IBotContext information lost upon thread switches

Hi,

Last few days I’ve been trying out a few things with the new botbuilder SDK. I’m using Akka.NET to implement my dialog flow. I really like Akka.NET because I can easily implement an actor based on the finite state machine pattern to model different stages of the conversation that my bot is in.

I noticed however that when I pass the IBotContext as a message to my Akka actor information is lost and the call ReplyToActivity on IBotContext doesn’t result in a message to the user of my bot.

I’m curious what happens with the IBotContext object when I pass it to another thread. Could it be that information is lost when I do this?

[wmeints]

Here’s the code that I wrote: https://github.com/wmeints/bot-actors-sample

I think I have time to extend the sample further tomorrow. Probably going to add stuff around LUIS and QnaMaker so that it becomes a real example 😃

[drub0y]

DISCLAIMER: I’m familiar with a couple of actor systems and the actor model in general, but not steeped in Akka.NET specifically.

First, to make sure I’m understanding you correctly, you’re trying to pass the IBotContext through to your actor via a message, correct? If so, I’m relatively certain that’s not going to work. Actor messages are meant to essentially be POCOs that get serialized, sent to a mailbox (in Akka.NET’s case) and then delivered to an actor “in time”. While IBotContext is technically thread safe, it is not able to be serialized and “remoted” in this this way. Besides, it would be violating the rule of passing a mutable object to an actor which is frowned upon.

You also wouldn’t be able to inject it via Akka.NET “props” because the props are only resolved when an actor instance is created and if that actor “lives” throughout many activity messages from the bot framework perspective, it would need to be working with the proper IBotContext for each of those messages.

I do actually think actor systems are potentially a really good match for implementing bots, I just don’t think the current abstractions of the v4 SDK as it stands right now are going to “fit” that kind of system naturally due to the major architectural differences actor systems present from a traditional application architectures. It would not be a stretch to imagine a more native SDK for Akka.NET (or other actor systems) at some point in the future, but, full disclosure, I’m not on the product team so I’m not promising anything. 😄

Anyway, let’s think… how could you do this right now? 🤔 I assume right now you are using some sort of API gateway leveraging ASP.NET, resolving an ActorRef and that’s when you tried to send it over the IBotContext via a Tell based message… maybe? Spitballing here: what if, instead of sending over the IBotContext itself, you sent over only the Activity and maybe even your state, but you do so with an Ask and then your API gateway awaits that, takes the result of the Ask, which would be a respone message with maybe List<Activity> and your state again, and marshals those back onto the IBotContext???