trx_t::commit_in_memory(): Do not initiate a redo log write if
the transaction has no visible effect. If anything for this
transaction had been made durable, crash recovery will roll back
the transaction just fine even if the end of ROLLBACK is not
durably written.
Rollbacks of transactions that are associated with XA identifiers
(possibly internally via the binlog) will always be persisted.
The test rpl.rpl_gtid_crash covers this.
commit_try_rebuild(): Invoke trx_t::drop_table_statistics()
with the correct (original) name of the table.
This fixes a regression that was introduced in
commit 1bd681c8b3 (MDEV-25506 part 3).
- InnoDB fails to check DB_COMPUTE_VALUE_FAILED error in
row_merge_read_clustered_index() and wrongly asserts that
the buffer shouldn't be ran out of memory. Alter table
should give warning when the column value is being
truncated.
In commit 49e2c8f0a6 (MDEV-25743)
we made dict_sys_t::find() incompatible with the rest of the
table name hash table operations in case the table name contains
non-ASCII octets (using a compatibility mode that facilitates the
upgrade into the MySQL 5.0 filename-safe encoding) and the target
platform implements signed char.
ut_fold_string(): Remove; replace with my_crc32c(). This also makes
table name hash value calculations independent on whether char
is unsigned or signed.
When doing a ALTER TABLE ... RENAME, MariaDB doesn't rename
original table to #sql-backup, which it does in other cases,
but insteads drops the original table directly. However
this optimization doesn't work in case of InnoDB table
with a foreign key constraint.
During copy algorithm, InnoDB fails to rename the foreign key
constraint(MDEV-25855). With this optimisation, InnoDB also
fails to drop the original table because the table has
FOREIGN Key constraint exist in INNODB_SYS_FOREIGN table.
This leads to orphan .ibd file in InnoDB dictionary.
so disabling this optimization when FK is involved.
Reviewer: monty@mariadb.org
This is a complete rewrite of DROP TABLE, also as part of other DDL,
such as ALTER TABLE, CREATE TABLE...SELECT, TRUNCATE TABLE.
The background DROP TABLE queue hack is removed.
If a transaction needs to drop and create a table by the same name
(like TRUNCATE TABLE does), it must first rename the table to an
internal #sql-ib name. No committed version of the data dictionary
will include any #sql-ib tables, because whenever a transaction
renames a table to a #sql-ib name, it will also drop that table.
Either the rename will be rolled back, or the drop will be committed.
Data files will be unlinked after the transaction has been committed
and a FILE_RENAME record has been durably written. The file will
actually be deleted when the detached file handle returned by
fil_delete_tablespace() will be closed, after the latches have been
released. It is possible that a purge of the delete of the SYS_INDEXES
record for the clustered index will execute fil_delete_tablespace()
concurrently with the DDL transaction. In that case, the thread that
arrives later will wait for the other thread to finish.
HTON_TRUNCATE_REQUIRES_EXCLUSIVE_USE: A new handler flag.
ha_innobase::truncate() now requires that all other references to
the table be released in advance. This was implemented by Monty.
ha_innobase::delete_table(): If CREATE TABLE..SELECT is detected,
we will "hijack" the current transaction, drop the table in
the current transaction and commit the current transaction.
This essentially fixes MDEV-21602. There is a FIXME comment about
making the check less failure-prone.
ha_innobase::truncate(), ha_innobase::delete_table():
Implement a fast path for temporary tables. We will no longer allow
temporary tables to use the adaptive hash index.
dict_table_t::mdl_name: The original table name for the purpose of
acquiring MDL in purge, to prevent a race condition between a
DDL transaction that is dropping a table, and purge processing
undo log records of DML that had executed before the DDL operation.
For #sql-backup- tables during ALTER TABLE...ALGORITHM=COPY, the
dict_table_t::mdl_name will differ from dict_table_t::name.
dict_table_t::parse_name(): Use mdl_name instead of name.
dict_table_rename_in_cache(): Update mdl_name.
