cluster2.killOneBackupZooKeeperServer();
assertEquals(0, cluster2.getBackupZooKeeperServerNum());
assertEquals(1, cluster2.getZooKeeperServerNum());
// killing the last zk server
assertTrue((cluster2.killCurrentActiveZooKeeperServer() == -1));
// this should do nothing.
cluster2.killOneBackupZooKeeperServer();
assertEquals(-1, cluster2.getBackupZooKeeperServerNum());
assertEquals(0, cluster2.getZooKeeperServerNum());
} finally {