[HDFS-3898] QJM: enable TCP_NODELAY for IPC

• Type: Sub-task
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: QuorumJournalManager (HDFS-3077)
• Fix Version/s: QuorumJournalManager (HDFS-3077)
• Target Version/s: QuorumJournalManager (HDFS-3077)
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 07/Sep/12 03:20
• Updated: 10/Sep/12 18:47
• Resolved: 10/Sep/12 18:47

Description

Currently, if the size of the edits batches is larger than the MTU, it can result in 40ms delays due to interaction between nagle's algorithm and delayed ack. Enabling TCP_NODELAY on the sockets solves this issue, so we should set those configs by default for all of the QJM-related IPC.