Johannes Zillmann created MAPREDUCE-5369:
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Summary: Progress for jobs with multiple splits in local mode is
wrong
Key: MAPREDUCE-5369
URL: https://issues.apache.org/jira/browse/MAPREDUCE-5369
Project: Hadoop Map/Reduce
Issue Type: Bug
Affects Versions: 0.20.2
Reporter: Johannes Zillmann
In case a job with multiple splits is executed in local mode (LocalJobRunner)
its progress calculation is wrong.
After the first split is processed it jumps to 100%, then back to 50% and so
on.
The reason lies in the progress calculation in LocalJobRunner:
{code}
float taskIndex = mapIds.indexOf(taskId);
if (taskIndex >= 0) { // mapping
float numTasks = mapIds.size();
status.setMapProgress(taskIndex/numTasks +
taskStatus.getProgress()/numTasks);
} else {
status.setReduceProgress(taskStatus.getProgress());
}
{code}
The problem is that {{mapIds}} is filled lazily in run(). There is an loop over
all splits. In the loop, the splits task id is added to {{mapIds}}, then the
split is processed. That means {{numTasks}} is 1 while the first split is
processed, it is 2 while the second task is processed and so on...
I tried Hadoop 0.20.2, 1.0.3, 1.1.2 and cdh-4.1. All the same behaviour!
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