Our benchmarking efforts indicate that the reasons for splitting the
buf_pool in commit c18084f71b
have mostly gone away, possibly as a result of
mysql/mysql-server@ce6109ebfd
or similar work.
Only in one write-heavy benchmark where the working set size is
ten times the buffer pool size, the buf_pool->mutex would be
less contended with 4 buffer pool instances than with 1 instance,
in buf_page_io_complete(). That contention could be alleviated
further by making more use of std::atomic and by splitting
buf_pool_t::mutex further (MDEV-15053).
We will deprecate and ignore the following parameters:
innodb_buffer_pool_instances
innodb_page_cleaners
There will be only one buffer pool and one page cleaner task.
In a number of INFORMATION_SCHEMA views, columns that indicated
the buffer pool instance will be removed:
information_schema.innodb_buffer_page.pool_id
information_schema.innodb_buffer_page_lru.pool_id
information_schema.innodb_buffer_pool_stats.pool_id
information_schema.innodb_cmpmem.buffer_pool_instance
information_schema.innodb_cmpmem_reset.buffer_pool_instance
During native table rebuild or index creation, InnoDB used to skip
redo logging and write MLOG_INDEX_LOAD records to inform crash recovery
and Mariabackup of the gaps in redo log. This is fragile and prohibits
some optimizations, such as skipping the doublewrite buffer for
newly (re)initialized pages (MDEV-19738).
row_merge_write_redo(): Remove. We do not write MLOG_INDEX_LOAD
records any more. Instead, we write full redo log.
FlushObserver: Remove.
fseg_free_page_func(): Remove the parameter log. Redo logging
cannot be disabled.
fil_space_t::redo_skipped_count: Remove.
We cannot remove buf_block_t::skip_flush_check, because PageBulk
will temporarily generate invalid B-tree pages in the buffer pool.
- n_ext value may be less than dtuple_get_n_ext(dtuple) when PK is being
updated and new record inherits the externally stored fields from
delete mark old record.
row_log_table_get_pk_old_col(): For replacing a NULL value for a
column of the being-added primary key, look up the correct
default value, even if columns had been instantly reordered or
dropped earlier. This ought to have been broken ever since
commit 0e5a4ac253 (MDEV-15562).
ha_innobase::commit_inplace_alter_table(): After
ALTER_STORED_COLUMN_ORDER, ensure that the virtual column metadata
will be reloaded also when the table is not being rebuilt.
This bug is a cousin of MDEV-18719 and MDEV-20190, which failed to
relax a debug assertion in one more code path.
row_log_table_apply_convert_mrec(): Use dict_col_t::same_format()
and ignore all format-agnostic flags in the assertions.
WL#6326 in MariaDB 10.2.2 introduced a potential hang on purge or rollback
when an index tree is being shrunk by multiple levels.
This fix is based on
mysql/mysql-server@f2c5852630
with the main difference that our version of the test case uses
DEBUG_SYNC instrumentation on ROLLBACK, not on purge.
btr_cur_will_modify_tree(): Simplify the check further.
This is the actual bug fix.
row_undo_mod_remove_clust_low(), row_undo_mod_clust(): Add DEBUG_SYNC
instrumentation for the test case.
By default (innodb_strict_mode=ON), InnoDB attempts to guarantee
at DDL time that any INSERT to the table can succeed.
MDEV-19292 recently revised the "row size too large" check in InnoDB.
The check still is somewhat inaccurate;
that should be addressed in MDEV-20194.
Note: If a table contains multiple long string columns so that each column
is part of a column prefix index, then an UPDATE that attempts to modify
all those columns at once may fail, because the undo log record might
not fit in a single undo log page (of innodb_page_size). In the worst case,
the undo log record would grow by about 3KiB of for each updated column.
The DDL-time check (since the InnoDB Plugin for MySQL 5.1) is optional
in the sense that when the maximum B-tree record size or undo log
record size would be exceeded, the DML operation will fail and the
transaction will be properly rolled back.
create_table_info_t::row_size_is_acceptable(): Add the parameter
'bool strict' so that innodb_strict_mode=ON can be overridden during
TRUNCATE, OPTIMIZE and ALTER TABLE...FORCE (when the storage format
is not changing).
create_table_info_t::create_table(): Perform a sloppy check for
TRUNCATE TABLE (create_fk=false).
prepare_inplace_alter_table_dict(): Perform a sloppy check for
simple operations.
trx_is_strict(): Remove. The function became unused in
commit 98694ab0cb (MDEV-20949).
Apparently, regular expression operations that remove entire lines
of output do not work with list_files, and hence the adjustments in
commit 1c282d4bc4 were ineffective.
For cat_file (preceded by list_files_write_file) the replace_regex
does work.
For some reason, for suite/parts/inc/partition_crash_exchange.inc
some file names will be lost when using list_files_write_file
instead of list_files.
We use a precise pattern match. dict_mem_create_temporary_tablename()
is generating #sql-ib names followed by decimal digits only.
This is joint work with Thirunarayanan Balathandayuthapani.
The MDL interface between InnoDB and the rest of the server
(in storage/innobase/dict/dict0dict.cc and in include/)
is my work, while most everything else is Thiru's.
