diff --git a/Source/Multiverso/include/multiverso/multiverso.h b/Source/Multiverso/include/multiverso/multiverso.h
index 145b49d96..4586221ee 100644
--- a/Source/Multiverso/include/multiverso/multiverso.h
+++ b/Source/Multiverso/include/multiverso/multiverso.h
@@ -5,15 +5,15 @@ namespace multiverso {
 
 
 enum Role {
-  kNull = 0,
-  kWorker = 1,
-  kServer = 2,
-  kAll = 3
+  Null = 0,
+  Worker = 1,
+  Server = 2,
+  All = 3
 };
 
 void MV_Init(int* argc = nullptr, 
              char* argv[] = nullptr, 
-             int role = kAll);
+             int role = All);
 
 void MV_Barrier();
 
@@ -24,17 +24,6 @@ int  MV_Size();
 
 int  MV_Worker_Id();
 int  MV_Server_Id();
-
-// will deprecate the following function name
-void MultiversoInit(int* argc = nullptr, 
-                    char* argv[] = nullptr, 
-                    int role = kAll);
-
-void MultiversoBarrier();
-
-void MultiversoShutDown(bool finalize_mpi = true);
-
-int MultiversoRank();
 }
 
 #endif // MULTIVERSO_INCLUDE_MULTIVERSO_H_
\ No newline at end of file
diff --git a/Source/Multiverso/include/multiverso/net/mpi_net.h b/Source/Multiverso/include/multiverso/net/mpi_net.h
index efd49672d..43c74a855 100644
--- a/Source/Multiverso/include/multiverso/net/mpi_net.h
+++ b/Source/Multiverso/include/multiverso/net/mpi_net.h
@@ -1,4 +1,4 @@
-#ifndef MULTIVERSO_NET_MPI_NET_H_
+#ifndef MULTIVERSO_NET_MPI_NET_H_ 
 #define MULTIVERSO_NET_MPI_NET_H_
 
 #ifdef MULTIVERSO_USE_MPI
@@ -22,6 +22,8 @@
 
 namespace multiverso {
 
+#define MV_MPI_CALL(mpi_return) CHECK((mpi_return) == MPI_SUCCESS)
+
 class MPINetWrapper : public NetInterface {
 public:
   MPINetWrapper() : more_(std::numeric_limits<char>::max()) {}
@@ -41,18 +43,18 @@ public:
       CHECK_NOTNULL(msg_.get());
       int count = static_cast<int>(handles_.size());
       MPI_Status* status = new MPI_Status[count];
-      MPI_Waitall(count, handles_.data(), status);
+      MV_MPI_CALL(MPI_Waitall(count, handles_.data(), status));
       delete[] status;
     }
 
-    bool Test() {
+    int Test() {
       CHECK_NOTNULL(msg_.get());
       int count = static_cast<int>(handles_.size());
       MPI_Status* status = new MPI_Status[count];
       int flag;
-      MPI_Testall(count, handles_.data(), &flag, status);
+      MV_MPI_CALL(MPI_Testall(count, handles_.data(), &flag, status));
       delete[] status;
-      return flag != 0;
+      return flag;
     }
   private:
     std::vector<MPI_Request> handles_;
@@ -62,11 +64,11 @@ public:
 
   void Init(int* argc, char** argv) override {
     // MPI_Init(argc, &argv);
-    MPI_Initialized(&inited_);
+    MV_MPI_CALL(MPI_Initialized(&inited_));
     if (!inited_) {
-      MPI_Init_thread(argc, &argv, MPI_THREAD_SERIALIZED, &thread_provided_);
+      MV_MPI_CALL(MPI_Init_thread(argc, &argv, MPI_THREAD_SERIALIZED, &thread_provided_));
     }
-    MPI_Query_thread(&thread_provided_);
+    MV_MPI_CALL(MPI_Query_thread(&thread_provided_));
     if (thread_provided_ < MPI_THREAD_SERIALIZED) {
       Log::Fatal("At least MPI_THREAD_SERIALIZED supported is needed by multiverso.\n");
     }
@@ -78,7 +80,7 @@ public:
     }
     MPI_Comm_rank(MPI_COMM_WORLD, &rank_);
     MPI_Comm_size(MPI_COMM_WORLD, &size_);
-	MPI_Barrier(MPI_COMM_WORLD);
+    MPI_Barrier(MPI_COMM_WORLD);
     Log::Debug("%s net util inited, rank = %d, size = %d\n",
       name().c_str(), rank(), size());
   }
@@ -135,9 +137,12 @@ public:
     MPI_Status status;
     int flag;
     // non-blocking probe whether message comes
-    MPI_Iprobe(MPI_ANY_SOURCE, 0, MPI_COMM_WORLD, &flag, &status);
+    MV_MPI_CALL(MPI_Iprobe(MPI_ANY_SOURCE, 0, MPI_COMM_WORLD, &flag, &status));
+    int count;
+    MV_MPI_CALL(MPI_Get_count(&status, MPI_BYTE, &count));
     if (!flag) return 0;
-    return RecvMsg(msg);
+    CHECK(count == Message::kHeaderSize);
+    return RecvMsgFrom(status.MPI_SOURCE, msg);
   }
 
