Elasticsearch NEST MultiSearch ArgumentNullException

Question

When I try to use a very simple example of MultiSearch operator from NEST documentation:

var request = new MultiSearchRequest
            {
                Operations = new Dictionary<string, ISearchRequest>
                {
                    { "esproj", new SearchRequest 
                        { 
                            Query = new QueryContainer(new MatchAllQuery()) 
                        } 
                    },
                    { "people", new SearchRequest 
                        { 
                            Query = new QueryContainer(new MatchAllQuery()) 
                        } 
                    }
                }
            };

var result = _client.MultiSearch(request);

then I have the following error:

System.ArgumentNullException was unhandled by user code HResult=-2147467261 Source=mscorlib StackTrace: in System.Reflection.RuntimeMethodInfo.MakeGenericMethod(Type[] methodInstantiation) in Nest.Resolvers.Converters.MultiSearchConverter.ReadJson(JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer) w C:\code\elasticsearch-net\src\Nest\Resolvers\Converters\MultiSearchConverter.cs:row 101 in Nest.Resolvers.Converters.MultiSearchConverter.ReadJson(JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer) w C:\code\elasticsearch-net\src\Nest\Resolvers\Converters\MultiSearchConverter.cs:row 78 in Newtonsoft.Json.Serialization.JsonSerializerInternalReader.DeserializeConvertable(JsonConverter converter, JsonReader reader, Type objectType, Object existingValue) in Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)

But only if I use Object Initializer Syntax - when I use Fluent Syntax:

var result2 = _client.MultiSearch(ms => ms
                .Search<MyClass>("esproj", s => s.MatchAll())
                .Search<MyClass>("people", s => s.MatchAll())
            );

everything is OK (I get results). Version of my Nest client is 1.4.2. What am I doing wrong?

I've never tried the MultiSearchRequest approach. I would stick with the fluent approach, that is going to be much more common and what is the way you'll find most people doing it. — jhilden

Greg Marzouka Greg Marzouka · Accepted Answer · 2015-03-18T17:11:55

This is definitely a bug. Just opened https://github.com/elastic/elasticsearch-net/issues/127 and will address this for the next release.

Elasticsearch NEST MultiSearch ArgumentNullException

1 Answers