We will remove the parameter innodb_disallow_writes because it is badly
designed and implemented. The parameter was never allowed at startup.
It was only internally used by Galera snapshot transfer.
If a user executed
SET GLOBAL innodb_disallow_writes=ON;
the server could hang even on subsequent read operations.
During Galera snapshot transfer, we will block writes
to implement an rsync friendly snapshot, as follows:
sst_flush_tables() will acquire a global lock by executing
FLUSH TABLES WITH READ LOCK, which will block any writes
at the high level.
sst_disable_innodb_writes(), invoked via ha_disable_internal_writes(true),
will suspend or disable InnoDB background tasks or threads that could
initiate writes. As part of this, log_make_checkpoint() will be invoked
to ensure that anything in the InnoDB buf_pool.flush_list will be written
to the data files. This has the nice side effect that the Galera joiner
will avoid crash recovery.
The changes to sql/wsrep.cc and to the tests are based on a prototype
that was developed by Jan Lindström.
Reviewed by: Jan Lindström
MDEV-22140 galera.galera_drop_database MTR failed: InnoDB: MySQL is trying to drop database `fts`.`` though there are still open handles
Add wait conditions to wait that all operations are done in both
nodes.
When converting table identifiers to a new format,
some tables can be renamed twice, which subsequently
leads to the appearance of "false" auxiliary tables
belonging to another main (parent) table (which does
not actually have auxiliary tables).
This is because the table number is repeatedly added
to the aux_tables_to_rename vector inside the function
fts_check_and_drop_orphaned_tables.
To correct this error, we must add a check for the
occurrence of the table number in the aux_tables_to_rename
vector before adding a new element.
https://jira.mariadb.org/browse/MDEV-16656
