diff --git a/pom.xml b/pom.xml
index 19d28250..35110f27 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>com.qcloud.cos</groupId>
     <artifactId>hadoop-cos</artifactId>
-    <version>8.0.2</version>
+    <version>8.0.3</version>
     <packaging>jar</packaging>
 
     <name>Apache Hadoop Tencent Qcloud COS Support</name>
diff --git a/src/main/java/org/apache/hadoop/fs/CosNConfigKeys.java b/src/main/java/org/apache/hadoop/fs/CosNConfigKeys.java
index 1a7c09d2..81d572ae 100644
--- a/src/main/java/org/apache/hadoop/fs/CosNConfigKeys.java
+++ b/src/main/java/org/apache/hadoop/fs/CosNConfigKeys.java
@@ -12,7 +12,7 @@
 @InterfaceStability.Unstable
 public class CosNConfigKeys extends CommonConfigurationKeys {
     public static final String USER_AGENT = "fs.cosn.user.agent";
-    public static final String DEFAULT_USER_AGENT = "cos-hadoop-plugin-v8.0.2";
+    public static final String DEFAULT_USER_AGENT = "cos-hadoop-plugin-v8.0.3";
 
     public static final String TENCENT_EMR_VERSION_KEY = "fs.emr.version";
 
@@ -61,6 +61,8 @@ public class CosNConfigKeys extends CommonConfigurationKeys {
     public static final long DEFAULT_RETRY_INTERVAL = 3;
     public static final String CLIENT_MAX_RETRIES_KEY = "fs.cosn.client.maxRetries";
     public static final int DEFAULT_CLIENT_MAX_RETRIES = 5;
+    public static final String CLIENT_SOCKET_ERROR_MAX_RETRIES = "fs.cosn.socket.error.maxRetries";
+    public static final int DEFAULT_CLIENT_SOCKET_ERROR_MAX_RETRIES = 5;
 
     public static final String UPLOAD_THREAD_POOL_SIZE_KEY = "fs.cosn.upload_thread_pool";
     public static final int DEFAULT_UPLOAD_THREAD_POOL_SIZE = 10;
@@ -87,7 +89,7 @@ public class CosNConfigKeys extends CommonConfigurationKeys {
 
     public static final String CUSTOMER_DOMAIN = "fs.cosn.customer.domain";
     public static final String OPEN_CHECK_MERGE_BUCKET = "fs.cosn.check.merge.bucket";
-    public static final boolean DEFAULT_CHECK_MERGE_BUCKET = true;
+    public static final boolean DEFAULT_CHECK_MERGE_BUCKET = false;
     public static final String MERGE_BUCKET_MAX_LIST_NUM = "fs.cosn.merge.bucket.max.list.num";
     public static final int DEFAULT_MERGE_BUCKET_MAX_LIST_NUM = 5000;
     public static final String NORMAL_BUCKET_MAX_LIST_NUM = "fs.cosn.normal.bucket.max.list.num";
diff --git a/src/main/java/org/apache/hadoop/fs/CosNFSInputStream.java b/src/main/java/org/apache/hadoop/fs/CosNFSInputStream.java
index 25462817..e7cfaf26 100644
--- a/src/main/java/org/apache/hadoop/fs/CosNFSInputStream.java
+++ b/src/main/java/org/apache/hadoop/fs/CosNFSInputStream.java
@@ -101,6 +101,7 @@ public long getEnd() {
     private final int maxReadPartNumber;
     private byte[] buffer;
     private boolean closed = false;
+    private final int socketErrMaxRetryTimes;
 
     private final ExecutorService readAheadExecutorService;
     private final Queue<ReadBuffer> readBufferQueue;
@@ -136,6 +137,9 @@ public CosNFSInputStream(
         this.maxReadPartNumber = conf.getInt(
                 CosNConfigKeys.READ_AHEAD_QUEUE_SIZE,
                 CosNConfigKeys.DEFAULT_READ_AHEAD_QUEUE_SIZE);
+        this.socketErrMaxRetryTimes = conf.getInt(
+                CosNConfigKeys.CLIENT_SOCKET_ERROR_MAX_RETRIES,
+                CosNConfigKeys.DEFAULT_CLIENT_SOCKET_ERROR_MAX_RETRIES);
         this.readAheadExecutorService = readAheadExecutorService;
         this.readBufferQueue =
                 new ArrayDeque<ReadBuffer>(this.maxReadPartNumber);
@@ -203,8 +207,8 @@ private synchronized void reopen(long pos) throws IOException {
                 readBuffer.setStatus(ReadBuffer.SUCCESS);
             } else {
                 this.readAheadExecutorService.execute(
-                        new CosNFileReadTask(
-                                this.conf, this.key, this.store, readBuffer));
+                        new CosNFileReadTask(this.conf, this.key, this.store,
+                                readBuffer, this.socketErrMaxRetryTimes));
             }
 
             this.readBufferQueue.add(readBuffer);
diff --git a/src/main/java/org/apache/hadoop/fs/CosNFileReadTask.java b/src/main/java/org/apache/hadoop/fs/CosNFileReadTask.java
index d068e366..ae89bff1 100644
--- a/src/main/java/org/apache/hadoop/fs/CosNFileReadTask.java
+++ b/src/main/java/org/apache/hadoop/fs/CosNFileReadTask.java
@@ -7,13 +7,17 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.net.SocketException;
+import java.util.concurrent.ThreadLocalRandom;
 
 public class CosNFileReadTask implements Runnable {
     static final Logger LOG = LoggerFactory.getLogger(CosNFileReadTask.class);
 
