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Hudson commented on HBASE-3899: ------------------------------- Integrated in HBase-TRUNK #1939 (See [https://builds.apache.org/hudson/job/HBase-TRUNK/1939/]) > enhance HBase RPC to support free-ing up server handler threads even if > response is not ready > --------------------------------------------------------------------------------------------- > > Key: HBASE-3899 > URL: https://issues.apache.org/jira/browse/HBASE-3899 > Project: HBase > Issue Type: Improvement > Components: ipc > Reporter: dhruba borthakur > Assignee: dhruba borthakur > Fix For: 0.92.0 > > Attachments: asyncRpc.txt, asyncRpc.txt > > > In the current implementation, the server handler thread picks up an item > from the incoming callqueue, processes it and then wraps the response as a > Writable and sends it back to the IPC server module. This wastes > thread-resources when the thread is blocked for disk IO (transaction logging, > read into block cache, etc). > It would be nice if we can make the RPC Server Handler threads pick up a call > from the IPC queue, hand it over to the application (e.g. HRegion), the > application can queue it to be processed asynchronously and send a response > back to the IPC server module saying that the response is not ready. The RPC > Server Handler thread is now ready to pick up another request from the > incoming callqueue. When the queued call is processed by the application, it > indicates to the IPC module that the response is now ready to be sent back to > the client. > The RPC client continues to experience the same behaviour as before. A RPC > client is synchronous and blocks till the response arrives. > This RPC enhancement allows us to do very powerful things with the > RegionServer. In future, we can make enhance the RegionServer's threading > model to a message-passing model for better performance. We will not be > limited by the number of threads in the RegionServer. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira