@Override
  public boolean hasSameFaultDomains(String host1, String host2) {
    return true;
  }
Simple placeholder implementation of {@link FaultDomainManager} which contains a single fault domain for all hosts.
This can be used when another concrete {@link FaultDomainManager} is undesirable or unavailable, but features which
depend on a {@link FaultDomainManager} (such as standby containers) may have unexpected behavior.
samza-core/src/main/java/org/apache/samza/clustermanager/SingleFaultDomainManager.java