diff --git a/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java b/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
index 68346fb..7e840d3 100644
--- a/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
+++ b/src/main/java/org/csource/fastdfs/pool/ConnectionManager.java
@@ -36,7 +36,7 @@ public class ConnectionManager {
     /**
      * free connections
      */
-    private volatile ConcurrentLinkedQueue<Connection> freeConnections = new ConcurrentLinkedQueue<Connection>();
+    private volatile LinkedList<Connection> freeConnections = new LinkedList<Connection>();
 
     private ConnectionManager() {
 
diff --git a/src/main/java/org/csource/fastdfs/pool/ConnectionPool.java b/src/main/java/org/csource/fastdfs/pool/ConnectionPool.java
index 0679fbc..b643adf 100644
--- a/src/main/java/org/csource/fastdfs/pool/ConnectionPool.java
+++ b/src/main/java/org/csource/fastdfs/pool/ConnectionPool.java
@@ -63,7 +63,7 @@ public class ConnectionPool {
         if (socketAddress == null) {
             return null;
         }
-        return String.format("%s:%s", socketAddress.getHostName().trim(), socketAddress.getPort());
+        return String.format("%s:%s", socketAddress.getHostName(), socketAddress.getPort());
     }
 
     @Override