CEP-58: Add satellite replication strategy stub

Patch by Blake Eggleston; Reviewed by Caleb Rackliffe for CASSANDRA-21105

Author: bdeggleston

src/java/org/apache/cassandra/locator/AbstractReplicationStrategy.java

@@ -372,9 +372,11 @@ protected void validateReplicationFactor(String s) throws ConfigurationException
         try
         {
             ReplicationFactor rf = ReplicationFactor.fromString(s);
-            
+
             if (rf.hasTransientReplicas())
             {
+                if (rf.fullReplicas == 0)
+                    throw new ConfigurationException("Replication factor must have at least one full replica, got " + s);
                 if (DatabaseDescriptor.getNumTokens() > 1)
                     throw new ConfigurationException("Transient replication is not supported with vnodes yet");
                 if (!replicationType.isTracked())

src/java/org/apache/cassandra/locator/ReplicationFactor.java

@@ -65,8 +65,8 @@ static void validate(int totalRF, int transientRF)
                                     "Transient replication is not enabled on this node");
         Preconditions.checkArgument(totalRF >= 0,
                                     "Replication factor must be non-negative, found %s", totalRF);
-        Preconditions.checkArgument(transientRF == 0 || transientRF < totalRF,
-                                    "Transient replicas must be zero, or less than total replication factor. For %s/%s", totalRF, transientRF);
+        Preconditions.checkArgument(transientRF <= totalRF,
+                                    "Transient replicas must be less than or equal to total replication factor. For %s/%s", totalRF, transientRF);
         if (transientRF > 0)
         {
             Preconditions.checkArgument(DatabaseDescriptor.getNumTokens() == 1,