[HDFS-9208] Disabling atime may fail clients like distCp

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Target Version/s: 2.8.0
• Hadoop Flags: Reviewed
• Assignee: Kihwal Lee
• Reporter: Kihwal Lee
• Created: 07/Oct/15 17:00
• Updated: 30/Aug/16 01:26
• Resolved: 20/Oct/15 03:45

Description

When atime is disabled, setTimes() throws an exception if the passed-in atime is not -1. But since atime is not -1, distCp fails when it tries to set the mtime and atime.

There are several options:

1) make distCp check for 0 atime and call setTimes() with -1. I am not very enthusiastic about it.
2) make NN also accept 0 atime in addition to -1, when the atime support is disabled.
3) support setting mtime & atime regardless of the atime support. The main reason why atime is disabled is to avoid edit logging/syncing during getBlockLocations() read calls. Explicit setting can be allowed.

Issue Links

• is duplicated by: HADOOP-12390 Enhance FsShell file put to support selectively preserving individual file attributes.