fix dblink hung and translate error

deps/oblib/src/lib/mysqlclient/ob_dblink_error_trans.cpp

@@ -51,13 +51,13 @@ int sqlclient::ObDblinkErrorTrans::external_errno_to_ob_errno(bool is_oracle_err
         external_errno <= 2075 && // you will known errno in [2000, 2075] is client error at dev.mysql.com
         (!is_oracle_err ||
         (is_oracle_err &&
-        OB_NOT_NULL(external_errmsg) &&
+        (OB_NOT_NULL(external_errmsg) && 0 != STRLEN(external_errmsg)) &&
         0 != std::memcmp(oracle_msg_prefix, external_errmsg,
         std::min(STRLEN(oracle_msg_prefix), STRLEN(external_errmsg)))))) {
       ob_errno = external_errno; // do not map, show user client errno directly.
     } else {
       ob_errno = OB_ERR_DBLINK_REMOTE_ECODE; // default ob_errno, if external_errno can not map to any valid ob_errno
-      if (OB_ISNULL(external_errmsg)) {
+      if (OB_ISNULL(external_errmsg) || 0 == STRLEN(external_errmsg)) {
         for (int i = 0; i < oceanbase::common::OB_MAX_ERROR_CODE; ++i) {
           if (external_errno == (is_oracle_err ? get_oracle_errno(i) : get_mysql_errno(i))) {
             ob_errno = -i;

deps/oblib/src/lib/mysqlclient/ob_mysql_connection.cpp

@@ -231,8 +231,11 @@ int ObMySQLConnection::connect(const char *user, const char *pass, const char *d
     MYSQL *mysql = mysql_real_connect(&mysql_, host, user, pass, db, port, NULL, 0);
     if (OB_ISNULL(mysql)) {
       ret = -mysql_errno(&mysql_);
+      char errmsg[256] = {0};
+      const char *srcmsg = mysql_error(&mysql_);
+      MEMCPY(errmsg, srcmsg, MIN(255, STRLEN(srcmsg)));
       LOG_WARN("fail to connect to mysql server", K(get_sessid()), KCSTRING(host), KCSTRING(user), KCSTRING(db), K(port),
-               "info", mysql_error(&mysql_), K(ret));
+               "info", errmsg, K(ret));
       if (OB_INVALID_ID != get_dblink_id()) {
         LOG_WARN("dblink connection error", K(ret),
                                             KP(this),
@@ -242,8 +245,9 @@ int ObMySQLConnection::connect(const char *user, const char *pass, const char *d
                                             K(user),
                                             K(db),
                                             K(host),
-                                            K(port));
+                                            K(port),
-        TRANSLATE_CLIENT_ERR_2(ret, false, mysql_error(&mysql_));
+                                            K(errmsg));
+        TRANSLATE_CLIENT_ERR_2(ret, false, errmsg);
       }
     } else {
       /*Note: mysql_real_connect() incorrectly reset the MYSQL_OPT_RECONNECT option

deps/oblib/src/lib/mysqlclient/ob_mysql_result_impl.cpp

@@ -150,7 +150,9 @@ int ObMySQLResultImpl::next()
       LOG_WARN("unexpected null ptr", K(ret));
     } else {
       ret = -mysql_errno(stmt_handler);
-      const char *errmsg = mysql_error(stmt_handler);
+      char errmsg[256] = {0};
+      const char *srcmsg = mysql_error(stmt_handler);
+      MEMCPY(errmsg, srcmsg, MIN(255, STRLEN(srcmsg)));
       ObMySQLConnection *conn = stmt_.get_connection();
       if (0 == ret) {
         ret = OB_ITER_END;

