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
Task 1:
If table is added to list using option TL_OPTION_SEQUENCE (done when we
have sequence functions) then then we are dealing with sequence instead
of table. So global table list will have sequence set to true. This is
used to check and give correct error message about unknown sequence
instead of table doesn't exist.
First, we do not add VERS_UPDATE_UNVERSIONED_FLAG for system field and
that fixes SHOW CREATE result.
Second, we have to call check_sys_fields() for any CREATE TABLE and
there correct type is checked for system fields.
Third, we update system_time like as_row structures for ALTER TABLE
and that makes check_sys_fields() happy for ALTER TABLE when we make
system fields hidden.
LIMIT history switching requires the number of history partitions to
be marked for read: from first to last non-empty plus one empty. The
least we can do is to fail with error message if the needed partition
was not marked for read. As this is handler interface we require new
handler error code to display user-friendly error message.
Switching by INTERVAL works out-of-the-box with
ER_ROW_DOES_NOT_MATCH_GIVEN_PARTITION_SET error.
MDEV-22617 Galera node crashes when trying to log to slow_log table in
streaming replication mode
Other things:
- Changed name of wsrep_after_row(two arguments) to
wsrep_after_row_internal(one argument) to not depended on the
function signature with unused arguments.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
Added test case
The old code erroneously used default_charset_info to compare field names.
default_charset_info can point to any arbitrary collation,
including ucs2*, utf16*, utf32*, including those that do not
support strcasecmp().
my_charset_utf8mb4_unicode_ci, which is used in this scenario:
CREATE TABLE t1 ENGINE=InnoDB WITH SYSTEM VERSIONING AS SELECT 0;
does not support strcasecmp().
Fixing the code to use Lex_ident::streq(), which uses
system_charset_info instead of default_charset_info.
versioning_fields flag indicates that any columns were specified WITH
SYSTEM VERSIONING. In that case we imply WITH SYSTEM VERSIONING for
the whole table and WITHOUT SYSTEM VERSIONING for the other columns.
Mutex order violation when wsrep bf thread kills a conflicting trx,
the stack is
wsrep_thd_LOCK()
wsrep_kill_victim()
lock_rec_other_has_conflicting()
lock_clust_rec_read_check_and_lock()
row_search_mvcc()
ha_innobase::index_read()
ha_innobase::rnd_pos()
handler::ha_rnd_pos()
handler::rnd_pos_by_record()
handler::ha_rnd_pos_by_record()
Rows_log_event::find_row()
Update_rows_log_event::do_exec_row()
Rows_log_event::do_apply_event()
Log_event::apply_event()
wsrep_apply_events()
and mutexes are taken in the order
lock_sys->mutex -> victim_trx->mutex -> victim_thread->LOCK_thd_data
When a normal KILL statement is executed, the stack is
innobase_kill_query()
kill_handlerton()
plugin_foreach_with_mask()
ha_kill_query()
THD::awake()
kill_one_thread()
and mutexes are
victim_thread->LOCK_thd_data -> lock_sys->mutex -> victim_trx->mutex
This patch is the plan D variant for fixing potetial mutex locking
order exercised by BF aborting and KILL command execution.
In this approach, KILL command is replicated as TOI operation.
This guarantees total isolation for the KILL command execution
in the first node: there is no concurrent replication applying
and no concurrent DDL executing. Therefore there is no risk of
BF aborting to happen in parallel with KILL command execution
either. Potential mutex deadlocks between the different mutex
access paths with KILL command execution and BF aborting cannot
therefore happen.
TOI replication is used, in this approach, purely as means
to provide isolated KILL command execution in the first node.
KILL command should not (and must not) be applied in secondary
nodes. In this patch, we make this sure by skipping KILL
execution in secondary nodes, in applying phase, where we
bail out if applier thread is trying to execute KILL command.
This is effective, but skipping the applying of KILL command
could happen much earlier as well.
This also fixed unprotected calls to wsrep_thd_abort
that will use wsrep_abort_transaction. This is fixed
by holding THD::LOCK_thd_data while we abort transaction.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
Mutex order violation when wsrep bf thread kills a conflicting trx,
the stack is
wsrep_thd_LOCK()
wsrep_kill_victim()
lock_rec_other_has_conflicting()
lock_clust_rec_read_check_and_lock()
row_search_mvcc()
ha_innobase::index_read()
ha_innobase::rnd_pos()
handler::ha_rnd_pos()
handler::rnd_pos_by_record()
handler::ha_rnd_pos_by_record()
Rows_log_event::find_row()
Update_rows_log_event::do_exec_row()
Rows_log_event::do_apply_event()
Log_event::apply_event()
wsrep_apply_events()
and mutexes are taken in the order
lock_sys->mutex -> victim_trx->mutex -> victim_thread->LOCK_thd_data
When a normal KILL statement is executed, the stack is
innobase_kill_query()
kill_handlerton()
plugin_foreach_with_mask()
ha_kill_query()
THD::awake()
kill_one_thread()
and mutexes are
victim_thread->LOCK_thd_data -> lock_sys->mutex -> victim_trx->mutex
This patch is the plan D variant for fixing potetial mutex locking
order exercised by BF aborting and KILL command execution.
