private static double getMachineFailureGeneratorRate(Unit root) {
Machine m = (Machine) root.getChildren().get(0).getChildren().get(0).getChildren().get(0);
if (m.getFailureGenerator() instanceof WeibullGenerator) {
return ((WeibullGenerator) m.getFailureGenerator()).getRate();
}
return -1;
}
public static void main(String[] args) throws Exception {
// Process command line arguments
if (args.length != 7)
throw new Exception(
"Usage: #iterations n k lazyThreshold totalActiveStorage(PB) disksPerMachine machinesPerRack");
int count = Integer.parseInt(args[0]);
if (count != 1) {
throw new RuntimeException("Count >1 is buggy");
}
Configuration.n = Integer.parseInt(args[1]);
Configuration.k = Integer.parseInt(args[2]);
Configuration.recoveryThreshold = Integer.parseInt(args[3]);
if (Configuration.recoveryThreshold == Configuration.n) {
System.err.println(
"Recovery threshold = # chunks per slice - making it one less: "
+ --Configuration.recoveryThreshold);
}
if (Configuration.recoveryThreshold < Configuration.n - 1 && !Configuration.lazyRecovery) {
System.err.println(
"Recovery threshold is less than # chunks per slice but lazy recovery is disabled - enabling");
Configuration.lazyRecovery = true;
}
Configuration.totalActiveStorage = Double.parseDouble(args[4]);
Configuration.disksPerMachine = Integer.parseInt(args[5]);
Configuration.machinesPerRack = Integer.parseInt(args[6]);
if (Configuration.disksPerMachine < 1 || Configuration.disksPerMachine > 40) {
throw new RuntimeException("Cannot have more than 40 disks per machine");
}
if (Configuration.machinesPerRack < 10 || Configuration.machinesPerRack > 80) {
throw new RuntimeException("Cannot have <10 or >80 machines per rack");
}
long eventsHandled = 0;
// Compute number of chunks each rack can store
int chunksPerMachine = Configuration.disksPerMachine * Configuration.chunksPerDisk;
int chunksPerRack = Configuration.machinesPerRack * chunksPerMachine;
// Compute storage capacity of a rack
double actualStorageRack = chunksPerRack / 1024.0 * Configuration.chunkSize; // GB
if (actualStorageRack <= 0) throw new RuntimeException("too many slices generated > 2^31");
// Compute amount of actual information that can be stored in a rack
// Amount of information = storage capacity * k/n * 5/6
double usefulStorageRack =
actualStorageRack * Configuration.k / Configuration.n * 5.0 / 6.0; // GB
// Compute number of racks needed to store totalActiveStorage amount of information
double racks = Configuration.totalActiveStorage * 1024 * 1024 / usefulStorageRack;
// Round up to nearest integer
Configuration.rackCount = (int) racks;
if (racks - Configuration.rackCount != 0) Configuration.rackCount++;
if (racks <= Configuration.numChunksDiffRacks * 20 / 10)
throw new Exception("Number of racks too small - adjust Configuration.numChunksDifRacks");
// Compute resulting total number of disks
int totalDisks =
Configuration.rackCount * Configuration.machinesPerRack * Configuration.disksPerMachine;
// Compute actual amount of information stored in the system --> this is different from
// totalActiveStorage because of the round-up error introduced in rackCount computation
double totalActualStorage = usefulStorageRack * Configuration.rackCount / 1024; // TB
// Compute total slices in the system
// Num slices = totalActualStorage*n/k / (chunkSize*n) = totalActualStorage/(chunkSize*k)
int totalSlices =
(int) (totalActualStorage * 1024.0 / (Configuration.chunkSize / 1024.0 * Configuration.k));
Configuration.totalSlices = totalSlices;
// print some of these stats
System.out.println(
"totalSlices="
+ totalSlices
+ " diskCount="
+ totalDisks
+ " totalStorage ="
+ totalActualStorage
+ "TB "
+ "diskSize="
+ Configuration.chunkSize * Configuration.chunksPerDisk / 1024
+ "GB ");
// counts for unavailability, undurability
int unAvailableCount = 0;
int unDurableCount = 0;
// If we are printing events to file, then annotate filename with timestamp
if (Configuration.eventFile != null) {
DateFormat dateFormat = new SimpleDateFormat("yyyy.MM.dd-HH.mm.ss");
Date date = new Date();
Configuration.eventFile += "-" + dateFormat.format(date) + ".txt";
System.out.println("Events printed to: " + Configuration.eventFile);
}
for (int i = 0; i < count; i++) {
Unit root = XmlParser.readFile("test.xml");
if (Machine.failFraction != 0) { // this is a fraction of perm. failures per month
// we update the fail fraction so that it matches the current machine failure rate
double rate = getMachineFailureGeneratorRate(root);
if (rate != -1 && rate != 0) {
int totalMachines = Configuration.machinesPerRack * Configuration.rackCount;
double allMachineFailuresPerHour = totalMachines / rate;
double permanentMachinesPerHour = Machine.failFraction * totalMachines / (24 * 30);
Machine.failFraction = permanentMachinesPerHour / allMachineFailuresPerHour;
}
}
EventQueue events = new EventQueue();
root.generateEvents(events, 0, Configuration.totalTime, true); // generate events
// We either print generated events to file, or handle them
if (Configuration.eventFile != null) { // print events to file
events.printAll(Configuration.eventFile, "\nIteration number: " + i);
} else { // handle events
Configuration.print();
EventHandler handler = new RandomDistributeEventHandler2();
handler.start(root, totalSlices, totalDisks);
System.err.println("Starting simulation");
// Event handling loop
Event e = events.removeFirst();
while (e != null) {
handler.handleEvent(e, events);
e = events.removeFirst();
eventsHandled++;
}
Result result = handler.end();
System.out.println(result);
System.out.println("Events handled: " + eventsHandled);
unAvailableCount += result.unAvailableCount;
unDurableCount += result.unDurableCount;
}
}
if (Configuration.eventFile == null) { // average across iterations
System.out.println("avg unavailable=" + (double) unAvailableCount / (double) count);
System.out.println("avg undurable=" + (double) unDurableCount / (double) count);
}
}