Akonadi dsaster

Martin Steigerwald martin at lichtvoll.de
Tue Oct 11 10:03:16 BST 2016

Am Montag, 10. Oktober 2016, 10:12:42 CEST schrieb Michael Mol:
> A *huge* chunk of this, for me, turned out to be in the abysmal MySQL
> configuration it defaults to. I posted about it on Google+ and on /r/kde
> several months ago. https://plus.google.com/+MichaelMolG/posts/HQQH6RHhLNw
> I'll note my understanding of Akonadi has improved slightly since I wrote
> that; I wasn't able to find where Akonadi's MySQL configuration was kept, so
> I switched out to using a system mysqld.That's not necessary if you know
> where Akonadi sources its MySQL configuration from.
> I'll also add that I'm syncing nearly a decade's worth of email from GMail
> into Akonadi, hundreds of thousands of emails. People without as much email
> history likely won't see the same kind of performance difficulties I do.
> Here's the relevant excerpt:
> Altogether, here are the changes I've made:
> In my.cnf
> innodb_buffer_pool_size = 1024M # I have 16GB of RAM. I can spare a gig to
> keep more of Akonadi's working set in memory.

Well yes, I raised this as well.

The default value is *ridiculously* low. I opened a bug report about this 
quite a time ago. I think 1 GiB may be too much for many use cases, but well I 
use that much as well with that 2000000+ mails. But for users with many mails: 
Raise it :). mysqltuner.pl can be used to determine a good value.

The global db config appears to be in /etc/xdg/akonadi, they may a source copy 
for that something in /usr as well. The local one is in ~/.local/share/
akonadi. I just edited this one and have it under version control. And yes if 
on upgrades it downgraded my config again I noticed quite lower performance and 
more waiting.

I also switched to MariaDB, but whether that makes sense… it works at least.

I may review other changes you made.

I do think Akonadi as a background service in general makes sense, whether a 
MySQL database is the best way to store the metadata… I am not so sure about. 
That said the Zimbra server we had at one time was able to handle insanely 
large folders (>450000+) with ease, using MySQL + Lucene. KMail still can´t 
handle such large folders in an usable way.


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