On 17/10/12 08:56, Platonides wrote:
> I think the problem was in writes to the page table locking the `page`
> table for read, which in turn slowed everything, since requests to read
> `page` are ubiquitous.
> This is clearly a problem with MyISAM. I would expect InnoDB to not have
> so much problems with the writes. Does anyone know?

Erik Moeller thought so:

<http://article.gmane.org/gmane.science.linguistics.wikipedia.technical/1337>

But Jimmy Wales suggested just getting rid of page view counters since
they are mostly pointless:

<http://article.gmane.org/gmane.science.linguistics.wikipedia.technical/2389>

They were disabled in the UI, but it took until approximately
September 2003 for someone to notice that the UPDATE queries were
still being done:

<https://www.mediawiki.org/wiki/Special:Code/MediaWiki/1711>

And that was 8 months after the switch to InnoDB:

<http://article.gmane.org/gmane.science.linguistics.wikipedia.technical/2279>

So I don't think the rationale for r1711 could have been to work
around MyISAM problems. In any case, it soon became a moot point,
since we deployed Squid in early 2004 and the existing feature could
not work with it. The hitcounter table was introduced in December 2003
by E23, but I don't think it was ever deployed to Wikimedia.

> Also, the page views could be moved to a separate table for freeing
> `page` from locks.
> Incrementing a counter doesn't even need to take a lock. The cost is
> probably just the journaling. Which is likely the reason we first
> aggregate in a MEMORY table.

It aggregates in a MEMORY table because the MEMORY table is faster, I
don't think it was ever analysed further than that.

> I think it could scale (while we still are with a single webserver),
> although I'm not good at determining where would the bottleneck lie.

That's a funny definition of "scale".

-- Tim Starling


_______________________________________________
MediaWiki-l mailing list
[email protected]
https://lists.wikimedia.org/mailman/listinfo/mediawiki-l

Reply via email to