In this chapter, we looked at how to use thread pools in microservices. We investigated three approaches: using plain threads, using the futures-cpupool crate, and using the tokio-threadpool crate. We used channels from the futures crate to interact with threads from asynchronous code. Special crates do all the interaction automatically; all you need to do is call a function that will be executed in a separate thread.

Also, we got acquainted with the actix crate and the actors model, which helps to split and run tasks as separate units that are managed by a smart runtime.

In the next chapter, we'll learn how to interact with different databases using Rust, including PostgreSQL, MySQL, Redis, MongoDB, and DynamoDB.