From cd4fb2b9c3d2f06a0cc040471096b2f305e1ebe8 Mon Sep 17 00:00:00 2001 From: Airton Lastori <6343615+alastori@users.noreply.github.com> Date: Fri, 20 Mar 2026 17:07:04 -0400 Subject: [PATCH 1/2] add LOCK TABLES note for managed MySQL sources in OSS DM docs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When migrating from managed MySQL services (RDS, Aurora) where FTWRL is restricted, DM's consistency=auto mode falls back to LOCK TABLES. Added conditional privilege documentation to dm-worker-intro, dm-precheck, and quick-start-with-dm. Confirmed with Minghao Guo: FTWRL→LOCK TABLES fallback is by design, Cloud DM defaults to consistency=auto. Lab evidence: https://github.com/alastori/tidb-sandbox/tree/main/labs/dm/lab-06-lock-tables-privilege Related: https://github.com/pingcap/docs/pull/22598 (Cloud DM docs) Related: https://tidb.atlassian.net/browse/DM-12687 (pre-check improvement) --- dm/dm-precheck.md | 6 +++++- dm/dm-worker-intro.md | 10 ++++++++++ dm/quick-start-with-dm.md | 4 ++++ 3 files changed, 19 insertions(+), 1 deletion(-) diff --git a/dm/dm-precheck.md b/dm/dm-precheck.md index 274581f8caffd..fd24b87dce39e 100644 --- a/dm/dm-precheck.md +++ b/dm/dm-precheck.md @@ -68,7 +68,11 @@ For the full data migration mode (`task-mode: full`), in addition to the [common - SELECT permission on INFORMATION_SCHEMA and dump tables - RELOAD permission if `consistency=flush` - - LOCK TABLES permission on the dump tables if `consistency=flush/lock` + - LOCK TABLES permission on the dump tables if `consistency=lock` + + > **Note:** + > + > When `consistency=auto` (the default), DM first attempts `FLUSH TABLES WITH READ LOCK` and falls back to `LOCK TABLES` if FTWRL is unavailable. This fallback commonly occurs on managed MySQL services (such as Amazon RDS, Aurora, Azure Database for MySQL, or Google Cloud SQL) where FTWRL is not permitted. In this case, the `LOCK TABLES` privilege is required at runtime, but the precheck does not currently validate it. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for the full privilege list. * (Mandatory) Consistency of upstream MySQL multi-instance sharding tables diff --git a/dm/dm-worker-intro.md b/dm/dm-worker-intro.md index a6328065ee005..8530591c71bc7 100644 --- a/dm/dm-worker-intro.md +++ b/dm/dm-worker-intro.md @@ -51,6 +51,10 @@ The upstream database (MySQL/MariaDB) user must have the following privileges: | `REPLICATION SLAVE` | Global | | `REPLICATION CLIENT` | Global | +> **Note:** +> +> If migrating from a managed MySQL service (such as Amazon RDS, Aurora, Azure Database for MySQL, or Google Cloud SQL) where `FLUSH TABLES WITH READ LOCK` is not permitted, the user also needs the `LOCK TABLES` privilege. DM's default `consistency=auto` mode falls back to `LOCK TABLES` for data consistency when FTWRL is unavailable. + If you need to migrate the data from `db1` to TiDB, execute the following `GRANT` statement: ```sql @@ -58,6 +62,12 @@ GRANT RELOAD,REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'your_user'@'your_w GRANT SELECT ON db1.* TO 'your_user'@'your_wildcard_of_host'; ``` +For managed MySQL services where FTWRL is not permitted, also grant `LOCK TABLES`: + +```sql +GRANT LOCK TABLES ON db1.* TO 'your_user'@'your_wildcard_of_host'; +``` + If you also need to migrate the data from other databases into TiDB, make sure the same privileges are granted to the user of the respective databases. ### Downstream database user privileges diff --git a/dm/quick-start-with-dm.md b/dm/quick-start-with-dm.md index f8fe19ab001b2..80d6142b3ec5f 100644 --- a/dm/quick-start-with-dm.md +++ b/dm/quick-start-with-dm.md @@ -90,6 +90,8 @@ You can use Docker to quickly deploy a test MySQL 8.0 instance. GRANT PROCESS, BACKUP_ADMIN, RELOAD, REPLICATION SLAVE, REPLICATION CLIENT, SELECT ON *.* TO 'tidb-dm'@'%'; ``` + > **Note:** If your MySQL source is a managed service (such as Amazon RDS, Aurora, Azure Database for MySQL, or Google Cloud SQL), also grant `LOCK TABLES`. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for details. + 4. Create sample data: ```sql @@ -147,6 +149,8 @@ On macOS, you can quickly install and start MySQL 8.0 locally using [Homebrew](h GRANT PROCESS, BACKUP_ADMIN, RELOAD, REPLICATION SLAVE, REPLICATION CLIENT, SELECT ON *.* TO 'tidb-dm'@'%'; ``` + > **Note:** If your MySQL source is a managed service (such as Amazon RDS, Aurora, Azure Database for MySQL, or Google Cloud SQL), also grant `LOCK TABLES`. