maria-discuss team mailing list archive

[Gordan Bobic <gordan.bobic@xxxxxxxxx>]

10.5.x still seem to be problematic. Is reverting an option for you?

https://www.percona.com/blog/2020/08/14/evaluating-performance-improvements-in-mariadb-10-5-5/



On Wed, 26 Aug 2020, 01:38 Jeff Dyke, <jeff.dyke@xxxxxxxxx> wrote:

> Thought it was worth adding, I only added the relevant details, i hope, as
> i've been dealing with scaling MariaDB and MySQL, with innodb, for a long
> time in both high data throughput and millions of sessions a day, so i've
> taken the normal steps to mitigate/investigate this on the server, btw is a
> EC2 C5XLarge, with NVMe SSDs.  I'm not calling myself an expert, just
> looking for the non low hanging fruit.
>
> On Tue, Aug 25, 2020 at 7:24 PM Jeff Dyke <jeff.dyke@xxxxxxxxx> wrote:
>
>> Unfortunately, I can't easily give you a repro case, or show you the
>> queries.  I upgraded a replica/DW server from 10.4.latest to 10.5.5. I did
>> this on Friday night.  We're not a high volume site (by design) so nothing
>> would really pop up over the weekend.  We use google data studio to present
>> reports of aggregated data after the daily events have run.  Any given
>> report page will generate from 5-25 connections from datastudio, lots of
>> joins, group bys etc.    All of the daily events and reporting and ad-hoc
>> querying by our data analyst was working fine on 10.4, but on 10.5.5,
>> started generating "Out of sort memory, consider increasing server sort
>> buffer size" errors.
>>
>> That's the background, there were no query changes, no significant
>> increase in data.  I changed sort_buffer_size and made a couple other
>> optimizations that fit our environment and table types. And i'll have more
>> information in the next few days.
>>
>> All that, leads me to a simple question, that I have not been able to
>> find an answer to or missed something in the changelogs that would indicate
>> this behaviour would have changed.  Has anyone seen anything similar.  Or
>> does this ring a bell to a change I need to tune other than increasing
>> sort_buffer_size.  The only thing that changed was an upgrade.
>>
>> Thanks for reading and giving it a thought.
>>
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