fix(agent): add flushBatch method (#11615)

agent/agent.go

@@ -824,19 +824,13 @@ func (a *Agent) flushLoop(
 		case <-flushRequested:
 			logError(a.flushOnce(output, ticker, output.Write))
 		case <-output.BatchReady:
-			// Favor the ticker over batch ready
+			logError(a.flushBatch(output, output.WriteBatch))
-			select {
-			case <-ticker.Elapsed():
-				logError(a.flushOnce(output, ticker, output.Write))
-			default:
-				logError(a.flushOnce(output, ticker, output.WriteBatch))
-			}
 		}
 	}
 }
 
 // flushOnce runs the output's Write function once, logging a warning each
-// interval it fails to complete before.
+// interval it fails to complete before the flush interval elapses.
 func (a *Agent) flushOnce(
 	output *models.RunningOutput,
 	ticker Ticker,
@@ -860,6 +854,17 @@ func (a *Agent) flushOnce(
 	}
 }
 
+// flushBatch runs the output's Write function once Unlike flushOnce the
+// interval elapsing is not considered during these flushes.
+func (a *Agent) flushBatch(
+	output *models.RunningOutput,
+	writeFunc func() error,
+) error {
+	err := writeFunc()
+	output.LogBufferStatus()
+	return err
+}
+
 // Test runs the inputs, processors and aggregators for a single gather and
 // writes the metrics to stdout.
 func (a *Agent) Test(ctx context.Context, wait time.Duration) error {