On Windows systems, occurrences of ERROR_SHARING_VIOLATION due to
conflicting share modes between processes accessing the same file can
result in CreateFile failures.
mysys' my_open() already incorporates a workaround by implementing
wait/retry logic on Windows.
But this does not help if files are opened using shell redirection like
mysqltest traditionally did it, i.e via
--echo exec "some text" > output_file
In such cases, it is cmd.exe, that opens the output_file, and it
won't do any sharing-violation retries.
This commit addresses the issue by introducing a new built-in command,
'write_line', in mysqltest. This new command serves as a brief alternative
to 'write_file', with a single line output, that also resolves variables
like "exec" would.
Internally, this command will use my_open(), and therefore retry-on-error
logic.
Hopefully this will eliminate the very sporadic "can't open file because
it is used by another process" error on CI.
Some s390x environments include
https://github.com/madler/zlib/pull/410
and a more pessimistic compressBound: (sourceLen * 16 + 2308) / 8 + 6.
Let us adjust the recently enabled tests accordingly.
The test innodb_zip.index_large_prefix_4k would not run unless it is
invoked as
./mtr --mysqld=--innodb-page-size=4k innodb_zip.index_large_prefix_4k
This test was originally developed to cover an option that was removed
in commit 0c92794db3. Starting with
MariaDB Server 10.2, which introduced innodb_default_row_format=dynamic,
the option innodb_large_prefix had become useless.
Let us remove some of the stale tests and adjust the outcome to the
expected behaviour.
Some GNU/Linux distributions ship a zlib that is modified to use
the s390x DFLTCC instruction. That modification would essentially
redefine compressBound(sourceLen) as (sourceLen * 16 + 2308) / 8 + 6.
Let us relax the tests for InnoDB ROW_FORMAT=COMPRESSED to cope with
such a weaker compression guarantee.
create_table_info_t::row_size_is_acceptable(): Remove a bogus debug-only
assertion that would fail to hold for the test innodb_zip.bug36169.
The function page_zip_empty_size() may indeed return 0.
The InnoDB DATA DIRECTORY attribute is not implemented via
symbolic links but something similar, *.isl files that contain
the names of data files.
InnoDB failed to ignore the DATA DIRECTORY attribute even though
the server was started with --skip-symbolic-links.
Native ALTER TABLE in InnoDB will retain the DATA DIRECTORY attribute
of the table, no matter if the table will be rebuilt or not.
Generic ALTER TABLE (with ALGORITHM=COPY) as well as TRUNCATE TABLE
will discard the DATA DIRECTORY attribute.
All tests have been run with and without the ./mtr option
--mysqld=--skip-symbolic-links
and some tests that use the InnoDB DATA DIRECTORY attribute
have been adjusted for this.
ALTER TABLE IMPORT doesn't properly handle instant alter metadata.
This patch makes IMPORT read, parse and apply instant alter metadata at the
very beginning of operation. So, cases when source table has some metadata
and destination table doesn't have it now works fine.
DISCARD already removes instant metadata so importing normal table into
instant table worked fine before this patch.
decrypt_decompress(): decrypts and decompresses page if needed
handle_instant_metadata(): this should be the first thing to read source
table. Basically, it applies instant metadata to a destination
dict_table_t object. This is the first thing to read FSP flags so
all possible checks of it were moved to this function.
PageConverter::update_index_page(): it doesn't now read instant metadata.
This logic were moved into handle_instant_metadata()
row_import::match_flags(): this is a first part row_import::match_schema().
As a separate function it's used by handle_instant_metadata().
fil_space_t::is_full_crc32_compressed(): added convenient function
ha_innobase::discard_or_import_tablespace(): do not reload table definition
to read instant metadata because handle_instant_metadata() does it better.
The reverted code was originally added in
4e7ee166a9
ANONYMOUS_VAR: this is a handy thing to use along with make_scope_exit()
full_crc32_import.test shows different results, because no
dict_table_close() and dict_table_open_on_id() happens.
Thus, SHOW CREATE TABLE shows a little bit older table definition.
