Remove the bug-compatible crc32 algorithm variant that was added
to allow an upgrade from data files from big-endian systems where
innodb_checksum_algorithm=crc32 was used on MySQL 5.6
or MariaDB 10.0 or 10.1.
Affected users should be able to recompute page checksums using
innochecksum.
In MySQL 5.7, it was noticed that files are not portable between
big-endian and little-endian processor architectures
(such as SPARC and x86), because the original implementation of
innodb_checksum_algorithm=crc32 was not byte order agnostic.
A byte order agnostic implementation of innodb_checksum_algorithm=crc32
was only added to MySQL 5.7, not backported to 5.6. Consequently,
MariaDB Server versions 10.0 and 10.1 only contain the CRC-32C
implementation that works incorrectly on big-endian architectures,
and MariaDB Server 10.2.2 got the byte-order agnostic CRC-32C
implementation from MySQL 5.7.
MySQL 5.7 introduced a "legacy crc32" variant that is functionally
equivalent to the big-endian version of the original crc32 implementation.
Thanks to this variant, old data files can be transferred from big-endian
systems to newer versions.
Introducing new variants of checksum algorithms (without introducing
new names for them, or something on the pages themselves to identify
the algorithm) generally is a bad idea, because each checksum algorithm
is like a lottery ticket. The more algorithms you try, the more likely
it will be for the checksum to match on a corrupted page.
So, essentially MySQL 5.7 weakened innodb_checksum_algorithm=crc32,
and MariaDB 10.2.2 inherited this weakening.
We introduce a build option that together with MDEV-17957
makes innodb_checksum_algorithm=strict_crc32 strict again
by only allowing one variant of the checksum to match.
WITH_INNODB_BUG_ENDIAN_CRC32: A new cmake option for enabling the
bug-compatible "legacy crc32" checksum. This is only enabled on
big-endian systems by default, to facilitate an upgrade from
MariaDB 10.0 or 10.1. Checked by #ifdef INNODB_BUG_ENDIAN_CRC32.
ut_crc32_byte_by_byte: Remove (unused function).
legacy_big_endian_checksum: Remove. This variable seems to have
unnecessarily complicated the logic. When the weakening is enabled,
we must always fall back to the buggy checksum.
buf_page_check_crc32(): A helper function to compute one or
two CRC-32C variants.
Big endian checksum is needed to workaround 10+ years old bug, where checksum
was calculated incorrectly on big endian hardware. We can still checksum such
tablespaces using software implementation of CRC32.
Contains also:
MDEV-10549 mysqld: sql/handler.cc:2692: int handler::ha_index_first(uchar*): Assertion `table_share->tmp_table != NO_TMP_TABLE || m_lock_type != 2' failed. (branch bb-10.2-jan)
Unlike MySQL, InnoDB still uses THR_LOCK in MariaDB
MDEV-10548 Some of the debug sync waits do not work with InnoDB 5.7 (branch bb-10.2-jan)
enable tests that were fixed in MDEV-10549
MDEV-10548 Some of the debug sync waits do not work with InnoDB 5.7 (branch bb-10.2-jan)
fix main.innodb_mysql_sync - re-enable online alter for partitioned innodb tables
Contains also
MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7
The failure happened because 5.7 has changed the signature of
the bool handler::primary_key_is_clustered() const
virtual function ("const" was added). InnoDB was using the old
signature which caused the function not to be used.
MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7
Fixed mutexing problem on lock_trx_handle_wait. Note that
rpl_parallel and rpl_optimistic_parallel tests still
fail.
MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan)
Reason: incorrect merge
MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan)
Reason: incorrect merge
- Make accelerated checksum available to InnoDB and XtraDB.
- Fall back to slice-by-eight if not available. The mode used is printed on startup.
- Will only build on POWER systems at the moment until CMakeLists are modified
to only add the crc32_power8/ files when building on POWER.
running MySQL-5.7 unittest/gunit/innodb/ut0crc32-t
Before:
1..2
Using software crc32 implementation, CPU is little-endian
ok 1
Using software crc32 implementation, CPU is little-endian
normal CRC32: real 0.148006 sec
normal CRC32: user 0.148000 sec
normal CRC32: sys 0.000000 sec
big endian CRC32: real 0.144293 sec
big endian CRC32: user 0.144000 sec
big endian CRC32: sys 0.000000 sec
ok 2
After:
1..2
Using POWER8 crc32 implementation, CPU is little-endian
ok 1
Using POWER8 crc32 implementation, CPU is little-endian
normal CRC32: real 0.008097 sec
normal CRC32: user 0.008000 sec
normal CRC32: sys 0.000000 sec
big endian CRC32: real 0.147043 sec
big endian CRC32: user 0.144000 sec
big endian CRC32: sys 0.000000 sec
ok 2
Author CRC32 ASM code: Anton Blanchard <anton@au.ibm.com>
ref: https://github.com/antonblanchard/crc32-vpmsum
Signed-off-by: Daniel Black <daniel.black@au.ibm.com>
