resource_control: add duration buffer for calibrate time window (#48172…

…) (#48353)

close #48162

executor/calibrate_resource.go

@@ -168,10 +168,12 @@ func (e *calibrateResourceExec) parseCalibrateDuration(ctx context.Context) (sta
 	}
 	// check the duration
 	dur = endTime.Sub(startTime)
-	if dur > maxDuration {
+	// add the buffer duration
+	if dur > maxDuration+time.Minute {
 		err = errors.Errorf("the duration of calibration is too long, which could lead to inaccurate output. Please make the duration between %s and %s", minDuration.String(), maxDuration.String())
 		return
 	}
+	// We only need to consider the case where the duration is slightly enlarged.
 	if dur < minDuration {
 		err = errors.Errorf("the duration of calibration is too short, which could lead to inaccurate output. Please make the duration between %s and %s", minDuration.String(), maxDuration.String())
 	}

executor/calibrate_resource_test.go

@@ -527,7 +527,7 @@ func TestCalibrateResource(t *testing.T) {
 		types.MakeDatums(datetime("2020-02-12 10:45:00"), "tikv-2", "tikv", 0.281),
 	}
 
-	rs, err = tk.Exec("CALIBRATE RESOURCE START_TIME '2020-02-12 10:35:00' END_TIME '2020-02-12 10:45:00'")
+	rs, err = tk.Exec("CALIBRATE RESOURCE START_TIME '2020-02-12 10:35:00' END_TIME '2020-02-13 10:35:01'")
 	require.NoError(t, err)
 	require.NotNil(t, rs)
 	err = rs.Next(ctx, rs.NewChunk(nil))