For the internal FTS_ tables of FULLTEXT INDEX, purge would
acquire MDL on the FTS_ table name, but not on the main table,
and therefore it would be able to run concurrently with a
DDL transaction that is dropping the table. Previously, the
DROP TABLE queue hack prevented a race between purge and DDL.
For now, we introduce purge_sys.stop_FTS() to prevent purge from
opening any table, while a DDL transaction that may drop FTS_
tables is in progress. The function fts_lock_table(), which will
be invoked before the dictionary is locked, will wait for
purge to release any table handles.
trx_t::drop_table_statistics(): Drop statistics for the table.
This replaces dict_stats_drop_index(). We will drop or rename
persistent statistics atomically as part of DDL transactions.
On lock conflict for dropping statistics, we will fail instantly
with DB_LOCK_WAIT_TIMEOUT, because we will be holding the
exclusive data dictionary latch.
trx_t::commit_cleanup(): Separated from trx_t::commit_in_memory().
Relax an assertion around fts_commit() and allow DB_LOCK_WAIT_TIMEOUT
in addition to DB_DUPLICATE_KEY. The call to fts_commit() is
entirely misplaced here and may obviously break the consistency
of transactions that affect FULLTEXT INDEX. It needs to be fixed
separately.
dict_table_t::n_foreign_key_checks_running: Remove (MDEV-21175).
The counter was a work-around for missing meta-data locking (MDL)
on the SQL layer, and not really needed in MariaDB.
ER_TABLE_IN_FK_CHECK: Replaced with ER_UNUSED_28.
HA_ERR_TABLE_IN_FK_CHECK: Remove.
row_ins_check_foreign_constraints(): Do not acquire
dict_sys.latch either. The SQL-layer MDL will protect us.
This was reviewed by Thirunarayanan Balathandayuthapani
and tested by Matthias Leich.
Many InnoDB data dictionary cache operations require that the
table name be copied so that it will be NUL terminated.
(For example, SYS_TABLES.NAME is not guaranteed to be NUL-terminated.)
dict_table_t::is_garbage_name(): Check if a name belongs to
the background drop table queue.
dict_check_if_system_table_exists(): Remove.
dict_sys_t::load_sys_tables(): Load the non-hard-coded system tables
SYS_FOREIGN, SYS_FOREIGN_COLS, SYS_VIRTUAL on startup.
dict_sys_t::create_or_check_sys_tables(): Replaces
dict_create_or_check_foreign_constraint_tables() and
dict_create_or_check_sys_virtual().
dict_sys_t::load_table(): Replaces dict_table_get_low()
and dict_load_table().
dict_sys_t::find_table(): Renamed from get_table().
dict_sys_t::sys_tables_exist(): Check whether all the non-hard-coded
tables SYS_FOREIGN, SYS_FOREIGN_COLS, SYS_VIRTUAL exist.
trx_t::has_stats_table_lock(): Moved to dict0stats.cc.
Some error messages will now report table names in the internal
databasename/tablename format, instead of `databasename`.`tablename`.
Ever since MDEV-24589, MDEV-18518 and other recent changes corrected the
rollback of CREATE and DROP operations, there is no need to crash the
server if we run out of space during a DROP operation. We can simply
let the transaction be rolled back.
MDEV-25604 Atomic DDL: Binlog event written upon recovery does not
have default database
The purpose of this task is to ensure that ALTER TABLE is atomic even if
the MariaDB server would be killed at any point of the alter table.
This means that either the ALTER TABLE succeeds (including that triggers,
the status tables and the binary log are updated) or things should be
reverted to their original state.
If the server crashes before the new version is fully up to date and
commited, it will revert to the original table and remove all
temporary files and tables.
If the new version is commited, crash recovery will use the new version,
and update triggers, the status tables and the binary log.