+    private final Configuration conf;
     private final String key;
     private final NativeFileSystemStore store;
     private final CosNFSInputStream.ReadBuffer readBuffer;
+    private final int socketErrMaxRetryTimes;
 
     /**
      * cos file read task
@@ -24,40 +28,86 @@ public class CosNFileReadTask implements Runnable {
      */
     public CosNFileReadTask(Configuration conf, String key,
                             NativeFileSystemStore store,
-                            CosNFSInputStream.ReadBuffer readBuffer) {
+                            CosNFSInputStream.ReadBuffer readBuffer,
+                            int socketErrMaxRetryTimes) {
+        this.conf = conf;
         this.key = key;
         this.store = store;
         this.readBuffer = readBuffer;
+        this.socketErrMaxRetryTimes = socketErrMaxRetryTimes;
     }
 
     @Override
     public void run() {
         try {
             this.readBuffer.lock();
-            try {
-                InputStream inputStream = this.store.retrieveBlock(
-                        this.key, this.readBuffer.getStart(),
-                        this.readBuffer.getEnd());
-                IOUtils.readFully(
-                        inputStream, this.readBuffer.getBuffer(), 0,
-                        readBuffer.getBuffer().length);
-                int readEof = inputStream.read();
-                if (readEof != -1) {
-                    LOG.error("Expect to read the eof, but the return is not -1. key: {}.", this.key);
+            int retryIndex = 1;
+            boolean needRetry = false;
+            while (true) {
+                try {
+                    this.retrieveBlock();
+                    needRetry = false;
+                } catch (SocketException se) {
+                    // if we get stream success, but exceptions occurs when read cos input stream
+                    String errMsg = String.format("retrieve block sdk socket failed, " +
+                                    "retryIndex: [%d / %d], key: %s, range: [%d , %d], exception: %s",
+                            retryIndex, this.socketErrMaxRetryTimes, this.key,
+                            this.readBuffer.getStart(), this.readBuffer.getEnd(), se.toString());
+                    if (retryIndex <= this.socketErrMaxRetryTimes) {
+                        LOG.info(errMsg, se);
+                        long sleepLeast = retryIndex * 300L;
+                        long sleepBound = retryIndex * 500L;
+                        try {
+                            Thread.sleep(ThreadLocalRandom.current().
+                                    nextLong(sleepLeast, sleepBound));
+                            ++retryIndex;
+                            needRetry = true;
+                        } catch (InterruptedException ie) {
+                            this.setFailResult(errMsg, new IOException(ie.toString()));
+                            break;
+                        }
+                    } else {
+                        this.setFailResult(errMsg, se);
+                        break;
+                    }
+                } catch (IOException e) {
+                    String errMsg = String.format("retrieve block sdk socket failed, " +
+                                    "retryIndex: [%d / %d], key: %s, range: [%d , %d], exception: %s",
+                            retryIndex, this.socketErrMaxRetryTimes, this.key,
+                            this.readBuffer.getStart(), this.readBuffer.getEnd(), e.toString());
+                    this.setFailResult(errMsg, e);
+                    break;
                 }
-                inputStream.close();
-                this.readBuffer.setStatus(CosNFSInputStream.ReadBuffer.SUCCESS);
-            } catch (IOException e) {
-                this.readBuffer.setStatus(CosNFSInputStream.ReadBuffer.ERROR);
-                this.readBuffer.setException(e);
-                LOG.error("Exception occurs when retrieve the block range " +
-                        "start: "
-                        + String.valueOf(this.readBuffer.getStart()) + " " +
-                        "end: " + this.readBuffer.getEnd(), e);
-            }
+
+                if (!needRetry) {
+                    break;
+                }
+            } // end of retry
             this.readBuffer.signalAll();
         } finally {
             this.readBuffer.unLock();
         }
     }
+
+    public void setFailResult(String msg, IOException e) {
+        this.readBuffer.setStatus(CosNFSInputStream.ReadBuffer.ERROR);
+        this.readBuffer.setException(e);
+        LOG.error(msg);
+    }
+
+    // not thread safe
+    public void retrieveBlock() throws IOException {
+        InputStream inputStream = this.store.retrieveBlock(
+                this.key, this.readBuffer.getStart(),
+                this.readBuffer.getEnd());
+        IOUtils.readFully(
+                inputStream, this.readBuffer.getBuffer(), 0,
+                readBuffer.getBuffer().length);
+        int readEof = inputStream.read();
+        if (readEof != -1) {
+            LOG.error("Expect to read the eof, but the return is not -1. key: {}.", this.key);
+        }
+        inputStream.close();
+        this.readBuffer.setStatus(CosNFSInputStream.ReadBuffer.SUCCESS);
+    }
 }