jelly

Jelly is a database system designed to function as blob-storage for online games. It's a C++ library that can either be embedded directly in a game server or as the inner-most moving parts of a larger distributed database system.

• Documentation and C++ examples
• Comparative benchmarks (SQLite/RocksDB)

In a nutshell

• Optimized for online games where high throughput and write performance are favored over low latency and read performance.
• Efficient and cheap to host for small-scale online games, but scales reasonably well into larger systems.
• Multiple options regarding how to design a network topography that match the requirements of your particular project.
• Persistent blob-locking mechanism to prevent game servers fighting over data.
• Improve write performance using request priorities: some player progress data updates will be less important than others.
• Implemented as a Log Structured database engine.

Usage

First of all you'll need git and cmake to acquire and build the project. Then you can run:

git clone /~https://github.com/demogorgon1/jelly.git
cd jelly
mkdir build
cd build
cmake ..
cmake --build .

If succesfull, this will build a static library, tests, and the examples. Run ctest immediately to verify that everything works as intended.

Optionally you can include jelly directly in your cmake build system using FetchContent:

FetchContent_Declare(jelly
  GIT_REPOSITORY /~https://github.com/demogorgon1/jelly.git
)
FetchContent_MakeAvailable(jelly)

Use jelly::jelly to link your target with jelly.

If you're not using CMake, you can just add the jelly and include subdirectories to your project.

See here for documentation and examples.

Limitations and things you should know

• Your blobs should be small (preferably less than 10 KB). Don't put too many GUIDs or strings in your blobs and you'll be fine.
• All metadata (not the blobs themselves) is expected to fit in memory. You need to have a lot of users before this becomes a problem, though. This makes jelly very simple.
• Jelly runs a pass on all data on disk (both stores and write-ahead logs) on startup. This means it can take some time if restart is required, but it's really not that bad even with a lot of users. Game servers will generate a lot of data, but the vast majority of it will be overwrites. And your blobs are small, right?
• This is mainly a low-level storage engine. No networking comes in the box, you'll have to glue everything together yourself.