We will remove the InnoDB background operation of merging buffered
changes to secondary index leaf pages. Changes will only be merged as a
result of an operation that accesses a secondary index leaf page,
such as a SQL statement that performs a lookup via that index,
or is modifying the index. Also ROLLBACK and some background operations,
such as purging the history of committed transactions, or computing
index cardinality statistics, can cause change buffer merge.
Encryption key rotation will not perform change buffer merge.
The motivation of this change is to simplify the I/O logic and to
allow crash recovery to happen in the background (MDEV-14481).
We also hope that this will reduce the number of "mystery" crashes
due to corrupted data. Because change buffer merge will typically
take place as a result of executing SQL statements, there should be
a clearer connection between the crash and the SQL statements that
were executed when the server crashed.
In many cases, a slight performance improvement was observed.
This is joint work with Thirunarayanan Balathandayuthapani
and was tested by Axel Schwenke and Matthias Leich.
The InnoDB monitor counter innodb_ibuf_merge_usec will be removed.
On slow shutdown (innodb_fast_shutdown=0), we will continue to
merge all buffered changes (and purge all undo log history).
Two InnoDB configuration parameters will be changed as follows:
innodb_disable_background_merge: Removed.
This parameter existed only in debug builds.
All change buffer merges will use synchronous reads.
innodb_force_recovery will be changed as follows:
* innodb_force_recovery=4 will be the same as innodb_force_recovery=3
(the change buffer merge cannot be disabled; it can only happen as
a result of an operation that accesses a secondary index leaf page).
The option used to be capable of corrupting secondary index leaf pages.
Now that capability is removed, and innodb_force_recovery=4 becomes 'safe'.
* innodb_force_recovery=5 (which essentially hard-wires
SET GLOBAL TRANSACTION ISOLATION LEVEL READ UNCOMMITTED)
becomes safe to use. Bogus data can be returned to SQL, but
persistent InnoDB data files will not be corrupted further.
* innodb_force_recovery=6 (ignore the redo log files)
will be the only option that can potentially cause
persistent corruption of InnoDB data files.
Code changes:
buf_page_t::ibuf_exist: New flag, to indicate whether buffered
changes exist for a buffer pool page. Pages with pending changes
can be returned by buf_page_get_gen(). Previously, the changes
were always merged inside buf_page_get_gen() if needed.
ibuf_page_exists(const buf_page_t&): Check if a buffered changes
exist for an X-latched or read-fixed page.
buf_page_get_gen(): Add the parameter allow_ibuf_merge=false.
All callers that know that they may be accessing a secondary index
leaf page must pass this parameter as allow_ibuf_merge=true,
unless it does not matter for that caller whether all buffered
changes have been applied. Assert that whenever allow_ibuf_merge
holds, the page actually is a leaf page. Attempt change buffer
merge only to secondary B-tree index leaf pages.
btr_block_get(): Add parameter 'bool merge'.
All callers of btr_block_get() should know whether the page could be
a secondary index leaf page. If it is not, we should avoid consulting
the change buffer bitmap to even consider a merge. This is the main
interface to requesting index pages from the buffer pool.
ibuf_merge_or_delete_for_page(), recv_recover_page(): Replace
buf_page_get_known_nowait() with much simpler logic, because
it is now guaranteed that that the block is x-latched or read-fixed.
mlog_init_t::mark_ibuf_exist(): Renamed from mlog_init_t::ibuf_merge().
On crash recovery, we will no longer merge any buffered changes
for the pages that we read into the buffer pool during the last batch
of applying log records.
buf_page_get_gen_known_nowait(), BUF_MAKE_YOUNG, BUF_KEEP_OLD: Remove.
btr_search_guess_on_hash(): Merge buf_page_get_gen_known_nowait()
to its only remaining caller.
buf_page_make_young_if_needed(): Define as an inline function.
Add the parameter buf_pool.
buf_page_peek_if_young(), buf_page_peek_if_too_old(): Add the
parameter buf_pool.
fil_space_validate_for_mtr_commit(): Remove a bogus comment
about background merge of the change buffer.
btr_cur_open_at_rnd_pos_func(), btr_cur_search_to_nth_level_func(),
btr_cur_open_at_index_side_func(): Use narrower data types and scopes.
ibuf_read_merge_pages(): Replaces buf_read_ibuf_merge_pages().
Merge the change buffer by invoking buf_page_get_gen().
It is not reproducible, but the issue seems to be the same as with
MDEV-20490 and rocksdb.ttl_primary_read_filtering - a compaction caused
by DROP TABLE gets behind and compacts away the expired rows for the next
test. Fix this in the same way.
