m2dev-server/docs/server-topology.md

Server topology

Companion diagram + port table for docs/server-runtime.md. Describes the intended production layout of the Debian VPS m2 stack. What is live today is only a subset (see the runtime audit for the actual state).

ASCII diagram

                          ┌─────────────────────────────┐
                          │          Players            │
                          │  (Metin2.exe + launcher)    │
                          └──────────────┬──────────────┘
                                         │  TCP (11000 auth, 11011..11013
                                         │        channel1, 11991 channel99)
                                         ▼
    ════════════════════════════ mt2.jakubkadlec.dev ════════════════════════════
    ║                                                                           ║
    ║   ┌──────────────────┐      ┌──────────────────┐      ┌────────────────┐ ║
    ║   │   metin-auth     │      │ metin-game@ch1_c1│      │ metin-game@    │ ║
    ║   │   (game_auth)    │ p2p  │ (channel1_core1) │ p2p  │ ch99_c1        │ ║
    ║   │  :11000 client   │◄────►│  :11011 client   │◄────►│  :11991 client │ ║
    ║   │  :12000 p2p      │      │  :12011 p2p      │      │  :12991 p2p    │ ║
    ║   └────────┬─────────┘      └────────┬─────────┘      └────────┬───────┘ ║
    ║            │                         │  metin-game@ch1_c2/c3  │         ║
    ║            │                         │ :11012/12012 :11013/12013         ║
    ║            │                         │                         │         ║
    ║            │   DB proxy/cache layer  │                         │         ║
    ║            └────────────┐  ┌─────────┴─────────────┐  ┌────────┘         ║
    ║                         ▼  ▼                       ▼  ▼                  ║
    ║                      ┌──────────────────────────────────┐                ║
    ║                      │          metin-db (db)           │                ║
    ║                      │       bind 0.0.0.0:9000          │                ║
    ║                      │  (gated by metin-db-ready.svc)   │                ║
    ║                      └──────────────┬───────────────────┘                ║
    ║                                     │  SQL                               ║
    ║                                     ▼                                    ║
    ║                      ┌──────────────────────────────────┐                ║
    ║                      │       mariadbd 11.8.6            │                ║
    ║                      │  127.0.0.1:3306                  │                ║
    ║                      │  DBs: account, player, common,   │                ║
    ║                      │       log, hotbackup             │                ║
    ║                      └──────────────────────────────────┘                ║
    ║                                                                           ║
    ║   systemd orchestration:                                                  ║
    ║     metin-server.service (oneshot umbrella, PartOf everything)            ║
    ║       ├─ Requires mariadb.service                                         ║
    ║       └─ metin-db → metin-db-ready → metin-auth + metin-game@<instance>   ║
    ║                                                                           ║
    ║   Secrets:                                                                ║
    ║     /etc/metin/metin.env  (root:root 600, EnvironmentFile= for all units) ║
    ║                                                                           ║
    ════════════════════════════════════════════════════════════════════════════

Process / port table

Process name	systemd unit	Client port	P2P port	Binds to	Role	Config file
db	metin-db.service	9000	—	0.0.0.0	DB proxy/cache; talks to MariaDB, serves auth+game	share/conf/db.txt (+ /etc/metin/metin.env)
game_auth	metin-auth.service	11000	12000	(default)	account login, token handoff to channels	channels/auth/CONFIG
channel1_core1	metin-game@channel1_core1.service	11011	12011	(default)	ch1 core1, MAP_ALLOW 1 4 5 6 3 23 43 112 107 67 68 72 208 302 304	channels/channel1/core1/CONFIG
channel1_core2	metin-game@channel1_core2.service	11012	12012	(default)	ch1 core2, same channel different core	channels/channel1/core2/CONFIG
channel1_core3	metin-game@channel1_core3.service	11013	12013	(default)	ch1 core3	channels/channel1/core3/CONFIG
channel99_core1	metin-game@channel99_core1.service	11991	12991	(default)	ch99 core1, event/test channel. MAP_ALLOW 113 81 100 101 103 105 110 111 114 118 119 120 121 122 123 124 125 126 127 128 181 182 183 200	channels/channel99/core1/CONFIG
mariadbd	mariadb.service (distro pkg)	3306	—	127.0.0.1	relational store	/etc/mysql/mariadb.conf.d/*

Supporting, not a process:

Unit	Type	Purpose
metin-server.service	oneshot	umbrella. Restarting it cycles all sub-units via PartOf=.
metin-db-ready.service	oneshot	metin-wait-port 127.0.0.1 9000 30 — gates auth+game on db up.

Data flow

1. Player connects to mt2.jakubkadlec.dev:11000 (auth).
2. game_auth authenticates against account via db (127.0.0.1:9000) which proxies to MariaDB.
3. game_auth hands the player a token and the channel pick.
4. Player connects to e.g. :11011 (channel1 core1). The core reads player state via db from player + common, loads maps per MAP_ALLOW and quest binaries from share/locale/.
5. Cross-core traffic (channel switch, whisper, guild) uses the P2P ports (12000, 12011..12013, 12991) on loopback.
6. db persists to MariaDB asynchronously (AsyncSQL pools, batch-writes at SAVE_EVENT_SECOND_CYCLE=180s from game.txt).
7. log DB receives audit/event rows (item trades, combat, etc.) through a dedicated AsyncSQL connection.