This is a safetly fix to try to fix random failures in
parallel_backup_xa_debug reported as:
sync_slave_with_master failed:
'select master_pos_wait('master-bin.000001', 1034, 300, '')' returned -1
One possible reason could be lost signals, which this patch fixes.
wait_for_prior_commit() can be called multiple times per event group,
only do my_error() the first time the call fails.
Remove redundant set_overwrite_status() calls.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Reviewed-by: Monty <monty@mariadb.org>
* rpl.rpl_system_versioning_partitions updated for MDEV-32188
* innodb.row_size_error_log_warnings_3 changed error for MDEV-33658
(checks are done in a different order)
In Log_event::read_log_event(), don't use IO_CACHE::error of the relay log's
IO_CACHE to signal an error back to the caller. When reading the active
relay log, this flag is also being used by the IO thread, and setting it can
randomly cause the IO thread to wrongly detect IO error on writing and
permanently disable the relay log.
This was seen sporadically in test case rpl.rpl_from_mysql80. The read
error set by the SQL thread in the IO_CACHE would be interpreted as a
write error by the IO thread, which would cause it to throw a fatal
error and close the relay log. And this would later cause CHANGE
MASTER to try to purge a closed relay log, resulting in nullptr crash.
SQL thread is not able to parse an event read from the relay log. This
can happen like here when replicating unknown events from a MySQL master,
potentially also for other reasons.
Also fix a mistake in my_b_flush_io_cache() introduced back in 2001
(fa09f2cd7e) where my_b_flush_io_cache() could wrongly return an error set
in IO_CACHE::error, even if the flush operation itself succeeded.
Also fix another sporadic failure in rpl.rpl_from_mysql80 where the outout
of MASTER_POS_WAIT() depended on timing of SQL and IO thread.
Reviewed-by: Monty <monty@mariadb.org>
Reviewed-by: Andrei Elkin <andrei.elkin@mariadb.com>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
The FLUSH TABLE WITH READ LOCK briefly set the state (in PROCESSLIST) to
"Waiting while replication worker thread pool is busy", even if there was
nothing to wait for. This is somewhat confusing on a server that might not
even have any replication configured, let alone replication workers.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
If both do_gco_wait() and do_ftwrl_wait() had to wait, the state was not restored correctly.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Parallel slave failed to retry in retry_event_group() with error
WSREP: Parallel slave worker failed at wsrep_before_command() hook
Fix wsrep transaction cleanup/restart in retry_event_group() to properly
clean up previous transaction by calling wsrep_after_statement().
Also move call to reset error after call to wsrep_after_statement()
to make sure that it remains effective.
Add a MTR test galera_as_slave_parallel_retry to reproduce the error
when the fix is not present.
Other issues which were detected when testing with sysbench:
Check if parallel slave is killed for retry before waiting for prior
commits in THD::wsrep_parallel_slave_wait_for_prior_commit(). This
is required with slave-parallel-mode=optimistic to avoid deadlock
when a slave later in commit order manages to reach prepare phase
before a lock conflict is detected.
Suppress wsrep applier specific warning for slave threads.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
The problem was that when using clang + asan, we do not get a correct value
for the thread stack as some local variables are not allocated at the
normal stack.
It looks like that for example clang 18.1.3, when compiling with
-O2 -fsanitize=addressan it puts local variables and things allocated by
alloca() in other areas than on the stack.
The following code shows the issue
Thread 6 "mariadbd" hit Breakpoint 3, do_handle_one_connection
(connect=0x5080000027b8,
put_in_cache=<optimized out>) at sql/sql_connect.cc:1399
THD *thd;
1399 thd->thread_stack= (char*) &thd;
(gdb) p &thd
(THD **) 0x7fffedee7060
(gdb) p $sp
(void *) 0x7fffef4e7bc0
The address of thd is 24M away from the stack pointer
(gdb) info reg
...
rsp 0x7fffef4e7bc0 0x7fffef4e7bc0
...
r13 0x7fffedee7060 140737185214560
r13 is pointing to the address of the thd. Probably some kind of
"local stack" used by the sanitizer
I have verified this with gdb on a recursive call that calls alloca()
in a loop. In this case all objects was stored in a local heap,
not on the stack.
To solve this issue in a portable way, I have added two functions:
my_get_stack_pointer() returns the address of the current stack pointer.
