ElasticSearch index exists not working / reliable

Question

I am writing a simple Java wrapper around ElasticSearch's admin client. To test it I have a main method that first checks if an index exists (IndicesExistsRequest), if so deletes it (DeleteIndexRequest), and creates the index again. See code below. Yet I consistently get an IndexAlreadyExistsException.

By the way I am trying to get a client for the node that you start from the command prompt (by simply typing "elastic search"). I have tried every combination of methods on nodeBuilder's fluent interface, but I can't seem to get one.

public static void main(String[] args) {
    ElasticSearchJavaClient esjc = new ElasticSearchJavaClient("nda");
    if (esjc.indexExists()) {
        esjc.deleteIndex();
    }
    esjc.createIndex();
    URL url = SchemaCreator.class.getResource("/elasticsearch/specimen.type.json");
    String mappings = FileUtil.getContents(url);
    esjc.createType("specimen", mappings);
}

final Client esClient;
final IndicesAdminClient adminClient;
final String indexName;

public ElasticSearchJavaClient(String indexName) {
    this.indexName = indexName;
    esClient = nodeBuilder().clusterName("elasticsearch").client(true).node().client();
    adminClient = esClient.admin().indices();
}

public boolean deleteIndex() {
    logger.info("Deleting index " + indexName);
    DeleteIndexRequest request = new DeleteIndexRequest(indexName);
    try {
        DeleteIndexResponse response = adminClient.delete(request).actionGet();
        if (!response.isAcknowledged()) {
            throw new Exception("Failed to delete index " + indexName);
        }
        logger.info("Index deleted");
        return true;
    } catch (IndexMissingException e) {
        logger.info("No such index: " + indexName);
        return false;
    }
}

public boolean indexExists() {
    logger.info(String.format("Verifying existence of index \"%s\"", indexName));
    IndicesExistsRequest request = new IndicesExistsRequest(indexName);
    IndicesExistsResponse response = adminClient.exists(request).actionGet();
    if (response.isExists()) {
        logger.info("Index exists");
        return true;
    }
    logger.info("No such index");
    return false;
}

public void createIndex() {
    logger.info("Creating index " + indexName);
    CreateIndexRequest request = new CreateIndexRequest(indexName);
    IndicesAdminClient iac = esClient.admin().indices();
    CreateIndexResponse response = iac.create(request).actionGet();
    if (!response.isAcknowledged()) {
        throw new Exception("Failed to create index " + indexName);
    }
    logger.info("Index created");
}

Answer 1

You can also execute a synchronous request like this:

boolean exists = client.admin().indices()
    .prepareExists(INDEX_NAME)
    .execute().actionGet().isExists();

Answer 2

Here is my solution when using RestHighLevelClient client;

Here a code-snippet: :

public boolean checkIfIndexExists(String indexName) throws IOException {
            Response response = client.getLowLevelClient().performRequest("HEAD", "/" + indexName);
            int statusCode = response.getStatusLine().getStatusCode(); 
            return (statusCode != 404);
    }

A contribution for someone else !