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for details. + 6. Create sample data: ```sql From 39d99df9ee9b679de703ca7eb5030f22e127b927 Mon Sep 17 00:00:00 2001 From: Airton Lastori <6343615+alastori@users.noreply.github.com> Date: Fri, 20 Mar 2026 17:59:25 -0400 Subject: [PATCH 2/2] add ApsaraDB RDS for MySQL to managed provider list --- dm/dm-precheck.md | 2 +- dm/dm-worker-intro.md | 2 +- dm/quick-start-with-dm.md | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/dm/dm-precheck.md b/dm/dm-precheck.md index fd24b87dce39e..ebe11a2eeef0c 100644 --- a/dm/dm-precheck.md +++ b/dm/dm-precheck.md @@ -72,7 +72,7 @@ For the full data migration mode (`task-mode: full`), in addition to the [common > **Note:** > - > When `consistency=auto` (the default), DM first attempts `FLUSH TABLES WITH READ LOCK` and falls back to `LOCK TABLES` if FTWRL is unavailable. This fallback commonly occurs on managed MySQL services (such as Amazon RDS, Aurora, Azure Database for MySQL, or Google Cloud SQL) where FTWRL is not permitted. In this case, the `LOCK TABLES` privilege is required at runtime, but the precheck does not currently validate it. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for the full privilege list. + > When `consistency=auto` (the default), DM first attempts `FLUSH TABLES WITH READ LOCK` and falls back to `LOCK TABLES` if FTWRL is unavailable. This fallback commonly occurs on managed MySQL services (such as Amazon RDS, Aurora, ApsaraDB RDS for MySQL, Azure Database for MySQL, or Google Cloud SQL) where FTWRL is not permitted. In this case, the `LOCK TABLES` privilege is required at runtime, but the precheck does not currently validate it. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for the full privilege list. * (Mandatory) Consistency of upstream MySQL multi-instance sharding tables diff --git a/dm/dm-worker-intro.md b/dm/dm-worker-intro.md index 8530591c71bc7..dc70efc678853 100644 --- a/dm/dm-worker-intro.md +++ b/dm/dm-worker-intro.md @@ -53,7 +53,7 @@ The upstream database (MySQL/MariaDB) user must have the following privileges: > **Note:** > -> If migrating from a managed MySQL service (such as Amazon RDS, Aurora, Azure Database for MySQL, or Google Cloud SQL) where `FLUSH TABLES WITH READ LOCK` is not permitted, the user also needs the `LOCK TABLES` privilege. DM's default `consistency=auto` mode falls back to `LOCK TABLES` for data consistency when FTWRL is unavailable. +> If migrating from a managed MySQL service (such as Amazon RDS, Aurora, ApsaraDB RDS for MySQL, Azure Database for MySQL, or Google Cloud SQL) where `FLUSH TABLES WITH READ LOCK` is not permitted, the user also needs the `LOCK TABLES` privilege. DM's default `consistency=auto` mode falls back to `LOCK TABLES` for data consistency when FTWRL is unavailable. If you need to migrate the data from `db1` to TiDB, execute the following `GRANT` statement: diff --git a/dm/quick-start-with-dm.md b/dm/quick-start-with-dm.md index 80d6142b3ec5f..37a0640940bdc 100644 --- a/dm/quick-start-with-dm.md +++ b/dm/quick-start-with-dm.md @@ -90,7 +90,7 @@ You can use Docker to quickly deploy a test MySQL 8.0 instance. GRANT PROCESS, BACKUP_ADMIN, RELOAD, REPLICATION SLAVE, REPLICATION CLIENT, SELECT ON *.* TO 'tidb-dm'@'%'; ``` - > **Note:** If your MySQL source is a managed service (such as Amazon RDS, Aurora, Azure Database for MySQL, or Google Cloud SQL), also grant `LOCK TABLES`. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for details. + > **Note:** If your MySQL source is a managed service (such as Amazon RDS, Aurora, ApsaraDB RDS for MySQL, Azure Database for MySQL, or Google Cloud SQL), also grant `LOCK TABLES`. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for details. 4. Create sample data: @@ -149,7 +149,7 @@ On macOS, you can quickly install and start MySQL 8.0 locally using [Homebrew](h GRANT PROCESS, BACKUP_ADMIN, RELOAD, REPLICATION SLAVE, REPLICATION CLIENT, SELECT ON *.* TO 'tidb-dm'@'%'; ``` - > **Note:** If your MySQL source is a managed service (such as Amazon RDS, Aurora, Azure Database for MySQL, or Google Cloud SQL), also grant `LOCK TABLES`. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for details. + > **Note:** If your MySQL source is a managed service (such as Amazon RDS, Aurora, ApsaraDB RDS for MySQL, Azure Database for MySQL, or Google Cloud SQL), also grant `LOCK TABLES`. See [DM-worker privileges](/dm/dm-worker-intro.md#upstream-database-user-privileges) for details. 6. Create sample data: