[HADOOP-7227] Remove protocol version check at proxy creation in Hadoop RPC.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.23.0
• Component/s: ipc
• Hadoop Flags: Incompatible change, Reviewed

Release Note

1. Protocol version check is removed from proxy creation, instead version check is performed at server in every rpc call.
2. This change is backward incompatible because format of the rpc messages is changed to include client version, client method hash and rpc version.
3. rpc version is introduced which should change when the format of rpc messages is changed.

• Assignee: Jitendra Nath Pandey
• Reporter: Jitendra Nath Pandey
• Created: 15/Apr/11 00:35
• Updated: 05/Jul/12 00:48
• Resolved: 04/May/11 16:57

Description

Currently when a proxy is created for a protocol, there is a round trip of messages to check the protocol version. The protocol version is not checked in any subsequent rpc which could be a problem if the server restarts with a new protocol version. This issue and also the additional round-trip at proxy creation can be avoided if we add the protocol version in every rpc, and server checks the protocol version for every call.

Issue Links

• breaks: HADOOP-8558 Hadoop RPC does not allow protocol extension with common interfaces.