[HADOOP-8048] Allow merging of Credentials

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.23.1, 0.24.0
• Fix Version/s: 0.23.2
• Component/s: util
• Target Version/s: 0.23.1, 0.24.0
• Assignee: Daryn Sharp
• Reporter: Daryn Sharp
• Created: 09/Feb/12 17:19
• Updated: 02/May/13 02:29
• Resolved: 10/Feb/12 00:38

Description

There is an existing Credentials#addAll which combines two Credentials, but it overwrites all existing Credentials. There should be a Credentials#mergeAll that will not overwrite. This will facility the cleanup of code in TokenCache denoted with:

//TODO: Need to come up with a better place to put
//this block of code to do with reading the file

The token cache basically needs to merge the contents of a binary credentials file when it fails to find a token. Performing the merge within Credentials is cleaner, and will break the cross-component dependency whereby the TokenCache currently has to have intimate knowledge of how the FileSystem will key tokens in the cache.

Issue Links

• is depended upon by: MAPREDUCE-3849 Change TokenCache's reading of the binary token file
• is related to: MAPREDUCE-3825 MR should not be getting duplicate tokens for a MR Job.
• is related to: HADOOP-7967 Need generalized multi-token filesystem support