From 4087ab08b4f7e2a3ca556182f09078ba2dbfda31 Mon Sep 17 00:00:00 2001 From: Ran Date: Wed, 31 May 2023 10:14:41 +0800 Subject: [PATCH] *: add a limit for smooth upgrade (#13713) --- smooth-upgrade-tidb.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/smooth-upgrade-tidb.md b/smooth-upgrade-tidb.md index 0e201c5d113b9..f73a2a62b1bf1 100644 --- a/smooth-upgrade-tidb.md +++ b/smooth-upgrade-tidb.md @@ -39,6 +39,8 @@ When using the smooth upgrade feature, note the following limitations. * Before the upgrade, if there is a canceling DDL job in the cluster, that is, an ongoing DDL job is being canceled by a user, because the job in the canceling state cannot be paused, TiDB will retry canceling the job. If the retry fails, an error is reported and the upgrade is exited. +* In scenarios of using TiUP to upgrade TiDB, because TiUP upgrade has a timeout period, if the cluster has a large number of DDL jobs (more than 300) waiting in queues before the upgrade, the upgrade might fail. + * During the upgrade, the following operations are not allowed: * Run DDL operations on system tables (`mysql.*`, `information_schema.*`, `performance_schema.*`, and `metrics_schema.*`).