The one execption is ALTER TABLE .. RENAME .. where no changes are done
to table definition. This one will work as RENAME and roll back unless
the whole statement completed, including updating the binary log (if
enabled).
Other changes:
- Added handlerton->check_version() function to allow the ddl recovery
code to check, in case of inplace alter table, if the table in the
storage engine is of the new or old version.
- Added handler->table_version() so that an engine can report the current
version of the table. This should be changed each time the table
definition changes.
- Added ha_signal_ddl_recovery_done() and
handlerton::signal_ddl_recovery_done() to inform all handlers when
ddl recovery has been done. (Needed by InnoDB).
- Added handlerton call inplace_alter_table_committed, to signal engine
that ddl_log has been closed for the alter table query.
- Added new handerton flag
HTON_REQUIRES_NOTIFY_TABLEDEF_CHANGED_AFTER_COMMIT to signal when we
should call hton->notify_tabledef_changed() during
mysql_inplace_alter_table. This was required as MyRocks and InnoDB
needed the call at different times.
- Added function server_uuid_value() to be able to generate a temporary
xid when ddl recovery writes the query to the binary log. This is
needed to be able to handle crashes during ddl log recovery.
- Moved freeing of the frm definition to end of mysql_alter_table() to
remove duplicate code and have a common exit strategy.
-------
InnoDB part of atomic ALTER TABLE
(Implemented by Marko Mäkelä)
innodb_check_version(): Compare the saved dict_table_t::def_trx_id
to determine whether an ALTER TABLE operation was committed.
We must correctly recover dict_table_t::def_trx_id for this to work.
Before purge removes any trace of DB_TRX_ID from system tables, it
will make an effort to load the user table into the cache, so that
the dict_table_t::def_trx_id can be recovered.
ha_innobase::table_version(): return garbage, or the trx_id that would
be used for committing an ALTER TABLE operation.
In InnoDB, table names starting with #sql-ib will remain special:
they will be dropped on startup. This may be revisited later in
MDEV-18518 when we implement proper undo logging and rollback
for creating or dropping multiple tables in a transaction.
Table names starting with #sql will retain some special meaning:
dict_table_t::parse_name() will not consider such names for
MDL acquisition, and dict_table_rename_in_cache() will treat such
names specially when handling FOREIGN KEY constraints.
Simplify InnoDB DROP INDEX.
Prevent purge wakeup
To ensure that dict_table_t::def_trx_id will be recovered correctly
in case the server is killed before ddl_log_complete(), we will block
the purge of any history in SYS_TABLES, SYS_INDEXES, SYS_COLUMNS
between ha_innobase::commit_inplace_alter_table(commit=true)
(purge_sys.stop_SYS()) and purge_sys.resume_SYS().
The completion callback purge_sys.resume_SYS() must be between
ddl_log_complete() and MDL release.
--------
MyRocks support for atomic ALTER TABLE
(Implemented by Sergui Petrunia)
Implement these SE API functions:
- ha_rocksdb::table_version()
- hton->check_version = rocksdb_check_versionMyRocks data dictionary
now stores table version for each table.
(Absence of table version record is interpreted as table_version=0,
that is, which means no upgrade changes are needed)
- For inplace alter table of a partitioned table, call the underlying
handlerton when checking if the table is ok. This assumes that the
partition engine commits all changes at once.
There are a few different cases to consider
Logging of CREATE TABLE and CREATE TABLE ... LIKE
- If REPLACE is used and there was an existing table, DDL log the drop of
the table.
- If discovery of table is to be done
- DDL LOG create table
else
- DDL log create table (with engine type)
- create the table
- If table was created
- Log entry to binary log with xid
- Mark DDL log completed
Crash recovery:
- If query was in binary log do nothing and exit
- If discoverted table
- Delete the .frm file
-else
- Drop created table and frm file
- If table was dropped, write a DROP TABLE statement in binary log
CREATE TABLE ... SELECT required a little more work as when one is using
statement logging the query is written to the binary log before commit is
done.
This was fixed by adding a DROP TABLE to the binary log during crash
recovery if the ddl log entry was not closed. In this case the binary log
will contain:
CREATE TABLE xxx ... SELECT ....
DROP TABLE xxx;
Other things:
- Added debug_crash_here() functionality to Aria to be able to test
crash in create table between the creation of the .MAI and the .MAD files.
This patch changes the main name of 3 byte character set from utf8 to
utf8mb3. New old_mode UTF8_IS_UTF8MB3 is added and set TRUE by default,
so that utf8 would mean utf8mb3. If not set, utf8 would mean utf8mb4.
During data file creation, InnoDB holds dict_sys mutex, tries to
write page 0 of the file and flushes the file. This not only causing
unnecessary contention but also a deviation from the write-ahead
logging protocol.
The clean sequence of operations is that we first start a dictionary
transaction and write SYS_TABLES and SYS_INDEXES records that identify
the tablespace. Then, we durably write a FILE_CREATE record to the
write-ahead log and create the file.
Recovery should not unnecessarily insist that the first page of each
data file that is referred to by the redo log is valid. It must be
enough that page 0 of the tablespace can be initialized based on the
redo log contents.
We introduce a new data structure deferred_spaces that keeps track
of corrupted-looking files during recovery. The data structure holds
the last LSN of a FILE_ record referring to the data file, the
tablespace identifier, and the last known file name.
There are two scenarios can happen during recovery:
i) Sufficient memory: InnoDB can reconstruct the
tablespace after parsing all redo log records.
ii) Insufficient memory(multiple apply phase): InnoDB should
store the deferred tablespace redo logs even though
tablespace is not present. InnoDB should start constructing
the tablespace when it first encounters deferred tablespace
id.
Mariabackup copies the zero filled ibd file in backup_fix_ddl() as
the extension of .new file. Mariabackup test case does page flushing
when it deals with DDL operation during backup operation.
fil_ibd_create(): Remove the write of page0 and flushing of file
fil_ibd_load(): Return FIL_LOAD_DEFER if the tablespace has
zero filled page0
Datafile: Clean up the error handling, and do not report errors
if we are in the middle of recovery. The caller will check
Datafile::m_defer.
fil_node_t::deferred: Indicates whether the tablespace loading was
deferred during recovery
FIL_LOAD_DEFER: Returned by fil_ibd_load() to indicate that tablespace
file was cannot be loaded.
recv_sys_t::recover_deferred(): Invoke deferred_spaces.create() to
initialize fil_space_t based on buffered metadata and records to
initialize page 0. Ignore the flags in fil_name_t, because they are
intentionally invalid.
fil_name_process(): Update deferred_spaces.
recv_sys_t::parse(): Store the redo log if the tablespace id
is present in deferred spaces
recv_sys_t::recover_low(): Should recover the first page of
the tablespace even though the tablespace instance is not
present
recv_sys_t::apply(): Initialize the deferred tablespace
before applying the deferred tablespace records
recv_validate_tablespace(): Skip the validation for deferred_spaces.
recv_rename_files(): Moved and revised from recv_sys_t::apply().
For deferred-recovery tablespaces, do not attempt to rename the
file if a deferred-recovery tablespace is associated with the name.
recv_recovery_from_checkpoint_start(): Invoke recv_rename_files()
and initialize all deferred tablespaces before applying redo log.
fil_node_t::read_page0(): Skip page0 validation if the tablespace
is deferred
buf_page_create_deferred(): A variant of buf_page_create() when
the fil_space_t is not available yet
This is joint work with Thirunarayanan Balathandayuthapani,
who implemented an initial prototype.
The counter metadata_table_reference_count was not updated consistently
ever since mysql-server@65c0af9a1dedae43b63797134aff6b32304ced52
or commit 2e814d4702
introduced dict_table_t::release().
