UpdateByQuery issue

[rtwent]

Given:
ES: 7.17
ruflin/elastica: 7.2.0 (but the issue is present on the dev version too)

Background: Due to architectural issues - we run updateByQuery in loop. Troubles in debugging had appeared.

By the ES documentation the response of UpdateByQuery request is documented. It seems, for now, is impossible to retrieve the message, why request was failed.

Response::HasError() will always return false, because of error property is not documented for _update_by_query. As a result error message will be empty:

Elastica/src/Response.php

Lines 134 to 139 in e2cb89b

	public function hasError()
	{
	$response = $this->getData();
	return isset($response['error']);
	}

isOk is a way to identify the response status. But still, no error message will be provided.

Example of failed response from elastic:

{
  "took":2,
  "timed_out":false,
  "total":1,
  "updated":0,
  "deleted":0,
  "batches":1,
  "version_conflicts":1,
  "noops":0,
  "retries":{
    "bulk":0,
    "search":0
  },
  "throttled_millis":0,
  "requests_per_second":-1,
  "throttled_until_millis":0,
  "failures":[
    {
      "index":"xxxxx",
      "type":"_doc",
      "id":"xxxxxx",
      "cause":{
        "type":"version_conflict_engine_exception",
        "reason":"[xxxxxx]: version conflict, required seqNo [15668298], primary term [2]. current document has seqNo [15668306] and primary term [2]",
        "index_uuid":"wUFh0yvBRkavh7cCHAxWcg",
        "shard":"1",
        "index":"xxxxx"
      },
      "status":409
    }
  ]
}

[ruflin]

Is my understanding correct that the info you are looking for is something like getFailures()? There is hasFailedShards() but it only returns a bool:

Elastica/src/Response.php

Line 146 in e2cb89b

public function hasFailedShards()

[rtwent]

Is my understanding correct that the info you are looking for is something like getFailures()?

Yep, something like that.

But to be honest for clients of the library is more convenient way to use generic ::getErrorMessage() than to keep in mind what kind of update is processed:

$response = $this->index->updateByQuery(...);
if ($response->isOk()) {
  $response->getData();
} else {
  $response->getErrorMessage();
}

(This is just my IMO that is not consistent with ES API)

[ruflin]

@rtwent Would you be interested to take a stab at this and open a PR?

[rtwent]

It seems that my problem is in using the obsolete version of Your library. I investigated a bit.
We use 7.2.0 and the code below gave us unexpected behavior:

Elastica/src/Transport/Http.php

Lines 177 to 179 in 8fe6176

	if ($response->hasError()) {
	throw new ResponseException($request, $response);
	}

since there is no error in the reponse body (only failures) - the response is successfully populated. No exception is thrown.

I forked the project and tried to reproduce such behaviour on 8.* branch. I was not successful. Http transport now is absent and guzzle throws an exception if something is wrong with the status code:

/**
* @group functional
*/
public function testUpdateByQueryFailure(): void
{
    $index = $this->_createIndex();
    $index->addDocument(new Document('1', ['name' => 'ruflin nicolas']),);
    $index->refresh();

    $this->assertEquals(1, $index->search('nicolas')->count());

    $this->expectException(ClientResponseException::class);
    // force updateByQuery failure by changing immutable field
    $index->updateByQuery('*', new Script('ctx._source._id = "marc"'));
}  

I hope I understood everything correctly. Is there a sense to fix it for ^7.2?