[MAPREDUCE-5831] Old MR client is not compatible with new MR application

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 2.2.0, 2.3.0
• Fix Version/s: 2.6.0
• Component/s: client, mr-am
• Target Version/s: 2.6.0
• Hadoop Flags: Reviewed
• Assignee: Junping Du
• Reporter: Zhijie Shen
• Created: 11/Apr/14 17:23
• Updated: 25/Oct/19 20:26
• Resolved: 26/Sep/14 06:48

Description

Recently, we saw the following scenario:

1. The user setup a cluster of hadoop 2.3., which contains YARN 2.3 and MR 2.3.

2. The user client on a machine that MR 2.2 is installed and in the classpath.

Then, when the user submitted a simple wordcount job, he saw the following message:

16:00:41,027  INFO main mapreduce.Job:1345 -  map 100% reduce 100%
16:00:41,036  INFO main mapreduce.Job:1356 - Job job_1396468045458_0006 completed successfully
16:02:20,535  WARN main mapreduce.JobRunner:212 - Cannot start job [wordcountJob]
java.lang.IllegalArgumentException: No enum constant org.apache.hadoop.mapreduce.JobCounter.MB_MILLIS_REDUCES
	at java.lang.Enum.valueOf(Enum.java:236)
	at org.apache.hadoop.mapreduce.counters.FrameworkCounterGroup.valueOf(FrameworkCounterGroup.java:148)
	at org.apache.hadoop.mapreduce.counters.FrameworkCounterGroup.findCounter(FrameworkCounterGroup.java:182)
	at org.apache.hadoop.mapreduce.counters.AbstractCounters.findCounter(AbstractCounters.java:154)
	at org.apache.hadoop.mapreduce.TypeConverter.fromYarn(TypeConverter.java:240)
	at org.apache.hadoop.mapred.ClientServiceDelegate.getJobCounters(ClientServiceDelegate.java:370)
	at org.apache.hadoop.mapred.YARNRunner.getJobCounters(YARNRunner.java:511)
	at org.apache.hadoop.mapreduce.Job$7.run(Job.java:756)
	at org.apache.hadoop.mapreduce.Job$7.run(Job.java:753)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:415)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1491)
	at org.apache.hadoop.mapreduce.Job.getCounters(Job.java:753)
	at org.apache.hadoop.mapreduce.Job.monitorAndPrintJob(Job.java:1361)
	at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1289)
        . . .

The problem is that the wordcount job was running on one or more than one nodes of the YARN cluster, where MR 2.3 libs were installed, and JobCounter.MB_MILLIS_REDUCES is available in the counters. On the other side, due to the classpath setting, the client was likely to run with MR 2.2 libs. After the client retrieved the counters from MR AM, it tried to construct the Counter object with the received counter name. Unfortunately, the enum didn't exist in the client's classpath. Therefore, "No enum constant" exception is thrown here.

JobCounter.MB_MILLIS_REDUCES is brought to MR2 via MAPREDUCE-5464 since Hadoop 2.3.

Issue Links

• is related to: MAPREDUCE-6168 Old MR client is still broken when receiving new counters from MR job
• relates to: MAPREDUCE-4150 Versioning and rolling upgrades for MR2
• relates to: MAPREDUCE-5464 Add analogs of the SLOTS_MILLIS counters that jive with the YARN resource model