influxdata · Obeyed · Apr 22, 2026 · Apr 28, 2026 · Apr 28, 2026 · Apr 28, 2026
diff --git a/plugins/outputs/opensearch/README.md b/plugins/outputs/opensearch/README.md
@@ -21,6 +21,23 @@ plugin ordering. See [CONFIGURATION.md][CONFIGURATION.md] for more details.
 
 [CONFIGURATION.md]: ../../../docs/CONFIGURATION.md#plugins
 
+## Startup error behavior options <!-- @/docs/includes/startup_error_behavior.md -->
+
+In addition to the plugin-specific and global configuration settings the plugin
+supports options for specifying the behavior when experiencing startup errors
+using the `startup_error_behavior` setting. Available values are:
+
+- `error`:  Telegraf with stop and exit in case of startup errors. This is the
+            default behavior.
+- `ignore`: Telegraf will ignore startup errors for this plugin and disables it
+            but continues processing for all other plugins.
+- `retry`:  Telegraf will try to startup the plugin in every gather or write
+            cycle in case of startup errors. The plugin is disabled until
+            the startup succeeds.
+- `probe`:  Telegraf will probe the plugin's function (if possible) and disables
+            the plugin in case probing fails. If the plugin does not support
+            probing, Telegraf will behave as if `ignore` was set instead.
+
 ## Configuration
 
 ```toml @sample.conf
@@ -129,9 +146,9 @@ plugin ordering. See [CONFIGURATION.md][CONFIGURATION.md] for more details.
 
 ### Required parameters
 
-* `urls`: A list containing the full HTTP URL of one or more nodes from your
+- `urls`: A list containing the full HTTP URL of one or more nodes from your
   OpenSearch instance.
-* `index_name`: The target index for metrics. You can use the date format
+- `index_name`: The target index for metrics. You can use the date format
 
 For example: "telegraf-{{.Time.Format \"2006-01-02\"}}" would set it to
 "telegraf-2023-07-27". You can also specify metric name (`{{ .Name }}`), tag

diff --git a/plugins/outputs/opensearch/opensearch.go b/plugins/outputs/opensearch/opensearch.go
@@ -22,6 +22,7 @@ import (
 
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/config"
+	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/internal/choice"
 	"github.com/influxdata/telegraf/plugins/common/tls"
 	"github.com/influxdata/telegraf/plugins/outputs"
@@ -134,18 +135,24 @@ func (o *Opensearch) Connect() error {
 		o.Log.Errorf("error creating OpenSearch client: %v", err)
 	}
 
+	_, err = o.osClient.Ping(o.osClient.Ping.WithContext(ctx))
+	if err != nil {
+		return &internal.StartupError{
+			Err:   fmt.Errorf("unable to ping OpenSearch server: %w", err),
+			Retry: true,
+		}
+	}
+
 	if o.ManageTemplate {
 		err := o.manageTemplate(ctx)
 		if err != nil {
-			return err
+			return &internal.StartupError{
+				Err:   err,
+				Retry: true,
+			}
 		}
 	}
 
-	_, err = o.osClient.Ping()
-	if err != nil {
-		return fmt.Errorf("unable to ping OpenSearch server: %w", err)
-	}
-
 	return nil
 }
 

diff --git a/plugins/outputs/opensearch/opensearch_test.go b/plugins/outputs/opensearch/opensearch_test.go
@@ -11,6 +11,8 @@ import (
 	"github.com/testcontainers/testcontainers-go/wait"
 
 	"github.com/influxdata/telegraf/config"
+	"github.com/influxdata/telegraf/internal"
+	"github.com/influxdata/telegraf/models"
 	"github.com/influxdata/telegraf/testutil"
 )
 
@@ -308,6 +310,54 @@ func TestDisconnectedServerOnConnect(t *testing.T) {
 	require.Error(t, e.Connect())
 }
 
+func TestConnectionIssueAtStartup(t *testing.T) {
+	ts := httptest.NewUnstartedServer(http.HandlerFunc(func(_ http.ResponseWriter, _ *http.Request) {}))
+
+	urls := []string{"http://" + ts.Listener.Addr().String()}
+
+	plugin := &Opensearch{
+		URLs:            urls,
+		ManageTemplate:  true,
+		TemplateName:    "telegraf",
+		IndexName:       `{{.Tag "tag1"}}-{{.Time.Format "2006-01-02"}}`,
+		Timeout:         config.Duration(time.Second * 5),
+		AuthBearerToken: config.NewSecret([]byte("0123456789abcdef")),
+		Log:             testutil.Logger{},
+	}
+	var err error
+	plugin.indexTmpl, err = template.New("index").Parse(plugin.IndexName)
+	require.NoError(t, err)
+
+	// Create a model to be able to use the startup retry strategy
+	model, err := models.NewRunningOutput(
+		plugin,
+		&models.OutputConfig{
+			Name:                 "opensearch",
+			StartupErrorBehavior: "retry",
+		},
+		1000, 1000,
+	)
+	require.NoError(t, err)
+	require.NoError(t, model.Init())
+
+	// The connect call should not fail even though the server is closed due to the "retry" strategy
+	require.NoError(t, model.Connect())
+
+	// Writing metrics in this state should fail since server is closed
+	metrics := testutil.MockMetrics()
+	for _, m := range metrics {
+		model.AddMetric(m)
+	}
+	require.ErrorIs(t, model.WriteBatch(), internal.ErrNotConnected)
+
+	// Start the server and check that writes succeed
+	ts.Start()
+	require.NoError(t, model.WriteBatch())
+
+	defer ts.Close()
+	model.Close()
+}
+
 func TestDisconnectedServerOnWrite(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		switch r.URL.Path {