InnoDB tablespace identifiers and page numbers are 32-bit numbers.
Let us use a 32-bit type for them in innochecksum.
The changes in commit 1918bdf32c
broke the build on 32-bit Windows.
Thanks to Vicențiu Ciorbaru for an initial version of this fixup.
A side effect of the MDEV-24589 bug fix is that if
FLUSH TABLE...FOR EXPORT is initiated before the history of an
earlier DROP INDEX operation has been purged, then the data file
will contain allocated pages that belonged to the dropped indexes.
These pages would never be freed after a subsequent IMPORT TABLESPACE.
We will work around this regression by making IMPORT TABLESPACE
tolerate pages that refer to an unknown index.
The background DROP TABLE queue may be blocked for some more time
due to MDEV-16678. Let us apply similar adjustments as earlier:
commit 6af00b2cc6
commit 89633995e4
commit ccd87d34a4
Remove CREATE/DROP database.
Remove some unnecessary suppressions, replacements, and
SQL statements.
Populate tables via have_sequence.inc to avoid the creation of
explicit InnoDB record locks in INSERT...SELECT. This will remove
some gaps in AUTO_INCREMENT values.
btr_cur_upd_rec_in_place(): Invoke page_zip_rec_set_deleted()
for ROW_FORMAT=COMPRESSED pages, so that the change will be
written to the redo log.
This part of crash recovery was broken in
commit 08ba388713 (MDEV-12353).
page_zip_compress_write_log_no_data(): Remove.
We no longer write the MLOG_ZIP_PAGE_COMPRESS_NO_DATA record.
Instead, we will write MLOG_ZIP_PAGE_COMPRESS records.
We should not need anywhere near 32 bits of entropy, so we might
just limit ourselves to a 32-bit random number generator.
Also, it might be cheaper to use exclusive-or, bit shifting and
conditional jumps, instead of multiplication and addition.
We use relaxed atomic operations on the global random number generator
state in order in an attempt to silence any warnings about race conditions.
There is an obvious race condition between the load and store in
ut_rnd_gen(), but we do not think that it matters much that the
state of the random number generator could 'stutter'.
This change seems makes the 'uncompress_ops' nondeterministic
in innodb_zip.cmp_per_index after the restart. It looks like
there is an inherent race condition in the test, because the
table could be opened for InnoDB statistics recalculation
already before innodb_cmp_per_index_enabled was set. We might
end up having uncompress_ops anywhere between 0 and 9, or perhaps
even more. Let us remove that part of the test.
btr_free_externally_stored_field(): Pass w=mtr_t::OPT to
note that the BTR_EXTERN_LEN is not necessarily changing
when a multi-page ROW_FORMAT=COMPRESSED off-page column
is being freed, and to allow redundant writes to the redo
log to be optimized away.
Ever since commit 56f6dab1d0
the refactored function mtr_t::write() asserts by default
that the page contents is being changed.
In the test innodb.instant_alter,4k we would be flagging an error
for too large row size. That error was previously only being reported
if the table was being rebuilt. Thus, this merge is fixing a small
omission in MDEV-11369 (instant ADD COLUMN).
Move row size check to early CREATE/ALTER TABLE phase. Stop checking
on table open.
dict_index_add_to_cache(): remove parameter 'strict', stop checking row size
dict_index_t::record_size_info_t: this is a result of row size check operation
create_table_info_t::row_size_is_acceptable(): performs row size check.
Issues error or warning. Writes first overflow field to InnoDB log.
create_table_info_t::create_table(): add row size check
dict_index_t::record_size_info(): this is a refactored version
of dict_index_t::rec_potentially_too_big(). New version doesn't change global
state of a program but return all interesting info. And it's callers who
decide how to handle row size overflow.
dict_index_t::rec_potentially_too_big(): removed
We will remove the InnoDB background operation of merging buffered
changes to secondary index leaf pages. Changes will only be merged as a
result of an operation that accesses a secondary index leaf page,
such as a SQL statement that performs a lookup via that index,
or is modifying the index. Also ROLLBACK and some background operations,
such as purging the history of committed transactions, or computing
index cardinality statistics, can cause change buffer merge.
Encryption key rotation will not perform change buffer merge.
The motivation of this change is to simplify the I/O logic and to
allow crash recovery to happen in the background (MDEV-14481).
We also hope that this will reduce the number of "mystery" crashes
due to corrupted data. Because change buffer merge will typically
take place as a result of executing SQL statements, there should be
a clearer connection between the crash and the SQL statements that
were executed when the server crashed.
In many cases, a slight performance improvement was observed.
This is joint work with Thirunarayanan Balathandayuthapani
and was tested by Axel Schwenke and Matthias Leich.
The InnoDB monitor counter innodb_ibuf_merge_usec will be removed.
On slow shutdown (innodb_fast_shutdown=0), we will continue to
merge all buffered changes (and purge all undo log history).
Two InnoDB configuration parameters will be changed as follows:
innodb_disable_background_merge: Removed.
This parameter existed only in debug builds.
All change buffer merges will use synchronous reads.
innodb_force_recovery will be changed as follows:
* innodb_force_recovery=4 will be the same as innodb_force_recovery=3
(the change buffer merge cannot be disabled; it can only happen as
a result of an operation that accesses a secondary index leaf page).
The option used to be capable of corrupting secondary index leaf pages.
Now that capability is removed, and innodb_force_recovery=4 becomes 'safe'.
* innodb_force_recovery=5 (which essentially hard-wires
SET GLOBAL TRANSACTION ISOLATION LEVEL READ UNCOMMITTED)
becomes safe to use. Bogus data can be returned to SQL, but
persistent InnoDB data files will not be corrupted further.
* innodb_force_recovery=6 (ignore the redo log files)
will be the only option that can potentially cause
persistent corruption of InnoDB data files.
Code changes:
buf_page_t::ibuf_exist: New flag, to indicate whether buffered
changes exist for a buffer pool page. Pages with pending changes
can be returned by buf_page_get_gen(). Previously, the changes
were always merged inside buf_page_get_gen() if needed.
ibuf_page_exists(const buf_page_t&): Check if a buffered changes
exist for an X-latched or read-fixed page.
buf_page_get_gen(): Add the parameter allow_ibuf_merge=false.
All callers that know that they may be accessing a secondary index
leaf page must pass this parameter as allow_ibuf_merge=true,
unless it does not matter for that caller whether all buffered
changes have been applied. Assert that whenever allow_ibuf_merge
holds, the page actually is a leaf page. Attempt change buffer
merge only to secondary B-tree index leaf pages.
btr_block_get(): Add parameter 'bool merge'.
All callers of btr_block_get() should know whether the page could be
a secondary index leaf page. If it is not, we should avoid consulting
the change buffer bitmap to even consider a merge. This is the main
interface to requesting index pages from the buffer pool.
ibuf_merge_or_delete_for_page(), recv_recover_page(): Replace
buf_page_get_known_nowait() with much simpler logic, because
it is now guaranteed that that the block is x-latched or read-fixed.
mlog_init_t::mark_ibuf_exist(): Renamed from mlog_init_t::ibuf_merge().
On crash recovery, we will no longer merge any buffered changes
for the pages that we read into the buffer pool during the last batch
of applying log records.
buf_page_get_gen_known_nowait(), BUF_MAKE_YOUNG, BUF_KEEP_OLD: Remove.
btr_search_guess_on_hash(): Merge buf_page_get_gen_known_nowait()
to its only remaining caller.
buf_page_make_young_if_needed(): Define as an inline function.
Add the parameter buf_pool.
buf_page_peek_if_young(), buf_page_peek_if_too_old(): Add the
parameter buf_pool.
fil_space_validate_for_mtr_commit(): Remove a bogus comment
about background merge of the change buffer.
btr_cur_open_at_rnd_pos_func(), btr_cur_search_to_nth_level_func(),
btr_cur_open_at_index_side_func(): Use narrower data types and scopes.
ibuf_read_merge_pages(): Replaces buf_read_ibuf_merge_pages().
