mget producing: Unable to parse response body for Response - elasticsearch

Question

I'm issuing a Multi-Get request via the Java High Level REST Client and I'm receiving the following exception:
"Unable to parse response body for Response{requestLine=POST /_mget HTTP/1.1, host=http://localhost:9200, response=HTTP/1.1 200 OK}"
I pulled the following JSON from the logs that was sent to Elastic:
{
"docs": [
{
"_index": "blah",
"_type": null,
"_id": "some-id-232332",
"routing": null,
"stored_fields": null,
"version": -3,
"version_type": "internal",
"_source": {
"includes": [],
"excludes": []
}
}
]
}
I sent the above JSON to Elastic via Postman and I'm seeing the following response (which is the same I see in the logs):
{
"docs": [
{
"_index": "blah",
"_type": null,
"_id": "some-id-232332",
"found": false
}
]
}
Isn't that a valid response? Is this an issue w/ the elasticsearch-rest-high-level-client?
Elastic 7.5.0, org.elasticsearch.client:elasticsearch-rest-high-level-client:7.5.2

Answer 1

I needed to check the getCause()'s of the exception for the real problem. I was passing null to Jackson on mapper.readValue(nullBytes, Customer.class); was the real problem.
Interestingly enough a NPE shows itself 🤷‍♂️.
Stack trace:
java.util.concurrent.ExecutionException: java.io.IOException: Unable to parse response body for Response{requestLine=POST /_mget HTTP/1.1, host=http://localhost:9200, response=HTTP/1.1 200 OK}
...
...
THE REAL PROBLEM IS HERE!!! 🚨🚨
Caused by: java.lang.IllegalArgumentException: argument "src" is null
at com.fasterxml.jackson.databind.ObjectMapper._assertNotNull(ObjectMapper.java:4429)
restHighLevelClient.mgetAsync(multiGetRequest, RequestOptions.DEFAULT, new ActionListener<MultiGetResponse>() {
#Override
public void onResponse(MultiGetResponse response) {
for (var responseItem : response.getResponses()) {
try {
// simulating a null source
byte[] nullBytes = null;
customer = mapper.readValue(nullBytes, Customer.class);
} catch (IOException e) {
result.completeExceptionally(e);
}
}
result.complete(true);
}
#Override
public void onFailure(Exception ex) {
//the real problem!!!
//log.error("ex.cause", ex.getCause());
log.error("error with mget", ex);
result.completeExceptionally(ex);
}
});
Full source of repro, Full log file