Kernel handling in mulit chat/service solution

[akordowski]

I am currently working on a multi chat/service solution with the Semantic Kernel and I wonder what is the best practice to handle the Kernel in such a scenario. As each chat could have its own unique configuation should the Kernel be used as singleton or a new instance for each chat?

Here an (very simplified) example:

var kernel = new KernelBuilder().Build();

var chat1 = kernel.GetRequiredService<IChatCompletionService>();
kernel.ImportPluginFromObject("abc");
var chat1Response = chat1.GetChatMessageContentsAsync(..., kernel);

var chat2 = kernel.GetRequiredService<IChatCompletionService>();
kernel.ImportPluginFromObject("def");
var chat2Response = chat2.GetChatMessageContentsAsync(..., kernel);

In this example chat1 should have access only to the abc plugin and the chat2 to the def plugin. But I guess both chats would have access to both plugins as the Kernel is an singelton instance.

I would guess that in a mutli chat scenario I should create a new Kernel instance for each chat and configure it respectively. Am I right?

[dmytrostruk]

@akordowski I think you can create a new Kernel instance for each chat and configure it respectively. We have AddKernel extension method for IServiceCollection, where we register it as Transient for exactly the same purpose, so in different places in your application you can configure your Kernel in unique way by adding different set of plugins, filters, data etc:

semantic-kernel/dotnet/src/SemanticKernel.Abstractions/Services/KernelServiceCollectionExtensions.cs

Lines 22 to 29 in f9247da

	// Register a KernelPluginCollection to be populated with any IKernelPlugins that have been
	// directly registered in DI. It's transient because the Kernel will store the collection
	// directly, and we don't want two Kernel instances to hold on to the same mutable collection.
	services.AddTransient<KernelPluginCollection>();
	// Register the Kernel as transient. It's mutable and expected to be mutated by consumers,
	// such as via adding event handlers, adding plugins, storing state in its Data collection, etc.
	services.AddTransient<Kernel>();