MDEV-21953 deadlock between BACKUP STAGE BLOCK_COMMIT and parallel
replication
Fixed by partly reverting MDEV-21953 to put back MDL_BACKUP_COMMIT locking
before log_and_order.
The original problem for MDEV-21953 was that while a thread was waiting in
for another threads to commit in 'log_and_order', it had the
MDL_BACKUP_COMMIT lock. The backup thread was waiting to get the
MDL_BACKUP_WAIT_COMMIT lock, which blocks all new MDL_BACKUP_COMMIT locks.
This causes a deadlock as the waited-for thread can never get past the
MDL_BACKUP_COMMIT lock in ha_commit_trans.
The main part of the bug fix is to release the MDL_BACKUP_COMMIT lock while
a thread is waiting for other 'previous' threads to commit. This ensures
that no transactional thread keeps MDL_BACKUP_COMMIT while waiting, which
ensures that there are no deadlocks anymore.
Protocol_local fixed so it can be used now.
Some Protocol:: methods made virtual so they can adapt.
as well as net_ok and net_send_error functions.
execute_sql_string function is exported to the plugins.
To be changed with the mysql_use_result.
and
MDEV-23414 Assertion `res->charset() == item->collation.collation' failed in Type_handler_string_result::make_packed_sort_key_part
pack_sort_string() *must* take a collation from the Item, not from the
String value. Because when casting a string to _binary the original
String is not copied for performance reasons, it's reused but its
collation does not match Item's collation anymore.
Note, that String's collation cannot be simply changed to _binary,
because for an Item_string literal the original String must stay
unchanged for the duration of the query.
this partially reverts 61c15ebe323
- Adding optional qualifiers to data types:
CREATE TABLE t1 (a schema.DATE);
Qualifiers now work only for three pre-defined schemas:
mariadb_schema
oracle_schema
maxdb_schema
These schemas are virtual (hard-coded) for now, but may turn into real
databases on disk in the future.
- mariadb_schema.TYPE now always resolves to a true MariaDB data
type TYPE without sql_mode specific translations.
- oracle_schema.DATE translates to MariaDB DATETIME.
- maxdb_schema.TIMESTAMP translates to MariaDB DATETIME.
- Fixing SHOW CREATE TABLE to use a qualifier for a data type TYPE
if the current sql_mode translates TYPE to something else.
The above changes fix the reported problem, so this script:
SET sql_mode=ORACLE;
CREATE TABLE t2 AS SELECT mariadb_date_column FROM t1;
is now replicated as:
SET sql_mode=ORACLE;
CREATE TABLE t2 (mariadb_date_column mariadb_schema.DATE);
and the slave can unambiguously treat DATE as the true MariaDB DATE
without ORACLE specific translation to DATETIME.
Similar,
SET sql_mode=MAXDB;
CREATE TABLE t2 AS SELECT mariadb_timestamp_column FROM t1;
is now replicated as:
SET sql_mode=MAXDB;
CREATE TABLE t2 (mariadb_timestamp_column mariadb_schema.TIMESTAMP);
so the slave treats TIMESTAMP as the true MariaDB TIMESTAMP
without MAXDB specific translation to DATETIME.
An overflow was happening with LONGTEXT columns, when the length was converted to the length
in the strxfrm form (mem-comparable keys).
Introduced a function to truncate the length to the max_sort_length before calculating
the length of the strxfrm form.
- Better to use 'String *' directly.
- Added String::get_value(LEX_STRING*) for the few cases where we want to
convert a String to LEX_CSTRING.
Other things:
- Use StringBuffer for some functions to avoid mallocs
When high priority replication slave applier encounters lock conflict in innodb,
it will force the conflicting lock holder transaction (victim) to rollback.
This is a must in multi-master sychronous replication model to avoid cluster lock-up.
This high priority victim abort (aka "brute force" (BF) abort), is started
from innodb lock manager while holding the victim's transaction's (trx) mutex.
Depending on the execution state of the victim transaction, it may happen that the
BF abort will call for THD::awake() to wake up the victim transaction for the rollback.
