ElasticSearch index exists not working / reliable

elasticsearch, java

Solution

OK, I figured out a solution. Since the java client's calls are done asynchronously you have to use the variant which takes an action listener. The solution still gets a bit contrived though:

// Inner class because it's just used to be thrown out of
// the action listener implementation to signal that the
// index exists
private class ExistsException extends RuntimeException {
}

public boolean exists() {
    logger.info(String.format("Verifying existence of index \"%s\"", indexName));
    IndicesExistsRequest request = new IndicesExistsRequest(indexName);
    try {
        adminClient.exists(request, new ActionListener<IndicesExistsResponse>() {
            public void onResponse(IndicesExistsResponse response) {
                if (response.isExists()) {
                    throw new ExistsException();
                }
            }
            public void onFailure(Throwable e) {
                ExceptionUtil.smash(e);
            }
        });
    }
    catch (ExistsException e) {
        return true;
    }
    return false;
}

Problem

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"); } ```

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