Hi, The latest quarterly releases of MariaDB Server 10.5 and later include a fix of https://jira.mariadb.org/browse/MDEV-30671 which fixes corruption due to premature purging of history.
It has turned out that this fix causes another bug where some undo log pages will never be freed (https://jira.mariadb.org/browse/MDEV-31234). I am working on a fix. Marko On Sat, May 13, 2023 at 9:37 PM <[email protected]> wrote: > > On a recently updated MariaDB 10.6.13 server (Debian Bullseye) I noticed > that my ibdata1 file was continuously growing; it had gotten a little > over 3G after running a couple days. I would rather keep this growth in > check so used it as an excuse to setup undo tablespaces that could be > truncated (I had wanted to try this for some time anyway). So: Dump the > whole DB, delete all the InnoDB tables, stop the server, delete the > innodb system tables, reset the appropriate undo variables (with > innodb_max_undo_log_size set to 750M, innodb_undo_tablespaces set to 4, > and innodb_undo_log_truncate set to ON), restart the server and reload > the data. > > I now have FOUR undo files that appear to be continuously growing; as of > this writing they are over 1G and still increasing. > > This is an active read-only replica (processing updates very frequently; > at times continuously but not constantly as such). How do I get it to > actually reclaim the space? Or am I misunderstanding how this is > supposed to work? > > Below are my current relevant settings (or at least what I think are > relevant). Normally I run with innodb_purge_rseg_truncate_frequency = > 128; but for testing I have it now set to 1 (but with no noticeable > difference). > > Things I have tried (no luck on any of them): > > Set innodb_purge_rseg_truncate_frequency = 1. > > Set innodb_max_purge_lag_wait=0 (it returned nearly immediately). > > Stop both slave threads and wait for several minutes. > > Set innodb_max_purge_lag and innodb_max_purge_lag_delay (see below). > > MariaDB [(none)]> show variables like '%trunc%'; > +--------------------------------------+-------+ > | Variable_name | Value | > +--------------------------------------+-------+ > | innodb_purge_rseg_truncate_frequency | 1 | > | innodb_undo_log_truncate | ON | > +--------------------------------------+-------+ > 2 rows in set (0.000 sec) > > MariaDB [(none)]> show variables like '%purge%'; > +--------------------------------------+------------+ > | Variable_name | Value | > +--------------------------------------+------------+ > | aria_log_purge_type | immediate | > | innodb_max_purge_lag | 1000 | > | innodb_max_purge_lag_delay | 5000 | > | innodb_max_purge_lag_wait | 4294967295 | > | innodb_purge_batch_size | 300 | > | innodb_purge_rseg_truncate_frequency | 1 | > | innodb_purge_threads | 4 | > | relay_log_purge | ON | > +--------------------------------------+------------+ > 8 rows in set (0.000 sec) > > MariaDB [(none)]> show variables like '%undo%'; > +--------------------------+-----------+ > | Variable_name | Value | > +--------------------------+-----------+ > | innodb_max_undo_log_size | 786432000 | > | innodb_undo_directory | ./ | > | innodb_undo_log_truncate | ON | > | innodb_undo_tablespaces | 4 | > +--------------------------+-----------+ > 4 rows in set (0.000 sec) > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-discuss > Post to : [email protected] > Unsubscribe : https://launchpad.net/~maria-discuss > More help : https://help.launchpad.net/ListHelp -- Marko Mäkelä, Lead Developer InnoDB MariaDB plc _______________________________________________ Mailing list: https://launchpad.net/~maria-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-discuss More help : https://help.launchpad.net/ListHelp
