On Wed, Jul 27, 2022 at 3:08 PM Marko Mäkelä <marko.makela@mariadb.com> wrote:
On Wed, Jul 27, 2022 at 2:48 PM Gordan Bobic <gordan.bobic@gmail.com> wrote:
There is no supported downgrade path other than logical dump+restore. There are also no packages built for distros where the major version is older than what ships with the distro.
Since your queries seem to end up stuck in commit stage, it could be related to redo log flushing, which behaves very erratically on 10.5+. If it leaves the log to fill up to 90% and the state transfer hits, it could be that with the checkpoint age already high, there just isn't enough headroom to avoid a massive stall. Purely guessing here without any telemetry.
I think that you may refer to InnoDB page flushing. There was some misunderstanding around that, and indeed some partly unintended or uninformed changes in behaviour (in 10.5.7 and 10.5.8) that were reverted later. It could be useful to read https://jira.mariadb.org/browse/MDEV-27295.
What version was it reverted in? I am still seeing the errant redo log flushing behaviour in 10.5.15. It looks like no flushing happens until the hwm is reached at about 85% full. It then tries to commit everything down to the lwm. And inbetween it doesn't do anything, even while everything is idle and it should be running down the