[MAPREDUCE-5704] Optimize nextJobId in JobTracker

• Type: Improvement
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.2.1
• Component/s: jobtracker, mrv1
• Labels: BB2015-05-TBR
• Assignee: JamesLi
• Reporter: JamesLi
• Created: 02/Jan/14 09:37
• Updated: 06/May/15 03:33

Description

When jobtracker start, nextJobId start with 1,if we have run 3000 jobs then restart jobtracker and run a new job,we can not see this new job on jobtracker:5030/jobhistory.jsp unless click "get more results" button.
In jobhistory_jsp.java, array SCAN_SIZES controls job numbers displayed on jobhistory.jsp.
I make a little chage,when jobtracker start,find the biggest id under history done directory,job will start with maxId+1 or 1 if can not find any job files.