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 341103c107..af4fbd1dcc 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
@@ -131,7 +131,7 @@ public synchronized List<MetricNode> findByTimeAndResource(long beginTimeMs, lon
         for (; i < fileNames.size(); i++) {
             String fileName = fileNames.get(i);
             long offset = findOffset(beginTimeMs, fileName,
-                fileName + MetricWriter.METRIC_FILE_INDEX_SUFFIX, offsetInIndex);
+                    MetricWriter.formIndexFileName(fileName), offsetInIndex);
             offsetInIndex = 0;
             if (offset != -1) {
                 return metricsReader.readMetricsByEndTime(fileNames, i, offset, endTimeMs, identity);
diff --git a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/MetricsReader.java b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/MetricsReader.java
index 3dc1e2c975..cb82f244ec 100644
--- a/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/MetricsReader.java
+++ b/sentinel-core/src/main/java/com/alibaba/csp/sentinel/node/metric/MetricsReader.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 1999-2018 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package com.alibaba.csp.sentinel.node.metric;
 
 import java.io.BufferedReader;