metrics not collected when server is down

[mentadev]

• build user: "ecastro"
• build date: "2020-02-25T18:49:45Z"
• go version: go1.13.8

When collecting data from a server, the iperf3_received_bytes & iperf3_received_seconds are stored in prometheus but if the server is stopped or goes down (or connectivity issues) these metrics are no longer stored in prometheus, only the "e.success" metric is stored with a 0 value.

The problem with this behaviour is that it creates gaps with no measure at all. I believe it would be better to include the
iperf3_received_bytes, iperf3_received_seconds both with 0 value.

if err != nil {
     ch <- prometheus.MustNewConstMetric(e.success, prometheus.GaugeValue, 0)
     ch <- prometheus.MustNewConstMetric(e.receivedSeconds, prometheus.GaugeValue, 0) //iperf3_received_bytes = 0
     ch <- prometheus.MustNewConstMetric(e.receivedBytes, prometheus.GaugeValue, 1)//iperf3_received_seconds = 1
     iperfErrors.Inc()
     log.Errorf("Failed to run iperf3: %s", err)
     return
}

Check the image attached, in red the resulting measure if the iperf3_received_bytes, iperf3_received_seconds are always stored

[Benedict1033]

Have you solved the problem? I have the same problem