Add use_int_samples option for backwards compatibility (influxdata#5563)

plugins/inputs/vsphere/endpoint.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"log"
+	"math"
 	"math/rand"
 	"net/url"
 	"regexp"
@@ -948,7 +949,7 @@ func (e *Endpoint) collectChunk(ctx context.Context, pqs []types.PerfQuerySpec,
 			e.populateTags(&objectRef, resourceType, res, t, &v)
 
 			nValues := 0
-			alignedInfo, alignedValues := alignSamples(em.SampleInfo, v.Value, interval) // TODO: Estimate interval
+			alignedInfo, alignedValues := alignSamples(em.SampleInfo, v.Value, interval)
 
 			for idx, sample := range alignedInfo {
 				// According to the docs, SampleInfo and Value should have the same length, but we've seen corrupted
@@ -981,7 +982,11 @@ func (e *Endpoint) collectChunk(ctx context.Context, pqs []types.PerfQuerySpec,
 				if info.UnitInfo.GetElementDescription().Key == "percent" {
 					bucket.fields[fn] = float64(v) / 100.0
 				} else {
-					bucket.fields[fn] = v
+					if e.Parent.UseIntSamples {
+						bucket.fields[fn] = int64(round(v))
+					} else {
+						bucket.fields[fn] = v
+					}
 				}
 				count++
 
@@ -1082,3 +1087,11 @@ func cleanDiskTag(disk string) string {
 	// Remove enclosing "<>"
 	return strings.TrimSuffix(strings.TrimPrefix(disk, "<"), ">")
 }
+
+func round(x float64) float64 {
+	t := math.Trunc(x)
+	if math.Abs(x-t) >= 0.5 {
+		return t + math.Copysign(1, x)
+	}
+	return t
+}

plugins/inputs/vsphere/vsphere.go

@@ -40,6 +40,7 @@ type VSphere struct {
 	DatastoreMetricExclude  []string
 	DatastoreInclude        []string
 	Separator               string
+	UseIntSamples           bool
 
 	MaxQueryObjects         int
 	MaxQueryMetrics         int
@@ -199,6 +200,12 @@ var sampleConfig = `
   ## timeout applies to any of the api request made to vcenter
   # timeout = "60s"
 
+  ## When set to true, all samples are sent as integers. This makes the output data types backwards compatible
+  ## with Telegraf 1.9 or lower. Normally all samples from vCenter, with the exception of percentages, are 
+  ## integer values, but under some conditions, some averaging takes place internally in the plugin. Setting this
+  ## flag to "false" will send values as floats to preserve the full precision when averaging takes place.
+  # use_int_samples = true
+
   ## Optional SSL Config
   # ssl_ca = "/path/to/cafile"
   # ssl_cert = "/path/to/certfile"
@@ -312,6 +319,7 @@ func init() {
 			DatastoreMetricExclude:  nil,
 			DatastoreInclude:        []string{"/*/datastore/**"},
 			Separator:               "_",
+			UseIntSamples:           true,
 
 			MaxQueryObjects:         256,
 			MaxQueryMetrics:         256,