[HDFS-1601] Pipeline ACKs are sent as lots of tiny TCP packets

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.22.0
• Fix Version/s: 0.23.0, 0.22.1
• Component/s: datanode
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 27/Jan/11 05:52
• Updated: 15/Mar/12 18:27
• Resolved: 08/Feb/11 23:35

Description

I noticed in an hbase benchmark that the packet counts in my network monitoring seemed high, so took a short pcap trace and found that each pipeline ACK was being sent as five packets, the first four of which only contain one byte. We should buffer these bytes and send the PipelineAck as one TCP packet.

Issue Links

• is related to: HDFS-1599 Umbrella Jira for Improving HBASE support in HDFS