Sandy Ryza created MAPREDUCE-5578: ------------------------------------- Summary: Miscellaneous Fair Scheduler speedups Key: MAPREDUCE-5578 URL: https://issues.apache.org/jira/browse/MAPREDUCE-5578 Project: Hadoop Map/Reduce Issue Type: Improvement Components: scheduler Reporter: Sandy Ryza Assignee: Sandy Ryza
I ran the Fair Scheduler's core scheduling loop through a profiler to and identified a bunch of minimally invasive changes that can shave off a few milliseconds. The main one is demoting a couple INFO log messages to DEBUG, which brought my benchmark down from 16000 ms to 6000. A few others (which had way less of an impact) were * Most of the time in comparisons was being spent in Math.signum. I switched this to direct ifs and elses and it halved the percent of time spent in comparisons. * I removed some unnecessary instantiations of Resource objects * I made it so that queues' usage wasn't calculated from the applications up each time getResourceUsage was called. -- This message was sent by Atlassian JIRA (v6.1#6144)