diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/ExtractedMetricSearcher.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/ExtractedMetricSearcher.java
new file mode 100644
index 0000000000..5159ab703c
--- /dev/null
+++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/ExtractedMetricSearcher.java
@@ -0,0 +1,107 @@
+package com.alibaba.csp.sentinel.node.metric;
+
+import java.io.BufferedReader;
+import java.io.FileInputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.List;
+
+class ExtractedMetricSearcher {
+    /**
+     * avoid OOM in any case
+     */
+    private static final int maxLinesReturn = 100000;
+    private Charset charset;
+
+    public ExtractedMetricSearcher(Charset charset) {
+        this.charset = charset;
+    }
+
+    /**
+     * @return if should continue read, return true, else false.
+     */
+    boolean readMetricsInOneFileByEndTime(List<MetricNode> list, String fileName,
+                                          long offset, long endTimeMs, String identity) throws Exception {
+        FileInputStream in = null;
+        long endSecond = endTimeMs / 1000;
+        try {
+            in = new FileInputStream(fileName);
+            in.getChannel().position(offset);
+            BufferedReader reader = new BufferedReader(new InputStreamReader(in, charset));
+            String line;
+            while ((line = reader.readLine()) != null) {
+                MetricNode node = MetricNode.fromFatString(line);
+                long currentSecond = node.getTimestamp() / 1000;
+                if (currentSecond <= endSecond) {
+                    // read all
+                    if (identity == null) {
+                        list.add(node);
+                    } else if (node.getResource().equals(identity)) {
+                        list.add(node);
+                    }
+                } else {
+                    return false;
+                }
+                if (list.size() >= maxLinesReturn) {
+                    return false;
+                }
+            }
+        } finally {
+            if (in != null) {
+                in.close();
+            }
+        }
+        return true;
+    }
+
+    void readMetricsInOneFile(List<MetricNode> list, String fileName,
+                              long offset, int recommendLines) throws Exception {
+        //if(list.size() >= recommendLines){
+        //    return;
+        //}
+        long lastSecond = -1;
+        if (list.size() > 0) {
+            lastSecond = list.get(list.size() - 1).getTimestamp() / 1000;
+        }
+        FileInputStream in = null;
+        try {
+            in = new FileInputStream(fileName);
+            in.getChannel().position(offset);
+            BufferedReader reader = new BufferedReader(new InputStreamReader(in, charset));
+            String line;
+            while ((line = reader.readLine()) != null) {
+                MetricNode node = MetricNode.fromFatString(line);
+                long currentSecond = node.getTimestamp() / 1000;
+
+                if (list.size() < recommendLines) {
+                    list.add(node);
+                } else if (currentSecond == lastSecond) {
+                    list.add(node);
+                } else {
+                    break;
+                }
+                lastSecond = currentSecond;
+            }
+        } finally {
+            if (in != null) {
+                in.close();
+            }
+        }
+    }
+
+    /**
+     * When identity is null, all metric between the time intervalMs will be read, otherwise, only the specific
+     * identity will be read.
+     */
+    List<MetricNode> readMetricsByEndTime(List<String> fileNames, int pos,
+                                          long offset, long endTimeMs, String identity) throws Exception {
+        List<MetricNode> list = new ArrayList<MetricNode>(1024);
+        if (readMetricsInOneFileByEndTime(list, fileNames.get(pos++), offset, endTimeMs, identity)) {
+            while (pos < fileNames.size()
+                    && readMetricsInOneFileByEndTime(list, fileNames.get(pos++), 0, endTimeMs, identity)) {
+            }
+        }
+        return list;
+    }
+}
\ No newline at end of file
diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/MetricSearcher.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/MetricSearcher.java
index 8151d4b1c9..2c6cca7e5e 100755
--- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/MetricSearcher.java
+++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/MetricSearcher.java
@@ -15,12 +15,10 @@
  */
 package com.alibaba.csp.sentinel.node.metric;
 
-import java.io.BufferedReader;
 import java.io.DataInputStream;
 import java.io.EOFException;
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.InputStreamReader;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.List;
@@ -37,18 +35,13 @@
 public class MetricSearcher {
 
     private static final Charset defaultCharset = Charset.forName(SentinelConfig.charset());
+    private final ExtractedMetricSearcher extractedMetricSearcher;
 
     private String baseDir;
     private String baseFileName;
-    private Charset charset;
 
     private Position lastPosition = new Position();
 
