dict_sys.lock(), dict_sys_lock(): Acquire both mutex and latch.
dict_sys.unlock(), dict_sys_unlock(): Release both mutex and latch.
dict_sys.assert_locked(): Assert that both mutex and latch are held.
In MySQL 5.7.8 an extra level of pointer indirection was added to
dict_operation_lock and some other rw_lock_t without solid justification,
in mysql/mysql-server@52720f1772.
Let us revert that change and remove the rather useless rw_lock_t
constructor and destructor and the magic_n field. In this way,
some unnecessary pointer dereferences and heap allocation will be avoided
and debugging might be a little easier.
log_checkpoint(), log_make_checkpoint_at(): Remove the parameter
write_always. It seems that the primary purpose of this parameter
was to ensure in the function recv_reset_logs() that both checkpoint
header pages will be overwritten, when the function is called from
the never-enabled function recv_recovery_from_archive_start().
create_log_files(): Merge recv_reset_logs() to its only caller.
Debug instrumentation: Prefer to flush the redo log, instead of
triggering a redo log checkpoint.
page_header_set_field(): Disable a debug assertion that will
always fail due to MDEV-19344, now that we no longer initiate
a redo log checkpoint before an injected crash.
In recv_reset_logs() there used to be two calls to
log_make_checkpoint_at(). The apparent purpose of this was
to ensure that both InnoDB redo log checkpoint header pages
will be initialized or overwritten.
The second call was removed (without any explanation) in MySQL 5.6.3:
mysql/mysql-server@4ca37968da
In MySQL 5.6.8 WL#6494, starting with
mysql/mysql-server@00a0ba8ad9
the function recv_reset_logs() was not only invoked during
InnoDB data file initialization, but also during a regular
startup when the redo log is being resized.
mysql/mysql-server@45e9167983
in MySQL 5.7.2 removed the UNIV_LOG_ARCHIVE code, but still
did not remove the parameter write_always.
Normally, the InnoDB master thread executes InnoDB log checkpoints
so frequently that bugs in crash recovery or redo logging can be
hard to reproduce. This is because crash recovery would start replaying
the log only from the latest checkpoint. Because the InnoDB redo log
format only allows saving information for at most 2 latest checkpoints,
and because the log files are written in a circular fashion, it would
be challenging to implement a debug option that would start the redo
log apply from the very start of the redo log file.
MySQL 5.7 introduced the class page_size_t and increased the size of
buffer pool page descriptors by introducing this object to them.
Maybe the intention of this exercise was to prepare for a future
where the buffer pool could accommodate multiple page sizes.
But that future never arrived, not even in MySQL 8.0. It is much
easier to manage a pool of a single page size, and typically all
storage devices of an InnoDB instance benefit from using the same
page size.
Let us remove page_size_t from MariaDB Server. This will make it
easier to remove support for ROW_FORMAT=COMPRESSED (or make it a
compile-time option) in the future, just by removing various
occurrences of zip_size.
dict_sys_get_size(): Replace the time-consuming loop with
a crude estimate that can be computed without holding any mutex.
Even before dict_sys->size was removed in MDEV-13325,
not all memory allocations by the InnoDB data dictionary cache
were being accounted for. One example is foreign key constraints.
Another example is virtual column metadata, starting with 10.2.
purge_sys_t::m_paused transition to Atomic_counter.
paused_latched() doesn't make much sense: in this particular case it is
as fast as atomic load. The sole caller has to reload it's value anyway,
due to rw_lock_x_lock(&purge_sys.latch) issuing acquire memory barrier.
Now that InnoDB startup drops tables whose name starts with #sql,
the table ID alone should be enough to create a unique table name.
dict_temp_file_num, dict_mem_init(): Remove.
dict_mem_create_temporary_tablename(): Use a combination of
"#sql-ib" and the ID of the table that is being rebuilt
in TRUNCATE TABLE, or discarded in the commit of table-rebuilding
ALTER TABLE...ALGORITHM=INPLACE, or deferred to the DROP queue.
Thanks to Sergey Vojtovich for pointing this out.