deps/oblib/src/lib/mysqlclient/ob_mysql_statement.cpp

@@ -101,8 +101,11 @@ int ObMySQLStatement::execute_update(int64_t &affected_rows)
     int64_t begin = ObTimeUtility::current_monotonic_raw_time();
     if (0 != (tmp_ret = mysql_real_query(stmt_, sql_str_, STRLEN(sql_str_)))) {
       ret = -mysql_errno(stmt_);
+      char errmsg[256] = {0};
+      const char *srcmsg = mysql_error(stmt_);
+      MEMCPY(errmsg, srcmsg, MIN(255, STRLEN(srcmsg)));
       LOG_WARN("fail to query server", "sessid",  conn_->get_sessid(), "server", stmt_->host, "port", stmt_->port,
-               "err_msg", mysql_error(stmt_), K(tmp_ret), K(ret), K(sql_str_));
+               "err_msg", errmsg, K(tmp_ret), K(ret), K(sql_str_));
       if (OB_NOT_MASTER == tmp_ret) {
         // conn -> server pool -> connection pool
         conn_->get_root()->get_root()->signal_refresh(); // refresh server pool immediately
@@ -116,10 +119,10 @@ int ObMySQLStatement::execute_update(int64_t &affected_rows)
                                             K(conn_->ping()),
                                             K(stmt_->host),
                                             K(stmt_->port),
-                                            K(mysql_error(stmt_)),
+                                            K(errmsg),
                                             K(STRLEN(sql_str_)),
                                             K(sql_str_));
-        TRANSLATE_CLIENT_ERR(ret, mysql_error(stmt_));
+        TRANSLATE_CLIENT_ERR(ret, errmsg);
       }
       if (is_need_disconnect_error(ret)) {
         conn_->set_usable(false);
@@ -150,13 +153,16 @@ ObMySQLResult *ObMySQLStatement::execute_query(bool enable_use_result)
     int64_t begin = ObTimeUtility::current_monotonic_raw_time();
     if (0 != mysql_real_query(stmt_, sql_str_, STRLEN(sql_str_))) {
       ret = -mysql_errno(stmt_);
+      char errmsg[256] = {0};
+      const char *srcmsg = mysql_error(stmt_);
+      MEMCPY(errmsg, srcmsg, MIN(255, STRLEN(srcmsg)));
       const int ER_LOCK_WAIT_TIMEOUT = -1205;
       if (ER_LOCK_WAIT_TIMEOUT == ret) {
         LOG_INFO("fail to query server", "sessid", conn_->get_sessid(), "host", stmt_->host, "port", stmt_->port,
-               "err_msg", mysql_error(stmt_), K(ret), K(sql_str_));
+               "err_msg", errmsg, K(ret), K(sql_str_));
       } else {
         LOG_WARN("fail to query server", "host", stmt_->host, "port", stmt_->port, K(conn_->get_sessid()),
-               "err_msg", mysql_error(stmt_), K(ret), K(STRLEN(sql_str_)), K(sql_str_));
+               "err_msg", errmsg, K(ret), K(STRLEN(sql_str_)), K(sql_str_));
       }
       if (OB_SUCCESS == ret) {
         ret = OB_ERR_SQL_CLIENT;
@@ -170,10 +176,10 @@ ObMySQLResult *ObMySQLStatement::execute_query(bool enable_use_result)
                                             K(conn_->ping()),
                                             K(stmt_->host),
                                             K(stmt_->port),
-                                            K(mysql_error(stmt_)),
+                                            K(errmsg),
                                             K(STRLEN(sql_str_)),
                                             K(sql_str_));
-        TRANSLATE_CLIENT_ERR(ret, mysql_error(stmt_));
+        TRANSLATE_CLIENT_ERR(ret, errmsg);
       }
       if (is_need_disconnect_error(ret)) {
         conn_->set_usable(false);

src/sql/engine/dml/ob_link_op.cpp

@@ -371,6 +371,7 @@ int ObLinkOp::init_dblink_param_ctx(dblink_param_ctx &param_ctx)
     param_ctx.dblink_id_ = dblink_id_;
     param_ctx.link_type_ = link_type_;
     param_ctx.sessid_ = sessid_;
+    param_ctx.sql_request_level_ = next_sql_req_level_;
   }
   return ret;
 }

src/sql/engine/table/ob_link_scan_op.cpp

@@ -274,6 +274,7 @@ int ObLinkScanOp::inner_open()
 int ObLinkScanOp::inner_get_next_row()
 {
   row_allocator_.reuse();
+  clear_evaluated_flag();
   return fetch_row();
 }
 
