Details
Critical Description
On HMaster Startup:
2019-07-02 12:38:11,312 FATAL [orc3:16000.activeMasterManager] master.HMaster: Failed to become active master
java.lang.NullPointerException
at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:936)
at java.util.concurrent.ConcurrentHashMap.containsKey(ConcurrentHashMap.java:964)
at java.util.concurrent.ConcurrentHashMap$KeySetView.contains(ConcurrentHashMap.java:4558)
at java.util.Collections$UnmodifiableCollection.contains(Collections.java:1032)
at org.apache.hadoop.hbase.master.AssignmentManager.rebuildUserRegions(AssignmentManager.java:3094)
at org.apache.hadoop.hbase.master.AssignmentManager.joinCluster(AssignmentManager.java:495)
at org.apache.hadoop.hbase.master.HMaster.finishActiveMasterInitialization(HMaster.java:830)
at org.apache.hadoop.hbase.master.HMaster.access$600(HMaster.java:202)
at org.apache.hadoop.hbase.master.HMaster$2.run(HMaster.java:1883)
at java.lang.Thread.run(Thread.java:748)
2019-07-02 12:38:11,312 FATAL [orc3:16000.activeMasterManager] master.HMaster: Master server abort: loaded coprocessors are: []
2019-07-02 12:38:11,312 FATAL [orc3:16000.activeMasterManager] master.HMaster: Unhandled exception. Starting shutdown.
java.lang.NullPointerException
at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:936)
at java.util.concurrent.ConcurrentHashMap.containsKey(ConcurrentHashMap.java:964)
at java.util.concurrent.ConcurrentHashMap$KeySetView.contains(ConcurrentHashMap.java:4558)
at java.util.Collections$UnmodifiableCollection.contains(Collections.java:1032)
at org.apache.hadoop.hbase.master.AssignmentManager.rebuildUserRegions(AssignmentManager.java:3094)
at org.apache.hadoop.hbase.master.AssignmentManager.joinCluster(AssignmentManager.java:495)
at org.apache.hadoop.hbase.master.HMaster.finishActiveMasterInitialization(HMaster.java:830)
at org.apache.hadoop.hbase.master.HMaster.access$600(HMaster.java:202)
at org.apache.hadoop.hbase.master.HMaster$2.run(HMaster.java:1883)
at java.lang.Thread.run(Thread.java:748)
It happens when regionLocation is null, which may happen just above on line 3086 (or as returned by getRegionServer)
We had this on 1.2.12 with the corresponding patch, but since it is not supported anymore, did not submit it.
Attached is the patch for 1.3.5. Did not test it in 1.4+