public void start(CoprocessorEnvironment env) throws IOException {
ZooKeeperWatcher zk = null;
if (env instanceof MasterCoprocessorEnvironment) {
// if running on HMaster
MasterCoprocessorEnvironment mEnv = (MasterCoprocessorEnvironment) env;
zk = mEnv.getMasterServices().getZooKeeper();
} else if (env instanceof RegionServerCoprocessorEnvironment) {
RegionServerCoprocessorEnvironment rsEnv = (RegionServerCoprocessorEnvironment) env;
zk = rsEnv.getRegionServerServices().getZooKeeper();
} else if (env instanceof RegionCoprocessorEnvironment) {
// if running at region