@Override
  protected void scheduleFlush(String encodedRegionName, List<byte[]> families) {
    MasterRegionFlusherAndCompactor flusher = this.flusherAndCompactor;
    if (flusher != null) {
      flusher.requestFlush();
    }
  }
As long as there is no RegionServerServices for a master local region, we need implement log
roller logic by our own.
<p/>
We can reuse most of the code for normal wal roller, the only difference is that there is only
one region, so in {@link #scheduleFlush(String, List)} method we can just schedule flush for the
master local region.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/region/MasterRegionWALRoller.java