Rename the 10.2-specific configuration option innodb_unsafe_truncate
to innodb_safe_truncate, and invert its value.
The default (for now) is innodb_safe_truncate=OFF, to avoid
disrupting users with an undo and redo log format change within
a Generally Available (GA) release series.
While MariaDB Server 10.2 is not really guaranteed to be compatible
with Percona XtraBackup 2.4 (for example, the MySQL 5.7 undo log format
change that could be present in XtraBackup, but was reverted from
MariaDB in MDEV-12289), we do not want to disrupt users who have
deployed xtrabackup and MariaDB Server 10.2 in their environments.
With this change, MariaDB 10.2 will continue to use the backup-unsafe
TRUNCATE TABLE code, so that neither the undo log nor the redo log
formats will change in an incompatible way.
Undo tablespace truncation will keep using the redo log only. Recovery
or backup with old code will fail to shrink the undo tablespace files,
but the contents will be recovered just fine.
In the MariaDB Server 10.2 series only, we introduce the configuration
parameter innodb_unsafe_truncate and make it ON by default. To allow
MariaDB Backup (mariabackup) to work properly with TRUNCATE TABLE
operations, use loose_innodb_unsafe_truncate=OFF.
MariaDB Server 10.3.10 and later releases will always use the
backup-safe TRUNCATE TABLE, and this parameter will not be
added there.
recv_recovery_rollback_active(): Skip row_mysql_drop_garbage_tables()
unless innodb_unsafe_truncate=OFF. It is too unsafe to drop orphan
tables if RENAME operations are not transactional within InnoDB.
LOG_HEADER_FORMAT_10_3: Replaces LOG_HEADER_FORMAT_CURRENT.
log_init(), log_group_file_header_flush(),
srv_prepare_to_delete_redo_log_files(),
innobase_start_or_create_for_mysql(): Choose the redo log format
and subformat based on the value of innodb_unsafe_truncate.
Stop supporting the additional *trunc.log files that were
introduced via MySQL 5.7 to MariaDB Server 10.2 and 10.3.
DB_TABLESPACE_TRUNCATED: Remove.
purge_sys.truncate: A new structure to track undo tablespace
file truncation.
srv_start(): Remove the call to buf_pool_invalidate(). It is
no longer necessary, given that we no longer access things in
ways that violate the ARIES protocol. This call was originally
added for innodb_file_format, and it may later have been necessary
for the proper function of the MySQL 5.7 TRUNCATE recovery, which
we are now removing.
trx_purge_cleanse_purge_queue(): Take the undo tablespace as a
parameter.
trx_purge_truncate_history(): Rewrite everything mostly in a
single function, replacing references to undo::Truncate.
recv_apply_hashed_log_recs(): If any redo log is to be applied,
and if the log_sys.log.subformat indicates that separately
logged truncate may have been used, refuse to proceed except if
innodb_force_recovery is set. We will still refuse crash-upgrade
if TRUNCATE TABLE was logged. Undo tablespace truncation would
only be logged in undo*trunc.log files, which we are no longer
checking for.
buf_dump(): Only generate the output when shutdown is in progress.
log_write_up_to(): Only generate the output before actually writing
to the redo log files.
srv_purge_should_exit(): Rate-limit the output, and instead of
displaying the work done, indicate the work that remains to be done
until the completion of the slow shutdown.
MDEV-9931 introduced a counter for keeping track of reads of the
first page of InnoDB data files, because the original implementation
of data-at-rest-encryption for InnoDB introduced new code paths for
reading the pages.
Ultimately, the extra reads of the first page were removed, and
the encryption subsystem will be initialized whenever we first read
the first page of each data file, in fil_node_open_file(). It should not
be that interesting to observe how many times an InnoDB data file was
opened for the first time.
thd_destructor_proxy(): Ensure that purge actually exits,
like the logic should have been ever since MDEV-14080.
srv_purge_shutdown(): A new function to wait for the
purge coordinator to exit. Before exiting, the
purge coordinator will ensure that all purge workers have exited.
