Note: currently in development, not ready for production! Only test in safe environments.
gsredis is a plugin for the Glowstone server software, that replaces the default Anvil file format used by Glowstone and other PC-edition servers (e.g. Vanilla, Spigot, Sponge) with a redis data store.
All of the mentioned server software, including Glowstone, use the file system to store and read world data (chunks). This makes it hard to have a centralized, concurrent storage system for multiple servers.
For example, a minigame server network with 10+ servers running the same world will need to deploy map changes on each server. Using network-based file storage solutions can be tedious and slow, especially because of file locks and concurrency issues.
Using a centralized and concurrent data storage system like redis, you can efficiently read and write world data to a common system. This also makes deployment a breeze, as you only need to deploy changes to the central data store and restart server instances. Each server will then stream world data directly from the redis server.
Vanilla and wrappers around it (Spigot, Paper, Sponge) have their world I/O code strictly tied to the file system (Anvil format). There is no easy way to adapt the system using only plugins on these platforms.
Glowstone is a clean-room rewrite of the Vanilla server software, and uses the Bukkit/Spigot/Paper plugin API. It is a more efficient server software, but because it is a rewrite, there may be inconsistencies and missing features between it and Vanilla wrappers.
Around the end of 2017, we introduced an API that lets plugins developed for Glowstone use custom world storage solutions, while keeping the Anvil file format as the default. gsredis uses that API to interface between the Redis client and Glowstone.
This project is currently work-in-progress and certain critical aspects may be broken.
Block storage (a.k.a. Chunk Service I/O) is currently functional. Other types of data, such as structures, statistics, scoreboards, tile entities, and tile ticks are planned but unsupported.
Entity storage (i.e. mobs and objects, except players) is not implemented, and I cannot guarantee they will be supported by gsredis.
Player data storage is limited to a few properties such as position, username, and first-played-time/last-played-time. Other properties such as health, inventory, and XP are not saved.