diff --git a/src/modules/collector/sys/plugins/reader.go b/src/modules/collector/sys/plugins/reader.go
index b8f2a3a8..28fc9837 100644
--- a/src/modules/collector/sys/plugins/reader.go
+++ b/src/modules/collector/sys/plugins/reader.go
@@ -2,7 +2,6 @@ package plugins
 
 import (
 	"io/ioutil"
-	"os"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -32,15 +31,9 @@ func ListPluginsFromMonapi() map[string]*Plugin {
 
 	for _, p := range plugins {
 		fpath := p.FilePath
-		fileInfo, err := os.Stat(fpath)
-		if err != nil {
-			logger.Warningf("plugin:%s get info err:%v", p.FilePath, err)
-			continue
-		}
-
 		plugin := &Plugin{
 			FilePath: fpath,
-			MTime:    fileInfo.ModTime().Unix(),
+			MTime:    p.LastUpdated.Unix(),
 			Cycle:    p.Step,
 			Params:   p.Params,
 		}
diff --git a/src/modules/collector/sys/plugins/scheduler.go b/src/modules/collector/sys/plugins/scheduler.go
index cde42295..25478198 100644
--- a/src/modules/collector/sys/plugins/scheduler.go
+++ b/src/modules/collector/sys/plugins/scheduler.go
@@ -117,5 +117,9 @@ func PluginRun(plugin *Plugin) {
 		return
 	}
 
+	for i := 0; i < len(items); i++ {
+		items[i].Step = int64(plugin.Cycle)
+	}
+
 	funcs.Push(items)
 }
diff --git a/src/modules/judge/judge/func.go b/src/modules/judge/judge/func.go
index 09ea6004..51d4cc33 100644
--- a/src/modules/judge/judge/func.go
+++ b/src/modules/judge/judge/func.go
@@ -217,7 +217,7 @@ func (f NodataFunction) Compute(vs []*dataobj.HistoryData) (leftValue dataobj.Js
 			return value.Value, false
 		}
 	}
-	return 0, true
+	return dataobj.JsonFloat(math.NaN()), true
 }
 
 type CAvgAbsFunction struct {
diff --git a/src/modules/judge/judge/judge.go b/src/modules/judge/judge/judge.go
index 11dbbb1e..00d737b8 100644
--- a/src/modules/judge/judge/judge.go
+++ b/src/modules/judge/judge/judge.go
@@ -5,6 +5,7 @@ import (
 	"container/list"
 	"encoding/json"
 	"fmt"
+	"math"
 	"strconv"
 	"strings"
 	"sync"
@@ -111,10 +112,14 @@ func Judge(stra *model.Stra, exps []model.Exp, historyData []*dataobj.HistoryDat
 	}()
 
 	leftValue, isTriggered = judgeItemWithStrategy(stra, historyData, exps[0], firstItem, now)
+	lastValue := "null"
+	if !math.IsNaN(float64(leftValue)) {
+		lastValue = strconv.FormatFloat(float64(leftValue), 'f', -1, 64)
+	}
 	if value == "" {
-		value = fmt.Sprintf("%s: %v", exp.Metric, leftValue)
+		value = fmt.Sprintf("%s: %s", exp.Metric, lastValue)
 	} else {
-		value += fmt.Sprintf("; %s: %v", exp.Metric, leftValue)
+		value += fmt.Sprintf("; %s: %s", exp.Metric, lastValue)
 	}
 	status = append(status, isTriggered)