@Test
  public void testDataSerializers() throws Exception {
    PORT1 = initServerCache(server1);
    PORT2 = initServerCache(server2);

    client1.invoke(() -> DataSerializerPropagationDUnitTest
        .createClientCache(NetworkUtils.getServerHostName(server1.getHost()), PORT1));
    client2.invoke(() -> DataSerializerPropagationDUnitTest
        .createClientCache(NetworkUtils.getServerHostName(server2.getHost()), PORT2));

    client1.invoke(() -> registerDataSerializer(DSObject1.class));

    server1.invoke(() -> registerDataSerializer(DSObject2.class));

    server2.invoke(() -> DataSerializerPropagationDUnitTest.verifyDataSerializers(2));

    server1.invoke(() -> DataSerializerPropagationDUnitTest.verifyDataSerializers(2));

    client1.invoke(() -> DataSerializerPropagationDUnitTest.verifyDataSerializers(2));

    client2.invoke(() -> DataSerializerPropagationDUnitTest.verifyDataSerializers(2));
  }
Register two DataSerializers on the server and verify that they get propagated to client.
geode-core/src/distributedTest/java/org/apache/geode/internal/cache/tier/sockets/DataSerializerPropagationDUnitTest.java