diff --git a/pom.xml b/pom.xml
index 89029f4..d44c210 100644
--- a/pom.xml
+++ b/pom.xml
@@ -118,7 +118,7 @@
             <groupId>org.apache.flink</groupId>
             <artifactId>flink-sql-connector-kafka_2.11</artifactId>
             <version>${flink.version}</version>
-            <!--<scope>provided</scope>-->
+            <scope>provided</scope>
         </dependency>
 
         <dependency>
@@ -128,23 +128,6 @@
             <!--<scope>provided</scope>-->
         </dependency>
 
-        <!--&lt;!&ndash; https://mvnrepository.com/artifact/org.apache.flink/flink-table &ndash;&gt;-->
-        <!--<dependency>-->
-            <!--<groupId>org.apache.flink</groupId>-->
-            <!--<artifactId>flink-table</artifactId>-->
-            <!--<version>${flink.version}</version>-->
-            <!--&lt;!&ndash;<scope>provided</scope>&ndash;&gt;-->
-        <!--</dependency>-->
-
-        <!-- https://mvnrepository.com/artifact/org.apache.flink/flink-json -->
-        <dependency>
-            <groupId>org.apache.flink</groupId>
-            <artifactId>flink-json</artifactId>
-            <version>${flink.version}</version>
-            <scope>provided</scope>
-        </dependency>
-
-
         <!-- https://mvnrepository.com/artifact/org.apache.kafka/kafka-clients -->
         <dependency>
             <groupId>org.apache.kafka</groupId>
diff --git a/src/main/java/com/zdjizhi/etl/DosDetection.java b/src/main/java/com/zdjizhi/etl/DosDetection.java
index 4f3c7b5..453b72c 100644
--- a/src/main/java/com/zdjizhi/etl/DosDetection.java
+++ b/src/main/java/com/zdjizhi/etl/DosDetection.java
@@ -43,10 +43,9 @@ public class DosDetection extends RichMapFunction<DosSketchLog, DosEventLog> {
                 if (baseline != null && baseline.size() == BASELINE_SIZE){
                     int timeIndex = getCurrentTimeIndex(value.getSketch_start_time());
                     Integer base = baseline.get(timeIndex);
-                    long sketchSessions = value.getSketch_sessions();
-                    long diff = sketchSessions - base;
+                    long diff = value.getSketch_sessions() - base;
                     if (diff > 0){
-                        String percent = getDiffPercent(diff, sketchSessions);
+                        String percent = getDiffPercent(diff, base);
                         double diffPercentDouble = getDiffPercentDouble(percent);
                         Severity severity = judgeSeverity(diffPercentDouble);
                         if (severity != Severity.NORMAL){
@@ -105,10 +104,15 @@ public class DosDetection extends RichMapFunction<DosSketchLog, DosEventLog> {
         return Integer.parseInt(Long.toString(indexLong));
     }
 
-    private String getDiffPercent(long diff,long sketchSessions){
+    private String getDiffPercent(long diff,long base){
         double diffDou = Double.parseDouble(Long.toString(diff));
-        double sessDou = Double.parseDouble(Long.toString(sketchSessions));
-        return PERCENT_INSTANCE.format(diffDou / sessDou);
+        double baseDou = Double.parseDouble(Long.toString(base));
+        return PERCENT_INSTANCE.format(diffDou / baseDou);
+    }
+
+    public static void main(String[] args) throws Exception {
+        System.out.println(new DosDetection().getDiffPercent(219, 0));
+        System.out.println(new DosDetection().getDiffPercentDouble("∞%"));
     }
 
     private double getDiffPercentDouble(String diffPercent) throws ParseException {