private static boolean registerInterestWithClientSession(String durableClientId,
      String regionName,
      Object keyOfInterest) {
    ClientSession session = getBridgeServer().getClientSession(durableClientId);
    boolean registered = false;
    if (session.isPrimary()) {
      session.registerInterest(regionName, keyOfInterest, InterestResultPolicy.KEYS_VALUES, true,
          true);
      registered = true;
    }
    return registered;
  }
Test that starting a durable client on multiple servers is processed correctly.
geode-cq/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/DurableClientSimpleDUnitTest.java