decide which replicas are byzantine during scenario setup

Author: joaomlneto

simulator/src/main/java/byzzbench/simulator/BaseScenario.java

@@ -166,6 +166,15 @@ public synchronized Node getNode(String nodeId) {
     @Override
     public final void setupScenario() {
         this.setup();
+
+        // sample f replicas to be faulty at start
+        List<String> replicaIds = new ArrayList<>(this.getReplicas().keySet());
+        Collections.shuffle(replicaIds);
+        int f = this.maxFaultyReplicas();
+        for (int i = 0; i < f; i++) {
+            this.markReplicaFaulty(replicaIds.get(i));
+        }
+
         this.getClients().values().forEach(Client::initialize);
         this.getNodes().values().forEach(Node::initialize);
         this.scheduler.initializeScenario(this);

simulator/src/main/java/byzzbench/simulator/faults/factories/ByzzFuzzScenarioFaultFactory.java

@@ -37,6 +37,7 @@ public List<Fault> generateFaults(FaultContext input) {
         int d = scheduler.getNumRoundsWithNetworkFaults();
         int r = scheduler.getNumRoundsWithFaults();
         Set<String> replicaIds = scenario.getReplicas().keySet();
+        Set<String> faultyReplicaIds = scenario.getFaultyReplicaIds();
 
         // Create network faults
         for (int i = 1; i <= d; i++) {
@@ -49,7 +50,7 @@ public List<Fault> generateFaults(FaultContext input) {
         // Create process faults
         for (int i = 1; i <= c; i++) {
             int round = rand.nextInt(r) + 1;
-            String sender = replicaIds.stream().skip(rand.nextInt(replicaIds.size())).findFirst().orElseThrow();
+            String sender = input.getScenario().getFaultyReplicaIds().stream().skip(rand.nextInt(faultyReplicaIds.size())).findFirst().orElseThrow();
             Set<String> recipientIds = SetSubsets.getRandomNonEmptySubset(replicaIds);
 
             // generate process fault