Test fixes:
Since fix for CONC-603 (wrong error handling in TLS read/write) in case
of a read/write error client doesn't return always error 2013 (server
has gone away), so in addition we need to check for error 2026
(TLS/SSL error) and 5014 (write error).
MDEV-28073 Slow query performance in MariaDB when using many table
The idea is to prefer and chain EQ_REF tables (tables that uses an
unique key to find a row) when searching for the best table combination.
This significantly reduces row combinations that has to be examined.
This is optimization is enabled when setting optimizer_prune_level=2
(which is now default).
Implementation:
- optimizer_prune_level has a new level, 2, which enables EQ_REF
optimization in addition to the pruning done by level 1.
Level 2 is now default.
- Added JOIN::eq_ref_tables that contains bits of tables that could use
potentially use EQ_REF access in the query. This is calculated
in sort_and_filter_keyuse()
Under optimizer_prune_level=2:
- When the greedy_optimizer notices that the preceding table was an
EQ_REF table, it tries to add an EQ_REF table next. If an EQ_REF
table exists, only this one will be considered at this level.
We also collect all EQ_REF tables chained by the next levels and these
are ignored on the starting level as we have already examined these.
If no EQ_REF table exists, we continue as normal.
This optimization speeds up the greedy_optimizer combination test with
~25%
Other things:
- I ported the changes in MySQL 5.7 to greedy_optimizer.test to MariaDB
to be able to ensure we can handle all cases that MySQL can do.
- I have run all tests with --mysqld=--optimizer_prune_level=1 to verify that
there where no test changes.
These system variables:
@@character_set_client
@@character_set_connection
@@character_set_database
@@character_set_filesystem
@@character_set_results
@@character_set_server
can now be set in numeric format only to IDs of default collations, e.g.:
SET @@character_set_xxx=9; -- OK (latin2_general_ci is default)
SET @@character_set_xxx=2; -- ERROR (latin2_czech_cs is not default)
SET @@character_set_xxx=21; -- ERROR (latin2_hungarian_ci is not default)
Before this change the server accepted IDs of non-default collations
so all three examples above worked without errors,
but this could lead to unexpected behavior in later statements.
In commit c4c8830709 (MDEV-28111) we disabled
the file system cache on the InnoDB write-ahead log file (ib_logfile0)
by default on Linux.
It turns out that especially with innodb_flush_trx_log_at_commit=2,
writing to the log via the file system cache typically improves throughput,
especially on slow storage or at a small number of concurrent transactions.
For other values of innodb_flush_log_at_trx_commit, direct writes were
observed to be mostly but not always faster. Whether it pays off to
disable the file system cache on the log may depend on the type of storage,
the workload, and the operating system kernel version.
On Linux and Microsoft Windows, we will introduce the settable Boolean
global variable innodb_log_file_buffering that indicates whether the
file system cache on the redo log file is enabled. The default value is
innodb_log_file_buffering=OFF. If the server is started up with
innodb_flush_log_at_trx_commit=2, the value will be changed to
innodb_log_file_buffering=ON.
When a persistent memory interface is being used for the log,
the value cannot be changed from innodb_log_file_buffering=OFF.
On Linux, when the physical block size cannot be determined
to be a power of 2 between 64 and 4096 bytes, the file system cache
cannot be disabled, and innodb_log_file_buffering=ON cannot be changed.
Server log messages will indicate whether the file system cache is
enabled for the redo log:
[Note] InnoDB: Buffered log writes (block size=512 bytes)
[Note] InnoDB: File system buffers for log disabled (block size=512 bytes)
After this change, the startup parameter innodb_flush_method will no
longer control whether O_DIRECT will be set on the redo log on Linux.
On other operating systems that support O_DIRECT, no interface has been
implemented for controlling the file system cache for the redo log.
The innodb_flush_method values O_DIRECT, O_DIRECT_NO_FSYNC, O_DSYNC
will enable O_DIRECT for data files, not the log.
Tested by: Matthias Leich, Axel Schwenke
The parameter innodb_prefix_index_cluster_optimization used to enable an
optimization that was added in cb37c55768
and was disabled by default.
We will unconditionally enable the extension and mark the parameter
as deprecated.
Related to this, the counters
Innodb_secondary_index_triggered_cluster_reads and
Innodb_secondary_index_triggered_cluster_reads_avoided
allowed to determine the usefulness of this optimization.
Now that the configuration parameter is disabled, the counters
do not serve any useful purpose and can be removed.
row_search_with_covering_prefix(): Fix a bug that caused an
incorrect result to be returned.
