anchor.diff:  
   The following metrics have been removed:
   
  -* Metrics related to the Distributed Log Replay feature are no longer present. They were previsouly found in the region server context under the name 'replay'. See the section <<upgrade2.0.distributed.log.replay>> for details.
  +* Metrics related to the Distributed Log Replay feature are no longer present. They were previously found in the region server context under the name 'replay'. See the section <<upgrade2.0.distributed.log.replay>> for details.
   
   The following metrics have been added:
   
  
positive.code: [[upgrade2.0.logging]]
  .Changed logging
  HBase-2.0.0 now uses link:https://www.slf4j.org/[slf4j] as its logging frontend.
  Prevously, we used link:http://logging.apache.org/log4j/1.2/[log4j (1.2)].
  For most the transition should be seamless; slf4j does a good job interpreting
  _log4j.properties_ logging configuration files such that you should not notice
  any difference in your log system emissions.
  
negative.code: * hbase.regionserver.hlog.blocksize defaults to 2x the HDFS default block size for the WAL dir. Previously it was equal to the HDFS default block size for the WAL dir.
  * hbase.client.start.log.errors.counter changed to 5. Previously it was 9.
  * hbase.ipc.server.callqueue.type changed to 'fifo'. In HBase versions 1.0 - 1.2 it was 'deadline'. In prior and later 1.x versions it already defaults to 'fifo'.
  * hbase.hregion.memstore.chunkpool.maxsize is 1.0 by default. Previously it was 0.0. Effectively, this means previously we would not use a chunk pool when our memstore is onheap and now we will. See the section <<gcpause>> for more information about the MSLAB chunk pool.
  * hbase.master.cleaner.interval is now set to 10 minutes. Previously it was 1 minute.
  * hbase.master.procedure.threads will now default to 1/4 of the number of available CPUs, but not less than 16 threads. Previously it would be number of threads equal to number of CPUs.
  * hbase.hstore.blockingStoreFiles is now 16. Previously it was 10.
  