[HDFS-7457] DatanodeID generates excessive garbage

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha, 3.0.0-alpha1
• Fix Version/s: 2.7.0
• Component/s: namenode
• Target Version/s: 2.7.0
• Hadoop Flags: Reviewed
• Assignee: Daryn Sharp
• Reporter: Daryn Sharp
• Created: 01/Dec/14 18:34
• Updated: 12/May/16 18:17
• Resolved: 15/Jan/15 22:46

Description

DatanodeID#getXferAddr is a dynamically generated string. This string is repeatedly generated for the hash code, equality, comparisons, and stringification. Every DN->NN RPC method calls DatanodeManager#getDatanode to validate if the node is registered, which involves a call to getXferAddr.

The dynamic computation generates unnecessary trash that puts unnecessary pressure on the GC.

Issue Links

• is related to: HDFS-7433 Optimize performance of DatanodeManager's node map