Different lower_case_table_names settings for server ('0') and data dictionary ('1').

[Thijmen]

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Hi there,

Not sure if this is the right repo, but here we go!

More about the problem

I created a PXC cluster with the following mysql configuration:

      [mysqld]

      lower_case_table_names=1

I created a backup and am now trying to restore that to the current running cluster, but I am getting:

│ mysqld 2025-08-22T15:08:46.301734Z 2 [Note] [MY-000000] [WSREP] wsrep_notify_cmd is not defined, skipping notification.                                                                                                                                                                         │
│ mysqld 2025-08-22T15:08:46.305437Z 3 [System] [MY-013576] [InnoDB] InnoDB initialization has started.                                                                                                                                                                                           │
│ mysqld 2025-08-22T15:08:46.685727Z 3 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.                                                                                                                                                                                             │
│ mysqld 2025-08-22T15:08:46.698213Z 3 [ERROR] [MY-011087] [Server] Different lower_case_table_names settings for server ('0') and data dictionary ('1').                                                                                                                                         │
│ mysqld 2025-08-22T15:08:46.698486Z 0 [ERROR] [MY-010020] [Server] Data Dictionary initialization failed.                                                                                                                                                                                        │
│ mysqld 2025-08-22T15:08:46.698516Z 0 [ERROR] [MY-010119] [Server] Aborting                                                                                                                                                                                                                      │
│ mysqld 2025-08-22T15:08:46.698524Z 0 [Note] [MY-000000] [WSREP] Initiating SST cancellation                                                                                                                                                                                                     │
│ mysqld 2025-08-22T15:08:48.698710Z 0 [Note] [MY-000000] [WSREP] Server status change initializing -> disconnecting                                                                                                                                                                              │
│ mysqld 2025-08-22T15:08:48.698778Z 0 [Note] [MY-000000] [WSREP] wsrep_notify_cmd is not defined, skipping notification.                                                                                                                                                                         │
│ mysqld 2025-08-22T15:08:48.698788Z 1 [Note] [MY-000000] [WSREP] rollbacker thread exiting 1                                                                                                                                                                                                     │
│ mysqld 2025-08-22T15:08:48.698827Z 0 [Note] [MY-000000] [Galera] Closing send monitor...                                                                                                                                                                                                        │
│ mysqld 2025-08-22T15:08:48.698838Z 0 [Note] [MY-000000] [Galera] Closed send monitor.                                                                                                                                                                                                           │
│ mysqld 2025-08-22T15:08:48.698850Z 0 [Note] [MY-000000] [Galera] gcomm: terminating thread                                                                                                                                                                                                      │
│ mysqld 2025-08-22T15:08:48.698870Z 0 [Note] [MY-000000] [Galera] gcomm: joining thread                                                                                                                                                                                                          │
│ mysqld 2025-08-22T15:08:48.698961Z 2 [ERROR] [MY-000000] [Galera] Exception: State wait was interrupted                                                                                                                                                                                         │
│ mysqld 2025-08-22T15:08:48.699198Z 2 [ERROR] [MY-000000] [Galera] View callback failed. This is unrecoverable, restart required. (FATAL)                                                                                                                                                        │
│ mysqld      at ../../../../percona-xtradb-cluster-galera/galera/src/replicator_smm.cpp:submit_view_info():2633                                                                                                                                                                                  │
│ mysqld 2025-08-22T15:08:48.699226Z 0 [Note] [MY-000000] [Galera] gcomm: closing backend                                                                                                                                                                                                         │
│ mysqld 2025-08-22T15:08:48.699246Z 2 [Note] [MY-000000] [Galera] ReplicatorSMM::abort()                                                                                                                                                                                                         │
│ mysqld 2025-08-22T15:08:48.699268Z 2 [Note] [MY-000000] [Galera] mysqld: Terminated.                                                                                                                                                                                                            │
│ mysqld 2025-08-22T15:08:48.699273Z 0 [Note] [MY-000000] [Galera] PC protocol downgrade 1 -> 0                                                                                                                                                                                                   │
│ mysqld 2025-08-22T15:08:48.699285Z 0 [Note] [MY-000000] [Galera] Current view of cluster as seen by this node                                                                                                                                                                                   │
│ mysqld view ((empty))                                                                                                                                                                                                                                                                           │
│ mysqld /var/lib/mysql/prepare_restored_cluster.sh: line 30:     7 Aborted                 mysqld --skip-grant-tables --skip-networking                                                                                                                                                          │
│ mysqld ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

Steps to reproduce

1. Create a cluster with lower_case_table_names=1 mysql config
2. Create a backup
3. Try to restore the backup

Versions

1. Kubernetes
2. Operator: 1.18
3. Database

Anything else?

What would be the best way to work around this, if I want to keep the lowercase option enabled?

[hors]

I think this PR #2164 should help