[Pdns-users] Increased CPU usage after upgrade to MariaDB 10.6.11

[abang at t-ipnet.net]

Hi, 

We recently had a similar problem when we updated from 10.5.12 to 10.6.10.

The cause was that the default behavior changed from

innodb_flush_method = fsync

to

innodb_flush_method = O_DIREC

Which means, no kernel file caching.

If you have a too small 

innodb_buffer_pool_size

in this case, there is a lot of disk I/O and thus a lot of CPU wait time.

Setting

innodb_buffer_pool_size = 8G

helped in our case.

Winfried


Am 26. November 2022 14:45:26 MEZ schrieb William Edwards via Pdns-users <pdns-users at mailman.powerdns.com>:
>Hi,
>
>Are people on this mailing list seeing increased CPU usage when using MariaDB 10.6.11 with PowerDNS 4.5.4?
>
>Context:
>
>I use PowerDNS with the gmysql backend. Last Wednesday, I upgraded MariaDB 10.6.10 to 10.6.11 on 8 machines running PowerDNS. Since then, MySQL's average CPU usage has increased from 2,5% to 55%. This happens on all upgraded machines. However, this issue does not occur on machines running MariaDB 10.6.11 without PowerDNS. PowerDNS itself was not upgraded.
>
>I am aware that this issue is (most likely) not caused by PowerDNS. I am therefore only wondering whether others have seen the same behaviour. If so, that would save me some debugging time.
>
>Thank you,
>
>William Edwards
>
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