In the parent commit, dict_sys.latch could theoretically have been
replaced with a mutex. But, we can do better and merge dict_sys.mutex
into dict_sys.latch. Generally, every occurrence of dict_sys.mutex_lock()
will be replaced with dict_sys.lock().
The PERFORMANCE_SCHEMA instrumentation for dict_sys_mutex
will be removed along with dict_sys.mutex. The dict_sys.latch
will remain instrumented as dict_operation_lock.
Some use of dict_sys.lock() will be replaced with dict_sys.freeze(),
which we will reintroduce for the new shared mode. Most notably,
concurrent table lookups are possible as long as the tables are present
in the dict_sys cache. In particular, this will allow more concurrency
among InnoDB purge workers.
Because dict_sys.mutex will no longer 'throttle' the threads that purge
InnoDB transaction history, a performance degradation may be observed
unless innodb_purge_threads=1.
The table cache eviction policy will become FIFO-like,
similar to what happened to fil_system.LRU
in commit 45ed9dd957.
The name of the list dict_sys.table_LRU will become somewhat misleading;
that list contains tables that may be evicted, even though the
eviction policy no longer is least-recently-used but first-in-first-out.
(Note: Tables can never be evicted as long as locks exist on them or
the tables are in use by some thread.)
As demonstrated by the test perfschema.sxlock_func, there
will be less contention on dict_sys.latch, because some previous
use of exclusive latches will be replaced with shared latches.
fts_parse_sql_no_dict_lock(): Replaced with pars_sql().
fts_get_table_name_prefix(): Merged to fts_optimize_create().
dict_stats_update_transient_for_index(): Deduplicated some code.
ha_innobase::info_low(), dict_stats_stop_bg(): Use a combination
of dict_sys.latch and table->stats_mutex_lock() to cover the
changes of BG_STAT_SHOULD_QUIT, because the flag is being read
in dict_stats_update_persistent() while not holding dict_sys.latch.
row_discard_tablespace_for_mysql(): Protect stats_bg_flag by
exclusive dict_sys.latch, like most other code does.
row_quiesce_table_has_fts_index(): Remove unnecessary mutex
acquisition. FLUSH TABLES...FOR EXPORT is protected by MDL.
row_import::set_root_by_heuristic(): Remove unnecessary mutex
acquisition. ALTER TABLE...IMPORT TABLESPACE is protected by MDL.
row_ins_sec_index_entry_low(): Replace a call
to dict_set_corrupted_index_cache_only(). Reads of index->type
were not really protected by dict_sys.mutex, and writes
(flagging an index corrupted) should be extremely rare.
dict_stats_process_entry_from_defrag_pool(): Only freeze the dictionary,
do not lock it exclusively.
dict_stats_wait_bg_to_stop_using_table(), DICT_BG_YIELD: Remove trx.
We can simply invoke dict_sys.unlock() and dict_sys.lock() directly.
dict_acquire_mdl_shared()<trylock=false>: Assert that dict_sys.latch is
only held in shared more, not exclusive mode. Only acquire it in
exclusive mode if the table needs to be loaded to the cache.
dict_sys_t::acquire(): Remove. Relocating elements in dict_sys.table_LRU
would require holding an exclusive latch, which we want to avoid
for performance reasons.
dict_sys_t::allow_eviction(): Add the table first to dict_sys.table_LRU,
to compensate for the removal of dict_sys_t::acquire(). This function
is only invoked by INFORMATION_SCHEMA.INNODB_SYS_TABLESTATS.
dict_table_open_on_id(), dict_table_open_on_name(): If dict_locked=false,
try to acquire dict_sys.latch in shared mode. Only acquire the latch in
exclusive mode if the table is not found in the cache.
Reviewed by: Thirunarayanan Balathandayuthapani
Let us replace os_event_t with mysql_cond_t, and replace the
necessary ib_mutex_t with mysql_mutex_t so that they can be
used with condition variables.
Also, let us replace polling (os_thread_sleep() or timed waits)
with plain mysql_cond_wait() wherever possible.
Furthermore, we will use the lightweight srw_mutex for trx_t::mutex,
to hopefully reduce contention on lock_sys.mutex.
FIXME: Add test coverage of
mariabackup --backup --kill-long-queries-timeout
fts_drop_orphaned_tables() takes long time to remove the orphaned
FTS tables. In order to reduce the time, do the following:
- Traverse fil_system.space_list and construct a set of
table_id,index_id of all FTS_*.ibd tablespaces.
- Traverse the sys_indexes table and ignore the entry
from the above collection if it exist.
- Existing elements in the collection can be considered as
orphaned fts tables. construct the table name from
(table_id,index_id) and invoke fts_drop_tables().
- Removed DICT_TF2_FTS_AUX_HEX_NAME flag usage from upgrade.
