If the InnoDB buffer pool contains many pages for a table or index
that is being dropped or rebuilt, and if many of such pages are
pointed to by the adaptive hash index, dropping the adaptive hash index
may consume a lot of time.
The time-consuming operation of dropping the adaptive hash index entries
is being executed while the InnoDB data dictionary cache dict_sys is
exclusively locked.
It is not actually necessary to drop all adaptive hash index entries
at the time a table or index is being dropped or rebuilt. We can let
the LRU replacement policy of the buffer pool take care of this gradually.
For this to work, we must detach the dict_table_t and dict_index_t
objects from the main dict_sys cache, and once the last
adaptive hash index entry for the detached table is removed
(when the garbage page is evicted from the buffer pool) we can free
the dict_table_t and dict_index_t object.
Related to this, in MDEV-16283, we made ALTER TABLE...DISCARD TABLESPACE
skip both the buffer pool eviction and the drop of the adaptive hash index.
We shifted the burden to ALTER TABLE...IMPORT TABLESPACE or DROP TABLE.
We can remove the eviction from DROP TABLE. We must retain the eviction
in the ALTER TABLE...IMPORT TABLESPACE code path, so that in case the
discarded table is being re-imported with the same tablespace identifier,
the fresh data from the imported tablespace will replace any stale pages
in the buffer pool.
rpl.rpl_failed_drop_tbl_binlog: Remove the test. DROP TABLE can
no longer be interrupted inside InnoDB.
fseg_free_page(), fseg_free_step(), fseg_free_step_not_header(),
fseg_free_page_low(), fseg_free_extent(): Remove the parameter
that specifies whether the adaptive hash index should be dropped.
btr_search_lazy_free(): Lazily free an index when the last
reference to it is dropped from the adaptive hash index.
buf_pool_clear_hash_index(): Declare static, and move to the
same compilation unit with the bulk of the adaptive hash index
code.
dict_index_t::clone(), dict_index_t::clone_if_needed():
Clone an index that is being rebuilt while adaptive hash index
entries exist. The original index will be inserted into
dict_table_t::freed_indexes and dict_index_t::set_freed()
will be called.
dict_index_t::set_freed(), dict_index_t::freed(): Note that
or check whether the index has been freed. We will use the
impossible page number 1 to denote this condition.
dict_index_t::n_ahi_pages(): Replaces btr_search_info_get_ref_count().
dict_index_t::detach_columns(): Move the assignment n_fields=0
to ha_innobase_inplace_ctx::clear_added_indexes().
We must have access to the columns when freeing the
adaptive hash index. Note: dict_table_t::v_cols[] will remain
valid. If virtual columns are dropped or added, the table
definition will be reloaded in ha_innobase::commit_inplace_alter_table().
buf_page_mtr_lock(): Drop a stale adaptive hash index if needed.
We will also reduce the number of btr_get_search_latch() calls
and enclose some more code inside #ifdef BTR_CUR_HASH_ADAPT
in order to benefit cmake -DWITH_INNODB_AHI=OFF.
On a checksum failure of a ROW_FORMAT=COMPRESSED page,
buf_LRU_free_one_page() would invoke buf_LRU_block_remove_hashed()
which will read the uncompressed page frame, although it would not
be initialized. With bad enough luck, fil_page_get_type(page)
could return an unrecognized value and cause the server to abort.
buf_page_io_complete(): On the corruption of a ROW_FORMAT=COMPRESSED
page, zerofill the uncompressed page frame.
Maybe this patch will help catch problems like buffer overflow.
log_t::first_in_use: removed
log_t::buf: this is where mtr_t are supposed to append data
log_t::flush_buf: this is from server writes to a file
Those two buffers are std::swap()ped when some thread is gonna write
to a file
Several MYSQL_SYSVAR_STR parameters that employ both a validate
function callback fail to copy the string for saving the
validated value. The affected variables include the following:
innodb_ft_aux_table
innodb_ft_server_stopword_table
innodb_ft_user_stopword_table
innodb_buffer_pool_filename
The test case is an enhanced version of
mysql/mysql-server@0b0c30641f
and the code changes are inspired by their fixes.
We are also importing and adjusting the test innodb_fts.stopword
to get coverage for the variable innodb_ft_user_stopword_table.
buf_dump(), buf_load(): Protect srv_buf_dump_filename with
LOCK_global_system_variables.
fts_load_user_stopword(): Minor cleanup
fts_load_stopword(): Remove the parameter global_stopword_table.
innobase_fts_load_stopword(): Protect innodb_server_stopword_table
against concurrent SET GLOBAL.
redo log during recovery
- InnoDB unnecessarily reads the page even though it has fully initialized
buffered redo log records. Allow the page initialization redo log to
apply for the page in buf_page_get_gen() during recovery.
