Allow floats in valuecounter aggregator (influxdata#5168)

plugins/aggregators/valuecounter/README.md

@@ -11,8 +11,9 @@ configuration directive. When no `fields` is provided the plugin will not count
 any fields. The results are emitted in fields in the format:
 `originalfieldname_fieldvalue = count`.
 
-Valuecounter only works on fields of the type int, bool or string. Float fields
-are being dropped to prevent the creating of too many fields.
+Counting fields with a high number of potential values may produce significant
+amounts of new fields and memory usage, take care to only count fields with a
+limited set of values.
 
 ### Configuration:
 

plugins/aggregators/valuecounter/valuecounter.go

@@ -2,7 +2,6 @@ package valuecounter
 
 import (
 	"fmt"
-	"log"
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/plugins/aggregators"
@@ -68,14 +67,6 @@ func (vc *ValueCounter) Add(in telegraf.Metric) {
 	for fk, fv := range in.Fields() {
 		for _, cf := range vc.Fields {
 			if fk == cf {
-				// Do not process float types to prevent memory from blowing up
-				switch fv.(type) {
-				default:
-					log.Printf("I! Valuecounter: Unsupported field type. " +
-						"Must be an int, string or bool. Ignoring.")
-					continue
-				case uint64, int64, string, bool:
-				}
 				fn := fmt.Sprintf("%v_%v", fk, fv)
 				vc.cache[id].fieldCount[fn]++
 			}

plugins/aggregators/valuecounter/valuecounter_test.go

@@ -22,9 +22,8 @@ func NewTestValueCounter(fields []string) telegraf.Aggregator {
 var m1, _ = metric.New("m1",
 	map[string]string{"foo": "bar"},
 	map[string]interface{}{
-		"status":    200,
-		"somefield": 20.1,
-		"foobar":    "bar",
+		"status": 200,
+		"foobar": "bar",
 	},
 	time.Now(),
 )