[HDFS-1542] Deadlock in Configuration.writeXml when serialized form is larger than one DFS block

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.22.0, 0.23.0
• Fix Version/s: 0.22.0
• Component/s: hdfs-client
• Hadoop Flags: Reviewed
• Assignee: Todd Lipcon
• Reporter: Todd Lipcon
• Created: 16/Dec/10 17:57
• Updated: 02/May/13 02:29
• Resolved: 06/Jan/11 19:00

Description

Configuration.writeXml holds a lock on itself and then writes the XML to an output stream, during which DFSOutputStream will try to get a lock on ackQueue/dataQueue. Meanwihle the DataStreamer thread will call functions like conf.getInt() and deadlock against the other thread, since it could be the same conf object.

This causes a deterministic deadlock whenever the serialized form is larger than block size.

Issue Links

• depends upon: HADOOP-7082 Configuration.writeXML should not hold lock while outputting