public boolean isolateRegions()
    throws ExecutionException, InterruptedException, TimeoutException {
    return unloadRegions(false, isolateRegionIdArray);
  }
Isolated regions specified in {@link #isolateRegionIdArray} on {@link #hostname} in ack Mode
and Unload regions from given {@link #hostname} using ack/noAck mode and {@link #maxthreads}.
In noAck mode we do not make sure that region is successfully online on the target region
server,hence it is the best effort. We do not unload regions to hostnames given in
{@link #excludeFile}. If designatedFile is present with some contents, we will unload regions
to hostnames provided in {@link #designatedFile}
@return true if region isolation succeeded, false otherwise
hbase-server/src/main/java/org/apache/hadoop/hbase/util/RegionMover.java