byte[] startKey = null;
Scan scan = null;
StopWatch stopWatch = new StopWatch();
// monitor one region on every region server
for (Map.Entry<String, List<HRegionInfo>> entry : rsAndRMap.entrySet()) {
stopWatch.reset();
serverName = entry.getKey();
// always get the first region
region = entry.getValue().get(0);
try {
tableName = region.getTable().getNameAsString();