org.apache.spark.deploy.master.FileSystemPersistenceEngine.scala Maven / Gradle / Ivy
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* 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
*
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package org.apache.spark.deploy.master
import java.io._
import scala.Serializable
import akka.serialization.Serialization
import org.apache.spark.Logging
/**
* Stores data in a single on-disk directory with one file per application and worker.
* Files are deleted when applications and workers are removed.
*
* @param dir Directory to store files. Created if non-existent (but not recursively).
* @param serialization Used to serialize our objects.
*/
private[spark] class FileSystemPersistenceEngine(
val dir: String,
val serialization: Serialization)
extends PersistenceEngine with Logging {
new File(dir).mkdir()
override def addApplication(app: ApplicationInfo) {
val appFile = new File(dir + File.separator + "app_" + app.id)
serializeIntoFile(appFile, app)
}
override def removeApplication(app: ApplicationInfo) {
new File(dir + File.separator + "app_" + app.id).delete()
}
override def addWorker(worker: WorkerInfo) {
val workerFile = new File(dir + File.separator + "worker_" + worker.id)
serializeIntoFile(workerFile, worker)
}
override def removeWorker(worker: WorkerInfo) {
new File(dir + File.separator + "worker_" + worker.id).delete()
}
override def readPersistedData(): (Seq[ApplicationInfo], Seq[WorkerInfo]) = {
val sortedFiles = new File(dir).listFiles().sortBy(_.getName)
val appFiles = sortedFiles.filter(_.getName.startsWith("app_"))
val apps = appFiles.map(deserializeFromFile[ApplicationInfo])
val workerFiles = sortedFiles.filter(_.getName.startsWith("worker_"))
val workers = workerFiles.map(deserializeFromFile[WorkerInfo])
(apps, workers)
}
private def serializeIntoFile(file: File, value: Serializable) {
val created = file.createNewFile()
if (!created) { throw new IllegalStateException("Could not create file: " + file) }
val serializer = serialization.findSerializerFor(value)
val serialized = serializer.toBinary(value)
val out = new FileOutputStream(file)
out.write(serialized)
out.close()
}
def deserializeFromFile[T <: Serializable](file: File)(implicit m: Manifest[T]): T = {
val fileData = new Array[Byte](file.length().asInstanceOf[Int])
val dis = new DataInputStream(new FileInputStream(file))
dis.readFully(fileData)
dis.close()
val clazz = m.erasure.asInstanceOf[Class[T]]
val serializer = serialization.serializerFor(clazz)
serializer.fromBinary(fileData).asInstanceOf[T]
}
}