[Labs-l] Database queries slower here than in the Toolserver

[Pietro De Nicolao]

Hi,
I'm the maintainer of the Intersect Contribs project. IC is a web tool [1] which finds the pages edited by two users (it does an intersection).

I noticed that my tool is VERY slow here on Tool Labs. I executed the same query on the Italian Wikipedia replicated database, on WMF Tool Labs and on the Toolserver, via command line, and I am pretty sure that the problem is related to the DB performance.

I asked for my contributions:

> SELECT page_namespace, page_title
> 	FROM revision
> 	JOIN page ON rev_page=page_id
> 	WHERE rev_user_text="Pietrodn";


The results are impressive.

On WMF Labs:

> pietrodn at tools-login:~$ time mysql -h itwiki.labsdb itwiki_p < query.sql > res.txt
> 
> real		0m41.052s
> user	0m0.016s
> sys		0m0.012s

On Toolserver:

> pietrodn at willow:~$ time mysql -h itwiki-p.rrdb.toolserver.org itwiki_p < query.sql > res.txt
> 
> real		0m0.665s
> user	0m0.015s
> sys		0m0.010s


[1] https://tools.wmflabs.org/intersect-contribs/

Pietro De Nicolao
powerpdn at gmail.com