For a while now I have been writing about how to analyze and optimize Hadoop jobs beyond just tweaking MapReduce options. The other day I took a look at some of our Outage Analyzer Hadoop jobs and put words into action.
A simple analysis of the Outage Analyzer jobs with Compuware APM 5.5 identified three hotspots and two potential Hadoop problems in one of our biggest jobs. It took the responsible developer a couple of hours to fix it and the result is a 2x improvement overall and a 6x improvement on the Reduce part of the job. Let’s see how we achieved that.