diff --git a/flex/bin/bulk_loader.cc b/flex/bin/bulk_loader.cc
index 0d74d4b6cb97..6157640df3c9 100644
--- a/flex/bin/bulk_loader.cc
+++ b/flex/bin/bulk_loader.cc
@@ -37,7 +37,7 @@ void signal_handler(int signal) {
                << ",Clearing directory: " << work_dir << ", exiting...";
     // remove all files in work_dir
     std::filesystem::remove_all(work_dir);
-    exit(0);
+    exit(signal);
   } else {
     LOG(ERROR) << "Received unexpected signal " << signal << ", exiting...";
     exit(1);
diff --git a/flex/engines/http_server/service/hqps_service.cc b/flex/engines/http_server/service/hqps_service.cc
index 342db5fb34e7..397caceebbc8 100644
--- a/flex/engines/http_server/service/hqps_service.cc
+++ b/flex/engines/http_server/service/hqps_service.cc
@@ -99,7 +99,9 @@ void HQPSService::init(const ServiceConfig& config) {
     }
   }
   if (config.start_compiler) {
-    start_compiler_subprocess();
+    if (!start_compiler_subprocess()) {
+      LOG(FATAL) << "Failed to start compiler subprocess! exiting...";
+    }
   }
   start_time_.store(gs::GetCurrentTimeStamp());
 }
diff --git a/flex/interactive/sdk/python/test/test_driver.py b/flex/interactive/sdk/python/test/test_driver.py
index 456f08541e26..eec2d8fb69df 100644
--- a/flex/interactive/sdk/python/test/test_driver.py
+++ b/flex/interactive/sdk/python/test/test_driver.py
@@ -62,7 +62,7 @@ def test_example(self):
         self._graph_id = self.createGraph()
         self.bulkLoading()
         self.bulkLoadingUploading()
-        self.waitJobFinish()
+        self.bulkLoadingFailure()
         self.list_graph()
         self.runCypherQuery()
         self.runGremlinQuery()
@@ -157,7 +157,8 @@ def bulkLoading(self):
         )
         resp = self._sess.bulk_loading(self._graph_id, schema_mapping)
         assert resp.is_ok()
-        self._job_id = resp.get_value().job_id
+        job_id = resp.get_value().job_id
+        assert self.waitJobFinish(job_id)
 
 
     def bulkLoadingUploading(self):
@@ -191,22 +192,59 @@ def bulkLoadingUploading(self):
         )
         resp = self._sess.bulk_loading(self._graph_id, schema_mapping)
         assert resp.is_ok()
-        self._job_id = resp.get_value().job_id
+        job_id = resp.get_value().job_id
+        assert self.waitJobFinish(job_id)
 
-    def waitJobFinish(self):
-        assert self._job_id is not None
+    def waitJobFinish(self, job_id: str):
+        assert job_id is not None
         while True:
-            resp = self._sess.get_job(self._job_id)
+            resp = self._sess.get_job(job_id)
             assert resp.is_ok()
             status = resp.get_value().status
             print("job status: ", status)
             if status == "SUCCESS":
-                break
+                return True
             elif status == "FAILED":
-                raise Exception("job failed")
+                return False
             else:
                 time.sleep(1)
-        print("job finished")
+    
+    def bulkLoadingFailure(self):
+        """
+        Submit a bulk loading job with invalid data, and expect the job to fail.
+        """
+        assert os.environ.get("FLEX_DATA_DIR") is not None
+        person_csv_path = os.path.join(os.environ.get("FLEX_DATA_DIR"), "person.csv")
+        knows_csv_path = os.path.join(
+            os.environ.get("FLEX_DATA_DIR"), "person_knows_person.csv"
+        )
+        print("test bulk loading: ", self._graph_id)
+        schema_mapping = SchemaMapping(
+            loading_config=SchemaMappingLoadingConfig(
+                import_option="init",
+                format=SchemaMappingLoadingConfigFormat(type="csv"),
+            ),
+            vertex_mappings=[
+                # Intentionally use the wrong file for the vertex mapping
+                VertexMapping(type_name="person", inputs=[knows_csv_path])
+            ],
+            edge_mappings=[
+                EdgeMapping(
+                    type_triplet=EdgeMappingTypeTriplet(
+                        edge="knows",
+                        source_vertex="person",
+                        destination_vertex="person",
+                    ),
+                    # Intentionally use the wrong file for the edge mapping
+                    inputs=[person_csv_path],
+                )
+            ],
+        )
+        resp = self._sess.bulk_loading(self._graph_id, schema_mapping)
+        assert resp.is_ok()
+        job_id = resp.get_value().job_id
+        # Expect to fail
+        assert self.waitJobFinish(job_id) == False
 
     def list_graph(self):
         resp = self._sess.list_graphs()
diff --git a/flex/tests/interactive/test_call_proc.py b/flex/tests/interactive/test_call_proc.py
index d6e82c016a79..d173d222a70e 100644
--- a/flex/tests/interactive/test_call_proc.py
+++ b/flex/tests/interactive/test_call_proc.py
@@ -104,14 +104,21 @@ def callProcedureWithEncoder(self, graph_id : str):
             print("call count_vertex_num failed: ", resp.get_status_message())
             exit(1)
 
-        # plus_one, should be with id 3
-        # construct a byte array with bytes: the 4 bytes of integer 1, and a byte 3
-        byte_string = bytes([0,0,0,0,2]) # 4 bytes of integer 1, and a byte 3
+        # plus_one, should be with id 2
+        # construct a byte array with bytes: the 4 bytes of integer 1, and a byte 2
+        value = 1
+        byte_string = value.to_bytes(4, byteorder=sys.byteorder) + bytes([2])
+        # byte_string = bytes([1,0,0,0,2]) # 4 bytes of integer 1, and a byte 3
         params = byte_string.decode('utf-8')
         resp = self._sess.call_procedure_raw(graph_id, params)
         if not resp.is_ok():
             print("call plus_one failed: ", resp.get_status_message())
             exit(1)
+        res = resp.get_value()
+        assert len(res) == 4
+        # the four byte represent a integer
+        res = int.from_bytes(res, byteorder=sys.byteorder)
+        assert(res == 2)
 
 if __name__ == "__main__":
     #parse command line args