2 Commits

Author SHA1 Message Date
Percy Wegmann
5095efd628 prober: make histogram buckets cumulative
Histogram buckets should include counts for all values under the bucket ceiling,
not just those between the ceiling and the next lower ceiling.

See https://prometheus.io/docs/tutorials/understanding_metric_types/\#histogram

Updates tailscale/corp#24522

Signed-off-by: Percy Wegmann <percy@tailscale.com>
2024-12-20 10:28:37 -06:00
Percy Wegmann
00a4504cf1 cmd/derpprobe,prober: add ability to perform continuous queuing delay measurements against DERP servers
This new type of probe sends DERP packets sized similarly to CallMeMaybe packets
at a rate of 10 packets per second. It records the round-trip times in a Prometheus
histogram. It also keeps track of how many packets are dropped. Packets that fail to
arrive within 5 seconds are considered dropped.

Updates tailscale/corp#24522

Signed-off-by: Percy Wegmann <percy@tailscale.com>
2024-12-19 10:45:56 -06:00