add AddError method to accumulator (#1536)

agent/accumulator.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log"
 	"math"
+	"sync/atomic"
 	"time"
 
 	"github.com/influxdata/telegraf"
@@ -33,6 +34,8 @@ type accumulator struct {
 	inputConfig *internal_models.InputConfig
 
 	precision time.Duration
+
+	errCount uint64
 }
 
 func (ac *accumulator) Add(
@@ -155,6 +158,17 @@ func (ac *accumulator) AddFields(
 	ac.metrics <- m
 }
 
+// AddError passes a runtime error to the accumulator.
+// The error will be tagged with the plugin name and written to the log.
+func (ac *accumulator) AddError(err error) {
+	if err == nil {
+		return
+	}
+	atomic.AddUint64(&ac.errCount, 1)
+	//TODO suppress/throttle consecutive duplicate errors?
+	log.Printf("ERROR in input [%s]: %s", ac.inputConfig.Name, err)
+}
+
 func (ac *accumulator) Debug() bool {
 	return ac.debug
 }