- is_aux_table() in dict_table_t to check whether the given name
is fts auxiliary table
fts_space_set_t is a structure to store set of parent table id
and index id
- Remove unused FTS function in fts0fts.cc
- Remove the fulltext index in row_format_redundant test case.
Because it deals with the condition that SYS_TABLES does have
corrupted entry and valid entry exist in SYS_INDEXES.
trx_t::rollback(): Renamed from trx_rollback_to_savepoint().
trx_t::rollback_low(): Renamed from trx_rollback_to_savepoint_low().
fts_sql_commit(): Defined as an alias of trx_commit_for_mysql().
fts_sql_rollback(): Defined as an alias of trx_t::rollback().
fts_rename_aux_tables_to_hex_format(): Fix the error handling
that likely never worked because we failed to roll back the
first transaction.
Problem:
=======
During dropping of fts index, InnoDB waits for fts_optimize_remove_table()
and it holds dict_sys->mutex and dict_operaiton_lock even though the
table id is not present in the queue. But fts_optimize_thread does wait
for dict_sys->mutex to process the unrelated table id from the slot.
Solution:
========
Whenever table is added to fts_optimize_wq, update the fts_status
of in-memory fts subsystem to TABLE_IN_QUEUE. Whenever drop index
wants to remove table from the queue, it can check the fts_status
to decide whether it should send the MSG_DELETE_TABLE to the queue.
Removed the following functions because these are all deadcode.
dict_table_wait_for_bg_threads_to_exit(),
fts_wait_for_background_thread_to_start(),fts_start_shutdown(), fts_shudown().
fts_get_table_name(): Output to a caller-allocated buffer.
fts_get_table_name_prefix(): Use the lower-overhead allocation
ut_malloc() instead of mem_alloc().
This is based on mysql/mysql-server@d1584b9f38
in MySQL 5.7.4.
Also, related to MDEV-15522, MDEV-17304, MDEV-17835,
remove the Galera xtrabackup tests, because xtrabackup never worked
with MariaDB Server 10.3 due to InnoDB redo log format changes.
This is a backport of the following fix from MySQL 5.7.23.
Some code refactoring has been omitted, and the test case has
been adapted to MariaDB.
commit 7a689acaa65e9d602575f7aa53fe36a64a07460f
Author: Krzysztof Kapuścik <krzysztof.kapuscik@oracle.com>
Date: Tue Mar 13 12:34:03 2018 +0100
Bug#27082268 Invalid FTS sync synchronization
The fix closes two issues:
Bug #27082268 - INNODB: FAILING ASSERTION: SYM_NODE->TABLE != NULL DURING FTS SYNC
Bug #27095935 - DEADLOCK BETWEEN FTS_DROP_INDEX AND FTS_OPTIMIZE_SYNC_TABLE
Both issues were related to a FTS cache sync being done during
operations that perfomed DDL actions on internal FTS tables
(ALTER TABLE, TRUNCATE). In some cases the FTS tables and/or
internal cache structures could get removed while still being
used to perform FTS synchronization leading to crashes. In other
the sync operations could not get finishes as it was waiting for
dict lock which was taken by thread waiting for the background
sync to be finished.
The changes done includes:
- Stopping background operations during ALTER TABLE and TRUNCATE.
- Removal of unused code in FTS.
- Cleanup of FTS sync related code to make it more readable and
easier to maintain.
RB#18262
Remove unused InnoDB function parameters and functions.
i_s_sys_virtual_fill_table(): Do not allocate heap memory.
mtr_is_block_fix(): Replace with mtr_memo_contains().
mtr_is_page_fix(): Replace with mtr_memo_contains_page().
When MySQL 5.7 introduced fulltext parser plugins to InnoDB,
it hard-coded the plugin name "ngram" to mean something special.
Because -fsanitize=undefined was issuing warnings for the
assignment in row_merge_create_index() that the value is out of
range for Boolean, we remove this code that was not intended to
be used in MariaDB 10.2.
fts_check_token(): Remove the special logic for N-gram tokens.
InnoDB defines some functions that are not called at all.
Other functions are called, but only from the same compilation unit.
Remove some function declarations and definitions, and add 'static'
keywords. Some symbols must be kept for separately compiled tools,
such as innochecksum.
Also, remove empty .ic files that were not removed by my MySQL commit.
Problem:
InnoDB used to support a compilation mode that allowed to choose
whether the function definitions in .ic files are to be inlined or not.
This stopped making sense when InnoDB moved to C++ in MySQL 5.6
(and ha_innodb.cc started to #include .ic files), and more so in
MySQL 5.7 when inline methods and functions were introduced
in .h files.
Solution:
Remove all references to UNIV_NONINL and UNIV_MUST_NOT_INLINE from
all files, assuming that the symbols are never defined.
Remove the files fut0fut.cc and ut0byte.cc which only mattered when
UNIV_NONINL was defined.
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
