stunstamp now sends data to Prometheus via remote write, and Prometheus
can serve the same data. Retaining and cleaning up old data in sqlite
leads to long probing pauses, and it's not worth investing more effort
to optimize the schema and/or concurrency model.
Updates tailscale/corp#20344
Signed-off-by: Jordan Whited <jordan@tailscale.com>
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>