diff --git a/server/gameserver/CMakeLists.txt b/server/gameserver/CMakeLists.txt
index e9f0966..1bf75ad 100644
--- a/server/gameserver/CMakeLists.txt
+++ b/server/gameserver/CMakeLists.txt
@@ -104,7 +104,8 @@ if (CMAKE_BUILD_TYPE STREQUAL "Debug")
     curl
     hiredis
     tinyxml2
-#    tcmalloc
+    #tcmalloc
+    backtrace
     behaviac_gcc_debug
     )
 else()
diff --git a/server/gameserver/app.cc b/server/gameserver/app.cc
index 92b3212..d5e1854 100644
--- a/server/gameserver/app.cc
+++ b/server/gameserver/app.cc
@@ -35,6 +35,8 @@
 
 #include "collider.h"
 
+#include "tracemgr.h"
+
 struct MsgNode
 {
     SocketFrom_e sockfrom;
@@ -174,6 +176,9 @@ bool App::Init(int argc, char* argv[])
 
     srand(time(nullptr));
     InitLog();
+#ifdef DEBUG
+    TraceMgr::Instance()->Init("gameserver2005");
+#endif
     PerfMonitor::Instance()->Init();
     HandlerMgr::Instance()->Init();
     a8::Timer::Instance()->Init();
@@ -235,6 +240,9 @@ void App::UnInit()
     HandlerMgr::Instance()->UnInit();
     PerfMonitor::Instance()->UnInit();
     f8::TGLog::Instance()->UnInit();
+#ifdef DEBUG
+    TraceMgr::Instance()->UnInit();
+#endif
     UnInitLog();
 
     FreeSocketMsgQueue();
diff --git a/server/gameserver/human.cc b/server/gameserver/human.cc
index 548c8da..e0f5cca 100644
--- a/server/gameserver/human.cc
+++ b/server/gameserver/human.cc
@@ -35,6 +35,7 @@
 #include "team.h"
 #include "explosion.h"
 #include "killmgr.h"
+#include "tracemgr.h"
 
 const int kReviveTimeAdd = 12;
 const int kSkinNum = 4;
@@ -821,6 +822,24 @@ void Human::AddToNewObjects(Entity* entity)
 
 void Human::AddToPartObjects(Entity* entity)
 {
+#ifdef DEBUG1
+    {
+        if (!follow_target_) {
+            for (Human* ob : observers_) {
+                if (ob->IsPlayer()) {
+                    TraceMgr::Instance()->Trace
+                        (a8::Format("add part_object %d->%d frameno:%d %d",
+                                    {
+                                     GetUniId(),
+                                     ob->GetUniId(),
+                                     room->GetFrameNo(),
+                                     entity->GetUniId()
+                                    }));
+                }
+            }
+        }
+    }
+#endif
     PartObject part_obj;
     part_obj.entity_uniid = entity->GetUniId();
     part_obj.entity_type = entity->GetEntityType();
@@ -834,11 +853,19 @@ void Human::AddToPartObjects(Entity* entity)
 void Human::RemovePartObjects(Entity* entity)
 {
     #ifdef DEBUG
-    SendDebugMsg(a8::Format("view_debug frameno:%d remove_part_obj:%d",
-                            {
-                             room->GetFrameNo(),
-                             entity->GetUniId()
-                            }));
+    if (!follow_target_) {
+        for (Human* observer : observers_) {
+            if (observer->IsPlayer()) {
+                observer->SendDebugMsg(a8::Format("view_debug %d->%d frameno:%d remove_part_obj:%d",
+                                                  {
+                                                   GetUniId(),
+                                                   observer->GetUniId(),
+                                                   room->GetFrameNo(),
+                                                   entity->GetUniId()
+                                                  }));
+            }
+        }
+    }
     #endif
     framedata_.part_objects.erase(entity->GetUniId());
     entity->OnRemoveFromTargetPartObject(this);
@@ -1357,12 +1384,23 @@ void Human::FollowTarget(Human* target)
     if (target == this) {
         return;
     }
+    int pre_uniid = 0;
     if (follow_target_) {
+        pre_uniid = follow_target_->GetUniId();
         follow_target_->RemoveObserver(this);
     }
     target->AddObserver(this);
     follow_target_ = target;
     follow_synced_active_player = false;
+#ifdef DEBUG
+    SendDebugMsg(a8::Format("观战 watch %d->%d->%d frameno:%d",
+                            {
+                             room->GetFrameNo(),
+                             pre_uniid,
+                             follow_target_->GetUniId(),
+                             GetUniId()
+                            }));
+#endif
 }
 
