// create NM simulators
Random random = new Random();
Set<String> rackSet = new HashSet<String>();
for (String hostName : nodeSet) {
// we randomize the heartbeat start time from zero to 1 interval
NMSimulator nm = new NMSimulator();
nm.init(hostName, nmMemoryMB, nmVCores,
random.nextInt(heartbeatInterval), heartbeatInterval, rm);
nmMap.put(nm.getNode().getNodeID(), nm);
runner.schedule(nm);
rackSet.add(nm.getNode().getRackName());
}
numRacks = rackSet.size();
numNMs = nmMap.size();
}