ha_innobase::statistics_init(), ha_innobase::info_low():
Correctly handle a DB_READ_ONLY return value from dict_stats_save().
Fixes up commit 6e6a1b316c (MDEV-35000)
Under unknown circumstances, the SQL layer may wrongly disregard an
invocation of thd_mark_transaction_to_rollback() when an InnoDB
transaction had been aborted (rolled back) due to one of the following errors:
* HA_ERR_LOCK_DEADLOCK
* HA_ERR_RECORD_CHANGED (if innodb_snapshot_isolation=ON)
* HA_ERR_LOCK_WAIT_TIMEOUT (if innodb_rollback_on_timeout=ON)
Such an error used to cause a crash of InnoDB during transaction commit.
These changes aim to catch and report the error earlier, so that not only
this crash can be avoided but also the original root cause be found and
fixed more easily later.
The idea of this fix is from Michael 'Monty' Widenius.
HA_ERR_ROLLBACK: A new error code that will be translated into
ER_ROLLBACK_ONLY, signalling that the current transaction
has been aborted and the only allowed action is ROLLBACK.
trx_t::state: Add TRX_STATE_ABORTED that is like
TRX_STATE_NOT_STARTED, but noting that the transaction had been
rolled back and aborted.
trx_t::is_started(): Replaces trx_is_started().
ha_innobase: Check the transaction state in various places.
Simplify the logic around SAVEPOINT.
ha_innobase::is_valid_trx(): Replaces ha_innobase::is_read_only().
The InnoDB logic around transaction savepoints, commit, and rollback
was unnecessarily complex and might have contributed to this
inconsistency. So, we are simplifying that logic as well.
trx_savept_t: Replace with const undo_no_t*. When we rollback to
a savepoint, all we need to know is the number of undo log records
that must survive.
trx_named_savept_t, DB_NO_SAVEPOINT: Remove. We can store undo_no_t
directly in the space allocated at innobase_hton->savepoint_offset.
fts_trx_create(): Do not copy previous savepoints.
fts_savepoint_rollback(): If a savepoint was not found, roll back
everything after the default savepoint of fts_trx_create().
The test innodb_fts.savepoint is extended to cover this code.
Reviewed by: Vladislav Lesin
Tested by: Matthias Leich
Problem:
========
- dict_stats_table_clone_create() does not initialize the
flag stats_error_printed in either dict_table_t or dict_index_t.
Because dict_stats_save_index_stat() is operating on a copy
of a dict_index_t object, it appears that
dict_index_t::stats_error_printed will always be false
for actual metadata objects, and uninitialized in
dict_stats_save_index_stat().
Solution:
=========
dict_stats_table_clone_create(): Assign stats_error_printed
for table and index while copying the statistics
Adding tests demonstrating that columns:
- mysql.innodb_table_stats.last_update
- mysql.innodb_index_stats.last_update
contain sane values close to NOW() rathar than a garbage.
Tests cover these three underlying TIMESTAMP data formats:
- MariaDB Field_timestamp0 - UINT4 based
Like in a MariaDB native installation running with mysql56_temporal_format=0
- MariaDB Field_timestampf - BINARY(4) based, with UNSIGNED_FLAG
Like in a MariaDB native installation running with mysql56_temporal_format=1
- MySQL-alike Field_timestampf - BINARY(4) based, without UNSIGNED_FLAG
Like with a MariaDB server running over a MySQL-5.6 directory
(e.g. during a migragion).
mysql_insert() first opens all affected tables (which implicitly
starts a transaction in InnoDB), then stat tables.
A failure to open a stat table caused open_tables() to abort
the current stmt transaction (trans_rollback_stmt()). So, from the
server point of view the following ha_write_row()-s happened outside
of a transactions, and the server didn't bother to commit them.
The server has a mechanism to prevent a transaction being
unexpectedly committed or rolled back in the middle of a statement -
if an operation takes place _in a sub-statement_ it cannot change
the transaction state. Operations on stat tables are exactly that -
they are not allowed to change a transaction state. Put them in
a sub-statement to make sure they don't.
