[HADOOP-13284] FileSystemStorageStatistics must not attempt to read non-existent rack-aware read stats in branch-2.8

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.0
• Fix Version/s: 2.8.0
• Component/s: fs
• Target Version/s: 2.8.0
• Assignee: Mingliang Liu
• Reporter: Mingliang Liu
• Created: 16/Jun/16 20:35
• Updated: 17/Jun/16 00:15
• Resolved: 16/Jun/16 23:46

Description

As HDFS-9579 was not committed to branch-2.8, FileSystemStorageStatistics#KEYS should not include those rack aware read stats brought by HDFS-9579, including bytesReadLocalHost, bytesReadDistanceOfOneOrTwo, bytesReadDistanceOfThreeOrFour, bytesReadDistanceOfFiveOrLarger. Or else, the long iterator will throw NPE when traversing. See detailed exception stack as following (it happens when Tez uses the new FileSystemStorageStatistics).

2016-06-15 15:56:59,242 [DEBUG] [TezChild] |impl.TezProcessorContextImpl|: Cleared TezProcessorContextImpl related information
2016-06-15 15:56:59,243 [WARN] [main] |task.TezTaskRunner2|: Exception from RunnerCallable
java.lang.NullPointerException
        at org.apache.hadoop.fs.FileSystemStorageStatistics$LongStatisticIterator.next(FileSystemStorageStatistics.java:74)
        at org.apache.hadoop.fs.FileSystemStorageStatistics$LongStatisticIterator.next(FileSystemStorageStatistics.java:51)
        at org.apache.tez.runtime.metrics.FileSystemStatisticsUpdater2.updateCounters(FileSystemStatisticsUpdater2.java:51)
        at org.apache.tez.runtime.metrics.TaskCounterUpdater.updateCounters(TaskCounterUpdater.java:118)
        at org.apache.tez.runtime.RuntimeTask.setFrameworkCounters(RuntimeTask.java:172)
        at org.apache.tez.runtime.task.TaskRunner2Callable.callInternal(TaskRunner2Callable.java:100)
        at org.apache.tez.runtime.task.TaskRunner2Callable.callInternal(TaskRunner2Callable.java:37)
        at org.apache.tez.common.CallableWithNdc.call(CallableWithNdc.java:36)
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
2016-06-15 15:56:59,245 [DEBUG] [main] |task.TaskReporter|: Sending heartbeat to AM, request={  containerId=container_1466028486194_0005_01_000002, requestId=10, startIndex=0, preRoutedStartIndex=1, maxEventsToGet=500, taskAttemptId=attempt_1466028486194_0005_1_00_000000_0, eventCount=4 }

Thanks hitesh for reporting this.