I found NPE is mainly because of im using the same JavaStreamingContext for some other kafka stream. if i change the name , its running successfully. how to run multiple JavaStreamingContext in a program ? I'm getting following exception if i run multiple JavaStreamingContext in single file.
15/10/30 11:04:29 INFO yarn.ApplicationMaster: Final app status: FAILED, exitCode: 15, (reason: User class threw exception: java.lang.IllegalStateException: Only one StreamingContext may be started in this JVM. Currently running StreamingContext was started atorg.apache.spark.streaming.api.java.JavaStreamingContext.start(JavaStreamingContext.scala:622) *Thanks*, <https://in.linkedin.com/in/ramkumarcs31> On Fri, Oct 30, 2015 at 3:25 PM, Saisai Shao <sai.sai.s...@gmail.com> wrote: > From the code, I think this field "rememberDuration" shouldn't be null, > it will be verified at the start, unless some place changes it's value in > the runtime that makes it null, but I cannot image how this happened. Maybe > you could add some logs around the place where exception happens if you > could reproduce it. > > On Fri, Oct 30, 2015 at 5:31 PM, Ramkumar V <ramkumar.c...@gmail.com> > wrote: > >> No. this is the only exception that im getting multiple times in my log. >> Also i was reading some other topics earlier but im not faced this NPE. >> >> *Thanks*, >> <https://in.linkedin.com/in/ramkumarcs31> >> >> >> On Fri, Oct 30, 2015 at 2:50 PM, Saisai Shao <sai.sai.s...@gmail.com> >> wrote: >> >>> I just did a local test with your code, seems everything is fine, the >>> only difference is that I use the master branch, but I don't think it >>> changes a lot in this part. Do you met any other exceptions or errors >>> beside this one? Probably this is due to other exceptions that makes this >>> system unstable. >>> >>> On Fri, Oct 30, 2015 at 5:13 PM, Ramkumar V <ramkumar.c...@gmail.com> >>> wrote: >>> >>>> No, i dont have any special settings. if i keep only reading line in my >>>> code, it's throwing NPE. >>>> >>>> *Thanks*, >>>> <https://in.linkedin.com/in/ramkumarcs31> >>>> >>>> >>>> On Fri, Oct 30, 2015 at 2:14 PM, Saisai Shao <sai.sai.s...@gmail.com> >>>> wrote: >>>> >>>>> Do you have any special settings, from your code, I don't think it >>>>> will incur NPE at that place. >>>>> >>>>> On Fri, Oct 30, 2015 at 4:32 PM, Ramkumar V <ramkumar.c...@gmail.com> >>>>> wrote: >>>>> >>>>>> spark version - spark 1.4.1 >>>>>> >>>>>> my code snippet: >>>>>> >>>>>> String brokers = "ip:port,ip:port"; >>>>>> String topics = "x,y,z"; >>>>>> HashSet<String> TopicsSet = new >>>>>> HashSet<String>(Arrays.asList(topics.split(","))); >>>>>> HashMap<String, String> kafkaParams = new HashMap<String, String>(); >>>>>> kafkaParams.put("metadata.broker.list", brokers); >>>>>> >>>>>> JavaPairInputDStream<String, String> messages = >>>>>> KafkaUtils.createDirectStream( >>>>>> jssc, >>>>>> String.class, >>>>>> String.class, >>>>>> StringDecoder.class, >>>>>> StringDecoder.class, >>>>>> kafkaParams, >>>>>> TopicsSet >>>>>> ); >>>>>> >>>>>> messages.foreachRDD(new Function<JavaPairRDD<String , String>,Void> >>>>>> () { >>>>>> public Void call(JavaPairRDD<String , String> tuple) { >>>>>> JavaRDD<String>rdd = tuple.values(); >>>>>> >>>>>> rdd.saveAsTextFile("hdfs://myuser:8020/user/hdfs/output"); >>>>>> return null; >>>>>> } >>>>>> }); >>>>>> >>>>>> >>>>>> *Thanks*, >>>>>> <https://in.linkedin.com/in/ramkumarcs31> >>>>>> >>>>>> >>>>>> On Fri, Oct 30, 2015 at 1:57 PM, Saisai Shao <sai.sai.s...@gmail.com> >>>>>> wrote: >>>>>> >>>>>>> What Spark version are you using, also a small code snippet of how >>>>>>> you use Spark Streaming would be greatly helpful. >>>>>>> >>>>>>> On Fri, Oct 30, 2015 at 3:57 PM, Ramkumar V <ramkumar.c...@gmail.com >>>>>>> > wrote: >>>>>>> >>>>>>>> I can able to read and print few lines. Afterthat i'm getting this >>>>>>>> exception. Any idea for this ? >>>>>>>> >>>>>>>> *Thanks*, >>>>>>>> <https://in.linkedin.com/in/ramkumarcs31> >>>>>>>> >>>>>>>> >>>>>>>> On Thu, Oct 29, 2015 at 6:14 PM, Ramkumar V < >>>>>>>> ramkumar.c...