In this approach, KILL command is replicated as TOI operation.
This guarantees total isolation for the KILL command execution
in the first node: there is no concurrent replication applying
and no concurrent DDL executing. Therefore there is no risk of
BF aborting to happen in parallel with KILL command execution
either. Potential mutex deadlocks between the different mutex
access paths with KILL command execution and BF aborting cannot
therefore happen.
TOI replication is used, in this approach, purely as means
to provide isolated KILL command execution in the first node.
KILL command should not (and must not) be applied in secondary
nodes. In this patch, we make this sure by skipping KILL
execution in secondary nodes, in applying phase, where we
bail out if applier thread is trying to execute KILL command.
This is effective, but skipping the applying of KILL command
could happen much earlier as well.
This also fixed unprotected calls to wsrep_thd_abort
that will use wsrep_abort_transaction. This is fixed
by holding THD::LOCK_thd_data while we abort transaction.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
In a rebase of the merge, two preceding commits were accidentally reverted:
commit 112b23969a (MDEV-26308)
commit ac2857a5fb (MDEV-25717)
Thanks to Daniele Sciascia for noticing this.
Contains following fixes:
* allow TOI commands to timeout while trying to acquire TOI with
override lock_wait_timeout with a LONG_TIMEOUT only after
succesfully entering TOI
* only ignore lock_wait_timeout on TOI
* fix galera_split_brain test as TOI operation now returns ER_LOCK_WAIT_TIMEOUT after lock_wait_timeout
* explicitly test for TOI
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
Updates to transaction registry table shouldn't be replicated in
cluster so there is no need to append wsrep keys.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
The underlying problem with MDEV-25551 turned out to be that
transactions having changes for tables with no primary key,
were not safe to apply in parallel. This is due to excessive locking
in innodb side, and even non related row modifications could end up
in lock conflict during applying.
The fix for MDEV-25551 has disabled parallel applying for tables with no PK.
This fix depends on change for wsrep-lib, where a separate PR allows
application to modify transaction flags in wsrep-lib.
This commit has also separate mtr test for verifying that transactions
modifying a table with no primary key, will not apply in parallel.
This test is a modified version of initial test created by Gabor Orosz,
the reporterr of MDEV-25551.
Another mtr test was added in galera_sr suite, for testing if modifying
tables with no primary key would causes issues for streaming replication
use cases.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>
Starting with MariaDB 10.5, roughly after MDEV-23855 was fixed,
we are observing sporadic hangs during the execution of the
RESET MASTER statement. We are hoping to fix the hangs with these
changes, but due to the rather infrequent occurrence of the hangs
and our inability to reliably reproduce the hangs, we cannot be
sure of this.
What we do know is that innodb_force_recovery=2 (or a larger setting)
will prevent srv_master_callback (the former srv_master_thread) from
running. In that mode, periodic log flushes would never occur and
RESET MASTER could hang indefinitely. That is demonstrated by the new
test case that was developed by Andrei Elkin. We fix this case by
implementing a special case for it.
This also includes some code cleanup and renames of misleadingly
named code. The interface has nothing to do with log checkpoints in
the storage engine; it is only about requesting log writes to be
persistent.
handlerton::commit_checkpoint_request,
commit_checkpoint_notify_ha(): Remove the unused parameter hton.
log_requests.start: Replaces pending_checkpoint_list.
log_requests.end: Replaces pending_checkpoint_list_end.
log_requests.mutex: Replaces pending_checkpoint_mutex.
log_flush_notify_and_unlock(), log_flush_notify(): Replaces
innobase_mysql_log_notify(). The new implementation should be
functionally equivalent to the old one.
innodb_log_flush_request(): Replaces innobase_checkpoint_request().
Implement a fast path for common cases, and reduce the mutex hold time.
POSSIBLE FIX OF THE HANG: We will invoke commit_checkpoint_notify_ha()
for the current request if it is already satisfied, as well as invoke
log_flush_notify_and_unlock() for any satisfied requests.
log_write(): Invoke log_flush_notify() when the write is already durable.
This was missing WITH_PMEM when the log is in persistent memory.
Reviewed by: Vladislav Vaintroub
* be strict in CREATE TABLE, just like in ALTER TABLE, because
CREATE TABLE, just like ALTER TABLE, can be rolled back for any engine
* but don't auto-convert warnings into errors for engine warnings
(handler::create) - this matches ALTER TABLE behavior
* and not when creating a default record, these errors are handled
specially (and replaced with ER_INVALID_DEFAULT)
* always issue a Note when a non-unique key is truncated, because it's
not a Warning that can be converted to an Error. Before this commit
it was a Note for blobs and a Warning for all other data types.
Server part:
kill_handlerton() was accessing thd->ha_data[] for some other thd,
while it could be concurrently modified by its owner thd.
protect thd->ha_data[] modifications with a mutex.
require this mutex when accessing thd->ha_data[] from kill_handlerton.
InnoDB part:
on close_connection, detach trx from thd before freeing the trx
