diff --git a/paddle/fluid/operators/detail/grpc_server.cc b/paddle/fluid/operators/detail/grpc_server.cc
index 25c6bb9ee2e1b1b651ffdb9efe30240334d760fc..8abcfbb4388aeb3dc263c1e6403f540561f7e007 100644
--- a/paddle/fluid/operators/detail/grpc_server.cc
+++ b/paddle/fluid/operators/detail/grpc_server.cc
@@ -82,7 +82,9 @@ class RequestSend final : public RequestBase {
   virtual std::string GetReqName() { return request_->Varname(); }
 
   virtual void Process() {
-    queue_->Push(std::make_pair(request_->Varname(), request_));
+    std::string var_name = GetReqName();
+    VLOG(3) << "RequestSend " << var_name;
+    queue_->Push(std::make_pair(var_name, request_));
 
     sendrecv::VoidMessage reply;
     responder_.Finish(reply, ::grpc::Status::OK, this);
@@ -106,7 +108,7 @@ class RequestGet final : public RequestBase {
         responder_(&ctx_),
         scope_(scope),
         queue_(queue) {
-    int method_id = static_cast<int>(detail::GrpcMethod::kGetVariable);
+    auto method_id = static_cast<int>(detail::GrpcMethod::kGetVariable);
     service_->RequestAsyncUnary(method_id, &ctx_, &request_, &responder_, cq_,
                                 cq_, this);
   }
@@ -118,6 +120,7 @@ class RequestGet final : public RequestBase {
   virtual void Process() {
     // proc request.
     std::string var_name = request_.varname();
+    VLOG(3) << "RequestGet " << var_name;
     auto* var = scope_->FindVar(var_name);
 
     ::grpc::ByteBuffer reply;
@@ -176,7 +179,7 @@ class RequestPrefetch final : public RequestBase {
     ::grpc::ByteBuffer reply;
 
     std::string var_name = request_->OutVarname();
-    VLOG(3) << "prefetch var " << var_name;
+    VLOG(3) << "RequestPrefetch " << var_name;
     auto var_desc = program_->Block(0).FindVar(var_name);
     framework::Scope* local_scope = &scope_->NewScope();
     auto* var = local_scope->FindVar(var_name);
@@ -307,18 +310,21 @@ void AsyncGRPCServer::HandleRequest(::grpc::ServerCompletionQueue* cq,
   bool ok = false;
 
   while (true) {
-    VLOG(3) << "HandleRequest for " << cq_name << " while in";
+    VLOG(3) << "HandleRequest for " << cq_name << " wait Next";
     if (!cq->Next(&tag, &ok)) {
       LOG(INFO) << cq_name << " CompletionQueue shutdown!";
       break;
     }
-    VLOG(3) << "HandleRequest for " << cq_name << " while after Next";
+    VLOG(3) << "HandleRequest for " << cq_name << " get Next";
 
     PADDLE_ENFORCE(tag);
+
     if (sync_mode_) {
       // FIXME(typhoonzero): de-couple the barriers with recv_op
+      VLOG(3) << "HandleRequest for " << cq_name << " before WaitCond";
       if (!is_shut_down_ && cq_name == "cq_get") WaitCond(1);
       if (!is_shut_down_ && cq_name == "cq_send") WaitCond(0);
+      VLOG(3) << "HandleRequest for " << cq_name << " after WaitCond";
     }
 
     RequestBase* base = reinterpret_cast<RequestBase*>(tag);
@@ -353,8 +359,10 @@ void AsyncGRPCServer::HandleRequest(::grpc::ServerCompletionQueue* cq,
 
 void AsyncGRPCServer::WaitCond(int cond) {
   std::unique_lock<std::mutex> lock(this->barrier_mutex_);
+  VLOG(3) << "WaitCond " << cond << " in";
   barrier_condition_.wait(lock,
                           [=] { return this->barrier_cond_step_ == cond; });
+  VLOG(3) << "WaitCond " << cond << " out";
 }
 
 void AsyncGRPCServer::SetCond(int cond) {
diff --git a/paddle/fluid/operators/listen_and_serv_op.cc b/paddle/fluid/operators/listen_and_serv_op.cc
index 36bd1d399342133d43621c3103225d30794217fe..e0b828548fea0bdce1e04bec492a40ab23fdf092 100644
--- a/paddle/fluid/operators/listen_and_serv_op.cc
+++ b/paddle/fluid/operators/listen_and_serv_op.cc
@@ -255,6 +255,7 @@ void ListenAndServOp::RunAsyncLoop(framework::Executor *executor,
   std::vector<std::future<void>> fs;
   for (auto iter = grad_to_queue.begin(); iter != grad_to_queue.end(); iter++) {
     std::string grad_name = iter->first;
+    VLOG(3) << "create async update thread for " << grad_name;
     fs.push_back(framework::Async([grad_name, &exit_flag, &executor,
                                    &grad_to_queue, &grad_to_prepared_ctx]() {
       AsyncUpdateThread(grad_name, exit_flag, grad_to_queue[grad_name],