[CP] reset get_sql_arena_allocator() after rpc callback finished

deps/oblib/src/rpc/frame/ob_req_transport.cpp

@@ -144,6 +144,7 @@ int async_cb(easy_request_t *r)
   if (!OB_SUCC(ret)) {
     LOG_WARN("process async request fail", K(r), K(ret), K(pcode));
   }
+  THIS_WORKER.get_sql_arena_allocator().reset();
 
   const int64_t cur_time = ObTimeUtility::current_time();
   const int64_t total_time = cur_time  - start_time;

deps/oblib/src/rpc/obrpc/ob_poc_rpc_proxy.cpp

@@ -157,6 +157,7 @@ int ObAsyncRespCallback::handle_resp(int io_err, const char* buf, int64_t sz)
   }
   pool_.destroy();
   ObCurTraceId::reset();
+  THIS_WORKER.get_sql_arena_allocator().reset();
   const int64_t cur_time = ObTimeUtility::current_time();
   const int64_t total_time = cur_time  - start_time;
   const int64_t decode_time = after_decode_time - start_time;