[HADOOP-8071] Avoid an extra packet in client code when nagling is disabled

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.23.1
• Fix Version/s: 0.23.2
• Component/s: ipc
• Target Version/s: 0.23.2
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 14/Feb/12 05:35
• Updated: 28/Mar/12 09:19
• Resolved: 14/Feb/12 19:47

Description

Currently, if you disable TCP_NODELAY in the IPC client, you get an extra packet for each call which contains the call's length. This is unnecessary. Instead, we can just reserve the 4 bytes in the buffer up front, then go back to fill it in before pushing the call to the wire.

Issue Links

• relates to: HADOOP-8069 Enable TCP_NODELAY by default for IPC