Problem was that dict_sys->size tries to maintain used memory
occupied by the data dictionary table and index objects.
However at least on table objects table->heap size can increase
between when table object is inserted to dict_sys and when
it is removed from dict_sys causing inconsistency on amount
of memory added to and removed from dict_sys->size variable.
Removed unnecessary dict_sys:size variable as it is really
used only for status output.
Introduced dict_sys_get_size function to calculate memory
occupied by the data dictionary table and index objects
that is then used on show engine innodb output.
dict_table_add_to_cache(),
dict_table_rename_in_cache(),
dict_table_remove_from_cache_low(),
dict_index_remove_from_cache_low(),
Remove size calculation.
srv_printf_innodb_monitor(): Use dict_sys_get_size function to
get dictionary memory allocated.
xtradb_internal_hash_tables_fill_table(): Use dict_sys_get_size
function to get dictionary memory allocated.
When a slow shutdown is performed soon after spawning some work for
background threads that can create or commit transactions, it is possible
that new transactions are started or committed after the purge has finished.
This is violating the specification of innodb_fast_shutdown=0, namely that
the purge must be completed. (None of the history of the recent transactions
would be purged.)
Also, it is possible that the purge threads would exit in slow shutdown
while there exist active transactions, such as recovered incomplete
transactions that are being rolled back. Thus, the slow shutdown could
fail to purge some undo log that becomes purgeable after the transaction
commit or rollback.
srv_undo_sources: A flag that indicates if undo log can be generated
or the persistent, whether by background threads or by user SQL.
Even when this flag is clear, active transactions that already exist
in the system may be committed or rolled back.
innodb_shutdown(): Renamed from innobase_shutdown_for_mysql().
Do not return an error code; the operation never fails.
Clear the srv_undo_sources flag, and also ensure that the background
DROP TABLE queue is empty.
srv_purge_should_exit(): Do not allow the purge to exit if
srv_undo_sources are active or the background DROP TABLE queue is not
empty, or in slow shutdown, if any active transactions exist
(and are being rolled back).
srv_purge_coordinator_thread(): Remove some previous workarounds
for this bug.
innobase_start_or_create_for_mysql(): Set buf_page_cleaner_is_active
and srv_dict_stats_thread_active directly. Set srv_undo_sources before
starting the purge subsystem, to prevent immediate shutdown of the purge.
Create dict_stats_thread and fts_optimize_thread immediately
after setting srv_undo_sources, so that shutdown can use this flag to
determine if these subsystems were started.
dict_stats_shutdown(): Shut down dict_stats_thread. Backported from 10.2.
srv_shutdown_table_bg_threads(): Remove (unused).
The function trx_purge_stop() was calling os_event_reset(purge_sys->event)
before calling rw_lock_x_lock(&purge_sys->latch). The os_event_set()
call in srv_purge_coordinator_suspend() is protected by that X-latch.
It would seem a good idea to consistently protect both os_event_set()
and os_event_reset() calls with a common mutex or rw-lock in those
cases where os_event_set() and os_event_reset() are used
like condition variables, tied to changes of shared state.
For each os_event_t, we try to document the mutex or rw-lock that is
being used. For some events, frequent calls to os_event_set() seem to
try to avoid hangs. Some events are never waited for infinitely, only
timed waits, and os_event_set() is used for early termination of these
waits.
os_aio_simulated_put_read_threads_to_sleep(): Define as a null macro
on other systems than Windows. TODO: remove this altogether and disable
innodb_use_native_aio on Windows.
os_aio_segment_wait_events[]: Initialize only if innodb_use_native_aio=0.
MariaDB Server 10.0.28 and 10.1.19 merged code from Percona XtraDB
that introduced support for compressed columns. Much but not all
of this code was disabled by placing #ifdef HAVE_PERCONA_COMPRESSED_COLUMNS
around it.
Among the unused but not disabled code is code to access
some new system tables related to compressed columns.
The creation of these system tables SYS_ZIP_DICT and SYS_ZIP_DICT_COLS
would cause a crash in --innodb-read-only mode when upgrading
from an earlier version to 10.0.28 or 10.1.19.
Let us remove all the dead code related to compressed columns.
Users who already upgraded to 10.0.28 and 10.1.19 will have the two
above mentioned empty tables in their InnoDB system tablespace.
Subsequent versions of MariaDB Server will completely ignore those tables.
Essentially revert MDEV-6759, which addressed a double free of memory
by removing the freeing altogether, introducing the memory leaks.
No double free was observed when running the test suite -DWITH_ASAN.
Replace some mem_heap_free(foreign->heap) with dict_foreign_free(foreign)
so that the calls can be located and instrumented more easily when needed.
(Fixing both InnoDB and XtraDB)
Re-opening a TABLE object (after e.g. FLUSH TABLES or open table cache
eviction) causes ha_innobase to call
dict_stats_update(DICT_STATS_FETCH_ONLY_IF_NOT_IN_MEMORY).
Inside this call, the following is done:
dict_stats_empty_table(table);
dict_stats_copy(table, t);
On the other hand, commands like UPDATE make this call to get the "rows in
table" statistics in table->stats.records:
ha_innobase->info(HA_STATUS_VARIABLE|HA_STATUS_NO_LOCK)
note the HA_STATUS_NO_LOCK parameter. It means, no locks are taken by
::info() If the ::info() call happens between dict_stats_empty_table
and dict_stats_copy calls, the UPDATE's optimizer will get an estimate
of table->stats.records=1, which causes it to pick a full table scan,
which in turn will take a lot of row locks and cause other bad
consequences.
commit ef92aaf9ec
Author: Jan Lindström <jan.lindstrom@mariadb.com>
Date: Wed Jun 22 22:37:28 2016 +0300
MDEV-10083: Orphan ibd file when playing with foreign keys
Analysis: row_drop_table_for_mysql did not allow dropping
referenced table even in case when actual creating of the
referenced table was not successfull if foreign_key_checks=1.
Fix: Allow dropping referenced table even if foreign_key_checks=1
if actual table create returned error.
Analysis: row_drop_table_for_mysql did not allow dropping
referenced table even in case when actual creating of the
referenced table was not successfull if foreign_key_checks=1.
Fix: Allow dropping referenced table even if foreign_key_checks=1
if actual table create returned error.
while according to Storage Engine API column names should be compared
case insensitively. This can cause FRM and InnoDB data dictionary to
go out of sync.
There is several different ways to incorrectly define
foreign key constraint. In many cases earlier MariaDB
versions the error messages produced by these cases
are not very clear and helpful. This patch improves
the warning messages produced by foreign key parsing.
