Timeouts could already be identified as NaN values on
stunstamp_derp_stun_rtt_ns, but we can't use NaN effectively with
promql to visualize them. So, this commit adds a timeouts metric that
we can use with rate/delta/etc promql functions.
Updates tailscale/corp#20689
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Evaluation of remote write errors was using errors.Is() where it should
have been using errors.As().
Updates tailscale/corp#20344
Signed-off-by: Jordan Whited <jordan@tailscale.com>
stunstamp timestamping includes userspace and SO_TIMESTAMPING kernel
timestamping where available. Measurements are written locally to a
sqlite DB, exposed over an HTTP API, and written to prometheus
via remote-write protocol.
Updates tailscale/corp#20344
Signed-off-by: Jordan Whited <jordan@tailscale.com>