-    /**
-     * avoid OOM in any case
-     */
-    private static final int maxLinesReturn = 100000;
-
     /**
      * @param baseDir      metric文件所在目录
      * @param baseFileName metric文件名的关键字，比如 alihot-metrics.log
@@ -77,7 +70,7 @@ public MetricSearcher(String baseDir, String baseFileName, Charset charset) {
             this.baseDir += File.separator;
         }
         this.baseFileName = baseFileName;
-        this.charset = charset;
+        extractedMetricSearcher = new ExtractedMetricSearcher(charset);
     }
 
     /**
@@ -142,7 +135,7 @@ public synchronized List<MetricNode> findByTimeAndResource(long beginTimeMs, lon
                 fileName + MetricWriter.METRIC_FILE_INDEX_SUFFIX, offsetInIndex);
             offsetInIndex = 0;
             if (offset != -1) {
-                return readMetricsByEndTime(fileNames, i, offset, endTimeMs, identity);
+                return extractedMetricSearcher.readMetricsByEndTime(fileNames, i, offset, endTimeMs, identity);
             }
         }
         return null;
@@ -198,99 +191,12 @@ private boolean validPosition(long beginTimeMs) {
         }
     }
 
-    /**
-     * @return if should continue read, return true, else false.
-     */
-    private boolean readMetricsInOneFileByEndTime(List<MetricNode> list, String fileName,
-                                                  long offset, long endTimeMs, String identity) throws Exception {
-        FileInputStream in = null;
-        long endSecond = endTimeMs / 1000;
-        try {
-            in = new FileInputStream(fileName);
-            in.getChannel().position(offset);
-            BufferedReader reader = new BufferedReader(new InputStreamReader(in, charset));
-            String line;
-            while ((line = reader.readLine()) != null) {
-                MetricNode node = MetricNode.fromFatString(line);
-                long currentSecond = node.getTimestamp() / 1000;
-                if (currentSecond <= endSecond) {
-                    // read all
-                    if (identity == null) {
-                        list.add(node);
-                    } else if (node.getResource().equals(identity)) {
-                        list.add(node);
-                    }
-                } else {
-                    return false;
-                }
-                if (list.size() >= maxLinesReturn) {
-                    return false;
-                }
-            }
-        } finally {
-            if (in != null) {
-                in.close();
-            }
-        }
-        return true;
-    }
-
-    private void readMetricsInOneFile(List<MetricNode> list, String fileName,
-                                      long offset, int recommendLines) throws Exception {
-        //if(list.size() >= recommendLines){
-        //    return;
-        //}
-        long lastSecond = -1;
-        if (list.size() > 0) {
-            lastSecond = list.get(list.size() - 1).getTimestamp() / 1000;
-        }
-        FileInputStream in = null;
-        try {
-            in = new FileInputStream(fileName);
-            in.getChannel().position(offset);
-            BufferedReader reader = new BufferedReader(new InputStreamReader(in, charset));
-            String line;
-            while ((line = reader.readLine()) != null) {
-                MetricNode node = MetricNode.fromFatString(line);
-                long currentSecond = node.getTimestamp() / 1000;
-
-                if (list.size() < recommendLines) {
-                    list.add(node);
-                } else if (currentSecond == lastSecond) {
-                    list.add(node);
-                } else {
-                    break;
-                }
-                lastSecond = currentSecond;
-            }
-        } finally {
-            if (in != null) {
-                in.close();
-            }
-        }
-    }
-
     private List<MetricNode> readMetrics(List<String> fileNames, int pos,
                                          long offset, int recommendLines) throws Exception {
         List<MetricNode> list = new ArrayList<MetricNode>(recommendLines);
-        readMetricsInOneFile(list, fileNames.get(pos++), offset, recommendLines);
+        extractedMetricSearcher.readMetricsInOneFile(list, fileNames.get(pos++), offset, recommendLines);
         while (list.size() < recommendLines && pos < fileNames.size()) {
-            readMetricsInOneFile(list, fileNames.get(pos++), 0, recommendLines);
-        }
-        return list;
-    }
-
-    /**
-     * When identity is null, all metric between the time intervalMs will be read, otherwise, only the specific
-     * identity will be read.
-     */
-    private List<MetricNode> readMetricsByEndTime(List<String> fileNames, int pos,
-                                                  long offset, long endTimeMs, String identity) throws Exception {
-        List<MetricNode> list = new ArrayList<MetricNode>(1024);
-        if (readMetricsInOneFileByEndTime(list, fileNames.get(pos++), offset, endTimeMs, identity)) {
-            while (pos < fileNames.size()
-                && readMetricsInOneFileByEndTime(list, fileNames.get(pos++), 0, endTimeMs, identity)) {
-            }
+            extractedMetricSearcher.readMetricsInOneFile(list, fileNames.get(pos++), 0, recommendLines);
         }
         return list;
     }