[HDFS-3376] DFSClient fails to make connection to DN if there are many unusable cached sockets

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha
• Fix Version/s: 2.0.0-alpha
• Component/s: hdfs-client
• Target Version/s: 2.0.0-alpha
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 05/May/12 21:11
• Updated: 28/Sep/15 20:58
• Resolved: 07/May/12 16:42

Description

After fixing the datanode side of keepalive to properly disconnect stale clients, (HDFS-3357), the client side has the following issue: when it connects to a DN, it first tries to use cached sockets, and will try a configurable number of sockets from the cache. If there are more cached sockets than the configured number of retries, and all of them have been closed by the datanode side, then the client will throw an exception and mark the replica node as dead.