[ http://issues.apache.org/jira/browse/HADOOP-252?page=comments#action_12413191 ]
Doug Cutting commented on HADOOP-252: ------------------------------------- One complication is that different RPC protocols share common connections, in order to minimize the number of per-connection threads and sockets. So the versions would really need to be transmitted with each request, or perhaps with the first request of each protocol over a given connection. > add versioning to RPC > --------------------- > > Key: HADOOP-252 > URL: http://issues.apache.org/jira/browse/HADOOP-252 > Project: Hadoop > Type: Improvement > Components: ipc > Reporter: Yoram Arnon > > currently, any change to any rpc message breaks the protocol, with mysterious > exceptions occurring at run time. > a versioning sceme would have two benefits: > - intelligent error messages, indicating that an upgrade is required > - backwards compatibility could be supported. > the proposal is to add a "const version" for each protocol, and a method: int > getVersion(int version) that sends the client's version and receives the > server's version. This would be the first method invoked on connection. Both > sides then either agree on the lowest version number, providing backwards > compatibility support, or abort the connection as "unsupported version". -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
