This repo contains a stress test of Warp's accepting new connections.

Before running the server or the client you probably need to increase opened files limit. On most Linux system ulimit -n 1000000 should do the trick. You may need to also increase the local port range:

sudo sysctl net.ipv4.ip_local_port_range="10000 61000"

In order to run the server:

cargo run --bin websockets-server --release

In order to run the client:

cargo run --bin stress-test --release

The client will open 50k new connections at roughly the same time.

The result for me looks something like:

connections: 0, elapsed: 0ms
connections: 15880, elapsed: 1009ms
connections: 18213, elapsed: 2026ms
connections: 20210, elapsed: 3052ms
connections: 22247, elapsed: 4065ms
connections: 24104, elapsed: 5071ms
connections: 25955, elapsed: 6074ms
connections: 27766, elapsed: 7097ms
connections: 29659, elapsed: 8100ms
connections: 31469, elapsed: 13690ms
connections: 50000, elapsed: 14691ms

In order to run a version that opens more than one port you can run:

PORTS=12 cargo run --bin websockets-server --release

and

PORTS=12 cargo run --bin stress-test --release

I used 12 ports as I have 12 CPU threads

Now the results look more like this for me:

connections: 0, elapsed: 0ms
connections: 44635, elapsed: 1000ms
connections: 50000, elapsed: 2001ms

There is also a version of the server that tries to bind N times to the same socket with the reuse_port option, but unfortunately it doesn't work, ie. the performance is the same of the single socket version.

In order to try it out you can run:

PORTS=12 REUSE_PORT=true cargo run --bin stress-test --release