diff --git a/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java b/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
index 7c5a927..68edb9b 100644
--- a/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
+++ b/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
@@ -13,7 +13,7 @@ import java.util.concurrent.locks.ReentrantLock;
 
 public class ConnectionManager {
     /**
-     * ip_port
+     * ip:port is key
      */
     private String key;
 
@@ -23,7 +23,7 @@ public class ConnectionManager {
     private AtomicInteger totalCount = new AtomicInteger();
 
     /**
-     * freeCP
+     * free connection count
      */
     private AtomicInteger freeCount = new AtomicInteger();
 
@@ -32,13 +32,10 @@ public class ConnectionManager {
      */
     private ReentrantLock lock = new ReentrantLock(true);
 
-    /**
-     * condition
-     */
     private Condition condition = lock.newCondition();
 
     /**
-     * connection container
+     * free connections
      */
     private volatile ConcurrentLinkedQueue<ConnectionInfo> freeConnections = new ConcurrentLinkedQueue<ConnectionInfo>();
 
@@ -109,11 +106,12 @@ public class ConnectionManager {
         }
     }
 
-    public  void freeConnection(ConnectionInfo connectionInfo) throws IOException {
-        if (connectionInfo == null || connectionInfo.getSocket() == null) {
+    public  void freeConnection(TrackerServer trackerServer) throws IOException {
+        if (trackerServer == null || !trackerServer.isConnected()) {
             return;
         }
-        if ((System.currentTimeMillis() - connectionInfo.getLastAccessTime()) < ClientGlobal.getG_connection_pool_max_idle_time()) {
+        ConnectionInfo connectionInfo = new ConnectionInfo(trackerServer.getSocket(),trackerServer.getInetSocketAddress(),System.currentTimeMillis(),true);
+        if ((System.currentTimeMillis() - trackerServer.getLastAccessTime()) < ClientGlobal.getG_connection_pool_max_idle_time()) {
             try {
                 lock.lock();
                 freeConnections.add(connectionInfo);
@@ -132,7 +130,7 @@ public class ConnectionManager {
             totalCount.decrementAndGet();
             try {
                 ProtoCommon.closeSocket(connectionInfo.getSocket());
-            } finally {
+            }  finally {
                 connectionInfo.setSocket(null);
             }
         }
diff --git a/src/main/java/org/csource/fastdfs/pool/ConnectionPool.java b/src/main/java/org/csource/fastdfs/pool/ConnectionPool.java
index 62813c6..c31465b 100644
--- a/src/main/java/org/csource/fastdfs/pool/ConnectionPool.java
+++ b/src/main/java/org/csource/fastdfs/pool/ConnectionPool.java
@@ -54,8 +54,7 @@ public class ConnectionPool {
         if (key != null) {
             ConnectionManager connectionManager = CP.get(key);
             if (connectionManager != null) {
-                ConnectionInfo connectionInfo = new ConnectionInfo(trackerServer.getSocket(),trackerServer.getInetSocketAddress(),System.currentTimeMillis(),true);
-                connectionManager.freeConnection(connectionInfo);
+                connectionManager.freeConnection(trackerServer);
             } else {
                 trackerServer.closeDirect();
             }