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Arpit Agarwal resolved HADOOP-8069. ----------------------------------- Resolution: Fixed Fix Version/s: 2.6.0 3.0.0 Target Version/s: 2.6.0 (was: 2.0.0-alpha, 3.0.0) Release Note: This change enables the TCP_NODELAY flag for all Hadoop IPC connections, hence bypassing TCP Nagling. Nagling interacts poorly with TCP delayed ACKs especially for request-response protocols. Hadoop Flags: Reviewed Committed to trunk and branch-2, resolving with release note. > Enable TCP_NODELAY by default for IPC > ------------------------------------- > > Key: HADOOP-8069 > URL: https://issues.apache.org/jira/browse/HADOOP-8069 > Project: Hadoop Common > Issue Type: Improvement > Components: ipc > Affects Versions: 0.23.0, 2.4.1 > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Fix For: 3.0.0, 2.6.0 > > Attachments: hadoop-8069.txt > > > I think we should switch the default for the IPC client and server NODELAY > options to true. As wikipedia says: > {quote} > In general, since Nagle's algorithm is only a defense against careless > applications, it will not benefit a carefully written application that takes > proper care of buffering; the algorithm has either no effect, or negative > effect on the application. > {quote} > Since our IPC layer is well contained and does its own buffering, we > shouldn't be careless. -- This message was sent by Atlassian JIRA (v6.2#6252)