To improve performance, I want to send documents to Elasticsearch in bulk instead sending one by one. I've read about elastic bulk API at https://www.elastic.co/guide/en/elasticsearch/client/java-api/current/java-docs-bulk.html
However, I am using Elasticsearch rest-client (https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/index.html) and couldn't find any example or documentation about how to make a bulk insert. All I could find was about bulk requests through transport client.
I guess I have to prepare request body as described here (https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-bulk.html) and pass it to restclient's performRequest method? Is there another way, for instance, a builder mechanism in the ES java rest-client library, to make bulk insert using rest?
Yes, that's correct, for now the REST client only allows to send raw REST queries to ES but nothing too sophisticated. Elastic is working on a high-level client next that will work on top of the REST client and allow you to send DSL queries, etc.
For now, here is a sample code that you can use to send documents in bulk to your ES server:
RestClient client = ...;
String actionMetaData = String.format("{ \"index\" : { \"_index\" : \"%s\", \"_type\" : \"%s\" } }%n", index, type);
List<String> bulkData = ...; // a list of your documents in JSON strings
StringBuilder bulkRequestBody = new StringBuilder();
for (String bulkItem : bulkData) {
bulkRequestBody.append(actionMetaData);
bulkRequestBody.append(bulkItem);
bulkRequestBody.append("\n");
}
HttpEntity entity = new NStringEntity(bulkRequestBody.toString(), ContentType.APPLICATION_JSON);
try {
Response response = client.performRequest("POST", "/your_index/your_type/_bulk", Collections.emptyMap(), entity);
return response.getStatusLine().getStatusCode() == HttpStatus.SC_OK;
} catch (Exception e) {
// do something
}