@Override
  public SystemConsumer getConsumer(String systemName, Config config, MetricsRegistry registry) {
    MockSystemConsumerConfig consumerConfig = new MockSystemConsumerConfig(systemName, config);

    return new MockSystemConsumer(consumerConfig.getMessagesPerBatch(), consumerConfig.getConsumerThreadCount(), consumerConfig.getBrokerSleepMs());
  }
MockSystemFactory was built to make performance testing easier.
samza-test/src/main/java/org/apache/samza/system/mock/MockSystemFactory.java