diff --git a/demos/xgboost/download_and_build_xgboost.sh b/demos/xgboost/download_and_build_xgboost.sh
index 9616db14..c8975181 100755
--- a/demos/xgboost/download_and_build_xgboost.sh
+++ b/demos/xgboost/download_and_build_xgboost.sh
@@ -9,11 +9,14 @@ apt-get update
 apt-get install -y python3-pip python3-setuptools
 pip3 install kubernetes
 
+#install the cmake
+./install_cmake.sh
+
 # Download and build XGBoost
 rm -rf xgboost_src && mkdir xgboost_src
 pushd xgboost_src
 git clone https://github.com/dmlc/xgboost .
-git checkout 6d5b34d82486cd1d0480c548f5d1953834659bd6
+git checkout 9e955fb9b06cac32a06c92c4715f749d9d87e932
 git submodule init
 git submodule update
 git apply ../patch/xgboost-01.diff
diff --git a/demos/xgboost/install_cmake.sh b/demos/xgboost/install_cmake.sh
new file mode 100755
index 00000000..cc99829c
--- /dev/null
+++ b/demos/xgboost/install_cmake.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+set -e
+cd ~
+wget https://github.com/Kitware/CMake/releases/download/v3.15.5/cmake-3.15.5.tar.gz && tar xf cmake-3.15.5.tar.gz
+cd cmake-3.15.5
+./bootstrap
+make -j4
+sudo make install
diff --git a/demos/xgboost/patch/dmlc-core-01.diff b/demos/xgboost/patch/dmlc-core-01.diff
index ab2a29c0..4f6d22ea 100644
--- a/demos/xgboost/patch/dmlc-core-01.diff
+++ b/demos/xgboost/patch/dmlc-core-01.diff
@@ -1,18 +1,18 @@
 diff --git a/tracker/dmlc_tracker/local.py b/tracker/dmlc_tracker/local.py
-index dff7c17..fca0f9d 100644
+index 6e4af12..09df15e 100644
 --- a/tracker/dmlc_tracker/local.py
 +++ b/tracker/dmlc_tracker/local.py
-@@ -24,6 +24,13 @@ def exec_cmd(cmd, role, taskid, pass_env):
- 
-     num_retry = env.get('DMLC_NUM_ATTEMPT', 0)
+@@ -26,6 +26,13 @@ def exec_cmd(cmd, num_attempt, role, taskid, pass_env):
+     num_retry = env.get('DMLC_NUM_ATTEMPT', num_attempt)
+     num_trial = 0
  
 +    cmd_str = ''
 +    for k, v in env.items():
 +        if str(k)[0:4] == 'DMLC':
 +            strenv = str(k) + '=' + str(v);
 +            cmd_str = cmd_str + ' ' + strenv
-+    cmd = cmd + cmd_str
++    cmdline = cmdline + ' ' + cmd_str
 +
+     logging.debug('num of retry %d',num_retry)
+ 
      while True:
-         if os.name == 'nt':
-             ret = subprocess.call(cmd, shell=True, env=env)
diff --git a/demos/xgboost/patch/rabit-01.diff b/demos/xgboost/patch/rabit-01.diff
index e710390a..3e4972fb 100644
--- a/demos/xgboost/patch/rabit-01.diff
+++ b/demos/xgboost/patch/rabit-01.diff
@@ -1,36 +1,36 @@
-diff --git a/src/allreduce_base.cc b/src/allreduce_base.cc
-index 143db6e..a6daf20 100644
---- a/src/allreduce_base.cc
-+++ b/src/allreduce_base.cc
-@@ -486,12 +486,13 @@ AllreduceBase::TryAllreduceTree(void *sendrecvbuf_,
+diff --git a/rabit/src/allreduce_base.cc b/rabit/src/allreduce_base.cc
+index d1959eaa..68cd377a 100644
+--- a/rabit/src/allreduce_base.cc
++++ b/rabit/src/allreduce_base.cc
+@@ -551,12 +551,13 @@ AllreduceBase::TryAllreduceTree(void *sendrecvbuf_,
      // select must return
      watcher.Poll();
      // exception handling
 -    for (int i = 0; i < nlink; ++i) {
-+    //FIXME:workaround for Occlum
-+    /*for (int i = 0; i < nlink; ++i) {
++    // FIXME:workaround for Occlum
++    /* for (int i = 0; i < nlink; ++i) {
        // recive OOB message from some link
        if (watcher.CheckExcept(links[i].sock)) {
          return ReportError(&links[i], kGetExcept);
        }
 -    }
-+    }*/
++    } */
      // read data from childs
      for (int i = 0; i < nlink; ++i) {
        if (i != parent_index && watcher.CheckRead(links[i].sock)) {
-@@ -641,12 +642,13 @@ AllreduceBase::TryBroadcast(void *sendrecvbuf_, size_t total_size, int root) {
+@@ -731,12 +732,13 @@ AllreduceBase::TryBroadcast(void *sendrecvbuf_, size_t total_size, int root) {
      // select
      watcher.Poll();
      // exception handling
 -    for (int i = 0; i < nlink; ++i) {
-+    //FIXME:workaround for Occlum
-+    /*for (int i = 0; i < nlink; ++i) {
++    // FIXME:workaround for Occlum
++    /* for (int i = 0; i < nlink; ++i) {
        // recive OOB message from some link
        if (watcher.CheckExcept(links[i].sock)) {
          return ReportError(&links[i], kGetExcept);
        }
 -    }
-+    }*/
++    } */
      if (in_link == -2) {
        // probe in-link
        for (int i = 0; i < nlink; ++i) {
diff --git a/demos/xgboost/patch/xgboost-01.diff b/demos/xgboost/patch/xgboost-01.diff
index 4fec3b01..c78afb20 100644
--- a/demos/xgboost/patch/xgboost-01.diff
+++ b/demos/xgboost/patch/xgboost-01.diff
@@ -1,21 +1,21 @@
 diff --git a/src/cli_main.cc b/src/cli_main.cc
-index faa93ad..a201615 100644
+index 5c602f37..d18a77c2 100644
 --- a/src/cli_main.cc
 +++ b/src/cli_main.cc
-@@ -339,6 +339,16 @@ int CLIRunTask(int argc, char *argv[]) {
-     printf("Usage: <config>\n");
-     return 0;
-   }
+@@ -444,6 +444,16 @@ class CLI {
+       this->PrintHelp();
+       exit(1);
+     }
 +
-+  //FIXME:workaroud for local distributed machine learning on Occlum
-+  for (int i = 2; i < argc; ++i) {
-+    char name[128], val[128];
-+    if (sscanf(argv[i], "%[^=]=%s", name, val) == 2) {
-+      //LOG(CONSOLE) << "setenv: " << std::string(name) << " = " << std::string(val);
-+      setenv(std::string(name).c_str(), std::string(val).c_str(), 1);
++    // FIXME:workaroud for local distributed machine learning on Occlum
++    for (int i = 2; i < argc; ++i) {
++      char name[128], val[128];
++      if (sscanf(argv[i], "%[^=]=%s", name, val) == 2) {
++        //LOG(CONSOLE) << "setenv: " << std::string(name) << " = " << std::string(val);
++        setenv(std::string(name).c_str(), std::string(val).c_str(), 1);
++      }
 +    }
-+  }
 +
-   rabit::Init(argc, argv);
- 
-   std::vector<std::pair<std::string, std::string> > cfg;
+     for (int i = 0; i < argc; ++i) {
+       std::string str {argv[i]};
+       if (str == "-h" || str == "--help") {