The background drop table queue in InnoDB is a work-around for
cases where the SQL layer is requesting DDL on tables on which
transactional locks exist.
One such case are XA transactions. Our test case exploits the
fact that the recovery of XA PREPARE transactions will
only resurrect InnoDB table locks, but not MDL that should
block any concurrent DDL.
srv_shutdown_t: Introduce the srv_shutdown_state=SRV_SHUTDOWN_INITIATED
for the initial part of shutdown, to wait for the background drop
table queue to be emptied.
srv_shutdown_bg_undo_sources(): Assign
srv_shutdown_state=SRV_SHUTDOWN_INITIATED
before waiting for the background drop table queue to be emptied.
row_drop_tables_for_mysql_in_background(): On slow shutdown, if
no active transactions exist (excluding ones that are in
XA PREPARE state), skip any tables on which locks exist.
row_drop_table_for_mysql(): Do not unnecessarily attempt to
drop InnoDB persistent statistics for tables that have
already been added to the background drop table queue.
row_mysql_close(): Relax an assertion, and free all memory
even if innodb_force_recovery=2 would prevent the background
drop table queue from being emptied.
When MySQL 5.0.3 introduced InnoDB support for two-phase commit,
it also introduced the questionable logic to roll back XA PREPARE
transactions on startup when innodb_force_recovery is 1 or 2.
Remove this logic in order to avoid unwanted side effects when
innodb_force_recovery is being set for other reasons. That is,
XA PREPARE transactions will always remain in that state until
InnoDB receives an explicit XA ROLLBACK or XA COMMIT request
from the upper layer.
At the time the logic was introduced in MySQL 5.0.3, there already
was a startup parameter that is the preferred way of achieving
the behaviour: --tc-heuristic-recover=ROLLBACK.
namely, restart_mysqld_with_option.inc and kill_and_restart_mysqld.inc -
use restart_mysqld.inc instead.
Also remove innodb_wl6501_crash_stripped.inc that wasn't used anywhere.
As noted in MDEV-8841, any test that kills the server must issue
FLUSH TABLES, so that tables of crash-unsafe storage engines will
not be corrupted. Consistently issue this statement after any
call mtr.add_suppression() calls.
Also, do not invoke shutdown_server directly, but use helpers instead.
As noted in MDEV-8841, any test that kills the server must issue
FLUSH TABLES, so that tables of crash-unsafe storage engines will
not be corrupted. Consistently issue this statement after any
call mtr.add_suppression() calls.
Also, do not invoke shutdown_server directly, but use helpers instead.
contains a bad and a good copy
Clean up the InnoDB doublewrite buffer code.
buf_dblwr_init_or_load_pages(): Do not add empty pages to the buffer.
buf_dblwr_process(): Do consider changes to pages that are all zero.
Do not abort when finding a corrupted copy of a page in the doublewrite
buffer, because there could be multiple copies in the doublewrite buffer,
and only one of them needs to be good.
The real problem is that when innodb.xa_recovery test intentionally
crashes the server, system tables can be opened and marked as crashed,
and the next test in line gets blamed for the error which appears
in the error log.
Fixed by flushing the tables before crashing the server
if XA PREPARE transactions hold explicit locks.
innobase_shutdown_for_mysql(): Call trx_sys_close() before lock_sys_close()
(and dict_close()) so that trx_free_prepared() will see all locks intact.
RB: 8561
Reviewed-by: Vasil Dimov <vasil.dimov@oracle.com>
