[HDFS-11993] Add log info when connect to datanode socket address failed

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.9.0, 3.0.0-alpha4
• Component/s: hdfs-client
• Target Version/s: 3.0.0-alpha4
• Assignee: chencan
• Reporter: chencan
• Created: 19/Jun/17 07:47
• Updated: 26/Jun/17 20:49
• Resolved: 26/Jun/17 20:26

Description

In function BlockSeekTo, when connect faild to datanode socket address,log as follow:

DFSClient.LOG.warn("Failed to connect to " + targetAddr + " for block"
+ ", add to deadNodes and continue. " + ex, ex);

add block info may be more explicit.