evennia/docs/source/Components/Portal-And-Server.md

Portal And Server

Evennia consists of two processes, known as Portal and Server. They can be controlled from inside the game or from the command line as described in the Running-Evennia doc.

In short, the Portal knows everything about internet protocols (telnet, websockets etc), but knows very little about the game.

In contrast, the Server knows everything about the game. It knows that a player has connected but now how they connected.

The effect of this is that you can fully reload the Server and have players still connected to the game. One the server comes back up, it will re-connect to the Portal and re-sync all players as if nothing happened.

Internet│  ┌──────────┐ ┌─┐           ┌─┐ ┌─────────┐
        │  │Portal    │ │S│   ┌───┐   │S│ │Server   │
    P   │  │          │ │e│   │AMP│   │e│ │         │
    l ──┼──┤ Telnet   ├─┤s├───┤   ├───┤s├─┤         │
    a   │  │ Webclient│ │s│   │   │   │s│ │ Game    │
    y ──┼──┤ SSH      ├─┤i├───┤   ├───┤i├─┤ Database│
    e   │  │ ...      │ │o│   │   │   │o│ │         │
    r ──┼──┤          ├─┤n├───┤   ├───┤n├─┤         │
    s   │  │          │ │s│   └───┘   │s│ │         │
        │  └──────────┘ └─┘           └─┘ └─────────┘
        │Evennia

The Server and Portal are glued together via an AMP (Asynchronous Messaging Protocol) connection. This allows the two programs to communicate seamlessly on the same machine.