Using `Rack::Session::Pool` over `Rack::Session::Cookie`

Question

What are the different use cases of Rack::Session::Pool and Rack::Session::Cookie? As far as I understand (correct me if I'm wrong): - `Cookie` stores all the session key:value pairs directly within the cookie (marshalled) - `Pool` only stores an id in the cookie, and maintains the rest of the session hash within `@pool` So: what are the implications/reasons for choosing one over the other? what's `@pool`? Why does `Pool` need to expose a different public interface from `Cookie`? Why is the documentation so lacking?

Accepted Answer

You are right, `Session::Cookie` marshaling and store sessions in cookies.

`Session::Pool` instead keeps sessions in memory.

`Pool` has some advantages:

```
- faster, no marshaling needed 
- you can keep any objects with it(read ones that can not be marshaled)
```

But when you restart your app all sessions are lost.

With `Cookie` instead you will have restart-persistent sessions at the price of marshaling.

Alternatives - Session::Memcache, Session::Mongo

Using `Rack::Session::Pool` over `Rack::Session::Cookie`

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