Todd Lipcon created HDFS-4049: --------------------------------- Summary: hflush performance regression due to nagling delays Key: HDFS-4049 URL: https://issues.apache.org/jira/browse/HDFS-4049 Project: Hadoop HDFS Issue Type: Bug Components: data-node, performance Affects Versions: 2.0.2-alpha, 3.0.0 Reporter: Todd Lipcon Assignee: Todd Lipcon Priority: Critical
HDFS-3721 reworked the way that packets are mirrored through the pipeline in the datanode. This caused two write() calls where there used to be one, which interacts badly with nagling so that there are 40ms bubbles on hflush() calls. We didn't notice this in the tests because the hflush perf test only uses a single datanode. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira