In commit b6923420f3 (MDEV-29445)
we started to specify the MAP_POPULATE flag for allocating the
InnoDB buffer pool. This would cause a lot of time to be spent
on __mm_populate() inside the Linux kernel, such as 16 seconds
to pre-fault or commit innodb_buffer_pool_size=64G.
Let us revert to the previous way of allocating the buffer pool
at startup. Note: An attempt to increase the buffer pool size by
SET GLOBAL innodb_buffer_pool_size (up to innodb_buffer_pool_size_max)
will invoke my_virtual_mem_commit(), which will use MAP_POPULATE
to zero-fill and prefault the requested additional memory area, blocking
buf_pool.mutex.
Before MDEV-29445 we allocated the InnoDB buffer pool by invoking
mmap(2) once (via my_large_malloc()). After the change, we would
invoke mmap(2) twice, first via my_virtual_mem_reserve() and then
via my_virtual_mem_commit(). Outside Microsoft Windows, we are
reverting back to my_large_malloc() like allocation.
my_virtual_mem_reserve(): Define only for Microsoft Windows.
Other platforms should invoke my_large_virtual_alloc() and
update_malloc_size() instead of my_virtual_mem_reserve() and
my_virtual_mem_commit().
my_large_virtual_alloc(): Define only outside Microsoft Windows.
Do not specify MAP_NORESERVE nor MAP_POPULATE, to preserve compatibility
with my_large_malloc(). Were MAP_POPULATE specified, the mmap()
system call would be significantly slower, for example 18 seconds
to reserve 64 GiB upfront.
Fixing the code adding MySQL _0900_ collations as _uca1400_ aliases
not to perform deep initialization of the corresponding _uca1400_
collations.
Only basic initialization is now performed which allows to watch
these collations (both _0900_ and _uca1400_) in queries to
INFORMATION_SCHEMA tables COLLATIONS and
COLLATION_CHARACTER_SET_APPLICABILITY,
as well as in SHOW COLLATION statements.
Deep initialization is now performed only when a collation
(either the _0900_ alias or the corresponding _uca1400_ collation)
is used for the very first time after the server startup.
Refactoring was done to maintain the code easier:
- most of the _uca1400_ code was moved from ctype-uca.c
to a new file ctype-uca1400.c
- most of the _0900_ code was moved from type-uca.c
to a new file ctype-uca0900.c
Change details:
- The original function add_alias_for_collation() added by the patch for
"MDEV-20912 Add support for utf8mb4_0900_* collations in MariaDB Server"
was removed from mysys/charset.c, as it had two two problems:
a. it forced deep initialization of the _uca1400_ collations
when adding _0900_ aliases for them at the server startup
(the main reported problem)
b. the collation initialization code in add_alias_for_collation()
was related more to collations rather than to memory management,
so /strings should be a better place for it than /mysys.
The code from add_alias_for_collation() was split into separate functions.
Cyclic dependency was removed. `#include <my_sys.h>` was removed
from /strings/ctype-uca.c. Collations are now added using a callback
function MY_CHARSET_LOADED::add_collation, like it is done for
user collations defined in Index.xml. The code in /mysys sets
MY_CHARSET_LOADED::add_collation to add_compiled_collation().
- The function compare_collations() was removed.
A new virtual function was added into my_collation_handler_st instead:
my_bool (*eq_collation)(CHARSET_INFO *self, CHARSET_INFO *other);
because it is the collation handler who knows how to detect equal
collations by comparing only some of CHARSET_INFO members without
their deep initialization.
Three implementations were added:
- my_ci_eq_collation_uca() for UCA collations, it compares
_0900_ collations as equal to their corresponding _uca1400_ collations.
- my_ci_eq_collation_utf8mb4_bin(), it compares
utf8mb4_nopad_bin and utf8mb4_0900_bin as equal.
- my_ci_eq_collation_generic() - the default implementation,
which compares all collations as not equal.
A C++ wrapper CHARSET_INFO::eq_collations() was added.
The code in /sql was changes to use the wrapper instead of
the former calls for the removed function compare_collations().
- A part of add_alias_for_collation() was moved into a new function
my_ci_alloc(). It allocates a memory for a new charset_info_st
instance together with the collation name and the comment using a single
MY_CHARSET_LOADER::once_alloc call, which points to my_once_alloc()
in the server.
- A part of add_alias_for_collation() was moved into a new function
my_ci_make_comment_for_alias(). It makes an "Alias for xxx" string,
e.g. "Alias for utf8mb4_uca1400_swedish_ai_ci" in case of
utf8mb4_sv_0900_ai_ci.
- A part of the code in create_tailoring() was moved to
a new function my_uca1400_collation_get_initialized_shared_uca(),
to reuse the code between _uca1400_ and _0900_ collations.
- A new function my_collation_id_is_mysql_uca0900() was added
in addition to my_collation_id_is_mysql_uca1400().
- Functions to build collation names were added:
my_uca0900_collation_build_name()
my_uca1400_collation_build_name()
- A shared function function was added:
my_bool
my_uca1400_collation_alloc_and_init(MY_CHARSET_LOADER *loader,
LEX_CSTRING name,
LEX_CSTRING comment,
const uca_collation_def_param_t *param,
uint id)
It's reused to add _uca1400_ and _0900_ collations, with basic
initialization (without deep initialization).
- The function add_compiled_collation() changed its return type from
void to int, to make it compatible with MY_CHARSET_LOADER::add_collation.
- Functions mysql_uca0900_collation_definition_add(),
mysql_uca0900_utf8mb4_collation_definitions_add(),
mysql_utf8mb4_0900_bin_add() were added into ctype-uca0900.c.
They get MY_CHARSET_LOADER as a parameter.
- Functions my_uca1400_collation_definition_add(),
my_uca1400_collation_definitions_add() were moved from
charset-def.c to strings/ctype-uca1400.c.
The latter now accepts MY_CHARSET_LOADER as the first parameter
instead of initializing a MY_CHARSET_LOADER inside.
- init_compiled_charsets() now initializes a MY_CHARSET_LOADER
variable and passes it to all functions adding collations:
- mysql_utf8mb4_0900_collation_definitions_add()
- mysql_uca0900_utf8mb4_collation_definitions_add()
- mysql_utf8mb4_0900_bin_add()
- A new structure was added into ctype-uca.h:
typedef struct uca_collation_def_param
{
my_cs_encoding_t cs_id;
uint tailoring_id;
uint nopad_flags;
uint level_flags;
} uca_collation_def_param_t;
It simplifies reusing the code for _uca1400_ and _0900_ collations.
- The definition of MY_UCA1400_COLLATION_DEFINITION was
moved from ctype-uca.c to ctype-uca1400.h, to reuse
the code for _uca1400_ and _0900_ collations.
- The definitions of "MY_UCA_INFO my_uca_v1400" and
"MY_UCA_INFO my_uca1400_info_tailored[][]" were moved from
ctype-uca.c to ctype-uca1400.c.
- The definitions/declarations of:
- mysql_0900_collation_start,
- struct mysql_0900_to_mariadb_1400_mapping
- mysql_0900_to_mariadb_1400_mapping
- mysql_utf8mb4_0900_collation_definitions_add()
were moved from ctype-uca.c to ctype-uca0900.c
- Functions
my_uca1400_make_builtin_collation_id()
my_uca1400_collation_definition_init()
my_uca1400_collation_id_uca400_compat()
my_ci_get_collation_name_uca1400_context()
were moved from ctype-uca.c to ctype-uca1400.c and ctype-uca1400.h
- A part of my_uca1400_collation_definition_init()
was moved into my_uca0520_builtin_collation_by_id(),
to make functions smaller.
We deprecate and ignore the parameter innodb_buffer_pool_chunk_size
and let the buffer pool size to be changed in arbitrary 1-megabyte
increments.
innodb_buffer_pool_size_max: A new read-only startup parameter
that specifies the maximum innodb_buffer_pool_size. If 0 or
unspecified, it will default to the specified innodb_buffer_pool_size
rounded up to the allocation unit (2 MiB or 8 MiB). The maximum value
is 4GiB-2MiB on 32-bit systems and 16EiB-8MiB on 64-bit systems.
This maximum is very likely to be limited further by the operating system.
The status variable Innodb_buffer_pool_resize_status will reflect
the status of shrinking the buffer pool. When no shrinking is in
progress, the string will be empty.
Unlike before, the execution of SET GLOBAL innodb_buffer_pool_size
will block until the requested buffer pool size change has been
implemented, or the execution is interrupted by a KILL statement
a client disconnect, or server shutdown. If the
buf_flush_page_cleaner() thread notices that we are running out of
memory, the operation may fail with ER_WRONG_USAGE.
SET GLOBAL innodb_buffer_pool_size will be refused
if the server was started with --large-pages (even if
no HugeTLB pages were successfully allocated). This functionality
is somewhat exercised by the test main.large_pages, which now runs
also on Microsoft Windows. On Linux, explicit HugeTLB mappings are
apparently excluded from the reported Redident Set Size (RSS), and
apparently unshrinkable between mmap(2) and munmap(2).
The buffer pool will be mapped to a contiguous virtual memory area
that will be aligned and partitioned into extents of 8 MiB on
64-bit systems and 2 MiB on 32-bit systems.
Within an extent, the first few innodb_page_size blocks contain
buf_block_t objects that will cover the page frames in the rest
of the extent. The number of such frames is precomputed in the
array first_page_in_extent[] for each innodb_page_size.
In this way, there is a trivial mapping between
page frames and block descriptors and we do not need any
lookup tables like buf_pool.zip_hash or buf_pool_t::chunk_t::map.
We will always allocate the same number of block descriptors for
an extent, even if we do not need all the buf_block_t in the last
extent in case the innodb_buffer_pool_size is not an integer multiple
of the of extents size.
The minimum innodb_buffer_pool_size is 256*5/4 pages. At the default
innodb_page_size=16k this corresponds to 5 MiB. However, now that the
innodb_buffer_pool_size includes the memory allocated for the block
descriptors, the minimum would be innodb_buffer_pool_size=6m.
my_large_virtual_alloc(): A new function, similar to my_large_malloc().
my_virtual_mem_reserve(), my_virtual_mem_commit(),
my_virtual_mem_decommit(), my_virtual_mem_release():
New interface mostly by Vladislav Vaintroub, to separately
reserve and release virtual address space, as well as to
commit and decommit memory within it.
After my_virtual_mem_decommit(), the virtual memory range will be
read-only or unaccessible, depending on whether the build option
cmake -DHAVE_UNACCESSIBLE_AFTER_MEM_DECOMMIT=1
has been specified. This option is hard-coded on Microsoft Windows,
where VirtualMemory(MEM_DECOMMIT) will make the memory unaccessible.
On IBM AIX, Linux, Illumos and possibly Apple macOS, the virtual memory
will be zeroed out immediately. On other POSIX-like systems,
madvise(MADV_FREE) will be used if available, to give the operating
system kernel a permission to zero out the virtual memory range.
We prefer immediate freeing so that the reported
resident set size (RSS) of the process will reflect the current
innodb_buffer_pool_size. Shrinking the buffer pool is a rarely
executed resource intensive operation, and the immediate configuration
of the MMU mappings should not incur significant additional penalty.
opt_super_large_pages: Declare only on Solaris. Actually, this is
specific to the SPARC implementation of Solaris, but because we
lack access to a Solaris development environment, we will not revise
this for other MMU and ISA.
buf_pool_t::chunk_t::create(): Remove.
buf_pool_t::create(): Initialize all n_blocks of the buf_pool.free list.
buf_pool_t::allocate(): Renamed from buf_LRU_get_free_only().
buf_pool_t::LRU_warned: Changed to Atomic_relaxed<bool>,
only to be modified by the buf_flush_page_cleaner() thread.
buf_pool_t::shrink(): Attempt to shrink the buffer pool.
There are 3 possible outcomes: SHRINK_DONE (success),
SHRINK_IN_PROGRESS (the caller may keep trying),
and SHRINK_ABORT (we seem to be running out of buffer pool).
While traversing buf_pool.LRU, release the contended
buf_pool.mutex once in every 32 iterations in order to
reduce starvation. Use lru_scan_itr for efficient traversal,
similar to buf_LRU_free_from_common_LRU_list().
buf_pool_t::shrunk(): Update the reduced size of the buffer pool
in a way that is compatible with buf_pool_t::page_guess(),
and invoke my_virtual_mem_decommit().
buf_pool_t::resize(): Before invoking shrink(), run one batch of
buf_flush_page_cleaner() in order to prevent LRU_warn().
Abort if shrink() recommends it, or no blocks were withdrawn in
the past 15 seconds, or the execution of the statement
SET GLOBAL innodb_buffer_pool_size was interrupted.
buf_pool_t::first_to_withdraw: The first block descriptor that is
out of the bounds of the shrunk buffer pool.
buf_pool_t::withdrawn: The list of withdrawn blocks.
If buf_pool_t::resize() is aborted before shrink() completes,
we must be able to resurrect the withdrawn blocks in the free list.
buf_pool_t::contains_zip(): Added a parameter for the
number of least significant pointer bits to disregard,
so that we can find any pointers to within a block
that is supposed to be free.
buf_pool_t::is_shrinking(): Return the total number or blocks that
were withdrawn or are to be withdrawn.
buf_pool_t::to_withdraw(): Return the number of blocks that will need to
be withdrawn.
buf_pool_t::usable_size(): Number of usable pages, considering possible
in-progress attempt at shrinking the buffer pool.
buf_pool_t::page_guess(): Try to buffer-fix a guessed block pointer.
If HAVE_UNACCESSIBLE_AFTER_MEM_DECOMMIT is set, the pointer will
be validated before being dereferenced.
buf_pool_t::get_info(): Replaces buf_stats_get_pool_info().
innodb_init_param(): Refactored. We must first compute
srv_page_size_shift and then determine the valid bounds of
innodb_buffer_pool_size.
buf_buddy_shrink(): Replaces buf_buddy_realloc().
Part of the work is deferred to buf_buddy_condense_free(),
which is being executed when we are not holding any
buf_pool.page_hash latch.
buf_buddy_condense_free(): Do not relocate blocks.
buf_buddy_free_low(): Do not care about buffer pool shrinking.
This will be handled by buf_buddy_shrink() and
buf_buddy_condense_free().
buf_buddy_alloc_zip(): Assert !buf_pool.contains_zip()
when we are allocating from the binary buddy system.
Previously we were asserting this on multiple recursion levels.
buf_buddy_block_free(), buf_buddy_free_low():
Assert !buf_pool.contains_zip().
buf_buddy_alloc_from(): Remove the redundant parameter j.
buf_flush_LRU_list_batch(): Add the parameter to_withdraw
to keep track of buf_pool.n_blocks_to_withdraw.
buf_do_LRU_batch(): Skip buf_free_from_unzip_LRU_list_batch()
if we are shrinking the buffer pool. In that case, we want
to minimize the page relocations and just finish as quickly
as possible.
trx_purge_attach_undo_recs(): Limit purge_sys.n_pages_handled()
in every iteration, in case the buffer pool is being shrunk
in the middle of a purge batch.
Reviewed by: Debarun Banerjee
The problem was that get_collation_number_internal() loops over all
collations for finding a collation based on name. For looking up
utf8mb4_0900_ aliases it used 22633 character strings comparisons at
startup.
Fixed by adding the MariaDB internal collation number in the "0900" alias
lookup array. This is fine as collation numbers never changes.
Discussed-with: serg@mariadb.com
This commit updates default memory allocations size used with MEM_ROOT
objects to minimize the number of calls to malloc().
Changes:
- Updated MEM_ROOT block sizes in sql_const.h
- Updated MALLOC_OVERHEAD to also take into account the extra memory
allocated by my_malloc()
- Updated init_alloc_root() to only take MALLOC_OVERHEAD into account as
buffer size, not MALLOC_OVERHEAD + sizeof(USED_MEM).
- Reset mem_root->first_block_usage if and only if first block was used.
- Increase MEM_ROOT buffers sized used by my_load_defaults, plugin_init,
Create_tmp_table, allocate_table_share, TABLE and TABLE_SHARE.
This decreases number of malloc calls during queries.
- Use a small buffer for THD->main_mem_root in THD::THD. This avoids
multiple malloc() call for new connections.
I tried the above changes on a complex select query with 12 tables.
The following shows the number of extra allocations that where used
to increase the size of the MEM_ROOT buffers.
Original code:
- Connection to MariaDB: 9 allocations
- First query run: 146 allocations
- Second query run: 24 allocations
Max memory allocated for thd when using with heap table: 61,262,408
Max memory allocated for thd when using Aria tmp table: 419,464
After changes:
Connection to MariaDB: 0 allocations
- First run: 25 allocations
- Second run: 7 allocations
Max memory allocated for thd when using with heap table: 61,347,424
Max memory allocated for thd when using Aria table: 529,168
The new code uses slightly more memory, but avoids memory fragmentation
and is slightly faster thanks to much fewer calls to malloc().
Reviewed-by: Sergei Golubchik <serg@mariadb.org>
This is done by mapping most of the existing MySQL unicode 0900 collations
to MariadB 1400 unicode collations. The assumption is that 1400 is a super
set of 0900 for all practical purposes.
I also added a new function 'compare_collations()' and changed most code
to use this instead of comparing character sets directly.
This enables one to seamlessly mix-and-match the corresponding 0900 and
1400 sets. Field comparision and alter table treats the character sets
as identical.
All MySQL 8.0 0900 collations are supported except:
- utf8mb4_ja_0900_as_cs
- utf8mb4_ja_0900_as_cs_ks
- utf8mb4_ru_0900_as_cs
- utf8mb4_zh_0900_as_cs
These do not have corresponding entries in the MariadB 01400 collations.
Other things:
- Added COMMENT colum to information_schema.collations. For utf8mb4_0900
colletions it contains the corresponding alias collation.
os_innodb_umask was of the incorrect type resulting in warnings
in clang-19. The correct type is mode_t.
As os_innodb_umask was set during innnodb_init from my_umask,
corrected the type there along with its companion my_umask_dir.
Because of this, the defaults mask values in innodb never
had an effect.
The resulting change allow found signed differences in
my_create{,_nosymlink}, open_nosymlinks:
mysys/my_create.c:47:20: error: operand of ?: changes signedness from ‘int’ to ‘mode_t’ {aka ‘unsigned int’} due to unsignedness of other operand [-Werror=sign-compare]
47 | CreateFlags ? CreateFlags : my_umask);
Ref: clang-19 warnings:
[55/123] Building CXX object storage/innobase/CMakeFiles/innobase.dir/os/os0file.cc.o
storage/innobase/os/os0file.cc:1075:46: warning: implicit conversion loses integer precision: 'ulint' (aka 'unsigned long') to 'mode_t' (aka 'unsigned int') [-Wshorten-64-to-32]
1075 | file = open(name, create_flag | O_CLOEXEC, os_innodb_umask);
| ~~~~ ^~~~~~~~~~~~~~~
storage/innobase/os/os0file.cc:1249:46: warning: implicit conversion loses integer precision: 'ulint' (aka 'unsigned long') to 'mode_t' (aka 'unsigned int') [-Wshorten-64-to-32]
1249 | file = open(name, create_flag | O_CLOEXEC, os_innodb_umask);
| ~~~~ ^~~~~~~~~~~~~~~
storage/innobase/os/os0file.cc:1381:45: warning: implicit conversion loses integer precision: 'ulint' (aka 'unsigned long') to 'mode_t' (aka 'unsigned int') [-Wshorten-64-to-32]
1381 | file = open(name, create_flag | O_CLOEXEC, os_innodb_umask);
| ~~~~ ^~~~~~~~~~~~~~~
Partial commit of the greater MDEV-34348 scope.
MDEV-34348: MariaDB is violating clang-16 -Wcast-function-type-strict
The functions queue_compare, qsort2_cmp, and qsort_cmp2
all had similar interfaces, and were used interchangable
and unsafely cast to one another.
This patch consolidates the functions all into the
qsort_cmp2 interface.
Reviewed By:
============
Marko Mäkelä <marko.makela@mariadb.com>
When using the default innodb_log_buffer_size=2m, mariadb-backup --backup
would spend a lot of time re-reading and re-parsing the log. For reads,
it would be beneficial to memory-map the entire ib_logfile0 to the
address space (typically 48 bits or 256 TiB) and read it from there,
both during --backup and --prepare.
We will introduce the Boolean read-only parameter innodb_log_file_mmap
that will be OFF by default on most platforms, to avoid aggressive
read-ahead of the entire ib_logfile0 in when only a tiny portion would be
accessed. On Linux and FreeBSD the default is innodb_log_file_mmap=ON,
because those platforms define a specific mmap(2) option for enabling
such read-ahead and therefore it can be assumed that the default would
be on-demand paging. This parameter will only have impact on the initial
InnoDB startup and recovery. Any writes to the log will use regular I/O,
except when the ib_logfile0 is stored in a specially configured file system
that is backed by persistent memory (Linux "mount -o dax").
We also experimented with allowing writes of the ib_logfile0 via a
memory mapping and decided against it. A fundamental problem would be
unnecessary read-before-write in case of a major page fault, that is,
when a new, not yet cached, virtual memory page in the circular
ib_logfile0 is being written to. There appears to be no way to tell
the operating system that we do not care about the previous contents of
the page, or that the page fault handler should just zero it out.
Many references to HAVE_PMEM have been replaced with references to
HAVE_INNODB_MMAP.
The predicate log_sys.is_pmem() has been replaced with
log_sys.is_mmap() && !log_sys.is_opened().
Memory-mapped regular files differ from MAP_SYNC (PMEM) mappings in the
way that an open file handle to ib_logfile0 will be retained. In both
code paths, log_sys.is_mmap() will hold. Holding a file handle open will
allow log_t::clear_mmap() to disable the interface with fewer operations.
It should be noted that ever since
commit 685d958e38 (MDEV-14425)
most 64-bit Linux platforms on our CI platforms
(s390x a.k.a. IBM System Z being a notable exception) read and write
/dev/shm/*/ib_logfile0 via a memory mapping, pretending that it is
persistent memory (mount -o dax). So, the memory mapping based log
parsing that this change is enabling by default on Linux and FreeBSD
has already been extensively tested on Linux.
::log_mmap(): If a log cannot be opened as PMEM and the desired access
is read-only, try to open a read-only memory mapping.
xtrabackup_copy_mmap_snippet(), xtrabackup_copy_mmap_logfile():
Copy the InnoDB log in mariadb-backup --backup from a memory
mapped file.
The problem was that the signal thread was not killed when using
unireg_abort().
The bug was introduced by:
MDEV-30260: Slave crashed:reload_acl_and_cache during shutdown
Other things fixed:
- Don't produce memory leaks with safemalloc if all threads was not
ended properly (not useful)
Fixed that internal temporary tables are not waiting for freed disk space.
Other things:
- 'kill id' will now kill a query waiting for free disk space instantly.
Before it could take up to 60 seconds for the kill would be noticed.
- Fixed that sorting one index is not using MY_WAIT_IF_FULL for temp files.
- Fixed bug where share->write_flag set MY_WAIT_IF_FULL for temp files.
It is quite hard to do a test case for this. Instead I tested all
combinations interactively.
The leaks are all 40 bytes and happens in this call stack when running
mtr vcol.vcol_syntax:
alloc_root()
...
Virtual_column_info::fix_and_check_exp()
...
Delayed_insert::get_local_table()
The problem was that one copied a MEM_ROOT from THD to a TABLE without
taking into account that new blocks would be allocated through the
TABLE memroot (and would thus be leaked).
