diff --git a/analytical_engine/core/fragment/dynamic_fragment.h b/analytical_engine/core/fragment/dynamic_fragment.h
index 5cea4fe47686..1fc009665707 100644
--- a/analytical_engine/core/fragment/dynamic_fragment.h
+++ b/analytical_engine/core/fragment/dynamic_fragment.h
@@ -1529,7 +1529,7 @@ class DynamicFragmentMutator {
       v_fid = partitioner.GetPartitionId(oid);
       if (modify_type == rpc::NX_ADD_NODES) {
         vm_ptr_->AddVertex(std::move(oid), gid);
-        if (!v_data.Empty()) {
+        if (v_data.IsObject() && !v_data.GetObject().ObjectEmpty()) {
           for (const auto& prop : v_data.GetObject()) {
             if (!fragment_->schema_["vertex"].HasMember(prop.name)) {
               dynamic::Value key(prop.name);
@@ -1606,7 +1606,7 @@ class DynamicFragmentMutator {
                                                   std::move(empty_data));
           }
         }
-        if (!e_data.Empty()) {
+        if (e_data.IsObject() && !e_data.GetObject().ObjectEmpty()) {
           for (const auto& prop : e_data.GetObject()) {
             if (!fragment_->schema_["edge"].HasMember(prop.name)) {
               dynamic::Value key(prop.name);
diff --git a/analytical_engine/core/fragment/fragment_reporter.h b/analytical_engine/core/fragment/fragment_reporter.h
index ad3f78156f1c..d055d6d0cf2d 100644
--- a/analytical_engine/core/fragment/fragment_reporter.h
+++ b/analytical_engine/core/fragment/fragment_reporter.h
@@ -105,7 +105,6 @@ class DynamicFragmentReporter : public grape::Communicator {
       }
       break;
     }
-
     case rpc::HAS_EDGE: {
       BOOST_LEAF_AUTO(edge_in_json, params.Get<std::string>(rpc::EDGE));
       dynamic::Value edge;
@@ -761,7 +760,9 @@ class ArrowFragmentReporter<
         }
       }
       // archive the start gid and nodes attribute array.
-      arc << gid << nodes_attr;
+      msgpack::sbuffer sbuf;
+      msgpack::pack(&sbuf, nodes_attr);
+      arc << gid << sbuf;
     }
   }
 
@@ -859,7 +860,9 @@ class ArrowFragmentReporter<
         }
       }
       // archive the start gid and edges attributes array.
-      arc << gid << adj_list;
+      msgpack::sbuffer sbuf;
+      msgpack::pack(&sbuf, adj_list);
+      arc << gid << sbuf;
     }
   }
 
diff --git a/python/graphscope/client/session.py b/python/graphscope/client/session.py
index 57d70e4d6cc4..83eb68dd7d3c 100755
--- a/python/graphscope/client/session.py
+++ b/python/graphscope/client/session.py
@@ -787,6 +787,10 @@ def info(self):
     def closed(self):
         return self._closed
 
+    @property
+    def disconnected(self):
+        return self._grpc_client is None or self._disconnected
+
     def eager(self):
         return self._config_params["mode"] == "eager"
 
diff --git a/python/graphscope/framework/app.py b/python/graphscope/framework/app.py
index 4ff78a2b34d8..ea62fd13c9ad 100644
--- a/python/graphscope/framework/app.py
+++ b/python/graphscope/framework/app.py
@@ -352,6 +352,10 @@ class name.
         # add op to dag
         self._session.dag.add_op(self._op)
 
+        # statically create the unload op to prevent a possible segmentation fault
+        # inside the protobuf library.
+        self._unload_op = unload_app(self)
+
     def __repr__(self):
         s = f"graphscope.App <type: {self._app_assets.type}, algorithm: {self._app_assets.algo} "
         s += f"bounded_graph: {str(self._graph)}>"
@@ -420,8 +424,7 @@ def _unload(self):
         Returns:
             :class:`graphscope.framework.app.UnloadedApp`: Evaluated in eager mode.
         """
-        op = unload_app(self)
-        return UnloadedApp(self._session, op)
+        return UnloadedApp(self._session, self._unload_op)
 
 
 class App(object):
diff --git a/python/graphscope/framework/context.py b/python/graphscope/framework/context.py
index 4e09e98bb356..4b6f94b66383 100644
--- a/python/graphscope/framework/context.py
+++ b/python/graphscope/framework/context.py
@@ -121,6 +121,9 @@ def __init__(self, bound_app, graph, *args, **kwargs):
         self._op = run_app(self._bound_app, *args, **kwargs)
         self._session.dag.add_op(self._op)
 
+        # statically create the unload op
+        self._unload_op = dag_utils.unload_context(self)
+
     def _check_selector(self, selector):
         raise NotImplementedError()
 