- Renamed buf_page_get_gen() to buf_page_get_low()
- Newly added buf_page_get_gen() will check for buffered redo log for
the particular page id during recovery
- Added new function buf_page_mtr_lock() which basically latches the page
for the given latch type.
- recv_recovery_create_page() is inline function which creates a page
if it has page initialization redo log records.
In my micro-benchmarks memcmp(4196) 3 times faster than old
implementation. Also, it's generally better to use as less
reinterpret_casts<> as possible.
buf_is_zeroes(): renamed from buf_page_is_zeroes() and
argument changed to span<> for convenience.
st_::span<T>::const_iterator: fixed
page_zip-verify_checksum(): make argument byte* instead of void*
buf_pool_resize(): Simplify the fault injection
for innodb.buf_pool_resize_oom.
innodb.buf_pool_resize_oom: Use a small buffer pool.
innodb.innodb_buffer_pool_load_now: Make use of the sequence engine,
to avoid creating explicit InnoDB record locks. Clean up the
accesses to information_schema.innodb_buffer_page_lru.
- This issue is caused by MDEV-19176
(bba59abb03).
- Problem is that there is miscalculation of available memory during
recovery if innodb_buffer_pool_instances > 1.
- Ignore the buffer pool instance while calculating available_memory
- Removed recv_n_pool_free_frames variable and use buf_pool_get_n_pages()
instead.
The write-heavy test innodb_zip.wl6501_scale_1 timed out on
10.2 60d7011c5f for me.
Out of os_aio_n_segments=6, 5 are waiting for an event in
os_aio_simulated_handler(). One thread is waiting for a
write to complete in buf_dblwr_add_to_batch(), but that
would never happen, because nothing is waking up the simulated AIO
handler threads.
This hang appears to have been introduced in MySQL 5.6.12
in mysql/mysql-server@26cfde776c.
buf_read_ibuf_merge_pages(): Discard any page numbers that are
outside the current bounds of the tablespace, by invoking the
function ibuf_delete_recs() that was introduced in MDEV-20934.
This could avoid an infinite change buffer merge loop on
innodb_fast_shutdown=0, because normally the change buffer merge
would only be attempted if a page was successfully loaded into
the buffer pool.
dict_drop_index_tree(): Add the parameter trx_t*.
To prevent the DROP TABLE crash, do not invoke btr_free_if_exists()
if the entire .ibd file will be dropped. Thus, we will avoid a crash
if the BTR_SEG_LEAF or BTR_SEG_TOP of the index is corrupted,
and we will also avoid unnecessarily accessing the to-be-dropped
tablespace via the buffer pool.
In MariaDB 10.2, we disable the DROP TABLE fix if innodb_safe_truncate=0,
because the backup-unsafe MySQL 5.7 WL#6501 form of TRUNCATE TABLE
requires that the individual pages be freed inside the tablespace.
Old InnoDB/XtraDB versions only initialized FIL_PAGE_TYPE for
B-tree pages (to FIL_PAGE_INDEX), and left it uninitialized
(possibly containing FIL_PAGE_INDEX) for others. In MySQL
or MariaDB 5.5, the field is initialized on almost all pages,
but still not all of them.
In MariaDB 10.2 and later, buf_flush_init_for_writing() would
initialize the FIL_PAGE_TYPE on such old pages, but only after
passing the debug assertion that we are now removing from 10.1.
There, we will be able to modify fil_crypt_rotate_page() so
that it will skip the key rotation for pages that contain 0
in FIL_PAGE_TYPE.
In MariaDB 10.1, there is no logic that would initialize
FIL_PAGE_TYPE on data pages in old data files after an update.
So, encryption key rotation may routinely cause page flushes
on pages that contain 0 in FIL_PAGE_TYPE.
The assertion that was added in
commit c0c003beb4
to augment the fix of MDEV-20805 turns out to be invalid when
innodb_immediate_scrub_data_uncompressed is enabled.
In this mode, fsp_init_file_page() will be invoked on data pages
that have been freed, causing writes of almost-all-zero pages.
btr_page_free(): Adjust the comment.
buf_flush_init_for_writing(): Disable the assertion with a note
that it should be re-enabled in MDEV-15528.
buf_flush_init_for_writing(): Assert that FIL_PAGE_TYPE is set
except when creating a new data file with a dummy first page.
buf_dblwr_create(): Ensure that FIL_PAGE_TYPE on all pages
will be initialized. Reset buf_dblwr_being_created at the end.
