After I added a jar file to the HBase Master I had a problem where regions failed to transition to a RegionServer. Below are the errors; removing the jar file from the hbase/lib folder resolved this problem (full path to jar: /opt/cloudera/parcels/CDH-5.0.2-1.cdh5.0.2.p0.13/lib/hbase/lib/). What tipped me off was the missing class definition: Caused by: java.lang.NoClassDefFoundError: org/apache/hadoop/hbase/ipc/CoprocessorProtocol.
Failed open of region=REGION.NAME,,4194066667839.6ea7d7ff9276f9c0e9b126c73e25bc54., starting to roll back the global memstore size.
java.lang.IllegalStateException: Could not instantiate a region instance.
at org.apache.hadoop.hbase.regionserver.HRegion.newHRegion(HRegion.java:3970)
at org.apache.hadoop.hbase.regionserver.HRegion.openHRegion(HRegion.java:4276)
at org.apache.hadoop.hbase.regionserver.HRegion.openHRegion(HRegion.java:4249)
at org.apache.hadoop.hbase.regionserver.HRegion.openHRegion(HRegion.java:4205)
at org.apache.hadoop.hbase.regionserver.HRegion.openHRegion(HRegion.java:4156)
at org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler.openRegion(OpenRegionHandler.java:475)
at org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler.process(OpenRegionHandler.java:140)
at org.apache.hadoop.hbase.executor.EventHandler.run(EventHandler.java:128)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.GeneratedConstructorAccessor7.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at org.apache.hadoop.hbase.regionserver.HRegion.newHRegion(HRegion.java:3967)
… 10 more
Caused by: java.lang.NoClassDefFoundError: org/apache/hadoop/hbase/ipc/CoprocessorProtocol
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
…
9:10:19.721 AM INFO org.apache.hadoop.hbase.regionserver.handler.OpenRegionHandler
Opening of region {ENCODED => 6ea7d7ff9276f9c0e9b126c73e25bc54, NAME => ‘REGION.NAME,,4194066667839.6ea7d7ff9276f9c0e9b126c73e25bc54.’, STARTKEY => ”, ENDKEY => ”} failed, transitioning from OPENING to FAILED_OPEN in ZK, expecting version 28