@@ -279,8 +282,7 @@ def __del__(self):
             pass
 
     def _unload(self):
-        op = dag_utils.unload_context(self)
-        return UnloadedContext(self._session, op)
+        return UnloadedContext(self._session, self._unload_op)
 
 
 class TensorContextDAGNode(BaseContextDAGNode):
diff --git a/python/graphscope/framework/graph.py b/python/graphscope/framework/graph.py
index bf3236cd3278..3b3243798608 100644
--- a/python/graphscope/framework/graph.py
+++ b/python/graphscope/framework/graph.py
@@ -292,6 +292,9 @@ def __init__(
         self._resolve_op(incoming_data)
         self._session.dag.add_op(self._op)
 
+        # statically create the unload op
+        self._unload_op = dag_utils.unload_graph(self)
+
     @property
     def v_labels(self):
         return self._v_labels
@@ -714,8 +717,7 @@ def _unload(self):
         Returns:
             :class:`graphscope.framework.graph.UnloadedGraph`: Evaluated in eager mode.
         """
-        op = dag_utils.unload_graph(self)
-        return UnloadedGraph(self._session, op)
+        return UnloadedGraph(self._session, self._unload_op)
 
     def project(
         self,
diff --git a/python/graphscope/nx/classes/cache.py b/python/graphscope/nx/classes/cache.py
index d6012ee4bc58..f961b0c0c2f1 100644
--- a/python/graphscope/nx/classes/cache.py
+++ b/python/graphscope/nx/classes/cache.py
@@ -113,9 +113,8 @@ def get_pred_attr(self, n):
     def align_node_attr_cache(self):
         """Check and align the node attr cache with node id cache"""
         if self.enable_iter_cache and self.node_attr_align is False:
-            f = self.futures["node_attr"]
-            if f is not None:
-                start_gid, self.node_attr_cache = f.result()
+            if self.futures["node_attr"] is not None:
+                start_gid, self.node_attr_cache = self.futures["node_attr"].result()
                 if start_gid == self.iter_pre_gid:
                     # align to current node_id_cache
                     if self.iter_gid != self.iter_pre_gid:
@@ -129,8 +128,7 @@ def align_node_attr_cache(self):
     def align_succ_cache(self):
         """Check and align the succ neighbor cache with node id cache"""
         if self.enable_iter_cache and self.succ_align is False:
-            f = self.futures["succ"]
-            start_gid, self.succ_cache = f.result()
+            start_gid, self.succ_cache = self.futures["succ"].result()
             if start_gid == self.iter_pre_gid:
                 if self.iter_gid != self.iter_pre_gid:
                     self._async_fetch_succ_cache(self.iter_gid)
@@ -143,9 +141,8 @@ def align_succ_cache(self):
     def align_succ_attr_cache(self):
         """Check and align the succ neighbor attr cache with node id cache"""
         if self.enable_iter_cache and self.succ_attr_align is False:
-            f = self.futures["succ_attr"]
-            if f is not None:
-                start_gid, self.succ_attr_cache = f.result()
+            if self.futures["succ_attr"] is not None:
+                start_gid, self.succ_attr_cache = self.futures["succ_attr"].result()
                 if start_gid == self.iter_pre_gid:
                     if self.iter_gid != self.iter_pre_gid:
                         self._async_fetch_succ_attr_cache(self.iter_gid)
@@ -160,8 +157,7 @@ def align_pred_cache(self):
         if self.enable_iter_cache and self.pred_align is False:
             if self.futures["pred"] is None:
                 self._async_fetch_pred_cache(self.iter_pre_gid)
-            f = self.futures["pred"]
-            start_gid, self.pred_cache = f.result()
+            start_gid, self.pred_cache = self.futures["pred"].result()
             if start_gid == self.iter_pre_gid:
                 if self.iter_gid != self.iter_pre_gid:
                     self._async_fetch_pred_cache(self.iter_gid)
@@ -177,8 +173,7 @@ def align_pred_attr_cache(self):
         if self.enable_iter_cache and self.pred_attr_align is False:
             if self.futures["pred_attr"] is None:
                 self._async_fetch_pred_attr_cache(self.iter_pre_gid)
-            f = self.futures["pred_attr"]
-            start_gid, self.pred_attr_cache = f.result()
+            start_gid, self.pred_attr_cache = self.futures["pred_attr"].result()
             if start_gid == self.iter_pre_gid:
                 if self.iter_gid != self.iter_pre_gid:
                     self._async_fetch_pred_attr_cache(self.iter_gid)
@@ -259,6 +254,9 @@ def shutdown(self):
                     pass
                 future = None
 
+    def shutdown_executor(self):
+        self.executor.shutdown(wait=True)
+
     def clear(self):
         """Clear batch cache and lru cache, reset the status and warmup again"""
         if self.enable_iter_cache:
diff --git a/python/graphscope/nx/classes/digraph.py b/python/graphscope/nx/classes/digraph.py
index 628712dfdb22..101330d65b87 100644
--- a/python/graphscope/nx/classes/digraph.py
+++ b/python/graphscope/nx/classes/digraph.py
@@ -29,7 +29,7 @@
 
 from graphscope.client.session import get_default_session
 from graphscope.client.session import get_session_by_id
-from graphscope.framework.dag_utils import copy_graph
+from graphscope.framework import dag_utils
 from graphscope.framework.errors import check_argument
 from graphscope.framework.graph_schema import GraphSchema
 from graphscope.nx import NetworkXError
@@ -295,6 +295,12 @@ def __init__(self, incoming_graph_data=None, default_label=None, **attr):
         self._saved_signature = self.signature
         self._is_client_view = False
 