The collection of InnoDB persistent statistics and the
defragmentation were not refactored to use MDL. They will
keep relying on lower-level interlocking with
fil_check_pending_operations().
The purge of transaction history and the background operations on
fulltext indexes will use MDL. We will revert
commit 2c4844c9e7
(MDEV-17813) because thanks to MDL, purge cannot conflict
with DDL operations anymore. For a similar reason, we will remove
the MDEV-16222 test case from gcol.innodb_virtual_debug_purge.
Purge is essentially replacing all use of the global dict_sys.latch
with MDL. Purge will skip the undo log records for tables whose names
start with #sql-ib or #sql2. Theoretically, such tables might
be renamed back to visible table names if TRUNCATE fails to
create a new table, or the final rename in ALTER TABLE...ALGORITHM=COPY
fails. In that case, purge could permanently leave some garbage
in the table. Such garbage will be tolerated; the table would not
be considered corrupted.
To avoid repeated MDL releases and acquisitions,
trx_purge_attach_undo_recs() will sort undo log records by table_id,
and purge_node_t will keep the MDL and table handle open for multiple
successive undo log records.
get_purge_table(): A new accessor, used during the purge of
history for indexed virtual columns. This interface should ideally
not exist at all.
thd_mdl_context(): Accessor of THD::mdl_context.
Wrapped in a new thd_mdl_service.
dict_get_db_name_len(): Define inline.
dict_acquire_mdl_shared(): Acquire explicit shared MDL on a table name
if needed.
dict_table_open_on_id(): Return MDL_ticket, if requested.
dict_table_close(): Release MDL ticket, if requested.
dict_fts_index_syncing(), dict_index_t::index_fts_syncing: Remove.
row_drop_table_for_mysql() no longer needs to check these, because
MDL guarantees that a fulltext index sync will not be in progress
while MDL_EXCLUSIVE is protecting a DDL operation.
dict_table_t::parse_name(): Parse the table name for acquiring MDL.
purge_node_t::undo_recs: Change the type to std::list<trx_purge_rec_t*>
(different container, and storing also roll_ptr).
purge_node_t: Add mdl_ticket, last_table_id, purge_thd, mdl_hold_recs
for acquiring MDL and for keeping the table open across multiple
undo log records.
purge_vcol_info_t, row_purge_store_vsec_cur(), row_purge_restore_vsec_cur():
Remove. We will acquire the MDL earlier.
purge_sys_t::heap: Added, for reading undo log records.
fts_sync_during_ddl(): Invoked during ALGORITHM=INPLACE operations
to ensure that fts_sync_table() will not conflict with MDL_EXCLUSIVE.
Uses fts_t::sync_message for bookkeeping.
The function fsp_header_get_space_id() returns ulint instead of
uint32_t, only to be able to complain that the two adjacent
tablespace ID fields in the page differ. Remove the function,
and merge the check to the callers.
Also, make some more use of aligned_malloc().
InnoDB startup was discovering undo tablespaces in a dirty way.
It was reading a possibly stale copy of the TRX_SYS page before
processing any redo log records.
srv_start(): Do not call buf_pool_invalidate(). Invoke
trx_rseg_get_n_undo_tablespaces() after the recovery has been initiated.
recv_recovery_from_checkpoint_start(): Assert that the buffer pool is
empty. This used to be guaranteed by the buf_pool_invalidate() call.
trx_rseg_get_n_undo_tablespaces(): Move to the calling compilation unit,
and reimplement in a simpler way.
srv_undo_tablespace_create(): Remove the constant parameter
size=SRV_UNDO_TABLESPACE_SIZE_IN_PAGES.
srv_undo_tablespace_open(): Reimplement in a cleaner way, with
more robust error handling.
srv_all_undo_tablespaces_open(): Split from srv_undo_tablespaces_init().
srv_undo_tablespaces_init(): Read all "undo001","undo002" tablespace
files directly, without consulting the TRX_SYS page via calling
trx_rseg_get_n_undo_tablespaces().
This is joint work with Thirunarayanan Balathandayuthapani.
Revert part of commit 6cedb671e9
because it turns out to be theoretically impossible to parse a
ROW_FORMAT=COMPACT or ROW_FORMAT=DYNAMIC metadata record where
the variable-length fields in the PRIMARY KEY have been written
as nonempty strings.
We must relax too strict debug assertions. For latin1_swedish_ci,
mtype=DATA_CHAR or mtype=DATA_VARCHAR will be used instead of
mtype=DATA_MYSQL or mtype=DATA_VARMYSQL. Likewise, some changes of
dtype_get_charset_coll() do not affect the data type encoding,
but only any indexes that are defined on the column.
Charset::same_encoding(): Check whether two charset-collations have
the same character set encoding.
dict_col_t::same_encoding(): Check whether two character columns
have the same character set encoding.
dict_col_t::same_type(): Check whether two columns have a compatible
data type encoding.
dict_col_t::same_format(), dict_table_t::instant_column(): Do not
compare mtype or the charset-collation of prtype directly.
Rely on dict_col_t::same_type() instead.
dtype_get_charset_coll(): Narrow the return type to uint16_t.
This is a refined version of a fix that was developed by
Thirunarayanan Balathandayuthapani.
