diff --git a/scripts/travis.sh b/scripts/travis.sh
index b6bc7ef9..7197c5c2 100755
--- a/scripts/travis.sh
+++ b/scripts/travis.sh
@@ -27,24 +27,16 @@ if [[ $(git status -s) ]]; then
 fi
 
 # start pegasus onebox environment
-wget https://github.com/XiaoMi/pegasus/releases/download/v1.11.2/pegasus-tools-1.11.2-a186d38-ubuntu-18.04-release.tar.gz
-tar xvf pegasus-tools-1.11.2-a186d38-ubuntu-18.04-release.tar.gz
-cd pegasus-tools-1.11.2-a186d38-ubuntu-release
+wget https://github.com/XiaoMi/pegasus/releases/download/v1.11.3/pegasus-1.11.3-b45cb06-linux-x86_64-release.zip
+unzip pegasus-1.11.3-b45cb06-linux-x86_64-release.zip
+cd pegasus-1.11.3-b45cb06-linux-x86_64-release
 
-# download zookeeper
-# TODO(wutao1): remove this when upgrading the server to latest version
-mkdir -p .zk_install && cd .zk_install
-wget "https://github.com/xiaomi/pegasus-common/raw/master/zookeeper-3.4.6.tar.gz"
-cd ..
-
-./run.sh start_onebox
-sleep 4
-./run.sh list_onebox
+./run.sh start_onebox -w
 cd ../
 
 if ! mvn clean test
 then
-    cd pegasus-tools-1.11.2-a186d38-ubuntu-release
+    cd pegasus-1.11.3-b45cb06-linux-x86_64-release
     ./run.sh list_onebox
     exit 1
 fi
diff --git a/src/main/java/com/xiaomi/infra/pegasus/client/PConfigUtil.java b/src/main/java/com/xiaomi/infra/pegasus/client/PConfigUtil.java
index 0ea28502..22011da8 100644
--- a/src/main/java/com/xiaomi/infra/pegasus/client/PConfigUtil.java
+++ b/src/main/java/com/xiaomi/infra/pegasus/client/PConfigUtil.java
@@ -95,7 +95,13 @@ public static byte[] loadConfigFromZK(String zkUri) throws PException {
     ZkClient client =
         new ZkClient(
             server, ZK_SESSION_TIMEOUT, ZK_CONNECTION_TIMEOUT, new BytesPushThroughSerializer());
-    return client.readData(path);
+    try {
+      return client.readData(path);
+    } catch (Exception e) {
+      throw new PException(e);
+    } finally {
+      client.close();
+    }
   }
 
   protected static String getBusinessConfigZkPath(String businessName) {
diff --git a/src/main/java/com/xiaomi/infra/pegasus/client/PegasusClientInterface.java b/src/main/java/com/xiaomi/infra/pegasus/client/PegasusClientInterface.java
index 7ef39b91..8450f33b 100644
--- a/src/main/java/com/xiaomi/infra/pegasus/client/PegasusClientInterface.java
+++ b/src/main/java/com/xiaomi/infra/pegasus/client/PegasusClientInterface.java
@@ -279,7 +279,7 @@ public int batchSet2(String tableName, List<SetItem> items, List<PException> res
    *
    * @param tableName table name
    * @param hashKey used to decide which partition to put this k-v, should not be null or empty.
-   * @param values all <sortkey,value> pairs to be set, should not be null or empty.
+   * @param values all {@literal <sortkey,value>} pairs to be set, should not be null or empty.
    * @param ttlSeconds time to live in seconds, 0 means no ttl. default value is 0.
    * @throws PException throws exception if any error occurs.
    */
diff --git a/src/main/java/com/xiaomi/infra/pegasus/client/PegasusScannerInterface.java b/src/main/java/com/xiaomi/infra/pegasus/client/PegasusScannerInterface.java
index 7fba1033..d8f0d0a4 100644
--- a/src/main/java/com/xiaomi/infra/pegasus/client/PegasusScannerInterface.java
+++ b/src/main/java/com/xiaomi/infra/pegasus/client/PegasusScannerInterface.java
@@ -14,7 +14,7 @@ public interface PegasusScannerInterface {
   /**
    * Get the next item.
    *
-   * @return item like <<hashKey, sortKey>, value>; null returned if scan completed.
+   * @return item like {@literal <<hashKey, sortKey>, value>}; null returned if scan completed.
    * @throws PException
    */
   public Pair<Pair<byte[], byte[]>, byte[]> next() throws PException;
diff --git a/src/main/java/com/xiaomi/infra/pegasus/client/PegasusTableInterface.java b/src/main/java/com/xiaomi/infra/pegasus/client/PegasusTableInterface.java
index f74ea249..92018d03 100644
--- a/src/main/java/com/xiaomi/infra/pegasus/client/PegasusTableInterface.java
+++ b/src/main/java/com/xiaomi/infra/pegasus/client/PegasusTableInterface.java
@@ -18,7 +18,7 @@
  *     <p>A synchronous example: <code>
  *     PegasusTableInterface table;
  *     ....
- *     Future<Boolean> future = table.asyncExist(hashKey, sortKey, 0);
+ *     Future{@literal <Boolean>} future = table.asyncExist(hashKey, sortKey, 0);
  *     future.await();
  *     if (future.isSuccess()) {
  *         Boolean result = future.getNow();
@@ -31,7 +31,7 @@
  *     ....
  *     table.asyncExist(hashKey, sortKey, 0).addListener(
  *         new ExistListener() {
- *             public void operationComplete(Future<Boolean> future) throws Exception {
+ *             public void operationComplete(Future{@literal <Boolean>} future) throws Exception {
  *                 if (future.isSuccess()) {
  *                     Boolean result = future.getNow();
  *                 }