e1c13d448a
In #9798, we added a check to map `ENOBUFS` to `WOUDLBLOCK` on MacOS. More experimentation on that front revealed that this was actually incorrect and the UDP sending task will hang as the OS does **not** notify us once there are new buffers available. This may explain some random connection hangs that some users have recently complained about. I've already disabled the feature flag in production, this PR therefore only removes code that is now inactive. In order to make this as robust as possible, we implement a retry loop with an exponential backoff, starting a 2ns. At most, we will be retrying such a packet for 16ms. Local experiments on my Macbook have shown that most of the time, new buffer space is available within 1ms. The exponential backoff ensures we retry very quickly on faster machines but still successfully send the packet on slower machines. According to the linked mailing list, the link-speed of the attached network has nothing to do with this which makes sense. UDP has no congestion control so sending packets is merely a function of how fast the CPU can process them. Related: https://lists.freebsd.org/pipermail/freebsd-hackers/2004-January/005369.html --------- Signed-off-by: Thomas Eizinger <thomas@eizinger.io> Co-authored-by: Jamil <jamilbk@users.noreply.github.com>
Rust development guide
Firezone uses Rust for all data plane components. This directory contains the Linux and Windows clients, and low-level networking implementations related to STUN/TURN.
We target the last stable release of Rust using rust-toolchain.toml.
If you are using rustup, that is automatically handled for you.
Otherwise, ensure you have the latest stable version of Rust installed.
Reading Client logs
The Client logs are written as JSONL for machine-readability.
To make them more human-friendly, pipe them through jq like this:
cd path/to/logs # e.g. `$HOME/.cache/dev.firezone.client/data/logs` on Linux
cat *.log | jq -r '"\(.time) \(.severity) \(.message)"'
Resulting in, e.g.
2024-04-01T18:25:47.237661392Z INFO started log
2024-04-01T18:25:47.238193266Z INFO GIT_VERSION = 1.0.0-pre.11-35-gcc0d43531
2024-04-01T18:25:48.295243016Z INFO No token / actor_name on disk, starting in signed-out state
2024-04-01T18:25:48.295360641Z INFO null
Benchmarking on Linux
The recommended way for benchmarking any of the Rust components is Linux' perf utility.
For example, to attach to a running application, do:
- Ensure the binary you are profiling is compiled with the
releaseprofile. sudo perf record -g --freq 10000 --pid $(pgrep <your-binary>).- Run the speed test or whatever load-inducing task you want to measure.
sudo perf script > profile.perf- Open profiler.firefox.com and load
profile.perf
Instead of attaching to a process with --pid, you can also specify the path to executable directly.
That is useful if you want to capture perf data for a test or a micro-benchmark.