Support Create_time and Update_time for MyRocks tables.
- Create_time is stored in the MyRocks' internal data dictionary.
- Update_time is in-memory only (like in InnoDB).
Make the test stable: after DROP TABLE, make sure the compaction is
run and finishes.
If we don't do this, the post-drop compaction may run during the next
testcase. It will cause a record from the next testcase to be compacted
away when the test logic doesn't expect it and the test will fail
This allows one to run the test suite even if any of the following
options are changed:
- character-set-server
- collation-server
- join-cache-level
- log-basename
- max-allowed-packet
- optimizer-switch
- query-cache-size and query-cache-type
- skip-name-resolve
- table-definition-cache
- table-open-cache
- Some innodb options
etc
Changes:
- Don't print out the value of system variables as one can't depend on
them to being constants.
- Don't set global variables to 'default' as the default may not
be the same as the test was started with if there was an additional
option file. Instead save original value and reset it at end of test.
- Test that depends on the latin1 character set should include
default_charset.inc or set the character set to latin1
- Test that depends on the original optimizer switch, should include
default_optimizer_switch.inc
- Test that depends on the value of a specific system variable should
set it in the test (like optimizer_use_condition_selectivity)
- Split subselect3.test into subselect3.test and subselect3.inc to
make it easier to set and reset system variables.
- Added .opt files for test that required specfic options that could
be changed by external configuration files.
- Fixed result files in rockdsb & tokudb that had not been updated for
a while.
Merge the changes to include/index_merge*inc from the upstream. The changes
add this command in many places:
+if ($engine_type == RocksDB)
+{
+ set global rocksdb_force_flush_memtable_now=1;
+}
also add it in one more place to make the test truly stable.
- Note that some issues was also fixed in 10.2 and 10.4. I also fixed them
here to be able to continue with making 10.5 valgrind safe again
- Disable connection threads warnings when doing shutdown
The MDEV-20265 commit e746f451d5
introduces DBUG_ASSERT(right_op == r_tbl) in
st_select_lex::add_cross_joined_table(), and that assertion would
fail in several tests that exercise joins. That commit was skipped
in this merge, and a separate fix of MDEV-20265 will be necessary in 10.4.
- Include the valgrind suppressions from the FB upstream
- Use HAVE_Valgrind, not HAVE_Purify (like the rest of MariaDB code does)
The call to DisownData() is now actually disabled under Valgrind
- Include the valgrind suppressions from the FB upstream
- Use HAVE_Valgrind, not HAVE_Purify (like the rest of MariaDB code does)
The call to DisownData() is now actually disabled under Valgrind
... produces "bytes lost" warnings
When rocksdb_validate_update_cf_options() returns an error,
the update won't happen.
Free the copy of the string in this case.
MDEV-17717
Assertion `!table->pos_in_locked_tables' failed in tc_release_table on
flushing RocksDB table under SERIALIZABLE
MDEV-17998
Deadlock and eventual Assertion `!table->pos_in_locked_tables' failed
in tc_release_table on KILL_TIMEOUT
MDEV-19591
Assertion `!table->pos_in_locked_tables' failed in tc_release_table upon
altering table into S3 under lock.
The problem was that thd->open_tables->pos_in_locked_tables was not reset
when alter table failed to reopen a locked table.
A combination of:
* lots of include'd test files where each has "--source
include/have_rocksdb.inc"
* for each such occurrence, MTR adds testsuite's arguments into server
arguments
* which hits some limit on the length of argv array on Windows, causing
the server to get garbage data in the last argument.
Work around this by commenting out one of the totally redundant
"source include/have_rocksdb.inc" lines.
- Fix the LooseScan code to support storage engines that return
HA_ERR_END_OF_FILE if the index scan goes out of provided range
bounds
- Add a DBUG_EXECUTE_IF("force_group_by",...) to allow a test to
force a LooseScan
- Adjust rocksdb.group_min_max test not to use features not present
in MariaDB 10.2 (e.g. optimizer_trace. In MariaDB 10.4 it's present
but it doesn't meet the assumptions that the test makes about it
- Adjust the test result file:
= MariaDB doesn't support "Enhanced Loose Scan" that FB/MySQL has
= MariaDB has different cost calculations.
This removes the test combination
rocksdb_rpl.mdev12179 'innodb,row,row-write-committed-slave-gtid-optimized'
for which the server failed to start due to the invalid parameter
slave_gtid_info=optimized.
This was broken in 5173e396ff
