[HADOOP-794] JobTracker crashes with ArithmeticException

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.1
• Fix Version/s: 0.10.0
• Assignee: Owen O'Malley
• Reporter: Nigel Daley
• Created: 07/Dec/06 18:28
• Updated: 08/Jul/09 16:52
• Resolved: 13/Dec/06 19:32

Description

The sort benchmark on 20 nodes failed for me with an ArithmeticException. Sort.java calculates the number of maps and reduces dynamically based on the cluster size. I'm guessing at the time it did the calculation, the jobtracker had heard from 0 task trackers (which seems odd since I wait 1 minute after starting the jobtracker before starting Sort).

From the job output:
Running on 0 nodes to sort from /sortBenchmark20/input into /sortBenchmark20/output with 0 reduces.

From the JobTracker log:
2006-12-07 07:10:06,709 ERROR org.apache.hadoop.mapred.JobTracker: Job initialization failed:
java.lang.ArithmeticException: / by zero
at org.apache.hadoop.mapred.InputFormatBase.getSplits(InputFormatBase.java:130)
at org.apache.hadoop.mapred.JobInProgress.initTasks(JobInProgress.java:125)
at org.apache.hadoop.mapred.JobTracker$JobInitThread.run(JobTracker.java:326)
at java.lang.Thread.run(Thread.java:595)

The jobtacker should check for illegal inputs like this and not fall over.