protected void clientPopulateServers() throws Exception {
    Properties properties2 = new Properties();
    ClientVM clientVM =
        clusterStartupRule.startClientVM(SERVER_ZONE_MAP.size() + 1, properties2,
            ccf -> ccf.addPoolLocator("localhost", locatorPort));

    clientVM.invoke(() -> {

      Map<Integer, String> putMap = new HashMap<>();
      for (int i = 0; i < 1000; i++) {
        putMap.put(i, "A");
      }

      ClientCache clientCache = ClusterStartupRule.getClientCache();
      ClientRegionFactory<Object, Object> clientRegionFactory =
          clientCache.createClientRegionFactory(
              ClientRegionShortcut.PROXY);
      clientRegionFactory.create(REGION_NAME);
      Region<Integer, String> region = clientCache.getRegion(REGION_NAME);
      region.putAll(putMap);
    });
  }
Startup a client to put all the data in the server regions
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/control/RebalanceOperationComplexPart2DistributedTest.java