@@ -302,32 +303,6 @@ int ObLinkScanOp::fetch_row()
     if (OB_ITER_END != ret) {
       LOG_WARN("failed to get next row", K(ret));
     } else {
-      // check if connection is alive, if not, then OB_ITER_END is a fake errno
-      if (sql::DblinkGetConnType::TM_CONN == conn_type_) {
-        if (OB_ISNULL(tm_rm_connection_)) {
-          ret = OB_ERR_UNEXPECTED;
-          LOG_WARN("unexpected null ptr", K(ret));
-        } else if (OB_FAIL(tm_rm_connection_->ping())) {
-          LOG_WARN("failed to ping tm_rm_connection_", K(ret));
-        }
-      } else if (sql::DblinkGetConnType::TEMP_CONN == conn_type_) {
-        if (OB_ISNULL(reverse_link_)) {
-          ret = OB_ERR_UNEXPECTED;
-          LOG_WARN("unexpected null ptr", K(ret));
-        } else if (OB_FAIL(reverse_link_->ping())) {
-          LOG_WARN("failed to ping reverse_link_", K(ret));
-        }
-      } else {
-        if (OB_ISNULL(dblink_conn_)) {
-          ret = OB_ERR_UNEXPECTED;
-          LOG_WARN("unexpected null ptr", K(ret));
-        } else if (OB_FAIL(dblink_conn_->ping())) {
-          LOG_WARN("failed to ping dblink_conn_", K(ret));
-        }
-      }
-      if (OB_SUCC(ret)) {
-        ret = OB_ITER_END;
-      }
       reset_result();
     }
   } else {
@@ -400,6 +375,7 @@ int ObLinkScanOp::inner_get_next_batch(const int64_t max_row_cnt)
 {
   int ret = OB_SUCCESS;
   int64_t row_cnt = 0;
+  clear_evaluated_flag();
   if (iter_end_) {
     brs_.size_ = 0;
     brs_.end_ = true;
@@ -415,14 +391,15 @@ int ObLinkScanOp::inner_get_next_batch(const int64_t max_row_cnt)
           LOG_WARN("inner get next row failed", K(ret));
         }
       } else {
-        const ObIArray<ObExpr *> &output = spec_.output_;
+        const ObIArray<ObExpr *> &select_exprs =
-        for (int64_t i = 0; OB_SUCC(ret) && i < output.count(); i++) {
+          (MY_SPEC.select_exprs_.empty() ? spec_.output_ : MY_SPEC.select_exprs_);
-          ObExpr *expr = output.at(i);
+        for (int64_t i = 0; OB_SUCC(ret) && i < select_exprs.count(); i++) {
-          if (!expr->is_const_expr() &&
+          ObExpr *expr = select_exprs.at(i);
-              T_FUN_SYS_REMOVE_CONST != expr->type_ &&
+          if (expr->is_const_expr()) {
-              T_QUESTIONMARK != expr->type_ &&
+            // do nothing
-              (ob_is_string_or_lob_type(expr->datum_meta_.type_) ||
+          } else if (T_QUESTIONMARK != expr->type_ &&
-              ob_is_raw(expr->datum_meta_.type_) || ob_is_json(expr->datum_meta_.type_))) {
+                     (ob_is_string_or_lob_type(expr->datum_meta_.type_) ||
+                     ob_is_raw(expr->datum_meta_.type_) || ob_is_json(expr->datum_meta_.type_))) {
             ObDatum &datum = expr->locate_expr_datum(eval_ctx_);
             char *buf = NULL;
             if (OB_ISNULL(buf = expr->get_str_res_mem(eval_ctx_, datum.len_))) {
@@ -445,14 +422,6 @@ int ObLinkScanOp::inner_get_next_batch(const int64_t max_row_cnt)
       brs_.size_ = row_cnt;
       brs_.end_ = iter_end_;
       brs_.skip_->reset(row_cnt);
-      const ObIArray<ObExpr *> &output = spec_.output_;
-      for (int64_t i = 0; OB_SUCC(ret) && i < output.count(); i++) {
-        ObExpr *expr = output.at(i);
-        if (expr->is_batch_result()) {
-          ObBitVector &eval_flags = expr->get_evaluated_flags(eval_ctx_);
-          eval_flags.set_all(row_cnt);
-        }
-      }
     }
   }
   return ret;

src/sql/ob_sql.cpp

@@ -4762,7 +4762,6 @@ int ObSql::check_batched_multi_stmt_after_resolver(ObPlanCacheCtx &pc_ctx,
   ObPhysicalPlanCtx *plan_ctx = NULL;
   is_valid = true;
   bool has_dblink = false;
-  bool has_any_dblink = false;
   bool is_ps_ab_opt = pc_ctx.sql_ctx_.multi_stmt_item_.is_ab_batch_opt();
   if (OB_ISNULL(plan_ctx = pc_ctx.exec_ctx_.get_physical_plan_ctx())
       || OB_ISNULL(pc_ctx.sql_ctx_.session_info_)) {
@@ -4785,9 +4784,9 @@ int ObSql::check_batched_multi_stmt_after_resolver(ObPlanCacheCtx &pc_ctx,
       is_valid = false;
     }
 
-    if (OB_FAIL(ObDblinkUtils::has_reverse_link_or_any_dblink(&delupd_stmt, has_dblink, has_any_dblink))) {
+    if (OB_FAIL(ObDblinkUtils::has_reverse_link_or_any_dblink(&delupd_stmt, has_dblink, true))) {
       LOG_WARN("failed to check dblink in stmt", K(delupd_stmt), K(ret));
-    } else if (has_any_dblink) {
+    } else if (has_dblink) {
       is_valid = false;
     }