The counter metadata_table_handles_closed was being incremented
unconditionally in ha_innobase::close(), while the corresponding
counter metadata_table_handles_opened would be incremented in
ha_innobase::open() if the function returned early due to an error.
MONITOR_TRX_ACTIVE: Remove. The count is not being updated consistently,
and it would also include read-only transactions that are otherwise
fully invisible to any other threads.
If it later turns out that a reliable count of active transactions
is needed, it can be exposed via a different interface.
trx_commit_for_mysql(): If the transaction was not started, return
immediately.
The test innodb.doublewrite could occasionally fail with 64KiB page size
because the page 0 would no longer be in the doublewrite buffer.
Let us stop purge before the server is killed, and ensure that
the entire buffer pool will be flushed before we initiate an extra
write of page 0.
Before we create an InnoDB data file, we must have persistently
started a DDL transaction and written a record in SYS_INDEXES
as well as a FILE_CREATE record for creating the file.
In that way, if InnoDB is killed before the DDL transaction is
committed, the rollback will be able to delete the file in
dict_drop_index_tree().
dict_build_table_def_step(): Do not create the tablespace.
At this point, we have not written any log, not even for
inserting the SYS_TABLES record.
dict_create_sys_indexes_tuple(): Relax an assertion to tolerate
a missing tablespace before the first index has been created in
dict_create_index_step().
dict_build_index_def_step(): Relax the dict_table_open_on_name()
parameter, because no tablespace may be available yet.
tab_create_graph_create(), row_create_table_for_mysql(), tab_node_t:
Remove key_id, mode.
ind_create_graph_create(), row_create_index_for_mysql(), ind_node_t:
Add key_id, mode.
dict_create_index_space(): New function, to create the tablespace
during clustered index creation.
dict_create_index_step(): After the SYS_INDEXES record has been
written, invoke dict_create_index_space() to create the tablespace
if needed.
fil_ibd_create(): Before creating the file, persistently write a
FILE_CREATE record. This will also ensure that an incomplete DDL
transaction will be recovered. After creating the file, invoke
fsp_header_init().
after previous error upon multi-RENAME
- InnoDB fails to rename the foreign key constraint while
rollbacking the rename operation. In that case, InnoDB should
rename the FK constraint too.
fil_ibd_load(): Remove a message that is basically saying that
everything works as expected. The other "Ignoring data file" message
about the presence of an extraneous file will be retained
(and expected by the test innodb.log_file_name).
In commit 91599701d0 (MDEV-25312)
some recovery code for TRUNCATE TABLE was broken
causing a regression in a case where undo log for a RENAME TABLE
operation had been durably written but the tablespace had not been
renamed yet.
row_rename_table_for_mysql(): Add a DEBUG_SYNC point for the
test case, and simplify the logic and trim the error messages.
fil_space_t::rename(): Simplify the operation. Merge the necessary
part of fil_rename_tablespace_check(). If there is no change to
the file name, do nothing.
dict_table_t::rename_tablespace(): Refactored from
dict_table_rename_in_cache().
row_undo_ins_parse_undo_rec(): On rolling back TRX_UNDO_RENAME_TABLE,
invoke dict_table_t::rename_tablespace() even if the table name matches.
os_file_rename_func(): Temporarily relax an assertion that would
fail during the recovery in the test innodb.truncate_crash.
Problem:
=======
InnoDB alter fails before applying instant operation. So rollback
assigns wrong column to the secondary index field. It leads
to the assert failure in the consecutive alter.
Fix:
===
InnoDB shouldn't do rollback of instant operation when it fails
before applying instant operation.
InnoDB startup hangs if a DDL transaction needs to be
rolled back and a recovered transaction on statistics
tables exists. In that case, InnoDB should rollback
the transaction which holds locks on innodb_table_stats
or innodb_index_stats during trx_rollback_or_clean_recovered().
InnoDB fails to fetch the index type when innodb dictionary
doesn't match with frm. InnoDB should return corrupted if it
can't find the index in ha_innobase::index_type().
