[HDFS-3342] SocketTimeoutException in BlockSender.sendChunks could have a better error message

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha
• Fix Version/s: 2.7.0
• Component/s: datanode
• Labels: supportability
• Assignee: Yongjun Zhang
• Reporter: Todd Lipcon
• Created: 01/May/12 22:24
• Updated: 24/Apr/15 23:22
• Resolved: 30/Oct/14 18:03

Description

Currently, if a client connects to a DN and begins to read a block, but then stops calling read() for a long period of time, the DN will log a SocketTimeoutException "480000 millis timeout while waiting for channel to be ready for write." This is because there is no "keepalive" functionality of any kind. At a minimum, we should improve this error message to be an INFO level log which just says that the client likely stopped reading, so disconnecting it.