The test case that was added for MDEV-21217
(commit b68f1d847f)
should have only two possible outcomes for the locking SELECT statement:
(1) The statement is blocked, and the test will eventually fail
with a lock wait timeout. This is what I observed when the
code fix for MDEV-21217 was missing.
(2) The lock conflict will ensure that the statement will execute
after the rollback has completed, and an empty table will be observed.
This is the expected outcome with the recovery fix.
What occasionally happens (in some of our CI environments only, so far)
is that the locking SELECT will return all 1,000 rows of the table that
had been inserted by the transaction that was never supposed to be
committed. One possibility is that the transaction was unexpectedly
committed when the server was killed.
Let us disable the test until the reason of the failure has been
determined and addressed.
The background drop table queue in InnoDB is a work-around for
cases where the SQL layer is requesting DDL on tables on which
transactional locks exist.
One such case are XA transactions. Our test case exploits the
fact that the recovery of XA PREPARE transactions will
only resurrect InnoDB table locks, but not MDL that should
block any concurrent DDL.
srv_shutdown_t: Introduce the srv_shutdown_state=SRV_SHUTDOWN_INITIATED
for the initial part of shutdown, to wait for the background drop
table queue to be emptied.
srv_shutdown_bg_undo_sources(): Assign
srv_shutdown_state=SRV_SHUTDOWN_INITIATED
before waiting for the background drop table queue to be emptied.
row_drop_tables_for_mysql_in_background(): On slow shutdown, if
no active transactions exist (excluding ones that are in
XA PREPARE state), skip any tables on which locks exist.
row_drop_table_for_mysql(): Do not unnecessarily attempt to
drop InnoDB persistent statistics for tables that have
already been added to the background drop table queue.
row_mysql_close(): Relax an assertion, and free all memory
even if innodb_force_recovery=2 would prevent the background
drop table queue from being emptied.
MDEV-22073 MSAN use-of-uninitialized-value in
collect_statistics_for_table()
Other things:
innodb.analyze_table was changed to mainly test statistic
collection. Was discussed with Marko.
only MDL-prelock but do not open FK child tables for read-only (RESTRICT)
FK actions.
Tables still needs to be opened for CASCADE actions, see 9180e8666b
FOREIGN_KEY_CHECKS is disabled
- Referenced index can be null While renaming the referenced column name.
In that case, rename the referenced column name in dict_foreign_t and
find the equivalent referenced index.
This is a way do disable DBUG_ENTER()/DBUG_EXIT() stuff which is
needed to dbug trace. Those who doesn't need it may avoid tests
slowdown with -DWITH_DBUG_TRACE=OFF
dbug/tests.c: add define which is neede always in this test
innodb.log_file_name_debug.test: do not depend on DBUG trace stuff
in test
Benchmark results: each test eats less CPU and you can have more
parallel jobs in MTR.
patched:
./mtr -mem -par=8 -suite=innodb 185.34s user 86.85s system 133% cpu 3:23.27 total
./mtr -mem -par=8 -suite=main 80.96s user 36.01s system 182% cpu 1:04.07 total
main.select [ pass ] 1660
main.select [ pass ] 1513
main.select [ pass ] 1543
main.select [ pass ] 1660
main.select [ pass ] 1521
main.select [ pass ] 1511
main.select [ pass ] 1508
main.select [ pass ] 1520
main.select [ pass ] 1514
main.select [ pass ] 1522
vanilla:
./mtr -mem -par=8 -suite=innodb 203.61s user 92.16s system 140% cpu 3:30.16 total
./mtr -mem -par=8 -suite=main 94.11s user 35.51s system 206% cpu 1:02.69 total
main.select [ pass ] 2032
main.select [ pass ] 2017
main.select [ pass ] 2040
main.select [ pass ] 2183
main.select [ pass ] 2253
main.select [ pass ] 2075
main.select [ pass ] 2109
main.select [ pass ] 2080
main.select [ pass ] 2098
main.select [ pass ] 2114
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.
Improve the test that was imported and adapted for MariaDB in
commit fb217449dc.
row_undo_step(): Move the DEBUG_SYNC point from trx_rollback_for_mysql().
This DEBUG_SYNC point is executed after rolling back one row.
trx_rollback_for_mysql(): Clarify the comments that describe the scenario,
and remove the DEBUG_SYNC point.
If the statement "if (trx->has_logged_persistent())" and its body are
removed from trx_rollback_for_mysql(), then the test
innodb.xa_recovery_debug will fail because the transaction would still
exist in the XA PREPARE state. If we allow the XA COMMIT statement
to succeed in the test, we would observe an incorrect state of the
XA transaction where the table would contain row (1,NULL). Depending
on whether the XA transaction was committed, the table should either
be empty or contain the record (1,1). The intermediate state of
(1,NULL) should never be observed after completed recovery.
Adapt the test that was added in
mysql/mysql-server@6b65d9032c
but omitted in commit 2e814d4702.
Instead of triggering a log checkpoint, we will only trigger
a redo log flush before killing the server.
Note: the mtr.commit() call in trx_rollback_for_mysql()
will not actually make the undo log header page state change durable.
