Added new test scenario in galera.galera_bf_kill
test to make the issue surface. The tetst scenario has
a multi statement transaction containing a KILL command.
When the KILL is submitted, another transaction is
replicated, which causes BF abort for the KILL command
processing. Handling BF abort rollback while executing
KILL command causes node hanging, in this scenario.
sql_kill() and sql_kill_user() functions have now fix,
to perform implicit commit before starting the KILL command
execution. BEcause of the implicit commit, the KILL execution
will not happen inside transaction context anymore.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
Replication of MyISAM and Aria DML is experimental and best
effort only. Earlier change make INSERT SELECT on both
MyISAM and Aria to replicate using TOI and STATEMENT
replication. Replication should happen only if user
has set needed wsrep_mode setting.
Note: This commit contains additional changes compared
to those already made for the 10.5 branch.
+ small refactoring after main fix.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
Problem was that we did not found that table was partitioned
and then we should find what is actual underlaying storage
engine.
We should not use RSU for !InnoDB tables.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
Replication of MyISAM and Aria DML is experimental and best
effort only. Earlier change make INSERT SELECT on both
MyISAM and Aria to replicate using TOI and STATEMENT
replication. Replication should happen only if user
has set needed wsrep_mode setting.
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
Commit a8a75ba2d causes the MariaDB server to crash, usually with signal
11, at random code locations due to invalid pointer values during any
table operation. This issue occurs when the server is built with -O3 and
other customized compiler flags.
For example, the command `use db1;` causes server to crash in the
`check_table_access` function at line sql_parse.cc:7080 because
`tables->correspondent_table` is an invalid pointer value of 0x1.
The crashes are due to undefined behavior from using uninitialized
variables. The problematic commit a8a75ba2d introduces code that
allocates memory and sets it to 0 using thd->calloc before initializing
it with a placement new operation.
This process depends on setting memory to 0 to initialize member
variables not explicitly set in the constructor. However, the compiler
can optimize out the memset/bfill, leading to uninitialized values and
unpredictable issues.
Once a constructor function initializes an object, any uninitialized
variables within that object are subject to undefined behavior. The
state of memory before the constructor runs, whether it involves
memset or was used for other purposes, is irrelevant after the
placement new operation.
This behavior can be demonstrated with this
[test](https://gcc.godbolt.org/z/5n87z1raG) I wrote to examine the
assembly code. The code in MariaDB can be abstracted to the following,
though it has many layers wrapped around it and more complex logic,
causing slight differences in optimization in the MariaDB build.
To summarize, on x86, the memset in the following code is optimized out
with both -O2 and -O3 in GCC 13, and is only preserved in the much older
GCC 4.9.
struct S {
int i; // uninitialized in consturctor
S() {};
};
int bar() {
void *buf = malloc(sizeof(S));
memset(buf, 0, sizeof(S)); // optimized out
S* s = new(buf) S;
return s->i;
}
With GCC13 -O3:
bar():
sub rsp, 8
mov edi, 4
call malloc
mov eax, DWORD PTR [rax]
add rsp, 8
ret
With GCC4.9 -O3
bar():
sub rsp, 8
mov edi, 4
call malloc
mov DWORD PTR [rax], 0
xor eax, eax
add rsp, 8
ret
Now we ensure the constructor initializes variables correctly by running
the reset() function in the constructor to perform the memset/bfill(0)
operation. After applying the fix, the crash is gone.
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.
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>
Address Sanitizer's know how to detect stack overrun, so there's
no point in us doing it.
As evidenced by perfschema tests where signficant test failures
because this function failed under ASAN (MDEV-33210).
Also, so since clang-16, we cannot assume much about how local
variables are allocated on the stack (MDEV-31605).
Disabling check idea thanks to Sanja.
Rectify cases of mismatched brackets and address
possible cases of division by zero by checking if
the denominator is zero before dividing.
No functional changes were made.
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.
One of possible use cases that reproduces the memory leakage listed below:
set timestamp= unix_timestamp('2000-01-01 00:00:00');
create or replace table t1 (x int) with system versioning
partition by system_time interval 1 hour auto
partitions 3;
create table t2 (x int);
create trigger tr after insert on t2 for each row update t1 set x= 11;
create or replace procedure sp2() insert into t2 values (5);
set timestamp= unix_timestamp('2000-01-01 04:00:00');
call sp2;
set timestamp= unix_timestamp('2000-01-01 13:00:00');
call sp2; # <<=== Memory leak happens there. In case MariaDB server is built
with the option -DWITH_PROTECT_STATEMENT_MEMROOT,
the second execution would hit assert failure.
The reason of leaking a memory is that once a new partition be created
the table should be closed and re-opened. It results in calling the function
extend_table_list() that indirectly invokes the function sp_add_used_routine()
to add routines implicitly used by the statement that makes a new memory
allocation.
To fix it, don't remove routines and tables the statement implicitly depends
on when a table being closed for subsequent re-opening.
Having Item_func_not items in item trees breaks assumptions during the
optimization phase about transformation possibilities in fix_fields().
Remove Item_func_not by extending normalization during parsing.
Reviewed by Oleksandr Byelkin (sanja@mariadb.com)
New error codes can only be added in the latest major version.
Adding ER_KILL_DENIED_HIGH_PRIORITY would shift by one all
error codes that were added in MariaDB Server 10.6 or later.
This amends commit 1001dae186
Suggested by: Sergei Golubchik
Changed error code for Galera unkillable threads to
be ER_KILL_DENIED_HIGH_PRIORITY giving message
This is a high priority thread/query and cannot be killed
without the compromising consistency of the cluster
also a warning is produced
Thread %lld is [wsrep applier|high priority] and cannot be killed
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