In general, one should NEVER copy MEM_ROOT from one object to another
without clearing the copied memroot!
Fixed by, at end of get_local_table(), copy all new allocated objects
to client_thd->mem_root.
Other things:
- Removed references to MEM_ROOT::total_alloc that was wrongly left
after a previous commit
Use ICU to work with timezones, to retrieve current timezone name,
abbreviation, and offset from GMT. However in case TZ environment variable
is used to set timezone, and ICU does not have corresponding one,
C runtime functions will be used.
Moved some of timezone handling to mysys.
Added unit tests.
Compute binlog checksums (when enabled) already when writing events
into the statement or transaction caches, where before it was done
when the caches are copied to the real binlog file. This moves the
checksum computation outside of holding LOCK_log, improving
scalabitily.
At stmt/trx cache write time, the final end_log_pos values are not
known, so with this patch these will be set to 0. Events that are
written directly to the binlog file (not through stmt/trx cache) keep
the correct end_log_pos value. The GTID and COMMIT/XID events at the
start and end of event groups are written directly, so the zero
end_log_pos is only for events in the middle of event groups, which
do not negatively affect replication.
An option --binlog-legacy-event-pos, off by default, is provided to
disable this behavior to provide backwards compatibility with any
external applications that might rely on end_log_pos in events in the
middle of event groups.
Checksums cannot be pre-computed when binlog encryption is enabled, as
encryption relies on correct end_log_pos to provide part of the
nonce/IV.
Checksum pre-computation is also disabled for WSREP/Galera, as it uses
events differently in its write-sets and so on. Extending pre-computation of
checksums to Galera where it makes sense could be added in a future patch.
The current --binlog-checksum configuration is saved in
binlog_cache_data at transaction start and used to pre-compute
checksums in cache, if applicable. When the cache is later copied to
the binlog, a check is made if the saved value still matches the
configured global value; if so, the events are block-copied directly
into the binlog file. If --binlog-checksum was changed during the
transaction, events are re-written to the binlog file one-by-one and
the checksums recomputed/discarded as appropriate.
Reviewed-by: Monty <monty@mariadb.org>
Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>
The MDEV-29693 conflict resolution is from Monty, as well as is
a bug fix where ANALYZE TABLE wrongly built histograms for
single-column PRIMARY KEY.
Also includes a fix for safe_malloc error reporting.
Other things:
- Copied main.log_slow from 10.4 to avoid mtr issue
Disabled test:
- spider/bugfix.mdev_27239 because we started to get
+Error 1429 Unable to connect to foreign data source: localhost
-Error 1158 Got an error reading communication packets
- main.delayed
- Bug#54332 Deadlock with two connections doing LOCK TABLE+INSERT DELAYED
This part is disabled for now as it fails randomly with different
warnings/errors (no corruption).
Problem:
Under terms of MDEV-27490, we'll update Unicode version used
to compare identifiers to 14.0.0. Unlike in the old Unicode version,
in the new version a string can grow during lower-case. We cannot
perform check_db_name() inplace any more.
Change summary:
- Allocate memory to store lower-cased identifiers in memory root
- Removing check_db_name() performing both in-place lower-casing and validation
at the same time. Splitting it into two separate stages:
* creating a memory-root lower-cased copy of an identifier
(using new MEM_ROOT functions and Query_arena wrapper methods)
* performing validation on a constant string
(using Lex_ident_fs methods)
Implementation details:
- Adding a mysys helper function to allocate lower-cased strings on MEM_ROOT:
lex_string_casedn_root()
and a Query_arena wrappers for it:
make_ident_casedn()
make_ident_opt_casedn()
- Adding a Query_arena method to perform both MEM_ROOT lower-casing and
database name validation at the same time:
to_ident_db_internal_with_error()
This method is very close to the old (pre-11.3) check_db_name(),
but performs lower-casing to a newly allocated MEM_ROOT
memory (instead of performing lower-casing the original string in-place).
- Adding a Table_ident method which additionally handles derived table names:
to_ident_db_internal_with_error()
- Removing the old check_db_name()
