@Override
  public SystemProducer getProducer(String name, Config config, MetricsRegistry metricsRegistry) {
    ElasticsearchConfig elasticsearchConfig = new ElasticsearchConfig(name, config);
    return new ElasticsearchSystemProducer(name,
                                           getBulkProcessorFactory(elasticsearchConfig),
                                           getClient(elasticsearchConfig),
                                           getIndexRequestFactory(elasticsearchConfig),
                                           new ElasticsearchSystemProducerMetrics(name, metricsRegistry));
  }
A {@link SystemFactory} for Elasticsearch.

<p>This only supports the {@link SystemProducer} so all other methods return an
{@link UnsupportedOperationException}
samza-elasticsearch/src/main/java/org/apache/samza/system/elasticsearch/ElasticsearchSystemFactory.java