MDEV-5817 query cache bug (returning inconsistent/old result
set) with aria table parallel inserts, row format = page
The problem is that for transactional aria tables
(row_type=PAGE and transactional=1), maria_lock_database()
didn't flush the state or the query cache.
Not flushing the state is correct for transactional tables as
this is done by checkpoint, but not flushing the query cache
was wrong and could cause concurrent SELECT queries to not
be deleted from the cache.
Fixed by introducing a flush of the query cache as part of commit, if the table has changed.
t for transactional aria tables (row_type=PAGE and transactional=1), maria_lock_table() didn't flush their state or the query cache.
The test cases for the MDEV found several independent bugs
in MariaDB server and Aria:
- If a temporary table was marked as crashed, it could never
be deleted.
- Opening of a crashed temporary table gave an error message
but the error was never forwarded to the caller which caused
an assert() in my_ok()
- init_read_record() did mmap of all temporary tables, which is
probably not a good idea as this area can potentially be
very big. Changed code to only mmap internal temporary tables.
- mmap-ed tables where not unmapped in case of repair/optimize
which caused bad data in table and crashes if the original
table files where replaced with new ones (as the old mmap
was still in place). Fixed by removing the mmap in case
of repair.
- Cleaned up usage of code that disabled mmap in Aria
Problem was that in case of implicit rollback for alter table
Aria did try to run commit twice.
The test case for this is tricky to do in 10.2, so it will
be added to 10.4 as part of BACKUP STAGE testing.
The issue is that two MARIA_HA instances shares the same MARIA_STATUS_INFO
object during UNION execution, so the second MARIA_HA instance state pointer
MARIA_HA::state points to the MARIA_HA::state_save of the first MARIA instance.
This happens in
thr_multi_lock(...) {
...
for (first_lock=data, pos= data+1 ; pos < end ; pos++)
{
...
if (pos[0]->lock == pos[-1]->lock && pos[0]->lock->copy_status)
(pos[0]->lock->copy_status)((*pos)->status_param,
(*first_lock)->status_param);
...
}
...
}
Usually the state is restored from ha_maria::external_lock(...):
\#0 _ma_update_status (param=0x6290000e6270) at ./storage/maria/ma_state.c:309
\#1 0x00005555577ccb15 in _ma_update_status_with_lock (info=0x6290000e6270) at ./storage/maria/ma_state.c:361
\#2 0x00005555577c7dcc in maria_lock_database (info=0x6290000e6270, lock_type=2) at ./storage/maria/ma_locking.c:66
\#3 0x0000555557802ccd in ha_maria::external_lock (this=0x61d0001b1308, thd=0x62a000048270, lock_type=2) at ./storage/maria/ha_maria.cc:2727
But _ma_update_status() does not take into account the case when
MARIA_HA::status points to the MARIA_HA::state_save of the other MARIA_HA
instance.
The fix is to restore MARIA_HA::state in ha_maria::external_lock() after
maria_lock_database() call for transactional tables.
This commit is based on the work of Michal Schorm, rebased on the
earliest MariaDB version.
Th command line used to generate this diff was:
find ./ -type f \
-exec sed -i -e 's/Foundation, Inc., 59 Temple Place, Suite 330, Boston, /Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, /g' {} \; \
-exec sed -i -e 's/Foundation, Inc. 59 Temple Place.* Suite 330, Boston, /Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, /g' {} \; \
-exec sed -i -e 's/MA.*.....-1307.*USA/MA 02110-1335 USA/g' {} \; \
-exec sed -i -e 's/Foundation, Inc., 59 Temple/Foundation, Inc., 51 Franklin/g' {} \; \
-exec sed -i -e 's/Place, Suite 330, Boston, MA.*02111-1307.*USA/Street, Fifth Floor, Boston, MA 02110-1335 USA/g' {} \; \
-exec sed -i -e 's/MA.*.....-1307/MA 02110-1335/g' {} \;
make live checksum to be returned in handler::info(),
and slow table-scan checksum to be calculated in handler::checksum().
part of
MDEV-16249 CHECKSUM TABLE for a spider table is not parallel and saves all data in memory in the spider head by default
Problem was that a parallel open of a table, overwrote info->state that
was in used by repair.
Fixed by changing _ma_tmp_disable_logging_for_table() to use
a new state buffer state.no_logging to store the temporary state.
Other things:
- Use original number of rows when retrying repair to get rid of a
potential warning "Number of rows changed from X to Y"
- Changed maria_commit() to make it easier to merge with 10.4
- If table is not locked (like with show commands), use the global
number of rows as the local number may not be up to date.
(Minor not critical fix)
- Added some missing DBUG_RETURN
MDEV-10130 Assertion `share->in_trans == 0' failed in storage/maria/ma_close.c
MDEV-10378 Assertion `trn' failed in virtual int ha_maria::start_stmt
The problem was that maria_handler->trn was not properly reset
at commit/rollback and ha_maria::exernal_lock() could get confused
because.
There was some old code in ha_maria::implicit_commit() that tried
to take care of this, but it was not bullet proof.
Fixed by adding list of all tables that is part of the maria transaction to
TRN.
A nice side effect was of the fix is that loops in
ha_maria::implict_commit() got to be much simpler.
Other things:
- Fixed a bug in mysql_admin_table() where argument open_for_modify
was wrongly reset for the next table in the chain
- rollback admin command also in case of fatal error.
- Split _ma_set_trn_for_table() to three version to simplify code
and debugging.
- Several new asserts to detect the original problem (that file was
not properly removed from trn before calling ma_close())
I was able to repeat the problem with old version of randgen
Reason for crash:
- It's not safe to change share->now_transactional if there are changed
bitmaps in the pagecache as flushing these can cause redo-entries and
the bitmap flush code checks that share->now_transactional is set.
Fixed by flushing bitmaps in _ma_tmp_disable_logging_for_table() before
we set share->now_transactional to 0
Problem was that if copy_data_between_tables() didn't do proper
clean up in case of failures:
- copy object was not properly freed
- end_bulk_insert() was not called
- mysql_trans_prepare_alter_copy_data() set THD->transaction.on to
false which was not properly restored
The last part caused a crash in Aria as Aria depends on that THD
is correct.
Other things:
- Reset info->switched_transactional after usage (safety)
- Reset bulk_insert_single_undo (safety)
Problem was that we the bitmap needs to be flushed before disabling
logging of redo entires, as writing the bitmap to disk by
background checkpoint may cause redo entries.
Modern compilers (such as GCC 8) emit warnings that the
'register' keyword is deprecated and not valid C++17.
Let us remove most use of the 'register' keyword.
Code in 'extra/' is not touched.
This bug happens when locking the same Aria "transactional" table
(page format) more then once with LOCK TABLES and inserting into one
of them with INSERT ... SELECT when the table is empty.
Fixed by ensuring we don't use fast bulk insert if table is opened
twice with LOCK TABLES (as this changes table->s->state)
Code changes:
- Added use_count to MARIA_USED_TABLES to be able to check if
table is opened twice for a statement/lock table
- Don't clear history or reset info->start_state if we
don't have versioning. One reason for the bug was
was that info->start_state was set to point to different
states for the two tables. If there is no versioning
info->start_state should always point to info->s->state.common.
Other things:
- Fixed also some typos that was noticed while scanning the code
- More DBUG_PRINT
- Fix win64 pointer truncation warnings
(usually coming from misusing 0x%lx and long cast in DBUG)
- Also fix printf-format warnings
Make the above mentioned warnings fatal.
- fix pthread_join on Windows to set return value.