The code is using asm instructions for intel 32/64 bit, powerpc,
arm 32/64 bit and sparc 32/64 bit.
Supported compilers are gcc, clang and MSVC.
For MSVC 64 bit we are using _AddressOfReturnAddress()
As a fallback for other compilers/arch we use the address of a local
variable.
my_get_stack_bounds() that will return the address of the base stack
and stack size using pthread_attr_getstack() or NtCurrentTed() with
fallback to using the address of a local variable and user provided
stack size.
Server changes are:
- Moving setting of thread_stack to THD::store_globals() using
my_get_stack_bounds().
- Removing setting of thd->thread_stack, except in functions that
allocates a lot on the stack before calling store_globals(). When
using estimates for stack start, we reduce stack_size with
MY_STACK_SAFE_MARGIN (8192) to take into account the stack used
before calling store_globals().
I also added a unittest, stack_allocation-t, to verify the new code.
Reviewed-by: Sergei Golubchik <serg@mariadb.org>
Before doing mark_start_commit(), check that there is no pending deadlock
kill. If there is a pending kill, we won't commit (we will abort, roll back,
and retry). Then we should not mark the commit as started, since that could
potentially make the following GCO start too early, before we completed the
commit after the retry.
This condition could trigger in some corner cases, where InnoDB would take
temporarily table/row locks that are released again immediately, not held
until the transaction commits. This happens with dict_stats updates and
possibly auto-increment locks.
Such locks can be passed to thd_rpl_deadlock_check() and cause a deadlock
kill to be scheduled in the background. But since the blocking locks are
held only temporarily, they can be released before the background kill
happens. This way, the kill can be delayed until after mark_start_commit()
has been called. Thus we need to check the synchronous indication
rgi->killed_for_retry, not just the asynchroneous thd->killed.
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
This commit adds 3 new status variables to 'show all slaves status':
- Master_last_event_time ; timestamp of the last event read from the
master by the IO thread.
- Slave_last_event_time ; Master timestamp of the last event committed
on the slave.
- Master_Slave_time_diff: The difference of the above two timestamps.
All the above variables are NULL until the slave has started and the
slave has read one query event from the master that changes data.
- Added information_schema.slave_status, which allows us to remove:
- show_master_info(), show_master_info_get_fields(),
send_show_master_info_data(), show_all_master_info()
- class Sql_cmd_show_slave_status.
- Protocol::store(I_List<i_string_pair>* str_list) as it is not
used anymore.
- Changed old SHOW SLAVE STATUS and SHOW ALL SLAVES STATUS to
use the SELECT code path, as all other SHOW ... STATUS commands.
Other things:
- Xid_log_time is set to time of commit to allow slave that reads the
binary log to calculate Master_last_event_time and
Slave_last_event_time.
This is needed as there is not 'exec_time' for row events.
- Fixed that Load_log_event calculates exec_time identically to
Query_event.
- Updated RESET SLAVE to reset Master/Slave_last_event_time
- Updated SQL thread's update on first transaction read-in to
only update Slave_last_event_time on group events.
- Fixed possible (unlikely) bugs in sql_show.cc ...old_format() functions
if allocation of 'field' would fail.
Reviewed By:
Brandon Nesterenko <brandon.nesterenko@mariadb.com>
Kristian Nielsen <knielsen@knielsen-hq.org>
Remove alter_algorithm but keep the variable as no-op (with a warning).
The reasons for removing alter_algorithm are:
- alter_algorithm was introduced as a replacement for the
old_alter_table that was used to force the usage of the original
alter table algorithm (copy) in the cases where the new alter
algorithm did not work. The new option was added as a way to force
the usage of a specific algorithm when it should instead have made
it possible to disable algorithms that would not work for some
reason.
- alter_algorithm introduced some cases where ALTER TABLE would not
work without specifying the ALGORITHM=XXX option together with
ALTER TABLE.
- Having different values of alter_algorithm on master and slave could
cause slave to stop unexpectedly.
- ALTER TABLE FORCE, as used by mariadb-upgrade, would not always work
if alter_algorithm was set for the server.
- As part of the MDEV-33449 "improving repair of tables" it become
clear that alter- algorithm made it harder to provide a better and
more consistent ALTER TABLE FORCE and REPAIR TABLE and it would be
better to remove it.
This patch extends the timestamp from
2038-01-19 03:14:07.999999 to 2106-02-07 06:28:15.999999
for 64 bit hardware and OS where 'long' is 64 bits.
