diff --git a/src/engine_robust.cc b/src/engine_robust.cc
index be950aa98..099e83934 100644
--- a/src/engine_robust.cc
+++ b/src/engine_robust.cc
@@ -16,7 +16,7 @@
 namespace rabit {
 namespace engine {
 AllReduceRobust::AllReduceRobust(void) {
-  result_buffer_round = 1;
+  result_buffer_round = 2;
   seq_counter = 0;
 }
 /*!
@@ -32,6 +32,7 @@ void AllReduceRobust::AllReduce(void *sendrecvbuf_,
                                 size_t count,
                                 ReduceFunction reducer) {
   bool recovered = RecoverExec(sendrecvbuf_, type_nbytes * count, 0, seq_counter);
+  utils::LogPrintf("[%d] AllReduce recovered=%d\n", rank, recovered);
   // now we are free to remove the last result, if any
   if (resbuf.LastSeqNo() != -1 &&
       (resbuf.LastSeqNo() % result_buffer_round != rank % result_buffer_round)) {
@@ -90,19 +91,21 @@ void AllReduceRobust::Broadcast(void *sendrecvbuf_, size_t total_size, int root)
 bool AllReduceRobust::LoadCheckPoint(utils::ISerializable *p_model) {
   // check if we succesfll
   if (RecoverExec(NULL, 0, ActionSummary::kLoadCheck, ActionSummary::kMaxSeq)) {
+    // reset result buffer
+    resbuf.Clear(); seq_counter = 0;
     // if loaded model is empty, this simply means we did not call checkpoint yet
     // ask caller to reinit model
     if (checked_model.length() == 0) return false;
     // load from buffer
     utils::MemoryBufferStream fs(&checked_model);
     p_model->Load(fs);
-    // reset result buffer
-    resbuf.Clear(); seq_counter = 0;
     // run another phase of check ack, if recovered from data
     utils::Assert(RecoverExec(NULL, 0, ActionSummary::kCheckAck, ActionSummary::kMaxSeq),
                   "check ack must return true");
     return true;
   } else {
+    // reset result buffer
+    resbuf.Clear(); seq_counter = 0;
     // nothing loaded, a fresh start, everyone init model
     return false;
   }
@@ -362,7 +365,7 @@ AllReduceRobust::TryDecideRouting(AllReduceRobust::RecoverType role,
       for (size_t i = 0; i < dist_in.size(); ++i) {
         if (dist_in[i].first != std::numeric_limits<int>::max()) {
           utils::Check(best_link == -2 || *p_size == dist_in[i].second,
-                       "AllReduce size inconsistent");
+                       "AllReduce size inconsistent, size=%lu, reporting=%lu", *p_size, dist_in[i].second);
           if (best_link == -2 || dist_in[i].first < dist_in[best_link].first) {
             best_link = static_cast<int>(i);
             *p_size = dist_in[i].second;
@@ -413,6 +416,7 @@ AllReduceRobust::TryRecoverData(RecoverType role,
                                 size_t size,
                                 int recv_link,
                                 const std::vector<bool> &req_in) {
+  utils::LogPrintf("[%d] recv_link=%d\n", rank, recv_link);
   // no need to run recovery for zero size message
   if (links.size() == 0 || size == 0) return kSuccess;
   utils::Assert(req_in.size() == links.size(), "TryRecoverData");
@@ -519,7 +523,7 @@ AllReduceRobust::ReturnType AllReduceRobust::TryLoadCheckPoint(bool requester) {
   if (role == kRequestData) {
     checked_model.resize(size);
   }
-  utils::Check(size != 0, "zero size check point is not allowed");
+  if (size == 0) return kSuccess;
   return TryRecoverData(role, &checked_model[0], size, recv_link, req_in);
 }
 /*!
@@ -574,6 +578,7 @@ bool AllReduceRobust::RecoverExec(void *buf, size_t size, int flag, int seqno) {
   }
   // request
   ActionSummary req(flag, seqno);  
+  utils::LogPrintf("[%d] propose flag=%d, seq=%d\n", rank, flag, seqno);  
   while (true) {
     // action
     ActionSummary act = req;    
diff --git a/test/test.sh b/test/test.sh
index 30d6bbca7..9b27abb8b 100755
--- a/test/test.sh
+++ b/test/test.sh
@@ -5,4 +5,4 @@ then
     exit -1
 fi
 
-../submit_job_tcp.py $1 test_recover $2 $3 $4
+../submit_job_tcp.py $1 test_recover $2 $3 $4 $5
diff --git a/test/test_recover.cpp b/test/test_recover.cpp
index 81e81c6fa..9267cdca5 100644
--- a/test/test_recover.cpp
+++ b/test/test_recover.cpp
@@ -103,20 +103,20 @@ int main(int argc, char *argv[]) {
       if (!rabit::LoadCheckPoint(&model)) {
         model.InitModel();
       }      
-      utils::LogPrintf("[%d] start at %s\n", rank, name.c_str());
+      utils::LogPrintf("[%d/%d] start at %s\n", rank, ntrial, name.c_str());
       TestMax(mock, n, ntrial);
-      utils::LogPrintf("[%d] !!!TestMax pass\n", rank);  
+      utils::LogPrintf("[%d/%d] !!!TestMax pass\n", rank, ntrial);  
       TestSum(mock, n, ntrial);
-      utils::LogPrintf("[%d] !!!TestSum pass\n", rank);
-      
-      for (int i = 0; i < nproc; i += nproc / 3) {
+      utils::LogPrintf("[%d/%d] !!!TestSum pass\n", rank, ntrial);
+      int step = std::max(nproc / 3, 1);
+      for (int i = 0; i < nproc; i += step) {
         TestBcast(mock, n, i, ntrial);
       }
       utils::LogPrintf("[%d] !!!TestBcast pass\n", rank);
       // reach here
       break;
     } catch (MockException &e) {
-      rabit::engine::GetEngine()->InitAfterException();
+      //rabit::engine::GetEngine()->InitAfterException();
       ++ntrial;
     }
   }