What is it

HTTP server for serving static files. Written in C++ using the io_uring API.

Features

1. ring-per-thread, (cpu_limit option in the config, or at the option of server).
2. io_uring workerpool is shared between all rings (share_ring_backend option in the config).
3. Buffers for reading and writing are allocated at the beginning of work and reused during server operation.
4. Buffers can be shared between kernel and servers, in this case there is no copying between kernel and user space (register_buffers option in the config, it is not working correctly now, leave 0).
5. The ability to run in the SQPOLL mode. I/O in this mode is performed without system calls (enable_sq_poll option in the config).
6. Using DMA when sending files.

Build and run

Cloning the repository and submodules:

git clone --recurse-submodules https://github.com/GeorgiyX/io-uring-static-server.git

Buid docker image:

docker build -t io-uring-static .

Run server:

docker run -p 80:80 -v <config_dir>:/etc/httpd.conf:ro -v <static_dir>:/var/www/html:ro --name io-uring-static -t io-uring-static

• <config_dir> - directory with configuration files
• <static_dir> - directory with static files

Run tests:

http-test-suite/httptest.py

Run benchmark (see the contents of the script to run correctly):

./benchmark.sh

Performance

Server performance was compared with nginx (epoll) using the wrk tool. Below are the benchmark results (RPS) for both servers, with different CPU configurations. To get metrics, you can use script benchmark.sh. The load is represented as a GET request for a file (98.6 KB). Load goes for 100 seconds in 8 threads for 100, 1000, 10000 connections. Tests were performed on AMD Ryzen 7 5800HS, 8 cores, 16 GB RAM, kernel 5.13.0.

1 CPU test:

• io-uring-static-server: config, result.
• nginx: config, result.

connections	io-uring-static-server	nginx	difference
100	33947	8306	x4.09
1K	33302	8462	x3.9
10K	33313	8454	x3.94

8 CPU test:

• io-uring-static-server: config, result.
• nginx: config, result.

connections	io-uring-static-server	nginx	difference
100	79438	65904	x1.2
1K	74167	65492	x1.13
10K	72126	64977	x1.11