Laszlo

Hello, I am Laszlo

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Cost of running a chatbot

04/14/2018

2 minutes

I have been using bot framework to run an unpublished chatbot. My chatbot is unpublished, as it is only used by a handful of people for testing purposes. As of end of last year, bot framework went live, and depricated the previous way to store the bot's state. we need to provide a way to manage data state, we can implement IBotDataStore, or just simply use one of the provided solutions. I went by using the latter option, using the CosmosDB. The reason was that I wanted to take a closer look at Cosmos DB, which has great features. After a couple of months I took a look the detailed costs in my bill, and I was striked me by the fact, that CosmosDB is expensive for a chatbot being a test phase.

CosmosDB

A pre-tax of nearly 50 Euros seems quite high for an unpublished chatbot having a couple of requests a day.

I changed to table store instead, it meant to give another implementation to IBotDataStore:

var connectionString = "DefaultEndpointsProtocol=https;Accou..."
var store = new TableBotDataStore(connectionString);
builder.Register(c => store).Keyed<IBotDataStore>(AzureModule.Key_DataStore).AsSelf().SingleInstance();
builder.Register(c => new CachingBotDataStore(store, CachingBotDataStoreConsistencyPolicy.ETagBasedConsistency)).As<IBotDataStore>().AsSelf().InstancePerLifetimeScope();
builder.Update(Conversation.Container);

Promptly my costs went down to nearly 0 Euros with the Storage Account, and the Cosmos DB could have been deleted (unless you prefer to migrate your data, which you would in a production application).

The picture below shows: half month usage with CosmosDB, and a half month usage with the Storage Account:

StorageAccount

To note, there is a third built in option to store the state, the InMemory solution, but this shall be used only for development purposes as it is not persistent.

chatbot bot framework storage