A call to log_write_up_to(mtr.commit_lsn(), true) would do that.
It is unclear what the originally reported bug scenario was.
As long as innobase_rollback_by_xid() will not return without
ensuring that the redo log has been durably written, we should be safe.
FOREIGN_KEY_CHECKS is disabled
- dict_foreign_find_index() can return NULL if InnoDB already dropped
the foreign index when FOREIGN_KEY_CHECKS is disabled.
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.
Remove CREATE/DROP database.
Remove some unnecessary suppressions, replacements, and
SQL statements.
Populate tables via have_sequence.inc to avoid the creation of
explicit InnoDB record locks in INSERT...SELECT. This will remove
some gaps in AUTO_INCREMENT values.
fil_delete_tablespace(): Remove the unused parameter drop_ahi,
and add the parameter if_exists=false. We want to suppress
error messages if we know that the tablespace has been discarded.
dict_table_rename_in_cache(): Pass the new parameter to
fil_delete_tablespace(), that is, do not complain about
missing tablespace if the tablespace has been discarded.
row_make_new_pathname(): Declare as static.
row_drop_table_for_mysql(): Tolerate !table->data_dir_path
when the tablespace has been discarded.
row_rename_table_for_mysql(): Skip part of the RENAME TABLE
when fil_space_get_first_path() returns NULL.
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.
Temporary tables are typically short-lived, and temporary tables
are assumed to be accessed only by the thread that is handling
the owning connection. Hence, they must not be subject to
defragmenting.
ha_innobase::optimize(): Do not add temporary tables to
the defragment_table() queue.
- 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.
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).
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.
Move row size check to early CREATE/ALTER TABLE phase. Stop checking
on table open.
dict_index_add_to_cache(): remove parameter 'strict', stop checking row size
dict_index_t::record_size_info_t: this is a result of row size check operation
create_table_info_t::row_size_is_acceptable(): performs row size check.
Issues error or warning. Writes first overflow field to InnoDB log.
create_table_info_t::create_table(): add row size check
dict_index_t::record_size_info(): this is a refactored version
of dict_index_t::rec_potentially_too_big(). New version doesn't change global
state of a program but return all interesting info. And it's callers who
decide how to handle row size overflow.
dict_index_t::rec_potentially_too_big(): removed
Due to a data corruption bug that may have occurred a long time earlier
(possibly involving physical backup and MySQL Bug #69122, which was
addressed in commit f166ec71b7)
it seems possible that the InnoDB change buffer might end up containing
entries, while no buffered changes exist according to the change buffer
bitmap pages in the .ibd files.
ibuf_delete_recs(): New function, to be invoked on slow shutdown only.
Remove all buffered changes for a specific page.
ibuf_merge_or_delete_for_page(): If the change buffer bitmap is clean
and a slow shutdown is in progress, invoke ibuf_delete_recs().
We do not want to do that during normal operation, due to the additional
overhead that is involved. The bitmap page should be consistent with
the change buffer in the first place.
mysql_insert() first opens all affected tables (which implicitly
starts a transaction in InnoDB), then stat tables.
A failure to open a stat table caused open_tables() to abort
the current stmt transaction (trans_rollback_stmt()). So, from the
server point of view the following ha_write_row()-s happened outside
of a transactions, and the server didn't bother to commit them.
The server has a mechanism to prevent a transaction being
unexpectedly committed or rolled back in the middle of a statement -
if an operation takes place _in a sub-statement_ it cannot change
the transaction state. Operations on stat tables are exactly that -
they are not allowed to change a transaction state. Put them in
a sub-statement to make sure they don't.
Apply the changes to InnoDB and XtraDB that had been
inadvertently skipped in the merge
commit ae476868a5
That merge failure sabotaged part of MDEV-20127:
>Revert a problematic auto_increment_increment 'fix' from 2014.
>This involves replacing the MDEV-8827 fix and in 10.1,
>removing some WSREP instrumentation.
The code changes were re-merged manually by executing the following:
# Get the parent of the problematic merge.
git checkout ae476868a5394041a00e75a29c7d45917e8dfae8^
# Perform the merge again.
git merge ae476868a5394041a00e75a29c7d45917e8dfae8^2
# Get the conflict resolution from that merge.
git checkout ae476868a5 .
# Note: Any changes to these files were removed (empty diff)!
git diff HEAD storage/{innobase,xtradb}/handler/ha_innodb.cc
# Apply the code changes:
git diff cf40393471b10ca68cc1d2804c22ab9203900978^2..MERGE_HEAD \
storage/{innobase,xtradb}/handler/ha_innodb.cc|
patch -p1
To diagnose a hang in slow shutdown (innodb_fast_shutdown=0),
let us introduce a Boolean startup option in debug builds
that will cause the contents of the InnoDB change buffer
to be dumped to the server error log at startup.
Test innodb_read_only startup (which will be refused after a crash),
and test also innodb_force_recovery=5, and extract some change buffer
merge statistics. Omit any statistics about delete (purge) buffering,
because purge could happen at any time.
Use the sequence storage engine for populating the table.