Now, if BF abort requires THD::awake() to be called, then the applier thread executed
locking protocol of: victim trx mutex -> victim THD::LOCK_thd_data
If, at the same time another DBMS super user issues KILL command to abort the same victim,
it will execute locking protocol of: victim THD::LOCK_thd_data -> victim trx mutex.
These two locking protocol acquire mutexes in opposite order, hence unresolvable mutex locking
deadlock may occur.
The fix in this commit adds THD::wsrep_aborter flag to synchronize who can kill the victim
This flag is set both when BF is called for from innodb and by KILL command.
Either path of victim killing will bail out if victim's wsrep_killed is already
set to avoid mutex conflicts with the other aborter execution. THD::wsrep_aborter
records the aborter THD's ID. This is needed to preserve the right to kill
the victim from different locations for the same aborter thread.
It is also good error logging, to see who is reponsible for the abort.
A new test case was added in galera.galera_bf_kill_debug.test for scenario where
wsrep applier thread and manual KILL command try to kill same idle victim
* Allocate items on thd->mem_root while refixing vcol exprs
* Make vcol tree changes register and roll them back after the statement is executed.
Explanation:
Due to collation implementation specifics an Item tree could change while fixing.
The tricky thing here is to make it on a proper arena.
It's usually not a problem when a field is deterministic, however, makes a pain vice-versa, during allocation allocating.
A non-deterministic field should be refixed on each statement, since it depends on the environment state.
Changing the tree will be temporary and therefore it should be reverted after the statement execution.
The COM_MULTI did not take off. No connector is using it.
Remove related code from server, and client.
If anything it is a step simplification of already-bloated
dispatch_command(), and related code.
When high priority replication slave applier encounters lock conflict in innodb,
it will force the conflicting lock holder transaction (victim) to rollback.
This is a must in multi-master sychronous replication model to avoid cluster lock-up.
This high priority victim abort (aka "brute force" (BF) abort), is started
from innodb lock manager while holding the victim's transaction's (trx) mutex.
Depending on the execution state of the victim transaction, it may happen that the
BF abort will call for THD::awake() to wake up the victim transaction for the rollback.
Now, if BF abort requires THD::awake() to be called, then the applier thread executed
locking protocol of: victim trx mutex -> victim THD::LOCK_thd_data
If, at the same time another DBMS super user issues KILL command to abort the same victim,
it will execute locking protocol of: victim THD::LOCK_thd_data -> victim trx mutex.
These two locking protocol acquire mutexes in opposite order, hence unresolvable mutex locking
deadlock may occur.
The fix in this commit adds THD::wsrep_aborter flag to synchronize who can kill the victim
This flag is set both when BF is called for from innodb and by KILL command.
Either path of victim killing will bail out if victim's wsrep_killed is already
set to avoid mutex conflicts with the other aborter execution. THD::wsrep_aborter
records the aborter THD's ID. This is needed to preserve the right to kill
the victim from different locations for the same aborter thread.
It is also good error logging, to see who is reponsible for the abort.
A new test case was added in galera.galera_bf_kill_debug.test for scenario where
wsrep applier thread and manual KILL command try to kill same idle victim
For low sort_buffer_size, in the cost calculation of using the Unique object the elements in the tree were evaluated to 0, make sure to have atleast 1 element in the Unique tree.
Also for the function Unique::get allocate memory for atleast MERGEBUFF2+1 keys.
cannot use the current THD::mem_root, because it can be temporarily
reassigned to something with a very different life time
(e.g. to TABLE::mem_root or range optimizer mem_root).
MDEV-21398 Deadlock (server hang) or assertion failure in
Diagnostics_area::set_error_status upon ALTER under lock
This failure could only happen if one locked the same table
multiple times and then did an ALTER TABLE on the table.
Major change is to change all instances of
table->m_needs_reopen= true;
to
table->mark_table_for_reopen();
The main fix for the problem was to ensure that we mark all
instances of the table in the locked_table_list and when we
reopen the tables, we first close all tables before reopening
and locking them.
