[HDFS-1335] HDFS side of HADOOP-6904: first step towards inter-version communications between dfs client and NameNode

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.22.0
• Fix Version/s: 0.23.0
• Component/s: hdfs-client, namenode
• Hadoop Flags: Reviewed
• Assignee: Hairong Kuang
• Reporter: Hairong Kuang
• Created: 09/Aug/10 17:02
• Updated: 02/May/13 02:29
• Resolved: 28/Jan/11 23:14

Description

The idea is that for getProtocolVersion, NameNode checks if the client and server versions are compatible if the server version is greater than the client version. If no, throws a VersionIncompatible exception; otherwise, returns the server version.

On the dfs client side, when creating a NameNode proxy, catches the VersionMismatch exception and then checks if the client version and the server version are compatible if the client version is greater than the server version. If not compatible, throws exception VersionIncomptible; otherwise, records the server version and continues.

Issue Links

• depends upon: HADOOP-6904 A baby step towards inter-version RPC communications