Implement a Map-Reduce application which can be used to reliably launch speculative tasks -----------------------------------------------------------------------------------------
Key: HADOOP-2214 URL: https://issues.apache.org/jira/browse/HADOOP-2214 Project: Hadoop Issue Type: Test Components: test Reporter: Arun C Murthy Fix For: 0.16.0 It would be very useful to have a reliable test case to help launch speculative tasks (maps and/or reduces) to help debug problems or fine-tune strategies for speculative execution. I propose we implement some along the lines of the SmallJobsBenchmark and put it in the hadoop-test.jar. I imagine it could be used like: {noformat} $ bin/hadoop jar hadoop-${version}-test.jar speculativejob -nMaps 1000 -nReduces 50 -specMaps 10 -specReduces 5 {noformat} The application should be minutely aware of the _current_ strategies for launching speculative tasks, and throttle requisite no. of maps/reduces to ensure that the speculative tasks are launched in a reliable and repeatable manner. Thoughts? -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.