diff --git a/flowgate-api/src/test/java/com/vmware/flowgate/controller/AssetControllerTest.java b/flowgate-api/src/test/java/com/vmware/flowgate/controller/AssetControllerTest.java
index 5306bd36..1d117b69 100644
--- a/flowgate-api/src/test/java/com/vmware/flowgate/controller/AssetControllerTest.java
+++ b/flowgate-api/src/test/java/com/vmware/flowgate/controller/AssetControllerTest.java
@@ -3007,6 +3007,22 @@ else if(String.format(MetricKeyName.PDU_HUMIDITY_LOCATIONX, "OUTLET").
       realtimeDataRepository.deleteById(humdityRealTimeData.getId());
    }
 
+   @Test
+   public void testGetServerMetricsByIDFormulaIsEmpty() {
+      Asset asset = createAsset();
+      long time = System.currentTimeMillis();
+      int duration = 30*60*1000;
+      long startTime = time - duration;
+      Map<String, String> formulars = new HashMap<String, String>();
+      asset.setMetricsformulars(formulars);
+      asset = assetRepository.save(asset);
+
+      List<MetricData> metricDatas =
+            assetService.getMetricsByID(asset.getId(), startTime, duration);
+      TestCase.assertEquals(0, metricDatas.size());
+      assetRepository.deleteById(asset.getId());
+   }
+
    @Test
    public void testGetServerMetricsByID() {
       Asset asset = createAsset();
@@ -3395,6 +3411,13 @@ public void testGetMetricDataForOther() {
       realtimeDataRepository.deleteById(realTimeData.getId());
    }
 
+   @Test
+   public void testMetricFormulaStringIsNull() {
+      Asset asset = createAsset();
+      Map<String,String> formulaInfo = asset.metricsFormulaToMap(null, new TypeReference<Map<String, String>>(){});
+      TestCase.assertEquals(null, formulaInfo);
+   }
+
    RealTimeData createPduRealTimeData(Long time) {
       RealTimeData realTimeData = createServerPDURealTimeData(time);
       List<ValueUnit> valueunits = realTimeData.getValues();
diff --git a/flowgate-common/src/main/java/com/vmware/flowgate/common/model/Asset.java b/flowgate-common/src/main/java/com/vmware/flowgate/common/model/Asset.java
index f9e4e3fb..80a63f0e 100644
--- a/flowgate-common/src/main/java/com/vmware/flowgate/common/model/Asset.java
+++ b/flowgate-common/src/main/java/com/vmware/flowgate/common/model/Asset.java
@@ -484,6 +484,9 @@ public void setTenant(Tenant tenant) {
 
    public <T> T metricsFormulaToMap(String formulasInfo, TypeReference<T> type){
       ObjectMapper mapper = new ObjectMapper();
+      if(formulasInfo == null) {
+         return null;
+      }
       try {
          return mapper.readValue(formulasInfo, type);
       }  catch (IOException e) {