patch 4.0

src/observer/mysql/ob_async_plan_driver.cpp

@@ -25,57 +25,77 @@
 #include "observer/mysql/obmp_query.h"
 #include "observer/mysql/ob_mysql_end_trans_cb.h"
 
-namespace oceanbase {
+namespace oceanbase
+{
 using namespace common;
 using namespace sql;
 using namespace obmysql;
-namespace observer {
+namespace observer
+{
 
-ObAsyncPlanDriver::ObAsyncPlanDriver(const ObGlobalContext& gctx, const ObSqlCtx& ctx, sql::ObSQLSessionInfo& session,
-    ObQueryRetryCtrl& retry_ctrl, ObIMPPacketSender& sender)
-    : ObQueryDriver(gctx, ctx, session, retry_ctrl, sender)
-{}
+ObAsyncPlanDriver::ObAsyncPlanDriver(const ObGlobalContext &gctx,
+                                     const ObSqlCtx &ctx,
+                                     sql::ObSQLSessionInfo &session,
+                                     ObQueryRetryCtrl &retry_ctrl,
+                                     ObIMPPacketSender &sender,
+                                     bool is_prexecute)
+    : ObQueryDriver(gctx, ctx, session, retry_ctrl, sender, is_prexecute)
+{
+}
 
 ObAsyncPlanDriver::~ObAsyncPlanDriver()
-{}
-
-int ObAsyncPlanDriver::response_result(ObMySQLResultSet& result)
 {
+}
+
+int ObAsyncPlanDriver::response_result(ObMySQLResultSet &result)
+{
+  ObActiveSessionGuard::get_stat().in_sql_execution_ = true;
   int ret = OB_SUCCESS;
-  ObCurTraceId::TraceId* cur_trace_id = NULL;
+  // result.open 后 pkt_param 所需的 last insert id 等各项参数都已经计算完毕
+  // 对于异步增删改的情况，需要提前update last insert id，以确保回调pkt_param参数正确
+  // 后续result set close的时候，还会进行一次store_last_insert_id的调用
+  ObCurTraceId::TraceId *cur_trace_id = NULL;
   if (OB_ISNULL(cur_trace_id = ObCurTraceId::get_trace_id())) {
     ret = OB_ERR_UNEXPECTED;
     LOG_ERROR("current trace id is NULL", K(ret));
-  } else if (OB_FAIL(result.sync_open())) {
+  } else if (OB_FAIL(result.open())) {
     LOG_WARN("failed to do result set open", K(ret));
-  } else if (OB_FAIL(result.update_last_insert_id())) {
+  } else if (OB_FAIL(result.update_last_insert_id_to_client())) {
     LOG_WARN("failed to update last insert id after open", K(ret));
   } else {
-    ObSqlEndTransCb& sql_end_cb = session_.get_mysql_end_trans_cb();
+    ObSqlEndTransCb &sql_end_cb = session_.get_mysql_end_trans_cb();
     ObEndTransCbPacketParam pkt_param;
-    if (OB_FAIL(sql_end_cb.set_packet_param(pkt_param.fill(result, session_, *cur_trace_id)))) {
-      LOG_ERROR("fail set packet param", K(ret));
+    if (is_prexecute_ && OB_FAIL(sender_.flush_buffer(false))) {
+      LOG_WARN("flush buffer fail before send async ok packet.", K(ret));
+    } else if (OB_FAIL(sql_end_cb.set_packet_param(
+                  pkt_param.fill(result, session_, *cur_trace_id)))) {
+        LOG_ERROR("fail set packet param", K(ret));
     } else {
       result.set_end_trans_async(true);
-      THIS_WORKER.disable_retry();
     }
   }
 
-  if (!OB_SUCC(ret)) {
+  if (OB_SUCCESS != ret) {
+    // 如果try_again为true，说明这条SQL需要重做。考虑到重做之前我们需要回滚整个事务，会调用EndTransCb
+    // 所以这里设置一个标记，告诉EndTransCb这种情况下不要给客户端回包。
     int cli_ret = OB_SUCCESS;
     retry_ctrl_.test_and_save_retry_state(gctx_, ctx_, result, ret, cli_ret);
     if (retry_ctrl_.need_retry()) {
       result.set_end_trans_async(false);
     }
+    // close背后的故事：
+    // if (try_again) {
+    //   result.close()结束后返回到这里，然后运行重试逻辑
+    // } else {
+    //   result.close()结束后，process流程应该干净利落地结束，有什么事留到callback里面做
+    // }
     int cret = result.close();
     if (retry_ctrl_.need_retry()) {
-      LOG_WARN("result set open failed, will retry", K(ret), K(cli_ret), K(cret), K(retry_ctrl_.need_retry()));
+      LOG_WARN("result set open failed, will retry",
+               K(ret), K(cli_ret), K(cret), K(retry_ctrl_.need_retry()));
     } else {
       LOG_WARN("result set open failed, let's leave process(). EndTransCb will clean this mess",
-          K(ret),
-          K(cli_ret),
-          K(cret),
-          K(retry_ctrl_.need_retry()));
+               K(ret), K(cli_ret), K(cret), K(retry_ctrl_.need_retry()));
     }
     ret = cli_ret;
   } else if (result.is_with_rows()) {
@@ -85,21 +105,39 @@ int ObAsyncPlanDriver::response_result(ObMySQLResultSet& result)
     LOG_WARN("result close failed, let's leave process(). EndTransCb will clean this mess", K(ret));
   }
 
+  // 仅在end_trans执行后（无论成功与否）才会设置，意味着一定会回调
+  // 之所以设计这么一个值，是因为open/close可能“半途而废”，根本没走到
+  // end_trans()接口。这个变量相当于一个最终的确认。
   bool async_resp_used = result.is_async_end_trans_submitted();
   if (async_resp_used && retry_ctrl_.need_retry()) {
     LOG_ERROR("the async request is ok, couldn't send request again");
   }
-  LOG_DEBUG("test if async end trans submitted", K(ret), K(async_resp_used), K(retry_ctrl_.need_retry()));
+  LOG_DEBUG("test if async end trans submitted",
+            K(ret), K(async_resp_used), K(retry_ctrl_.need_retry()));
 
+  //if the error code is ob_timeout, we add more error info msg for dml query.
+  if (OB_TIMEOUT == ret) {
+    LOG_USER_ERROR(OB_TIMEOUT, THIS_WORKER.get_timeout_ts() - session_.get_query_start_time());
+  }
+
+  // 错误处理，没有走异步的时候负责回错误包
   if (!OB_SUCC(ret) && !async_resp_used && !retry_ctrl_.need_retry()) {
     int sret = OB_SUCCESS;
     bool is_partition_hit = session_.get_err_final_partition_hit(ret);
     if (OB_SUCCESS != (sret = sender_.send_error_packet(ret, NULL, is_partition_hit))) {
       LOG_WARN("send error packet fail", K(sret), K(ret));
     }
+    //根据与事务层的约定，无论end_participant和end_stmt是否成功，
+    //判断事务commit或回滚是否成功都只看最后的end_trans是否成功，
+    //而SQL是要保证一定要调到end_trans的，调end_trans的时候判断了是否需要断连接，
+    //所以这里不需要判断是否需要断连接了
   }
+  ObActiveSessionGuard::get_stat().in_sql_execution_ = false;
   return ret;
 }
 
-}  // namespace observer
-}  // namespace oceanbase
+
+}/* ns observer*/
+}/* ns oceanbase */
+
+