e84e58c567
With auto exit nodes enabled, the client picks exit nodes from the ones advertised in the network map. Usually, it picks the one with the highest priority score, but when the top spot is tied, it used to pick randomly. Then, once it made a selection, it would strongly prefer to stick with that exit node. It wouldn’t even consider another exit node unless the client was shutdown or the exit node went offline. This is to prevent flapping, where a client constantly chooses a different random exit node. The major problem with this algorithm is that new exit nodes don’t get selected as often as they should. In fact, they wouldn’t even move over if a higher scoring exit node appeared. Let’s say that you have an exit node and it’s overloaded. So you spin up a new exit node, right beside your existing one, in the hopes that the traffic will be split across them. But since the client had this strong affinity, they stick with the exit node they know and love. Using rendezvous hashing, we can have different clients spread their selections equally across their top scoring exit nodes. When an exit node shuts down, its clients will spread themselves evenly to their other equal options. When an exit node starts, a proportional number of clients will migrate to their new best option. Read more: https://en.wikipedia.org/wiki/Rendezvous_hashing The trade-off is that starting up a new exit node may cause some clients to move over, interrupting their existing network connections. So this change is only enabled for tailnets with `traffic-steering` enabled. Updates tailscale/corp#29966 Fixes #16551 Signed-off-by: Simon Law <sfllaw@tailscale.com>
Tailscale
Private WireGuard® networks made easy
Overview
This repository contains the majority of Tailscale's open source code.
Notably, it includes the tailscaled daemon and
the tailscale CLI tool. The tailscaled daemon runs on Linux, Windows,
macOS, and to varying degrees
on FreeBSD and OpenBSD. The Tailscale iOS and Android apps use this repo's
code, but this repo doesn't contain the mobile GUI code.
Other Tailscale repos of note:
- the Android app is at https://github.com/tailscale/tailscale-android
- the Synology package is at https://github.com/tailscale/tailscale-synology
- the QNAP package is at https://github.com/tailscale/tailscale-qpkg
- the Chocolatey packaging is at https://github.com/tailscale/tailscale-chocolatey
For background on which parts of Tailscale are open source and why, see https://tailscale.com/opensource/.
Using
We serve packages for a variety of distros and platforms at https://pkgs.tailscale.com.
Other clients
The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers. The GUI wrappers on non-open source platforms are themselves not open source.
Building
We always require the latest Go release, currently Go 1.23. (While we build releases with our Go fork, its use is not required.)
go install tailscale.com/cmd/tailscale{,d}
If you're packaging Tailscale for distribution, use build_dist.sh
instead, to burn commit IDs and version info into the binaries:
./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled
If your distro has conventions that preclude the use of
build_dist.sh, please do the equivalent of what it does in your
distro's way, so that bug reports contain useful version information.
Bugs
Please file any issues about this code or the hosted service on the issue tracker.
Contributing
PRs welcome! But please file bugs. Commit messages should reference bugs.
We require Developer Certificate of
Origin
Signed-off-by lines in commits.
See commit-messages.md (or skim git log) for our commit message style.
About Us
Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:
- https://github.com/tailscale/tailscale/graphs/contributors
- https://github.com/tailscale/tailscale-android/graphs/contributors
Legal
WireGuard is a registered trademark of Jason A. Donenfeld.