[MAPREDUCE-6718] add progress log to JHS during startup

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.9.0, 3.0.0-alpha2
• Component/s: jobhistoryserver
• Labels: supportability
• Hadoop Flags: Reviewed
• Assignee: Haibo Chen
• Reporter: Haibo Chen
• Created: 19/Jun/16 01:52
• Updated: 26/Feb/20 05:29
• Resolved: 28/Sep/16 23:05

Description

lWhen the JHS starts up, it initializes the internal caches and storage via the HistoryFileManager. If we have a large number of existing finished jobs then we could spent minutes in this startup phase without logging progress:
2016-03-14 10:56:01,444 INFO org.apache.hadoop.mapreduce.v2.jobhistory.JobHistoryUtils: Default file system [hdfs://hadoopcdh.itnas01.ieee.org:8020]
2016-03-14 10:56:11,455 INFO org.apache.hadoop.mapreduce.v2.hs.HistoryFileManager: Initializing Existing Jobs...
2016-03-14 12:01:36,926 INFO org.apache.hadoop.mapreduce.v2.hs.CachedHistoryStorage: CachedHistoryStorage Init
This makes it really difficult to assess if things are working correctly (it looks hung). We can add logs to notify users of progress.