[HDFS-2759] Pre-allocate HDFS edit log files after writing version number

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.0-alpha
• Fix Version/s: 2.0.2-alpha
• Component/s: ha, namenode
• Hadoop Flags: Reviewed
• Assignee: Aaron Myers
• Reporter: Aaron Myers
• Created: 06/Jan/12 01:44
• Updated: 10/Mar/15 04:36
• Resolved: 28/Jan/12 20:27

Description

In HDFS-2709 it was discovered that there's a potential race wherein edits log files are pre-allocated before the version number is written into the header of the file. This can cause the NameNode to read an invalid HDFS layout version, and hence fail to read the edit log file. We should write the header, then pre-allocate the rest of the file after this point.

Issue Links

• is related to: HDFS-2709 HA: Appropriately handle error conditions in EditLogTailer