fix(outputs.execd): Fixing the execd behavior to not throw error when partially unserializable metrics are written. (#11767)

plugins/outputs/execd/README.md

@@ -22,6 +22,11 @@ Telegraf minimum version: Telegraf 1.15.0
   ## Delay before the process is restarted after an unexpected termination
   restart_delay = "10s"
 
+  ## Flag to determine whether execd should throw error when part of metrics is unserializable
+  ## Setting this to true will skip the unserializable metrics and process the rest of metrics
+  ## Setting this to false will throw error when encountering unserializable metrics and none will be processed
+  # ignore_serialization_error = false
+
   ## Data format to export.
   ## Each data format has its own unique set of configuration options, read
   ## more about them here:

plugins/outputs/execd/execd.go

@@ -22,10 +22,11 @@ import (
 var sampleConfig string
 
 type Execd struct {
-	Command      []string        `toml:"command"`
-	Environment  []string        `toml:"environment"`
-	RestartDelay config.Duration `toml:"restart_delay"`
-	Log          telegraf.Logger
+	Command                  []string        `toml:"command"`
+	Environment              []string        `toml:"environment"`
+	RestartDelay             config.Duration `toml:"restart_delay"`
+	IgnoreSerializationError bool            `toml:"ignore_serialization_error"`
+	Log                      telegraf.Logger
 
 	process    *process.Process
 	serializer serializers.Serializer
@@ -82,7 +83,11 @@ func (e *Execd) Write(metrics []telegraf.Metric) error {
 	for _, m := range metrics {
 		b, err := e.serializer.Serialize(m)
 		if err != nil {
-			return fmt.Errorf("error serializing metrics: %s", err)
+			if !e.IgnoreSerializationError {
+				return fmt.Errorf("error serializing metrics: %w", err)
+			}
+			e.Log.Error("Skipping metric due to a serialization error: %w", err)
+			continue
 		}
 
 		if _, err = e.process.Stdin.Write(b); err != nil {

plugins/outputs/execd/execd_test.go

@@ -70,6 +70,80 @@ func TestExternalOutputWorks(t *testing.T) {
 	wg.Wait()
 }
 
+func TestPartiallyUnserializableThrowError(t *testing.T) {
+	influxSerializer, err := serializers.NewInfluxSerializer()
+	require.NoError(t, err)
+
+	exe, err := os.Executable()
+	require.NoError(t, err)
+
+	e := &Execd{
+		Command:                  []string{exe, "-testoutput"},
+		Environment:              []string{"PLUGINS_OUTPUTS_EXECD_MODE=application", "METRIC_NAME=cpu"},
+		RestartDelay:             config.Duration(5 * time.Second),
+		IgnoreSerializationError: false,
+		serializer:               influxSerializer,
+		Log:                      testutil.Logger{},
+	}
+
+	require.NoError(t, e.Init())
+
+	m1 := metric.New(
+		"cpu",
+		map[string]string{"name": "cpu1"},
+		map[string]interface{}{"idle": 50, "sys": 30},
+		now,
+	)
+
+	m2 := metric.New(
+		"cpu",
+		map[string]string{"name": "cpu2"},
+		map[string]interface{}{},
+		now,
+	)
+
+	require.NoError(t, e.Connect())
+	require.Error(t, e.Write([]telegraf.Metric{m1, m2}))
+	require.NoError(t, e.Close())
+}
+
+func TestPartiallyUnserializableCanBeSkipped(t *testing.T) {
+	influxSerializer, err := serializers.NewInfluxSerializer()
+	require.NoError(t, err)
+
+	exe, err := os.Executable()
+	require.NoError(t, err)
+
+	e := &Execd{
+		Command:                  []string{exe, "-testoutput"},
+		Environment:              []string{"PLUGINS_OUTPUTS_EXECD_MODE=application", "METRIC_NAME=cpu"},
+		RestartDelay:             config.Duration(5 * time.Second),
+		IgnoreSerializationError: true,
+		serializer:               influxSerializer,
+		Log:                      testutil.Logger{},
+	}
+
+	require.NoError(t, e.Init())
+
+	m1 := metric.New(
+		"cpu",
+		map[string]string{"name": "cpu1"},
+		map[string]interface{}{"idle": 50, "sys": 30},
+		now,
+	)
+
+	m2 := metric.New(
+		"cpu",
+		map[string]string{"name": "cpu2"},
+		map[string]interface{}{},
+		now,
+	)
+
+	require.NoError(t, e.Connect())
+	require.NoError(t, e.Write([]telegraf.Metric{m1, m2}))
+	require.NoError(t, e.Close())
+}
+
 var testoutput = flag.Bool("testoutput", false,
 	"if true, act like line input program instead of test")
 

plugins/outputs/execd/sample.conf

@@ -13,6 +13,11 @@
   ## Delay before the process is restarted after an unexpected termination
   restart_delay = "10s"
 
+  ## Flag to determine whether execd should throw error when part of metrics is unserializable
+  ## Setting this to true will skip the unserializable metrics and process the rest of metrics
+  ## Setting this to false will throw error when encountering unserializable metrics and none will be processed
+  # ignore_serialization_error = false
+
   ## Data format to export.
   ## Each data format has its own unique set of configuration options, read
   ## more about them here: