed checkpoint at sequence number" +
s" $latestSeqNum for shardId $shardId")
lastCheckpointedSeqNums.put(shardId, latestSeqNum)
}
}
} else {
logDebug(s"Checkpointing skipped for shardId $shardId. Checkpointer not set.")
}
} catch {
case NonFatal(e) =>
logWarning(s"Failed to checkpoint shardId $shardId to DynamoDB.", e)
}
}
/** Checkpoint the latest saved sequence numbers for all active shardId's. */
private def checkpointAll(): Unit = synchronized {
// if this method throws an exception, then the scheduled task will not run again
try {
val shardIds = checkpointers.keys()
while (shardIds.hasMoreElements) {
val shardId = shardIds.nextElement()
checkpoint(shardId, checkpointers.get(shardId))
}
} catch {
case NonFatal(e) =>
logWarning("Failed to checkpoint to DynamoDB.", e)
}
}
/**
* Start the checkpointer thread with the given checkpoint duration.
*/
private def startCheckpointerThread(): RecurringTimer = {
val period = checkpointInterval.milliseconds
val threadName = s"Kinesis Checkpointer - Worker $workerId"
val timer = new RecurringTimer(clock, period, _ => checkpointAll(), threadName)
timer.start()
logDebug(s"Started checkpointer thread: $threadName")
timer
}
/**
* Shutdown the checkpointer. Should be called on the onStop of the Receiver.
*/
def shutdown(): Unit = {
// the recurring timer checkpoints for us one last time.
checkpointerThread.stop(interruptTimer = false)
checkpointers.clear()
lastCheckpointedSeqNums.clear()
logInfo("Successfully shutdown Kinesis Checkpointer.")
}
}
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