func()

in image/resources/knfsd-metrics-agent/internal/mounts/scraper.go [352:401]

• 27 lines of code
• 5 McCabe index (conditional complexity)

func (s *mountScraper) reportDelta(stats nfsStats, now pdata.Timestamp) {
	// TODO: Report counters instead of gauges

	// This is a direct port of the original script that used
	// nfsiostat, so is limited to the data that was output by nfsiostat.
	// Now that we have the raw data we can report a lot more metrics.
	// We can also use counters instead of calculating the diff for many of
	// the metrics and let the monitoring tool calculate the rate.

	// This is a new mount, no previous metrics yet so cannot calculate a diff
	// on this scrape.
	prev, found := s.previous[stats.server]
	if !found {
		return
	}

	// if new.age < prev.summary.age, then the counters must have reset
	// i.e. the NFS share was re-mounted.
	// If the counters have reset then we cannot derive any useful metrics
	// on this scrape, so just treat this as if it were a new summary.
	if stats.summary.age <= prev.summary.age {
		return
	}

	diff := diffSummary(stats.summary, prev.summary)

	delta := diff.age.Seconds()
	if delta <= 0 {
		// This should not happen, as any summaries that have an age smaller
		// than the previous entry are handled as a reset to the counters.
		// Just in case, skip reporting this scrape to avoid divide by zero
		// errors or spurious values.
		return
	}

	sends := float64(diff.transport.Sends)
	var backlog float64
	if sends > 0 {
		backlog = float64(diff.transport.CumulativeBacklog) / sends
	}
	read := calc(delta, diff.operations["READ"])
	write := calc(delta, diff.operations["WRITE"])

	s.mb.RecordNfsMountOpsPerSecondDataPoint(now, sends/delta, stats.server, stats.instance)
	s.mb.RecordNfsMountRPCBacklogDataPoint(now, backlog/delta, stats.server, stats.instance)
	s.mb.RecordNfsMountReadExeDataPoint(now, read.exePerOp, stats.server, stats.instance)
	s.mb.RecordNfsMountReadRttDataPoint(now, read.rttPerOp, stats.server, stats.instance)
	s.mb.RecordNfsMountWriteExeDataPoint(now, write.exePerOp, stats.server, stats.instance)
	s.mb.RecordNfsMountWriteRttDataPoint(now, write.rttPerOp, stats.server, stats.instance)
}