Other things:
- Don't call thd->locked_tables_list.reopen_tables if there
are no tables marked for reopen. (performance)
MDEV-22531 Remove maria::implicit_commit()
MDEV-22607 Assertion `ha_info->ht() != binlog_hton' failed in
MYSQL_BIN_LOG::unlog_xa_prepare
From the handler point of view, Aria now looks like a transactional
engine. One effect of this is that we don't need to call
maria::implicit_commit() anymore.
This change also forces the server to call trans_commit_stmt() after doing
any read or writes to system tables. This work will also make it easier
to later allow users to have system tables in other engines than Aria.
To handle the case that Aria doesn't support rollback, a new
handlerton flag, HTON_NO_ROLLBACK, was added to engines that has
transactions without rollback (for the moment only binlog and Aria).
Other things
- Moved freeing of MARIA_SHARE to a separate function as the MARIA_SHARE
can be still part of a transaction even if the table has closed.
- Changed Aria checkpoint to use the new MARIA_SHARE free function. This
fixes a possible memory leak when using S3 tables
- Changed testing of binlog_hton to instead test for HTON_NO_ROLLBACK
- Removed checking of has_transaction_manager() in handler.cc as we can
assume that as the transaction was started by the engine, it does
support transactions.
- Added new class 'start_new_trans' that can be used to start indepdendent
sub transactions, for example while reading mysql.proc, using help or
status tables etc.
- open_system_tables...() and open_proc_table_for_Read() doesn't anymore
take a Open_tables_backup list. This is now handled by 'start_new_trans'.
- Split thd::has_transactions() to thd::has_transactions() and
thd::has_transactions_and_rollback()
- Added handlerton code to free cached transactions objects.
Needed by InnoDB.
squash! 2ed35999f2a2d84f1c786a21ade5db716b6f1bbc
All changes (except one) is of type
thd->transaction. -> thd->transaction->
thd->transaction points by default to 'thd->default_transaction'
This allows us to 'easily' have multiple active transactions for a
THD object, like when reading data from the mysql.proc table
MDEV-22088 S3 partitioning support
All ALTER PARTITION commands should now work on S3 tables except
REBUILD PARTITION
TRUNCATE PARTITION
REORGANIZE PARTITION
In addition, PARTIONED S3 TABLES can also be replicated.
This is achived by storing the partition tables .frm and .par file on S3
for partitioned shared (S3) tables.
The discovery methods are enchanced by allowing engines that supports
discovery to also support of the partitioned tables .frm and .par file
Things in more detail
- The .frm and .par files of partitioned tables are stored in S3 and kept
in sync.
- Added hton callback create_partitioning_metadata to inform handler
that metadata for a partitoned file has changed
- Added back handler::discover_check_version() to be able to check if
a table's or a part table's definition has changed.
- Added handler::check_if_updates_are_ignored(). Needed for partitioning.
- Renamed rebind() -> rebind_psi(), as it was before.
- Changed CHF_xxx hadnler flags to an enum
- Changed some checks from using table->file->ht to use
table->file->partition_ht() to get discovery to work with partitioning.
- If TABLE_SHARE::init_from_binary_frm_image() fails, ensure that we
don't leave any .frm or .par files around.
- Fixed that writefrm() doesn't leave unusable .frm files around
- Appended extension to path for writefrm() to be able to reuse to function
for creating .par files.
- Added DBUG_PUSH("") to a a few functions that caused a lot of not
critical tracing.
* The overlaps check is implemented on a handler level per row command.
It creates a separate cursor (actually, another handler instance) and
caches it inside the original handler, when ha_update_row or
ha_insert_row is issued. Cursor closes on unlocking the handler.
* Containing the same key in index means unique constraint violation
even in usual terms. So we fetch left and right neighbours and check
that they have same key prefix, excluding from the key only the period part.
If it doesnt match, then there's no such neighbour, and the check passes.
Otherwise, we check if this neighbour intersects with the considered key.
* The check does not introduce new error and fails with ER_DUPP_KEY error.
This might break REPLACE workflow and should be fixed separately
MDEV-21605 Clean up and speed up interfaces for binary row logging
MDEV-21617 Bug fix for previous version of this code
The intention is to have as few 'if' as possible in ha_write() and
related functions. This is done by pre-calculating once per statement the
row_logging state for all tables.
