TaskOrchestrator re-serializes message payload using Newtonsoft.Json.

I get a JsonException when passing complex types from Orchestrator to Activity. The payload received in the TaskActivity is not compatible with System.Text.Json.

After investigation, it appears that the orchestrator re-serializes all messages using Newtonsoft.Json, with TypeNameHandling = TypeNameHandling.Objects. This results in a JSON payload that is not parseable using System.Text.Json (which is default for TaskActivity payload)

The class that does the conversion: https://github.com/Azure/durabletask/blob/main/src/DurableTask.Core/Serializing/JsonDataConverter.cs

Here is a sample project to demonstrate the issue: https://github.com/ulvesked/DurablePocoPayloadSample And a corresponding SO question: https://stackoverflow.com/questions/73776121/json-serialization-fails-with-functioninputconverterexception-for-complex-types

My original payload:

{
    "Name": "Test",
    "Items": [{
            "Id": "4b42d183-02c8-4108-b274-cde71f792832",
            "Image": "xH5hV...",
            "Thumbnail": "v8Tc3..."
       }, {
            "Id": "4eb034f6-eed0-4ad4-942d-c9bf20e465be",
            "Image": "wAj...",
            "Thumbnail": "juSiE",
        }
    ]
}

The payload received in TaskActivity:

{
    "Name": "Test",
    "Items": [{
            "$type": "DurablePocoPayloadSample.TestPayloadItem, DurablePocoPayloadSample",
            "Id": "4b42d183-02c8-4108-b274-cde71f792832",
            "Image": {
                "$type": "System.Byte[], System.Private.CoreLib",
                "$value": "xH5hV..."
            },
            "Thumbnail": {
                "$type": "System.Byte[], System.Private.CoreLib",
                "$value": "v8Tc3..."
            }
        }, {
            "$type": "DurablePocoPayloadSample.TestPayloadItem, DurablePocoPayloadSample",
            "Id": "4eb034f6-eed0-4ad4-942d-c9bf20e465be",
            "Image": {
                "$type": "System.Byte[], System.Private.CoreLib",
                "$value": "wAj..."
            },
            "Thumbnail": {
                "$type": "System.Byte[], System.Private.CoreLib",
                "$value": "juSiE..."
            }
        }
    ]
}

[jviau]

@plamber to fully replace the converter in DurableTask, there are a several locations you need to perform that:

1. In the constructor of TaskHubClient
2. Property on AsyncTaskActivity<TInput, TResult>
   • It is a protected set, so you can derive another interface ISettableDataConverter which has a method or property to set the data converter. Make sure all your activities implement this, then add a middleware to the DTFx pipeline to retrieve the current activity, attempt a cast to this, and set it.
3. Property on TaskOrchestration<TResult, TInput, TEvent, TStatus>
   • Again a protected set, so use the same steps as AsyncTaskActivity in point 2
4. Properties on OrchestrationContext (MessageDataConverter and ErrorDataConverter).
   • You might be able to also set this in middleware, can’t remember if you have access to this object there. Otherwise, you would need to derive your own base classes that implement the various TaskOrchestration types, and add a new step as part of its run method to set these properties on the context before calling the derived implementation.

[ulvesked]

Thanks for your comments. I have worked around the issue by using my own ObjectSerializer.

services.Configure<WorkerOptions>(opts => opts.Serializer = new MyNewtonsoftJsonObjectSerializer());

https://gist.github.com/ulvesked/44a6fc30d8fd622671343100eef8f1ae

I will keep it like this until the next preview, which hopefully has implemented the same serializer across the pipeline as @jviau wrote.