[improvement](fragment) optimize to get query context logic (apache#2…

…5621)

be/src/runtime/fragment_mgr.cpp

@@ -584,6 +584,17 @@ Status FragmentMgr::_get_query_ctx(const Params& params, TUniqueId query_id, boo
         }
         query_ctx = search->second;
     } else {
+        {
+            // Find _query_ctx_map, in case some other request has already
+            // create the query fragments context.
+            std::lock_guard<std::mutex> lock(_lock);
+            auto search = _query_ctx_map.find(query_id);
+            if (search != _query_ctx_map.end()) {
+                query_ctx = search->second;
+                return Status::OK();
+            }
+        }
+
         // This may be a first fragment request of the query.
         // Create the query fragments context.
         query_ctx = QueryContext::create_shared(query_id, params.fragment_num_on_host, _exec_env,