solrnet crashes if you add a lot of filter queries

Question

We use solrnet in our ASP.NET Core backend. In the startup.cs it is initialized like:

public void ConfigureServices(IServiceCollection services)
{
     services.AddSolrNet<SolrPunt>(solrEndpointAddressForPunt, setup =>
     {
           setup.HttpClient.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Basic", credentialsBase64);                
     });  
}

The search code itself is quite simple. We inject an instance of ISolrOperations<solrEndpointAddressForPunt>, and use it accordingly:

var queryOptions = new QueryOptions
{
    FilterQueries = new List<ISolrQuery>()
};

// FilterQueries are added 

var solrResponse = await solrOperationsVoorPunten.QueryAsync("*:*", queryOptions);

This all works fine and we receive results correctly.

However, if we add a lot of filter queries, like more than 105, it throws an exception:

Data at the root level is invalid. Line 1, position 1

I'm wondering why this is and how this can be fixed.

It has nothing to do with XML/JSON setting, as it works perfectly with a small amount of filter queries.

I'm thinking it has to do with the limit of a GET request. But then I read that normally it should then switch to a POST automatically? Can I tell solrnet to always use POST? And if so, how to do that in ASP.NET core?

Or is there another limitation that is causing this?

Thanks for any advice!

Answer 1

I think I found it. Instead of concatenating the fields in a for loop:

solrQueryByField = solrQueryByField || new SolrQueryByField(filterVeld, filterValue);

... I simply use SolrQueryInList:

queryOptions.FilterQueries.Add(new SolrQueryInList(filterVeld, filterValues));

With this change, it started working...