@gmail.com> wrote: >>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> I'm trying to read from kafka stream and printing it textfile. I'm >>>>>>>>> using java over spark. I dont know why i'm getting the following >>>>>>>>> exception. >>>>>>>>> Also exception message is very abstract. can anyone please help me ? >>>>>>>>> >>>>>>>>> Log Trace : >>>>>>>>> >>>>>>>>> 15/10/29 12:15:09 ERROR scheduler.JobScheduler: Error in job >>>>>>>>> generator >>>>>>>>> java.lang.NullPointerException >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.DStreamGraph$$anonfun$getMaxInputStreamRememberDuration$2.apply(DStreamGraph.scala:172) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.DStreamGraph$$anonfun$getMaxInputStreamRememberDuration$2.apply(DStreamGraph.scala:172) >>>>>>>>> at >>>>>>>>> scala.collection.TraversableOnce$$anonfun$maxBy$1.apply(TraversableOnce.scala:225) >>>>>>>>> at >>>>>>>>> scala.collection.IndexedSeqOptimized$class.foldl(IndexedSeqOptimized.scala:51) >>>>>>>>> at >>>>>>>>> scala.collection.IndexedSeqOptimized$class.reduceLeft(IndexedSeqOptimized.scala:68) >>>>>>>>> at >>>>>>>>> scala.collection.mutable.ArrayBuffer.reduceLeft(ArrayBuffer.scala:47) >>>>>>>>> at >>>>>>>>> scala.collection.TraversableOnce$class.maxBy(TraversableOnce.scala:225) >>>>>>>>> at >>>>>>>>> scala.collection.AbstractTraversable.maxBy(Traversable.scala:105) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.DStreamGraph.getMaxInputStreamRememberDuration(DStreamGraph.scala:172) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.scheduler.JobGenerator.clearMetadata(JobGenerator.scala:267) >>>>>>>>> at org.apache.spark.streaming.scheduler.JobGenerator.org >>>>>>>>> $apache$spark$streaming$scheduler$JobGenerator$$processEvent(JobGenerator.scala:178) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.scheduler.JobGenerator$$anon$1.onReceive(JobGenerator.scala:83) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.scheduler.JobGenerator$$anon$1.onReceive(JobGenerator.scala:82) >>>>>>>>> at >>>>>>>>> org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48) >>>>>>>>> 15/10/29 12:15:09 ERROR yarn.ApplicationMaster: User class threw >>>>>>>>> exception: java.lang.NullPointerException >>>>>>>>> java.lang.NullPointerException >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.DStreamGraph$$anonfun$getMaxInputStreamRememberDuration$2.apply(DStreamGraph.scala:172) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.DStreamGraph$$anonfun$getMaxInputStreamRememberDuration$2.apply(DStreamGraph.scala:172) >>>>>>>>> at >>>>>>>>> scala.collection.TraversableOnce$$anonfun$maxBy$1.apply(TraversableOnce.scala:225) >>>>>>>>> at >>>>>>>>> scala.collection.IndexedSeqOptimized$class.foldl(IndexedSeqOptimized.scala:51) >>>>>>>>> at >>>>>>>>> scala.collection.IndexedSeqOptimized$class.reduceLeft(IndexedSeqOptimized.scala:68) >>>>>>>>> at >>>>>>>>> scala.collection.mutable.ArrayBuffer.reduceLeft(ArrayBuffer.scala:47) >>>>>>>>> at >>>>>>>>> scala.collection.TraversableOnce$class.maxBy(TraversableOnce.scala:225) >>>>>>>>> at >>>>>>>>> scala.collection.AbstractTraversable.maxBy(Traversable.scala:105) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.DStreamGraph.getMaxInputStreamRememberDuration(DStreamGraph.scala:172) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.scheduler.JobGenerator.clearMetadata(JobGenerator.scala:267) >>>>>>>>> at org.apache.spark.streaming.scheduler.JobGenerator.org >>>>>>>>> $apache$spark$streaming$scheduler$JobGenerator$$processEvent(JobGenerator.scala:178) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.scheduler.JobGenerator$$anon$1.onReceive(JobGenerator.scala:83) >>>>>>>>> at >>>>>>>>> org.apache.spark.streaming.scheduler.JobGenerator$$anon$1.onReceive(JobGenerator.scala:82) >>>>>>>>> at >>>>>>>>> org.apache.spark.util.EventLoop$$anon$1.run(EventLoop.scala:48) >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> *Thanks*, >>>>>>>>> <https://in.linkedin.com/in/ramkumarcs31> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