 void Human::SendDebugMsg(const std::string& debug_msg)
@@ -2404,7 +2442,24 @@ void Human::NotifyObservers(cs::SMUpdate* msg, cs::MFActivePlayerData* active_pl
 #endif
                         }
                     }
+#ifdef DEBUG
+                    observer->SendDebugMsg(a8::Format("观战 notify %d->%d frameno:%d part_obj:%d",
+                                                      {
+                                                       GetUniId(),
+                                                       observer->GetUniId(),
+                                                       room->GetFrameNo(),
+                                                       pair.second.entity_uniid
+                                                      }));
+#endif
                 }
+#ifdef DEBUG
+                observer->SendDebugMsg(a8::Format("观战 notify %d->%d frameno:%d",
+                                                  {
+                                                   GetUniId(),
+                                                   observer->GetUniId(),
+                                                   room->GetFrameNo()
+                                                  }));
+#endif
             }
             observer->follow_synced_active_player = true;
         } else {
@@ -3686,7 +3741,6 @@ void Human::DoFollow(int target_id)
 void Human::OnWatcherDie(Human* watcher)
 {
     if (follow_target_ == watcher) {
-        follow_target_ = nullptr;
         if (socket_handle != 0 && IsPlayer()) {
             ((Player*)this)->AsyncRequestWatchWar(true);
         }
diff --git a/server/gameserver/tracemgr.cc b/server/gameserver/tracemgr.cc
new file mode 100644
index 0000000..06e3715
--- /dev/null
+++ b/server/gameserver/tracemgr.cc
@@ -0,0 +1,49 @@
+#include "precompile.h"
+
+#include "tracemgr.h"
+
+#ifdef DEBUG
+
+static void ErrorCallback(void *data, const char *msg, int errnum)
+{
+    abort();
+}
+
+static int SimpleCallback(void *data, uintptr_t pc)
+{
+    return 0;
+}
+
+void TraceMgr::Init(const std::string& filename)
+{
+    filename_ = filename;
+    state_ = backtrace_create_state(filename_.c_str(),
+                                    0,
+                                    ErrorCallback,
+                                    nullptr);
+    if (!state_) {
+        abort();
+    }
+    log_file_ = fopen("backtrace.log", "w");
+    if (!log_file_) {
+        abort();
+    }
+}
+
+void TraceMgr::UnInit()
+{
+    if (log_file_) {
+        fclose(log_file_);
+        log_file_ = nullptr;
+    }
+}
+
+void TraceMgr::Trace(const std::string& hint)
+{
+    fputs(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n", log_file_);
+    fputs(hint.c_str(), log_file_);
+    backtrace_print(state_, 0, log_file_);
+    fputs("<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<\n", log_file_);
+}
+
+#endif
diff --git a/server/gameserver/tracemgr.h b/server/gameserver/tracemgr.h
new file mode 100644
index 0000000..a490e53
--- /dev/null
+++ b/server/gameserver/tracemgr.h
@@ -0,0 +1,27 @@
+#pragma once
+
+#ifdef DEBUG
+
+#include <backtrace.h>
+
+class TraceMgr : public a8::Singleton<TraceMgr>
+{
+
+ private:
+    TraceMgr() {};
+    friend class a8::Singleton<TraceMgr>;
+
+ public:
+
+    void Init(const std::string& filename);
+    void UnInit();
+
+    void Trace(const std::string& hint);
+
+ private:
+    std::string filename_;
+    backtrace_state* state_ = nullptr;
+    FILE* log_file_ = nullptr;
+};
+
+#endif