// stop current leader in controller cluster
ZkBaseDataAccessor<ZNRecord> baseAccessor =
new ZkBaseDataAccessor<ZNRecord>(_gZkClient);
ZKHelixDataAccessor accessor = new ZKHelixDataAccessor(controllerClusterName, baseAccessor);
Builder keyBuilder = accessor.keyBuilder();
LiveInstance leader = accessor.getProperty(keyBuilder.controllerLeader());
String leaderName = leader.getId();
int j = Integer.parseInt(leaderName.substring(leaderName.lastIndexOf('_') + 1));
controllers[j].syncStop();