[development] Counterintuitive but true: Caching makes a high-traffic site slower

[Bèr Kessels]

I am a sql-clueless person. So can someone explain me why the --- we have 
myisam there, if it performs so bad?

Ber

Op donderdag 29 december 2005 18:24, schreef John Handelaar:
> In the continuing absence of anywhere to discuss these
> performance edge-cases (more below)...
>
>
> I've already mentioned recently that MyISAM is the
> enemy of Drupal performance.  Because it requires a
> full-table lock, if you have lots of active members
> logged in at once, the process of posting a comment
> causes page rendering to cease entirely for several
> seconds.
>
> Onto today's point:
>
> The same table-level locking is *lethal* on a heavily-
> trafficked site which has both
>
> a)  Content which alters regularly (like a busy forum),
>      and
>
> b)  Caching turned on.
>
>
> Try turning it off if your slow query log starts showing
> cache-related things taking 90 seconds (!) or more (!!).
>
> And then take a backup of your database and change these
> table types to InnoDB format.
>
> And then start looking at delayed inserts.
>
>
> jh
>
>
> PS:  Still no bigsite/performance forum.  Have we decided
> that Drupal doesn't *need* to scale?  I missed that meeting.