Merge the change buffer by invoking buf_page_get_gen().
This allows one to run the test suite even if any of the following
options are changed:
- character-set-server
- collation-server
- join-cache-level
- log-basename
- max-allowed-packet
- optimizer-switch
- query-cache-size and query-cache-type
- skip-name-resolve
- table-definition-cache
- table-open-cache
- Some innodb options
etc
Changes:
- Don't print out the value of system variables as one can't depend on
them to being constants.
- Don't set global variables to 'default' as the default may not
be the same as the test was started with if there was an additional
option file. Instead save original value and reset it at end of test.
- Test that depends on the latin1 character set should include
default_charset.inc or set the character set to latin1
- Test that depends on the original optimizer switch, should include
default_optimizer_switch.inc
- Test that depends on the value of a specific system variable should
set it in the test (like optimizer_use_condition_selectivity)
- Split subselect3.test into subselect3.test and subselect3.inc to
make it easier to set and reset system variables.
- Added .opt files for test that required specfic options that could
be changed by external configuration files.
- Fixed result files in rockdsb & tokudb that had not been updated for
a while.
Also, move part of the test back to innodb.innodb_mysql
and another part to a new test innodb.purge.
Last but not least, merge the tests innodb_zip.4k and innodb_zip.8k
to innodb_zip.page_size.
MariaDB data-at-rest encryption (innodb_encrypt_tables)
had repurposed the same unused data field that was repurposed
in MySQL 5.7 (and MariaDB 10.2) for the Split Sequence Number (SSN)
field of SPATIAL INDEX. Because of this, MariaDB was unable to
support encryption on SPATIAL INDEX pages.
Furthermore, InnoDB page checksums skipped some bytes, and there
are multiple variations and checksum algorithms. By default,
InnoDB accepts all variations of all algorithms that ever existed.
This unnecessarily weakens the page checksums.
We hereby introduce two more innodb_checksum_algorithm variants
(full_crc32, strict_full_crc32) that are special in a way:
When either setting is active, newly created data files will
carry a flag (fil_space_t::full_crc32()) that indicates that
all pages of the file will use a full CRC-32C checksum over the
entire page contents (excluding the bytes where the checksum
is stored, at the very end of the page). Such files will always
use that checksum, no matter what the parameter
innodb_checksum_algorithm is assigned to.
For old files, the old checksum algorithms will continue to be
used. The value strict_full_crc32 will be equivalent to strict_crc32
and the value full_crc32 will be equivalent to crc32.
ROW_FORMAT=COMPRESSED tables will only use the old format.
These tables do not support new features, such as larger
innodb_page_size or instant ADD/DROP COLUMN. They may be
deprecated in the future. We do not want an unnecessary
file format change for them.
The new full_crc32() format also cleans up the MariaDB tablespace
flags. We will reserve flags to store the page_compressed
compression algorithm, and to store the compressed payload length,
so that checksum can be computed over the compressed (and
possibly encrypted) stream and can be validated without
decrypting or decompressing the page.
In the full_crc32 format, there no longer are separate before-encryption
and after-encryption checksums for pages. The single checksum is
computed on the page contents that is written to the file.
We do not make the new algorithm the default for two reasons.
First, MariaDB 10.4.2 was a beta release, and the default values
of parameters should not change after beta. Second, we did not
yet implement the full_crc32 format for page_compressed pages.
This will be fixed in MDEV-18644.
This is joint work with Marko Mäkelä.
The parameters innodb_file_format and innodb_large_prefix were overridden
in the Debian-distributed configuration files, because the default values
of these parameters between MariaDB 5.5 and MariaDB 10.2
did not make any sense.
To allow a more seamless upgrade from MariaDB 10.1 to later versions,
let InnoDB recognize the parameters innodb_file_format and
innodb_large_prefix and issue deprecation warnings for them if they
are specified. A deprecation period of only one major release
(one year between the MariaDB 10.2 and 10.3 releases) is insufficient
for these widely used parameters.
