I have been running into ingestion failures intermittently. Here is the stack trace from the overlord logs
[task-runner-0-priority-0] io.druid.indexing.overlord.ThreadPoolTaskRunner - Exception while running task[HadoopIndexTask{id=index_hadoop_sales-rank-daily_2017-07-27T04:33:48.922Z, type=index_hadoop, dataSource=sales-rank-daily}]
java.util.NoSuchElementException
at java.util.ArrayList$Itr.next(ArrayList.java:854) ~[?:1.8.0_131]
at com.google.common.collect.Iterators.getOnlyElement(Iterators.java:297) ~[guava-16.0.1.jar:?]
at com.google.common.collect.Iterables.getOnlyElement(Iterables.java:285) ~[guava-16.0.1.jar:?]
at io.druid.indexing.common.task.HadoopIndexTask.run(HadoopIndexTask.java:202) ~[druid-indexing-service-0.9.2.jar:0.9.2]
at io.druid.indexing.overlord.ThreadPoolTaskRunner$ThreadPoolTaskRunnerCallable.call(ThreadPoolTaskRunner.java:436) [druid-indexing-service-0.9.2.jar:0.9.2]
at io.druid.indexing.overlord.ThreadPoolTaskRunner$ThreadPoolTaskRunnerCallable.call(ThreadPoolTaskRunner.java:408) [druid-indexing-service-0.9.2.jar:0.9.2]
at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:1.8.0_131]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_131]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_131]
at java.lang.Thread.run(Thread.java:748) [?:1.8.0_131]
2017-07-27T04:34:02,584 INFO [task-runner-0-priority-0] io.druid.indexing.overlord.TaskRunnerUtils - Task [index_hadoop_sales-rank-daily_2017-07-27T04:33:48.922Z] status changed to [FAILED].
2017-07-27T04:34:02,586 INFO [task-runner-0-priority-0] io.druid.indexing.worker.executor.ExecutorLifecycle - Task completed with status: {
"id" : "index_hadoop_sales-rank-daily_2017-07-27T04:33:48.922Z",
"status" : "FAILED",
"duration" : 6574
}
Not sure where to get more information about the issue or how to go about debugging it. Attaching the ingestion spec file as well. Any help would be highly appreciated.