INNODB_VERSION_STR: Replaced with PACKAGE_VERSION (non-functional change).
INNODB_VERSION_SHORT: Replaced with direct use of
MYSQL_VERSION_MAJOR << 8 | MYSQL_VERSION_MINOR.
check_version(): Simplify the mariadb-backup version check,
and require the server version to be MariaDB 10.8 or later,
because that is when the InnoDB redo log format was last changed.
InnoDB buffer pool resize messages are more succinct from this change:
Before:
```
2022-05-07 17:10:33 0 [Note] InnoDB: Completed resizing buffer pool from 14745600 to 19660800 bytes.
2022-05-07 17:10:33 0 [Note] InnoDB: Completed resizing buffer pool.
2022-05-07 17:10:33 8 [Note] InnoDB: Completed resizing buffer pool. (New size: 19660800 bytes).
```
After:
```
2022-05-07 17:10:33 0 [Note] InnoDB: Completed resizing buffer pool from 14745600 to 19660800 bytes.
```
Additionally, the INNODB_BUFFER_POOL_RESIZE_STATUS has more complete
info: it contains both the old and new buffer pool size values.
Make two existing command line options "allow-suspicious-udfs" and
"skip-grant-tables" visible as global system variables.
Both options have security implications, but users were not able to check
their states in the server prior to this change. This was a security
issue, as the user may not be aware if the options are enabled. By adding
them into system variables, it increases users’ visibility into their
security configurations.
Create new MTR tests to verify that the system variables align with the
command line options. Minor adjustments to the existing MTR due to the new
members in system variables.
Before:
mysql> SHOW VARIABLES WHERE
Variable_Name LIKE 'allow_suspicious_udfs' OR
Variable_Name LIKE 'skip_grant_tables';
Empty set (0.000 sec)
After:
mysql> SHOW VARIABLES WHERE
Variable_Name LIKE 'allow_suspicious_udfs' OR
Variable_Name LIKE 'skip_grant_tables';
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| allow_suspicious_udfs | OFF |
| skip_grant_tables | OFF |
+-----------------------+-------+
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.
Arythmetic can overrun the uint type when possible group_concat_max_len
is multiplied to collation.mbmaxlen (can easily be like 4).
So use ulonglong there for calculations.
This is a backport of commit 4489a89c71
in order to remove the test innodb.redo_log_during_checkpoint
that would cause trouble in the DBUG subsystem invoked by
safe_mutex_lock() via log_checkpoint(). Before
commit 7cffb5f6e8
these mutexes were of different type.
The following options were introduced in
commit 2e814d4702 (mariadb-10.2.2)
and have little use:
innodb_disable_resize_buffer_pool_debug had no effect even in
MariaDB 10.2.2 or MySQL 5.7.9. It was introduced in
mysql/mysql-server@5c4094cf49
to work around a problem that was fixed in
mysql/mysql-server@2957ae4f99
(but the parameter was not removed).
innodb_page_cleaner_disabled_debug and innodb_master_thread_disabled_debug
are only used by the test innodb.redo_log_during_checkpoint
that will be removed as part of this commit.
innodb_dict_stats_disabled_debug is only used by that test,
and it is redundant because one could simply use
innodb_stats_persistent=OFF or the STATS_PERSISTENT=0 attribute
of the table in the test to achieve the same effect.
Analysis: There are 2 server variables- "old_mode" and "old". "old" is no
longer needed as "old_mode" has replaced it (however still used in some places
in the code). "old_mode" and "old" has same purpose- emulate behavior from
previous MariaDB versions. So they can be merged to avoid confusion.
Fix: Deprecate "old" variable and create another mode for @@old_mode to mimic
behavior of previous "old" variable. Create specific modes for specifix task
that --old sql variable was doing earlier and use the new modes instead.
`m_status == DA_ERROR' failed on SELECT after setting tmp_disk_table_size.
Analysis: Mismatch in number of warnings between "194 warnings" vs
"64 rows in set" is because of max_error_count variable which has default
value of 64.
About the corrupted tables, the error that occurs because of insufficient
tmp_disk_table_size variable is not reported correctly and we continue to
execute the statement. But because the previous error (about table being
full)is not reported correctly, this error moves up the stack and is
wrongly reported as parsing error later on while parsing frm file of one
of the information schema table. This parsing error gives corrupted table
error.
As for the innodb error, it occurs even when tmp_disk_table_size is not
insufficient is default but the internal error handler takes care of it
and the error doesn't show. But when tmp_disk_table_size is insufficient,
the fatal error which wasn't reported correctly moves up the stack so
internal error handler is not called. So it shows errors.
