[ https://issues.apache.org/jira/browse/SPARK-21703?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16123071#comment-16123071 ]
neoremind edited comment on SPARK-21703 at 8/11/17 9:18 AM: ------------------------------------------------------------ Thanks Sean to guide me to the right place. Here's the http://apache-spark-user-list.1001560.n3.nabble.com/SPARK-CORE-Why-RPC-message-are-transferred-with-header-and-body-separately-in-TCP-frame-td29054.html. was (Author: xu.zhang): Thanks Sean to guide me to the right place. Here's the [link](http://apache-spark-user-list.1001560.n3.nabble.com/SPARK-CORE-Why-RPC-message-are-transferred-with-header-and-body-separately-in-TCP-frame-td29054.html). > Why RPC message are transferred with header and body separately in TCP frame > ---------------------------------------------------------------------------- > > Key: SPARK-21703 > URL: https://issues.apache.org/jira/browse/SPARK-21703 > Project: Spark > Issue Type: Question > Components: Spark Core > Affects Versions: 1.6.0 > Reporter: neoremind > Priority: Trivial > Labels: RPC > > After seeing the details of how spark leverage netty, I found one question, > typically RPC message wire format would have a header+payload structure, and > netty uses a TransportFrameDecoder to deal with how to determine a complete > message from remote peer. But after using Wireshark sniffing tool, I found > that the message are sent separately with header and then followed by body, > although this works fine, but for underlying TCP there would be ACK segments > sent back to acknowledge, there might be a little bit redundancy since we can > sent them together and the header are usually very small. > The main reason can be found in MessageWithHeader class, since transferTo > method write tow times for header and body. > Could someone help me understand the background story on why to implement in > such way? Thanks! -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org For additional commands, e-mail: issues-h...@spark.apache.org