@Override
        public void logRollRequested(WALActionsListener.RollRequestReason reason) {
          switch (reason) {
            case LOW_REPLICATION:
              lowReplicationHookCalled.lazySet(true);
              break;
            default:
              break;
          }
        }
When we reuse the code of AsyncFSWAL to FSHLog, the low replication is only checked by
{@link LogRoller#checkLowReplication},so in order to make this test spend less time,we
should minimize following config which is maximized by
{@link AbstractTestLogRolling#setUpBeforeClass}
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/wal/TestLogRolling.java