NullPointerException when push a kafka indexing task

Hi, all

the kafka indexing task stop by the NullPointerException. Anybody who knows what’s the matter.

2017-08-09T15:44:28,325 ERROR [task-runner-0-priority-0] io.druid.indexing.overlord.ThreadPoolTaskRunner - Exception while running task[KafkaIndexTask{id=index_kafka_m2_dos_order_test_a712d861b4a808d_jokilbmh, type=index_kafka, dataSource=m2_dos_order_test}]
java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at com.google.common.base.Throwables.propagate(Throwables.java:160) ~[guava-16.0.1.jar:?]
	at io.druid.segment.realtime.appenderator.FiniteAppenderatorDriver.persist(FiniteAppenderatorDriver.java:240) ~[druid-server-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at io.druid.indexing.kafka.KafkaIndexTask.run(KafkaIndexTask.java:471) ~[?:?]
	at io.druid.indexing.overlord.ThreadPoolTaskRunner$ThreadPoolTaskRunnerCallable.call(ThreadPoolTaskRunner.java:436) [druid-indexing-service-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at io.druid.indexing.overlord.ThreadPoolTaskRunner$ThreadPoolTaskRunnerCallable.call(ThreadPoolTaskRunner.java:408) [druid-indexing-service-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_65]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_65]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_65]
	at java.lang.Thread.run(Thread.java:745) [?:1.8.0_65]
Caused by: java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(FutureTask.java:122) ~[?:1.8.0_65]
	at java.util.concurrent.FutureTask.get(FutureTask.java:192) ~[?:1.8.0_65]
	at io.druid.segment.realtime.appenderator.FiniteAppenderatorDriver.persist(FiniteAppenderatorDriver.java:232) ~[druid-server-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	... 7 more
Caused by: java.lang.NullPointerException
	at java.util.TreeMap.getEntry(TreeMap.java:347) ~[?:1.8.0_65]
	at java.util.TreeMap.get(TreeMap.java:278) ~[?:1.8.0_65]
	at io.druid.java.util.common.io.smoosh.SmooshedFileMapper.mapFile(SmooshedFileMapper.java:116) ~[java-util-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at io.druid.segment.IndexIO$V9IndexLoader.load(IndexIO.java:1040) ~[druid-processing-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at io.druid.segment.IndexIO.loadIndex(IndexIO.java:220) ~[druid-processing-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at io.druid.segment.realtime.appenderator.AppenderatorImpl.persistHydrant(AppenderatorImpl.java:1011) ~[druid-server-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at io.druid.segment.realtime.appenderator.AppenderatorImpl.access$200(AppenderatorImpl.java:95) ~[druid-server-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at io.druid.segment.realtime.appenderator.AppenderatorImpl$2.doCall(AppenderatorImpl.java:389) ~[druid-server-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	at io.druid.common.guava.ThreadRenamingCallable.call(ThreadRenamingCallable.java:44) ~[druid-common-0.10.1-SNAPSHOT.jar:0.10.1-SNAPSHOT]
	... 4 more
2017-08-09T15:44:28,330 INFO [task-runner-0-priority-0] io.druid.indexing.overlord.TaskRunnerUtils - Task [index_kafka_m2_dos_order_test_a712d861b4a808d_jokilbmh] status changed to [FAILED].
2017-08-09T15:44:28,331 INFO [task-runner-0-priority-0] io.druid.indexing.worker.executor.ExecutorLifecycle - Task completed with status: {
  "id" : "index_kafka_m2_dos_order_test_a712d861b4a808d_jokilbmh",
  "status" : "FAILED",
  "duration" : 3831