我已经编写了一个 Spark Streaming 应用程序，它需要对具有底层转换的各种 Dstream 进行一些检查，如该线程中所建议的（启动 Spark 流式传输上下文时出错），我已经在定义的函数中完成了所有转换以创建上下文,
object StreamingEngine2 {
val filterF = { (x: Path) => true }
// === Configuration to control the flow of the application ===
val stopActiveContext = true
val batchIntervalSeconds = 10
val eventsPerSecond = 10 // For the dummy source
var newContextCreated = false // Flag to detect whether new context was created or not
// Function to create a new StreamingContext and set it up
val creatingFunc = { () =>
//add winutil to avoid: ERROR org.apache.spark.streaming.scheduler.JobScheduler - Error generating jobs for time 1471237080000 ms java.lang.NullPointerException
System.setProperty("hadoop.home.dir", "C:\\hadoop")
println("Creating function called to create new StreamingContext")
val conf = new SparkConf().setMaster("local[10]").setAppName("FileStreaming").set("spark.streaming.fileStream.minRememberDuration", "2000000h") /*.set("SPARK_CONF_DIR","src/main/resources")*/.registerKryoClasses(Array(classOf[org.apache.hadoop.io.LongWritable],
classOf[org.apache.hadoop.io.Text], classOf[GGSN]))
// Verify that the attached Spark cluster is 1.4.0+
val sc = new SparkContext(conf)
require(sc.version.replace(".", "").substring(0, 3).toInt >= 160, "Spark 1.6.0+ is required to run this code. Please attach it to a Spark 1.6.0+ cluster.")
val ssc = new StreamingContext(sc, Seconds(batchIntervalSeconds))
ssc.checkpoint("c:\\checkpoints")
val ggsnFileLines = ssc.fileStream[LongWritable, Text, TextInputFormat]("C:\\Users\\Mbazarganigilani\\Documents\\RA\\GGSN\\Files", filterF, false)
val ccnFIleLines = ssc.fileStream[LongWritable, Text, TextInputFormat]("C:\\Users\\Mbazarganigilani\\Documents\\RA\\CCN\\Files1", filterF, false)
//some mapping and transfomration
probeFileLines.checkpoint(Duration(batchIntervalSeconds*1000*5))
ggsnFileLines.checkpoint(Duration(batchIntervalSeconds*1000*5))
//check GGSSN...
probeFileLines.foreachRDD(s=>
{
println(s.count())
}
)
ssc.remember(Minutes(1)) // To make sure data is not deleted by the time we query it interactively
newContextCreated = true
ssc
}
def main(args: Array[String]): Unit = {
System.setProperty("hadoop.home.dir", "C:\\hadoop")
if (stopActiveContext) {
StreamingContext.getActive.foreach {
_.stop(stopSparkContext = false)
}
}
val ssc=StreamingContext.getOrCreate("c:\\checkpoints", creatingFunc)
if (newContextCreated) {
println("New context created from currently defined creating function")
} else {
println("Existing context running or recovered from checkpoint, may not be running currently defined creating function")
}
// Start the streaming context in the background.
ssc.start()
// This is to ensure that we wait for some time before the background streaming job starts. This will put this cell on hold for 5 times the batchIntervalSeconds.
ssc.awaitTerminationOrTimeout(batchIntervalSeconds * 2 * 1000*1000)
}
}
但是，当我的上下文从检查点目录加载时，我仍然会遇到异常
16/08/19 22:28:01 ERROR Utils: Exception encountered
java.lang.NullPointerException
at org.apache.spark.streaming.dstream.DStreamCheckpointData$$anonfun$writeObject$1.apply$mcV$sp(DStreamCheckpointData.scala:126)
at org.apache.spark.streaming.dstream.DStreamCheckpointData$$anonfun$writeObject$1.apply(DStreamCheckpointData.scala:124)
at org.apache.spark.streaming.dstream.DStreamCheckpointData$$anonfun$writeObject$1.apply(DStreamCheckpointData.scala:124)
at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1253)
at org.apache.spark.streaming.dstream.DStreamCheckpointData.writeObject(DStreamCheckpointData.scala:124)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:988)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
at org.apache.spark.streaming.dstream.DStream$$anonfun$writeObject$1.apply$mcV$sp(DStream.scala:516)
at org.apache.spark.streaming.dstream.DStream$$anonfun$writeObject$1.apply(DStream.scala:511)
at org.apache.spark.streaming.dstream.DStream$$anonfun$writeObject$1.apply(DStream.scala:511)
at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1253)
at org.apache.spark.streaming.dstream.DStream.writeObject(DStream.scala:511)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:988)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:441)
at org.apache.spark.streaming.DStreamGraph$$anonfun$writeObject$1.apply$mcV$sp(DStreamGraph.scala:182)
at org.apache.spark.streaming.DStreamGraph$$anonfun$writeObject$1.apply(DStreamGraph.scala:177)
at org.apache.spark.streaming.DStreamGraph$$anonfun$writeObject$1.apply(DStreamGraph.scala:177)
at org.apache.spark.util.Utils$.tryOrIOException(Utils.scala:1253)
at org.apache.spark.streaming.DStreamGraph.writeObject(DStreamGraph.scala:177)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:988)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1496)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
at org.apache.spark.streaming.Checkpoint$$anonfun$serialize$1.apply$mcV$sp(Checkpoint.scala:143)
at org.apache.spark.streaming.Checkpoint$$anonfun$serialize$1.apply(Checkpoint.scala:143)
at org.apache.spark.streaming.Checkpoint$$anonfun$serialize$1.apply(Checkpoint.scala:143)
at org.apache.spark.util.Utils$.tryWithSafeFinally(Utils.scala:1287)
at org.apache.spark.streaming.Checkpoint$.serialize(Checkpoint.scala:144)
at org.apache.spark.streaming.StreamingContext.validate(StreamingContext.scala:525)
at org.apache.spark.streaming.StreamingContext.liftedTree1$1(StreamingContext.scala:573)
at org.apache.spark.streaming.StreamingContext.start(StreamingContext.scala:572)
at StreamingEngine2$.main(StreamEngine2.scala:694)
at StreamingEngine2.main(StreamEngine2.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)
谁能帮我在我的代码中解决这个问题，我在 Spark 1.6 和 2.0 中都尝试过我的代码，但得到了同样的异常。