[HADOOP-4813] Avoid a buffer copy while replying to RPC requests.

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Incomplete
• Component/s: ipc
• Labels: newbie
• Assignee: Unassigned
• Reporter: Raghu Angadi
• Created: 09/Dec/08 23:15
• Updated: 21/Jul/14 17:05
• Resolved: 21/Jul/14 17:05

Description

RPC server first serializes RPC response to a ByteArrayOutputStream and then creates a new array to write to socket. For most responses the RPC handler is able to write the entire response in-line. If we could use the same buffer used by ByteArrayOutputStream, we can avoid this copy.

As mentioned in HADOOP-4802, yet another copy could be avoided (in most cases) if we use a static direct buffer for the responses (not proposed for this jira).

Issue Links

• relates to: HADOOP-4802 RPC Server send buffer retains size of largest response ever sent