database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

MDEV-32050: Deprecate&ignore innodb_purge_rseg_truncate_frequency

Browse Source 
The motivation of introducing the parameter
innodb_purge_rseg_truncate_frequency in
mysql/mysql-server@28bbd66ea5 and
mysql/mysql-server@8fc2120fed
seems to have been to avoid stalls due to freeing undo log pages
or truncating undo log tablespaces. In MariaDB Server,
innodb_undo_log_truncate=ON should be a much lighter operation
than in MySQL, because it will not involve any log checkpoint.

Another source of performance stalls should be
trx_purge_truncate_rseg_history(), which is shrinking the history list
by freeing the undo log pages whose undo records have been purged.
To alleviate that, we will introduce a purge_truncation_task that will
offload this from the purge_coordinator_task. In that way, the next
innodb_purge_batch_size pages may be parsed and purged while the pages
from the previous batch are being freed and the history list being shrunk.

The processing of innodb_undo_log_truncate=ON will still remain the
responsibility of the purge_coordinator_task.

purge_coordinator_state::count: Remove. We will ignore
innodb_purge_rseg_truncate_frequency, and act as if it had been
set to 1 (the maximum shrinking frequency).

purge_coordinator_state::do_purge(): Invoke an asynchronous task
purge_truncation_callback() to free the undo log pages.

purge_sys_t::iterator::free_history(): Free those undo log pages
that have been processed. This used to be a part of
trx_purge_truncate_history().

purge_sys_t::clone_end_view(): Take a new value of purge_sys.head
as a parameter, so that it will be updated while holding exclusive
purge_sys.latch. This is needed for race-free access to the field
in purge_truncation_callback().

Reviewed by: Vladislav Lesin
This commit is contained in:
Marko Mäkelä
2023-10-25 09:11:58 +03:00
parent 21bec97044
commit 14685b10df
107 changed files with 102 additions and 331 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
mysql-test/suite/innodb/r/innodb-system-table-view.result
View File

@ -1,5 +1,3 @@
SET @save_frequency=@@GLOBAL.innodb_purge_rseg_truncate_frequency;
SET GLOBAL innodb_purge_rseg_truncate_frequency=1;
SELECT table_id INTO @table_stats_id FROM information_schema.innodb_sys_tables
WHERE name = 'mysql/innodb_table_stats';
SELECT table_id INTO @index_stats_id FROM information_schema.innodb_sys_tables
@ -168,7 +166,6 @@ name num_rows ref_count
test/parent 1 2
DROP TABLE child;
DROP TABLE parent;
SET GLOBAL innodb_purge_rseg_truncate_frequency=@save_frequency;
#
# MDEV-29479 I_S.INNODB_SYS_TABLESPACES doesn't have
# temporary tablespace information