+        # statically create the unload op
+        if self.op is None:
+            self._unload_op = None
+        else:
+            self._unload_op = dag_utils.unload_graph(self)
+
     @property
     @clear_mutation_cache
     @patch_docstring(RefDiGraph.adj)
@@ -494,7 +500,7 @@ def reverse(self, copy=True):
             g = self.__class__(create_empty_in_engine=False)
             g.graph = self.graph
             g.name = self.name
-            op = copy_graph(self, "reverse")
+            op = dag_utils.copy_graph(self, "reverse")
             g._op = op
             graph_def = op.eval(leaf=False)
             g._key = graph_def.key
diff --git a/python/graphscope/nx/classes/graph.py b/python/graphscope/nx/classes/graph.py
index bdfd7c4989a7..7b0feac84767 100644
--- a/python/graphscope/nx/classes/graph.py
+++ b/python/graphscope/nx/classes/graph.py
@@ -20,7 +20,6 @@
 #
 
 import copy
-import threading
 
 import orjson as json
 from networkx import freeze
@@ -369,6 +368,12 @@ def __init__(self, incoming_graph_data=None, default_label=None, **attr):
         self._saved_signature = self.signature
         self._is_client_view = False
 
+        # statically create the unload op
+        if self.op is None:
+            self._unload_op = None
+        else:
+            self._unload_op = dag_utils.unload_graph(self)
+
     def _is_gs_graph(self, incoming_graph_data):
         return (
             hasattr(incoming_graph_data, "graph_type")
@@ -376,22 +381,16 @@ def _is_gs_graph(self, incoming_graph_data):
         )
 
     def __del__(self):
-        if self._session.info["status"] != "active" or self._key is None:
+        if self._key is None or self._session.disconnected:
             return
 
-        # use thread to avoid dead-lock
-        def _del(graph):
-            # cancel cache fetch future
-            if graph.cache.enable_iter_cache:
-                graph.cache.shutdown()
-            op = dag_utils.unload_graph(graph)
-            op.eval()
-            graph._key = None
+        if self.cache.enable_iter_cache:
+            self.cache.shutdown()
+        self.cache.shutdown_executor()
 
-        if not self._is_client_view:
-            t = threading.Thread(target=_del, args=(self,))
-            t.daemon = True
-            t.start()
+        if not self._is_client_view and self._unload_op is not None:
+            self._unload_op.eval()
+        self._key = None
 
     @property
     def op(self):
diff --git a/python/graphscope/nx/tests/classes/test_graphviews.py b/python/graphscope/nx/tests/classes/test_graphviews.py
index 0aaffadda3c8..455154ab093a 100644
--- a/python/graphscope/nx/tests/classes/test_graphviews.py
+++ b/python/graphscope/nx/tests/classes/test_graphviews.py
@@ -29,7 +29,7 @@
 
 @pytest.mark.usefixtures("graphscope_session")
 class TestReverseView(test_gvs.TestReverseView):
-    def setup(self):
+    def setup_method(self):
         self.G = nx.path_graph(9, create_using=nx.DiGraph())
         self.rv = self.G.reverse(copy=False)
         # self.rv = nx.reverse_view(self.G)
@@ -67,7 +67,7 @@ def test_pickle(self):
 
 @pytest.mark.usefixtures("graphscope_session")
 class TestToDirected(test_gvs.TestToDirected):
-    def setup(self):
+    def setup_method(self):
         self.G = nx.path_graph(9)
         self.dv = nx.to_directed(self.G)
 
@@ -87,7 +87,7 @@ def test_iter(self):
 
 @pytest.mark.usefixtures("graphscope_session")
 class TestToUndirected(test_gvs.TestToUndirected):
-    def setup(self):
+    def setup_method(self):
         self.DG = nx.path_graph(9, create_using=nx.DiGraph())
         self.uv = nx.to_undirected(self.DG)
 
diff --git a/python/requirements.txt b/python/requirements.txt
index c25860bc1950..04bbb677676b 100644
--- a/python/requirements.txt
+++ b/python/requirements.txt
@@ -3,7 +3,7 @@ gremlinpython==3.6.3rc1
 grpcio>=1.49
 grpcio-tools>=1.49
 kubernetes>=24.2.0
-msgpack
+msgpack>=1.0.5
 mypy-protobuf>=3.4.0
 nest_asyncio
 networkx==2.8.0;python_version>="3.8"
diff --git a/python/setup.py b/python/setup.py
index 7a06946a86e1..827beca0d973 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -193,6 +193,7 @@ def parsed_package_data():
     return {
         "graphscope": [
             "VERSION",
+            "proto/*.pyi",
         ],
     }