The flushing of the InnoDB temporary tablespace is unnecessarily
tied to the write-ahead redo logging and redo log checkpoints,
which must be tied to the page writes of persistent tablespaces.
Let us simply omit any pages of temporary tables from buf_pool.flush_list.
In this way, log checkpoints will never incur any 'collateral damage' of
writing out unmodified changes for temporary tables.
After this change, pages of the temporary tablespace can only be written
out by buf_flush_lists(n_pages,0) as part of LRU eviction. Hopefully,
most of the time, that code will never be executed, and instead, the
temporary pages will be evicted by buf_release_freed_page() without
ever being written back to the temporary tablespace file.
This should improve the efficiency of the checkpoint flushing and
the buf_flush_page_cleaner thread.
Reviewed by: Vladislav Vaintroub
This hang was caused by MDEV-23855, and we failed to fix it in
MDEV-24109 (commit 4cbfdeca84).
When buf_flush_ahead() is invoked soon before server shutdown
and the non-default setting innodb_flush_sync=OFF is in effect
and the buffer pool contains dirty pages of temporary tables,
the page cleaner thread may remain in an infinite loop
without completing its work, thus causing the shutdown to hang.
buf_flush_page_cleaner(): If the buffer pool contains no
unmodified persistent pages, ensure that buf_flush_sync_lsn= 0
will be assigned, so that shutdown will proceed.
The test case is not deterministic. On my system, it reproduced
the hang with 95% probability when running multiple instances
of the test in parallel, and 4% when running single-threaded.
Thanks to Eugene Kosov for debugging and testing this.
Problem:
=======
Autoincrement value gives duplicate values because of the following reasons.
(1) In InnoDB handler function, current autoincrement value is not changed
based on newly set auto_increment_increment or auto_increment_offset variable.
(2) Handler function does the rounding logic and changes the current
autoincrement value and InnoDB doesn't aware of the change in current
autoincrement value.
Solution:
========
Fix the problem(1), InnoDB always respect the auto_increment_increment
and auto_increment_offset value in case of current autoincrement value.
By fixing the problem (2), handler layer won't change any current
autoincrement value.
Reviewed-by: Jimmy Yang <jimmy.yang@oracle.com>
RB: 13748