Benefits are simpler and faster code both when binary logging is disabled
and when it's enabled.
Changes:
- Added handler->row_logging to make it easy to check it table should be
row logged. This also made it easier to disabling row logging for system,
internal and temporary tables.
- The tables row_logging capabilities are checked once per "statements
that updates tables" in THD::binlog_prepare_for_row_logging() which
is called when needed from THD::decide_logging_format().
- Removed most usage of tmp_disable_binlog(), reenable_binlog() and
temporary saving and setting of thd->variables.option_bits.
- Moved checks that can't change during a statement from
check_table_binlog_row_based() to check_table_binlog_row_based_internal()
- Removed flag row_already_logged (used by sequence engine)
- Moved binlog_log_row() to a handler::
- Moved write_locked_table_maps() to THD::binlog_write_table_maps() as
most other related binlog functions are in THD.
- Removed binlog_write_table_map() and binlog_log_row_internal() as
they are now obsolete as 'has_transactions()' is pre-calculated in
prepare_for_row_logging().
- Remove 'is_transactional' argument from binlog_write_table_map() as this
can now be read from handler.
- Changed order of 'if's in handler::external_lock() and wsrep_mysqld.h
to first evaluate fast and likely cases before more complex ones.
- Added error checking in ha_write_row() and related functions if
binlog_log_row() failed.
- Don't clear check_table_binlog_row_based_result in
clear_cached_table_binlog_row_based_flag() as it's not needed.
- THD::clear_binlog_table_maps() has been replaced with
THD::reset_binlog_for_next_statement()
- Added 'MYSQL_OPEN_IGNORE_LOGGING_FORMAT' flag to open_and_lock_tables()
to avoid calculating of binary log format for internal opens. This flag
is also used to avoid reading statistics tables for internal tables.
- Added OPTION_BINLOG_LOG_OFF as a simple way to turn of binlog temporary
for create (instead of using THD::sql_log_bin_off.
- Removed flag THD::sql_log_bin_off (not needed anymore)
- Speed up THD::decide_logging_format() by remembering if blackhole engine
is used and avoid a loop over all tables if it's not used
(the common case).
- THD::decide_logging_format() is not called anymore if no tables are used
for the statement. This will speed up pure stored procedure code with
about 5%+ according to some simple tests.
- We now get annotated events on slave if a CREATE ... SELECT statement
is transformed on the slave from statement to row logging.
- In the original code, the master could come into a state where row
logging is enforced for all future events if statement could be used.
This is now partly fixed.
Other changes:
- Ensure that all tables used by a statement has query_id set.
- Had to restore the row_logging flag for not used tables in
THD::binlog_write_table_maps (not normal scenario)
- Removed injector::transaction::use_table(server_id_type sid, table tbl)
as it's not used.
- Cleaned up set_slave_thread_options()
- Some more DBUG_ENTER/DBUG_RETURN, code comments and minor indentation
changes.
- Ensure we only call THD::decide_logging_format_low() once in
mysql_insert() (inefficiency).
- Don't annotate INSERT DELAYED
- Removed zeroing pos_in_table_list in THD::open_temporary_table() as it's
already 0
MDEV-21606 Improve update handler (long unique keys on blobs)
MDEV-21470 MyISAM and Aria start_bulk_insert doesn't work with long unique
MDEV-21606 Bug fix for previous version of this code
MDEV-21819 2 Assertion `inited == NONE || update_handler != this'
- Move update_handler from TABLE to handler
- Move out initialization of update handler from ha_write_row() to
prepare_for_insert()
- Fixed that INSERT DELAYED works with update handler
- Give an error if using long unique with an autoincrement column
- Added handler function to check if table has long unique hash indexes
- Disable write cache in MyISAM and Aria when using update_handler as
if cache is used, the row will not be inserted until end of statement
and update_handler would not find conflicting rows.
- Removed not used handler argument from
check_duplicate_long_entries_update()
- Syntax cleanups
- Indentation fixes
- Don't use single character indentifiers for arguments
