Discussion:
one big bump in the wire for latency monitoring
(too old to reply)
Dave Taht
2018-01-25 20:00:08 UTC
Permalink
https://blog.apnic.net/2018/01/22/ruru-real-time-wide-area-tcp-latency-monitoring/
--
Dave Täht
CEO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-669-226-2619
Toke Høiland-Jørgensen
2018-01-25 22:15:17 UTC
Permalink
Post by Dave Taht
https://blog.apnic.net/2018/01/22/ruru-real-time-wide-area-tcp-latency-monitoring/
Neat! The packet tapping part could probably be implemented in XDP to
avoid the DPDK space heater... ;)

-Toke
Jesper Dangaard Brouer
2018-01-26 08:50:21 UTC
Permalink
On Thu, 25 Jan 2018 23:15:17 +0100
Post by Toke Høiland-Jørgensen
Post by Dave Taht
https://blog.apnic.net/2018/01/22/ruru-real-time-wide-area-tcp-latency-monitoring/
Neat! The packet tapping part could probably be implemented in XDP to
avoid the DPDK space heater... ;)
I was thinking the exact same thing ;-)

It should be fairly simple to write a XDP/eBPF program, that timestamp
via bpf_ktime_get_ns() and queue the events via a perf ring-buffer via
bpf_perf_event_output() (the only kernel example is [1]). And a
userspace side tool[2] that reads these perf_event's.

Cc. xdp-***@vger.kernel.org hoping someone want to give it a go?

[1] https://github.com/torvalds/linux/blob/master/samples/bpf/trace_output_kern.c
[2] https://github.com/torvalds/linux/blob/master/samples/bpf/trace_output_user.c
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
Loading...