Hi Dan, quite a few performance improvements were made since 3.13.0 (btw, I can't find evidence that we published a 3.13.3, are you sure that's the version you are on?)
Clients hit Redis to determine what, if any, live queries they should run.
We've run quite a few more than 40,000 clients on a fairly moderate Redis instance in our recent load tests (
https://github.com/fleetdm/fleet/blob/main/CHANGELOG.md#load-test-infrastructure), with the hosts configured on a 10s
distributed_interval
.
Overall, I'd strongly recommend upgrading as a lot has changed in a year!