Cannot Write Data to ElasticSearch with AbstractReactiveElasticsearchConfiguration - spring-boot

Question

I am trying out to write data to my local Elasticsearch Docker Container (7.4.2), for simplicity I used the AbstractReactiveElasticsearchConfiguration given from Spring also Overriding the entityMapper function. The I constructed my repository extending the ReactiveElasticsearchRepository
Then in the end I used my autowired repository to saveAll() my collection of elements containing the data. However Elasticsearch doesn't write any data. Also i have a REST controller which is starting my whole process returning nothing basicly, DeferredResult>
The REST method coming from my ApiDelegateImpl
#Override
public DeferredResult<ResponseEntity<Void>> openUsageExporterStartPost() {
final DeferredResult<ResponseEntity<Void>> deferredResult = new DeferredResult<>();
ForkJoinPool.commonPool().execute(() -> {
try {
openUsageExporterAdapter.startExport();
deferredResult.setResult(ResponseEntity.accepted().build());
} catch (Exception e) {
deferredResult.setErrorResult(e);
}
}
);
return deferredResult;
}
My Elasticsearch Configuration
#Configuration
public class ElasticSearchConfig extends AbstractReactiveElasticsearchConfiguration {
#Value("${spring.data.elasticsearch.client.reactive.endpoints}")
private String elasticSearchEndpoint;
#Bean
#Override
public EntityMapper entityMapper() {
final ElasticsearchEntityMapper entityMapper = new ElasticsearchEntityMapper(elasticsearchMappingContext(), new DefaultConversionService());
entityMapper.setConversions(elasticsearchCustomConversions());
return entityMapper;
}
#Override
public ReactiveElasticsearchClient reactiveElasticsearchClient() {
ClientConfiguration clientConfiguration = ClientConfiguration.builder()
.connectedTo(elasticSearchEndpoint)
.build();
return ReactiveRestClients.create(clientConfiguration);
}
}
My Repository
public interface OpenUsageRepository extends ReactiveElasticsearchRepository<OpenUsage, Long> {
}
My DTO
#Data
#Document(indexName = "open_usages", type = "open_usages")
#TypeAlias("OpenUsage")
public class OpenUsage {
#Field(name = "id")
#Id
private Long id;
......
}
My Adapter Implementation
#Autowired
private final OpenUsageRepository openUsageRepository;
...transform entity into OpenUsage...
public void doSomething(final List<OpenUsage> openUsages){
openUsageRepository.saveAll(openUsages)
}
And finally my IT test
#SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
#Testcontainers
#TestPropertySource(locations = {"classpath:application-it.properties"})
#ContextConfiguration(initializers = OpenUsageExporterApplicationIT.Initializer.class)
class OpenUsageExporterApplicationIT {
#LocalServerPort
private int port;
private final static String STARTCALL = "http://localhost:%s/open-usage-exporter/start/";
#Container
private static ElasticsearchContainer container = new ElasticsearchContainer("docker.elastic.co/elasticsearch/elasticsearch:6.8.4").withExposedPorts(9200);
static class Initializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
#Override
public void initialize(final ConfigurableApplicationContext configurableApplicationContext) {
final List<String> pairs = new ArrayList<>();
pairs.add("spring.data.elasticsearch.client.reactive.endpoints=" + container.getContainerIpAddress() + ":" + container.getFirstMappedPort());
pairs.add("spring.elasticsearch.rest.uris=http://" + container.getContainerIpAddress() + ":" + container.getFirstMappedPort());
TestPropertyValues.of(pairs).applyTo(configurableApplicationContext);
}
}
#Test
void testExportToES() throws IOException, InterruptedException {
final List<OpenUsageEntity> openUsageEntities = dbPreparator.insertTestData();
assertTrue(openUsageEntities.size() > 0);
final String result = executeRestCall(STARTCALL);
// Awaitility here tells me nothing is in ElasticSearch :(
}
private String executeRestCall(final String urlTemplate) throws IOException {
final String url = String.format(urlTemplate, port);
final HttpUriRequest request = new HttpPost(url);
final HttpResponse response = HttpClientBuilder.create().build().execute(request);
// Get the result.
return EntityUtils.toString(response.getEntity());
}
}

Answer 1

public void doSomething(final List<OpenUsage> openUsages){
openUsageRepository.saveAll(openUsages)
}
This lacks a semicolon at the end, so it should not compile.
But I assume this is just a typo, and there is a semicolon in reality.
Anyway, saveAll() returns a Flux. This Flux is just a recipe for saving your data, and it is not 'executed' until subscribe() is called by someone (or something like blockLast()). You just throw that Flux away, so the saving never gets executed.
How to fix this? One option is to add .blockLast() call:
openUsageRepository.saveAll(openUsages).blockLast();
But this will save the data in a blocking way effectively defeating the reactivity.
Another option is, if the code you are calling saveAll() from supports reactivity is just to return the Flux returned by saveAll(), but, as your doSomething() has void return type, this is doubtful.
It is not seen how your startExport() connects to doSomething() anyway. But it looks like your 'calling code' does not use any notion of reactivity, so a real solution would be to either rewrite the calling code to use reactivity (obtain a Publisher and subscribe() on it, then wait till the data arrives), or revert to using blocking API (ElasticsearchRepository instead of ReactiveElasticsearchRepository).