This is true for 64 bit Linux but not for Windows.
This is done by treating the 32 bit stored int as unsigned instead of
signed. This is safe as MariaDB has never accepted dates before the epoch
(1970).
The benefit of this approach that for normal timestamp the storage is
compatible with earlier version.
However for tables using system versioning we before stored a
timestamp with the year 2038 as the 'max timestamp', which is used to
detect current values. This patch stores the new 2106 year max value
as the max timestamp. This means that old tables using system
versioning needs to be updated with mariadb-upgrade when moving them
to 11.4. That will be done in a separate commit.
Similar to #2480.
567b681 introduced safe_strcpy() to minimize the use of C with
potentially unsafe memory overflow with strcpy() whose use is
discouraged.
Replace instances of strcpy() with safe_strcpy() where possible, limited
here to files in the `sql/` directory.
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer
Amazon Web Services, Inc.
Clear any pending deadlock kill after completing XA PREPARE, and before
updating the mysql.gtid_slave_pos table in a separate transaction.
Reviewed-by: Andrei Elkin <andrei.elkin@mariadb.com>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Keep track of each recently active XID, recording which worker it was queued
on. If an XID might still be active, choose the same worker to queue event
groups that refer to the same XID to avoid conflicts.
Otherwise, schedule the XID freely in the next round-robin slot.
This way, XA PREPARE can normally be scheduled without restrictions (unless
duplicate XID transactions come close together). This improves scheduling
and parallelism over the old method, where the worker thread to schedule XA
PREPARE on was fixed based on a hash value of the XID.
XA COMMIT will normally be scheduled on the same worker as XA PREPARE, but
can be a different one if the XA PREPARE is far back in the event history.
Testcase and code for trimming dynamic array due to Andrei.
Reviewed-by: Andrei Elkin <andrei.elkin@mariadb.com>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
This is a preparatory patch to facilitate the next commit to improve
the scheduling of XA transactions in parallel replication.
When choosing the scheduling bucket for the next event group in
rpl_parallel_entry::choose_thread(), use an explicit FIFO for the
round-robin selection instead of a simple cyclic counter i := (i+1) % N.
This allows to schedule XA COMMIT/ROLLBACK dependencies explicitly without
changing the round-robin scheduling of other event groups.
Reviewed-by: Andrei Elkin <andrei.elkin@mariadb.com>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
Some fixes related to commit f838b2d799 and
Rows_log_event::do_apply_event() and Update_rows_log_event::do_exec_row()
for system-versioned tables were provided by Nikita Malyavin.
This was required by test versioning.rpl,trx_id,row.
When rolling back and retrying a transaction in parallel replication, don't
release the domain ownership (for --gtid-ignore-duplicates) as part of the
rollback. Otherwise another master connection could grab the ownership and
double-apply the transaction in parallel with the retry.
Reviewed-by: Brandon Nesterenko <brandon.nesterenko@mariadb.com>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
This will makes it easier to find out what replication workers are
doing and what they are waiting for.
Things changed in processlist:
- Slave_SQL time was not consistent. Now time for state "Slave has
read all relay log; waiting for more updates" shows how long it has
waited for getting the next event.
- Slave_worker threads did often show "Closing tables" for a long
time. Now the state is reverted to the previous state after
"Closing tables" is done.
- Commit and Rollback states where not shown for replication (and some
other threads). Now Commit and Rollback states are always shown and
the state is reverted to previous state when the Commit/Rollback
have finished.
Code changes:
- Added thd->set_time_for_next_stage() for parallel replication when
when starting to wait for prior transactions to commit, group commit,
and FTWRL and for free space in thread pool.
Before we reset the time only after the above events.
- Moved THD_STAGE_INFO(stage_rollback) and THD_STAGE_INFO(stage_commit)
from sql_parse.cc to transaction.cc to ensure this is done for
all commits and not only 'normal connection queries'.
Test case changes:
- close_thread_tables() reverting stage to previous stage caused the
counter in performance_schema to be increased. In many case it is
the 'sql/starting' stage that was effected.
- We only change to "Commit" stage if there is a need for a commit.
This caused some "Commit" stages to disapper from perfschema reports.
TODO in 11.#:
- Slave_IO always showes "Waiting for master to send event" and the time is
from SLAVE START. We should in 11.# change this to be the time since
reading the last event.