Fix: Report the error correctly.
We will remove the parameter innodb_disallow_writes because it is badly
designed and implemented. The parameter was never allowed at startup.
It was only internally used by Galera snapshot transfer.
If a user executed
SET GLOBAL innodb_disallow_writes=ON;
the server could hang even on subsequent read operations.
During Galera snapshot transfer, we will block writes
to implement an rsync friendly snapshot, as follows:
sst_flush_tables() will acquire a global lock by executing
FLUSH TABLES WITH READ LOCK, which will block any writes
at the high level.
sst_disable_innodb_writes(), invoked via ha_disable_internal_writes(true),
will suspend or disable InnoDB background tasks or threads that could
initiate writes. As part of this, log_make_checkpoint() will be invoked
to ensure that anything in the InnoDB buf_pool.flush_list will be written
to the data files. This has the nice side effect that the Galera joiner
will avoid crash recovery.
The changes to sql/wsrep.cc and to the tests are based on a prototype
that was developed by Jan Lindström.
Reviewed by: Jan Lindström
We support online log resizing by replicating the current ib_logfile0
to a new file ib_logfile101, which will eventually replace the
ib_logfile0 on the first applicable log checkpoint.
Unless the log is located in a persistent memory file system (PMEM),
an attempt to SET GLOBAL innodb_log_file_size to less than
innodb_log_buffer_size will be refused. (With PMEM, a.k.a. mmap()
based log, that parameter has no meaning.)
Should the server be killed while the log was being resized,
both files ib_logfile0 and ib_logfile101 may exist on startup,
and since commit 3b06415cb8
the extra file ib_logfile101 will be removed.
We will initiate checkpoint flushing by invoking buf_flush_ahead(),
to let buf_flush_page_cleaner() write out pages until the
buf_flush_async_lsn target has been reached.
On a log checkpoint, if the new checkpoint LSN is not older than
log_sys.resize_lsn (the start LSN of the ib_logfile101),
we can switch files and complete the log resizing. Else, we will
attempt to switch files on the next checkpoint.
Log resizing can be aborted by killing the connection that is
executing the SET GLOBAL statement.
If the ib_logfile101 wraps around to the beginning, we must
advance the log_sys.resize_lsn. In the resized log file,
the sequence bit will always be written as 1 (no wrap-around).
The log will be duplicated in log_t::resize_write(), invoked by
mtr_t::finish_write().
When the log is being written via system calls (not PMEM), the initial
log_sys.resize_lsn is the current log_sys.first_lsn, plus an integer
multiple of log_sys.block_size, corresponding to the LSN at the start
of the block that was written by log_sys.write_lsn. The log_sys.resize_buf
will be of the same size as the log_sys.buf. During resizing, the
contents of log_sys.buf and log_sys.resize_buf will be identical,
except that the sequence bit of each mini-transaction will always be 1 in
log_sys.resize_buf. If resizing is in progress, log_t::write_buf()
will write log_sys.resize_buf to log_sys.resize_log (ib_logfile101).
If the file would wrap around, the buffer will be written to
log_sys.START_OFFSET and the log_sys.resize_lsn advanced accordingly.
When using mmap() on /dev/shm or a PMEM mount -o dax file system,
the initial log_sys.resize_lsn will be the log_sys.lsn at the time
the resizing is initiated. If the log file wraps around during resizing,
then the log_sys.resize_lsn will be advanced by
(log_sys.resize_target - log_sys.START_OFFSET).
log_t::resize_start(), log_t::resize_abort(), log_t::write_checkpoint():
Unless the log is mmap() based, acquire flush_lock and write_lock.
In any case, acquire exclusive log_sys.latch to prevent race conditions.
log_t::resize_rename(): Renamed from log_t::rename_resized(),
and moved some code to the previous sole caller srv_start().
Thanks to Vladislav Vaintroub for helpful review comments
and to Matthias Leich for testing this, in particular, testing
crash recovery, multiple concurrent SET GLOBAL innodb_log_file_size
and frequently killed connections.
- Make innodb_ft_cache_size & innodb_ft_total_cache_size are dynamic
variable and increase the maximum value of innodb_ft_cache_size to
512MB for 32-bit system and 1 TB for 64-bit system and set
innodb_ft_total_cache_size maximum value to 1 TB for 64-bit system.
- Print warning if the fts cache exceeds the innodb_ft_cache_size
and also unlock the cache if fts cache memory reduces less than
innodb_ft_cache_size.
