[MAPREDUCE-2319] MultithreadedMapper doesn't update completion percentage before mapper is finished

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.20.2
• Assignee: Unassigned
• Reporter: Forest Tan
• Created: 11/Feb/11 08:16
• Updated: 11/Feb/11 08:16

Description

MultithreadedMapper runs multiple threads in one mapper, but it doesn't update the completion percentage before all the threads are completed.

If is better to update the completion percentage when threads are running to reflect real progress.

The code is like this:
runners = new ArrayList(numberOfThreads);
for(int i = 0; i < numberOfThreads; i++)

{ MapRunner thread = new MapRunner(context); thread.start(); runners.add(i, thread); }

for(int i = 0; i < numberOfThreads; i++)

{ MapRunner thread = (MapRunner)runners.get(i); thread.join(); // wait ... }