   int thread_level_support() override { 
@@ -152,44 +157,44 @@ private:
     CHECK_NOTNULL(msg_handle);
     size_t size = Message::kHeaderSize;
     MPI_Request handle;
-    MPI_Isend(msg->header(), Message::kHeaderSize, MPI_BYTE,
-      msg->dst(), 0, MPI_COMM_WORLD, &handle);
+    CHECK_NOTNULL(msg->header());
+    MV_MPI_CALL(MPI_Isend(msg->header(), Message::kHeaderSize, MPI_BYTE,
+      msg->dst(), 0, MPI_COMM_WORLD, &handle));
     msg_handle->add_handle(handle);
     // Send multiple msg 
     for (auto& blob : msg->data()) {
       CHECK_NOTNULL(blob.data());
-      MPI_Isend(blob.data(), static_cast<int>(blob.size()), MPI_BYTE, msg->dst(),
-        0, MPI_COMM_WORLD, &handle);
+      MV_MPI_CALL(MPI_Isend(blob.data(), static_cast<int>(blob.size()), 
+        MPI_BYTE, msg->dst(),
+        0, MPI_COMM_WORLD, &handle));
       size += blob.size();
       msg_handle->add_handle(handle);
     }
     // Send an extra over tag indicating the finish of this Message
-    MPI_Isend(&more_, sizeof(char), MPI_BYTE, msg->dst(),
-      0, MPI_COMM_WORLD, &handle);
+    MV_MPI_CALL(MPI_Isend(&more_, sizeof(char), MPI_BYTE, msg->dst(),
+      0, MPI_COMM_WORLD, &handle));
     // Log::Debug("MPI-Net: rank %d send msg size = %d\n", rank(), size+4);
     msg_handle->add_handle(handle);
     return size + sizeof(char);
   }
 
-  size_t RecvMsg(MessagePtr* msg_ptr) {
+  size_t RecvMsgFrom(int source, MessagePtr* msg_ptr) {
     if (!msg_ptr->get()) msg_ptr->reset(new Message());
     MessagePtr& msg = *msg_ptr;
     msg->data().clear();
     MPI_Status status;
-    MPI_Recv(msg->header(), Message::kHeaderSize,
-      MPI_BYTE, MPI_ANY_SOURCE,
-      0, MPI_COMM_WORLD, &status);
+    CHECK_NOTNULL(msg->header());
+    MV_MPI_CALL(MPI_Recv(msg->header(), Message::kHeaderSize,
+      MPI_BYTE, source, 0, MPI_COMM_WORLD, &status));
     size_t size = Message::kHeaderSize;
-    int i = 0;
-    int num_probe = 0;
     while (true) {
       int count;
-      CHECK(MPI_SUCCESS == MPI_Probe(msg->src(), 0, MPI_COMM_WORLD, &status));
-      MPI_Get_count(&status, MPI_BYTE, &count);
+      MV_MPI_CALL(MPI_Probe(source, 0, MPI_COMM_WORLD, &status));
+      MV_MPI_CALL(MPI_Get_count(&status, MPI_BYTE, &count));
       Blob blob(count);
       // We only receive from msg->src() until we recv the overtag msg
-      MPI_Recv(blob.data(), count, MPI_BYTE, msg->src(),
-        0, MPI_COMM_WORLD, &status);
+      MV_MPI_CALL(MPI_Recv(blob.data(), count, MPI_BYTE, source,
+        0, MPI_COMM_WORLD, &status));
       size += count;
       if (count == sizeof(char)) {
         if (blob.As<char>() == more_) break;
@@ -197,7 +202,6 @@ private:
       }
       msg->Push(blob);
     }
-    // Log::Debug("MPI-Net: rank %d end recv from src %d, size = %d\n", rank(), msg->src(), size);
     return size;
   }
 
diff --git a/Source/Multiverso/include/multiverso/net/zmq_net.h b/Source/Multiverso/include/multiverso/net/zmq_net.h
index b9dfea8b9..f013b1b0f 100644
--- a/Source/Multiverso/include/multiverso/net/zmq_net.h
+++ b/Source/Multiverso/include/multiverso/net/zmq_net.h
@@ -1,6 +1,7 @@
 #ifndef MULTIVERSO_NET_ZMQ_NET_H_
 #define MULTIVERSO_NET_ZMQ_NET_H_
 
+// #define MULTIVERSO_USE_ZMQ
 #ifdef MULTIVERSO_USE_ZMQ
 
 #include "multiverso/net.h"
diff --git a/Source/Multiverso/include/multiverso/util/mt_queue.h b/Source/Multiverso/include/multiverso/util/mt_queue.h
index af95453f7..3d43f870f 100644
--- a/Source/Multiverso/include/multiverso/util/mt_queue.h
+++ b/Source/Multiverso/include/multiverso/util/mt_queue.h
@@ -95,7 +95,6 @@ bool MtQueue<T>::Pop(T& result)
   // empty_condition_.wait(lock,
   //  [this]{ return !buffer_.empty() || exit_; });
   while (buffer_.empty() && !exit_) {
-  // while (true) {
      empty_condition_.wait(lock);
   }
   if (buffer_.empty()) return false;
diff --git a/Source/Multiverso/include/multiverso/zoo.h b/Source/Multiverso/include/multiverso/zoo.h
index 777b35cef..d403fe695 100644
--- a/Source/Multiverso/include/multiverso/zoo.h
+++ b/Source/Multiverso/include/multiverso/zoo.h
@@ -36,6 +36,9 @@ public:
   int size() const;
 
   // TODO(to change)
+  int worker_rank() const;
+  int server_rank() const;
+
   int num_workers() const { return num_workers_; }
   int num_servers() const { return num_servers_; }
 
diff --git a/Source/Multiverso/x64/release/libmultiverso.a b/Source/Multiverso/x64/release/libmultiverso.a
index a4f89996a..62698b8a2 100644
Binary files a/Source/Multiverso/x64/release/libmultiverso.a and b/Source/Multiverso/x64/release/libmultiverso.a differ