Iterator<Map.Entry<String, DatanodeRegistration>> it =
sIdToDnReg.entrySet().iterator();
for(int j=0; j<randomIndex-1; ++j) {
it.next();
}
DatanodeRegistration toRemove = it.next().getValue();
Log.info("Removing node " + toRemove.getStorageID() + " ip " +
toRemove.getXferAddr() + " version : " + toRemove.getSoftwareVersion());
//Remove that random node
dm.removeDatanode(toRemove);
it.remove();
}
// Otherwise register a node. This node may be a new / an old one
else {
//Pick a random storageID to register.
String storageID = "someStorageID" + rng.nextInt(5000);
DatanodeRegistration dr = Mockito.mock(DatanodeRegistration.class);
Mockito.when(dr.getStorageID()).thenReturn(storageID);
//If this storageID had already been registered before
if(sIdToDnReg.containsKey(storageID)) {
dr = sIdToDnReg.get(storageID);
//Half of the times, change the IP address
if(rng.nextBoolean()) {
dr.setIpAddr(dr.getIpAddr() + "newIP");
}
} else { //This storageID has never been registered
//Ensure IP address is unique to storageID
String ip = "someIP" + storageID;
Mockito.when(dr.getIpAddr()).thenReturn(ip);
Mockito.when(dr.getXferAddr()).thenReturn(ip + ":9000");
Mockito.when(dr.getXferPort()).thenReturn(9000);
}
//Pick a random version to register with
Mockito.when(dr.getSoftwareVersion()).thenReturn(
"version" + rng.nextInt(5));
Log.info("Registering node storageID: " + dr.getStorageID() +
", version: " + dr.getSoftwareVersion() + ", IP address: "
+ dr.getXferAddr());
//Register this random node
dm.registerDatanode(dr);
sIdToDnReg.put(storageID, dr);
}