How do you debug your Nest queries?

Question

I\'m new to Nest, and I very likely am not creating my query like I think I am. My question is more along the lines of teach a man to fish rather than give me a fish. However,

Answer 1

Using the latest elastic search 5+, I was able to get mine (thanks to Adrian Carr's method) with the following:

var jsonOutput = System.Text.Encoding.UTF8.GetString(
    response.ApiCall.RequestBodyInBytes
)

Which gave me the following output:

{
   "from":0,
   "size":0,
   "query":{
      "bool":{
      ...
      }
   }
}

Answer 2

You can use EnableTrace or ConnectionStatusHandler. More details here.

Answer 3

Elasticsearch.Net and NEST: the .NET clients [7.x]

ref: https://www.elastic.co/guide/en/elasticsearch/client/net-api/current/debug-information.html`

1. Enable DisableDirectStreaming in ES Global setting like following.

ref code

Var connectionPool = new SingleNodeConnectionPool(new Uri("http://localhost:9200"));

var settings = new ConnectionSettings(connectionPool)
    .DisableDirectStreaming(true); 

var client = new ElasticClient(settings);

2.) var response = client.Search<Project>(s =>....)

3.)

var jsonOutput = System.Text.Encoding.UTF8.GetString(
            result.ApiCall.RequestBodyInBytes);

Above can be achieved on a per request basis with following.

var response = client.Search<Project>(s => s
    .RequestConfiguration(r => r
        .DisableDirectStreaming() 
    )
    .Query(q => q
        .MatchAll()
    )
);

Answer 4

Really easily. If this is my code that searches:

var results = client.Search<SearchItem>(s => s.AllIndices()
    .Query(q =>
            q.Term(p => p.LastName, searchItem.LastName)
            && q.Term(p => p.FirstName, searchItem.FirstName)
            && q.Term(p => p.ApplicationCode, searchItem.ApplicationCode)
            )
    .Size(1000)
    );
var list = results.Documents.ToList();

I then set a breakpoint on the line above. Then, in Visual Studio Immediate Window, I enter this:

?results.ConnectionStatus

and it gives me this:

{StatusCode: 200, 
    Method: POST, 
    Url: http://localhost:9200/_all/searchitem/_search, 
    Request: {
  "size": 1000,
  "query": {
    "bool": {
      "must": [
        {
          "term": {
            "lastName": {
              "value": "carr"
            }
          }
        },
        {
          "term": {
            "firstName": {
              "value": "adrian"
            }
          }
        }
      ]
    }
  }
}

Hope this helps.

Answer 5

You can get the values of search request URL and JSON request body as under:

var requestURL = response.RequestInformation.RequestUrl;
var jsonBody = Encoding.UTF8.GetString(response.RequestInformation.Request);

You can find other useful properties in RequestInformation for debugging.

Answer 6

Tested in Nest 6.2.0

You can now just do:

#if DEBUG
  connectionSettings.EnableDebugMode(details =>
  {
    Logger.Debug($"ES Request: {Encoding.UTF8.GetString(details.RequestBodyInBytes ?? new byte[0])}");
    Logger.Verbose($"ES Response: {Encoding.UTF8.GetString(details.ResponseBodyInBytes ?? new byte[0])}");
  });
#endif

The call EnableDebugMode will automatically call DisableDirectStreaming, PrettyJson, and then OnRequestCompleted, passing in the function you gave it.

NOTE: There may be a bug somewhere in their response stuff. The response seems to be lacking some closing brackets for some reason.