[exporter/loki] Do not retry on 4xx status code (excluding 429) (#18083)

.chloggen/loki-do-not-retry-on-permanent-error.yaml

@@ -0,0 +1,11 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'bug_fix'
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: exporter/loki
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Do not retry on 4xx status code (excluding 429), as these are permanent errors"
+
+# One or more tracking issues related to the change
+issues: [18059]

exporter/lokiexporter/next_exporter.go

@@ -109,6 +109,14 @@ func (l *nextLokiExporter) sendPushRequest(ctx context.Context, tenant string, r
 			line = scanner.Text()
 		}
 		err = fmt.Errorf("HTTP %d %q: %s", resp.StatusCode, http.StatusText(resp.StatusCode), line)
+
+		// Errors with 4xx status code (excluding 429) should not be retried
+		if resp.StatusCode >= http.StatusBadRequest &&
+			resp.StatusCode < http.StatusInternalServerError &&
+			resp.StatusCode != http.StatusTooManyRequests {
+			return consumererror.NewPermanent(err)
+		}
+
 		return consumererror.NewLogs(err, ld)
 	}