[HADOOP-3583] Pull out configuration element names from inline code to interface classes for use across Hadoop and other apps

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 0.18.0
• Component/s: conf
• Assignee: Unassigned
• Reporter: Steve Loughran
• Created: 17/Jun/08 13:11
• Updated: 29/Apr/10 08:09

Description

If we had different interfaces for the different configuration names as a set of constants, instead of using inline strings

1. we could detect naming inconsistencies (and spelling errors) faster
2. it would be easier for other applications (downstream, such as HBase) or tools that set the parameters) to actually set the parameters.
3. It would be eaiser to change the names, if desired.
4. it would be easy to detect all usages within a single project.

The interface classes could be hand generated (turn existing references into constants), or they could be auto-generated from an XML template. The latter would work if the default values included a definition of every possible supported attribute, somehow grouped so that jobconf values could be kept separate from dfs constants.

There is an incomplete hand-generated example at

http://smartfrog.svn.sourceforge.net/viewvc/smartfrog/trunk/core/components/hadoop/src/org/smartfrog/services/hadoop/conf/ConfigurationAttributes.java?view=markup

Issue Links

• is part of: HADOOP-3582 Improve how Hadoop gets configured