Hi, As promised yesterday, I would follow up to verify that InnoDB buffer pool usage would no longer drop when downgrading from 11.4.4 to 11.4.3. Confirmed. See attachment. The time at which usage stabilised is the time at which MariaDB was downgraded. Anyone recognise this behaviour? Thank you, William William David Edwards via discuss schreef op 2024-12-09 16:37:
Hi,
We see an odd pattern where InnoDB buffer pool usage drops regularly. Attached are two screenshots of memory usage on an 11.4.4 node: one at 20:15 with an InnoDB buffer pool of 47,5 GiB, and 5 minutes later with a 3,69 GiB one. The times at which this occurs are -seemingly- random. Other internal memory structures are stable.
On at least one node with this issue, the InnoDB buffer pool is smaller (48 GiB) than the sum of data + indexes (87,57 GiB).
As far as I can see (graphing history is limited), this has started occurring after upgrading from MariaDB 10.11.9 to 10.11.10 and from 11.4.3 to 11.4.4 respectively. At first sight, in the pre-release notes for 10.11.11 and 11.4.5, I don't see any related issues. To make absolutely sure this is related to the upgrade, we will be downgrading a troubled node tonight, to see if it fixes anything. I will report back.
In userland, these drops cause a domino effect: no cache -> more I/O -> slower queries -> nuisance in application.
Has anyone else seen this pattern, possibly after upgrading to the aforementioned versions? Although 1) neither of these versions are bleeding edge and 2) I haven't seen any such reports, asking is worth a shot as this started occurring on several machines after upgrading with no configuration nor (obvious) usage changes.
With kind regards,
William David Edwards _______________________________________________ discuss mailing list -- discuss@lists.mariadb.org To unsubscribe send an email to discuss-leave@lists.mariadb.org
Met vriendelijke groeten, William David Edwards
