====== What's here? =====
https://oss.oetiker.ch/smokeping/ exists, I wanted to create something like it but with PCP as backend.

<code>
$ cat /var/lib/pcp/pmdas/openmetrics/config.d/smokeping.sh
#!/bin/bash

function smokeping {
        for i in $(ping -c1 $REMOTE |grep icmp_seq|sed -e 's,.* time=,,' -e 's, ms$,,'); do
                echo "$REMOTE {var=\"latency\"} $i";
        done
}


for REMOTE in fluxcoil.net ipv6.fluxcoil.net www.heise.de \
  ftp.NetBSD.org global.jaxa.jp ftp2.jp.NetBSD.org; do
        smokeping;
done
$ chmod +x /var/lib/pcp/pmdas/openmetrics/config.d/smokeping.sh
</code>

Then add it to the pmlogger conf /var/lib/pcp/config/pmlogger/config.default:
<code>
[...]
# DO NOT UPDATE THE FILE ABOVE THIS LINE
# Otherwise any changes may be lost the next time pmlogconf is
# used on this file.
#
# It is safe to make additions from here on ...
#
log advisory on every 5 min {
        openmetrics.smokeping
}
</code>
Then restart pmlogger, and verify smokeping is getting archived:
<code>
$ systemctl restart pmlogger
$ pcp
Performance Co-Pilot configuration on fluxcoil:

 platform: Linux fluxcoil 4.19.0-16-amd64 #1 SMP Debian 4.19.181-1 (2021-03-19) x86_64
 hardware: 4 cpus, 1 disk, 1 node, 16042MB RAM
 timezone: CEST-2
 services: pmcd pmproxy
     pmcd: Version 5.3.1-1, 15 agents, 1 client
     pmda: root pmcd proc pmproxy xfs bind2 linux mmv kvm postfix rsyslog
           nginx jbd2 openmetrics netcheck
 pmlogger: primary logger: /var/log/pcp/pmlogger/fluxcoil/20210516.07.24
$ pmrep -a /var/log/pcp/pmlogger/fluxcoil/20210516.07.24 openmetrics.smokeping
[...]
      158.000      0.044        0.018       3.990     218.000        261.000
      158.000      0.044        0.018       3.990     218.000        261.000
      158.000      0.044        0.018       3.990     218.000        261.000
      158.000      0.044        0.018       3.990     218.000        261.000
      158.000      0.044        0.018       3.990     218.000        261.000
</code>

Then you can visualize the archived data with grafana, using a heat diagram.