ASP.NET MVC 4 WebAPI (beta) - how to change the maximum size of the response buffer

Question

In ASP.NET MVC 4.0 WebAPI (beta), I return an object that is serialized in JSON that is larger than 65K. As you can see from the stack trace below, the framework throws an exception because it exceeds some internal limit.

System.Net.Http.HttpRequestException: Cannot write more bytes to the buffer than the configured maximum buffer size: 65536. at System.Net.Http.HttpContent.LimitMemoryStream.CheckSize(Int32 countToAdd) at System.Net.Http.HttpContent.LimitMemoryStream.Write(Byte[] buffer, Int32 offset, Int32 count) at System.IO.StreamWriter.Flush(Boolean flushStream, Boolean flushEncoder) at System.IO.StreamWriter.Write(Char value) at Newtonsoft.Json.JsonWriter.AutoComplete(JsonToken tokenBeingWritten) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\JsonWriter.cs:line 634 at Newtonsoft.Json.JsonTextWriter.WritePropertyName(String name) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\JsonTextWriter.cs:line 204 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.WriteMemberInfoProperty(JsonWriter writer, Object memberValue, JsonProperty property, JsonContract contract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 209 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 336 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.WriteMemberInfoProperty(JsonWriter writer, Object memberValue, JsonProperty property, JsonContract contract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 209 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 336 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 445 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.WriteMemberInfoProperty(JsonWriter writer, Object memberValue, JsonProperty property, JsonContract contract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 209 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 336 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.WriteMemberInfoProperty(JsonWriter writer, Object memberValue, JsonProperty property, JsonContract contract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 209 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 336 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeList(JsonWriter writer, IWrappedCollection values, JsonArrayContract contract, JsonProperty member, JsonContract collectionValueContract) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 445 at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value) in d:\Development\Releases\Json\Working\Src\Newtonsoft.Json\Serialization\JsonSerializerInternalWriter.cs:line 59 at xxx.Api.JsonNetFormatter.<>c__DisplayClass5.<OnWriteToStreamAsync>b__4() in c:\xxx\xxx\xxx.Api\JsonNetFormatter.cs:line 79 at System.Threading.Tasks.Task.Execute() 

I cannot find a way to change this default value. Can anyone help?

thanks

Answer 1

According to System.Net.Http.dll, released with a nightly build of the source code, the maximum buffer size value is defined in HttpContent as:

 internal const long MaxBufferSize = 0x7fffffffL; // 2147483647 

So, if you upgrade to a new version (and not a beta install), the problem should go away.

I suggest switching in any case, regardless of this problem, since there are quite a few changes , and everything that you are building now is guaranteed not to work with the final version.