Wikimedia Toolserver users' discussion ()

Marlen Caemmerer | 27 Jun 2012 11:42

What is slow

Hello,

I sometimes get complaints that toolserver was slow. This regards web applications and it is not always
slow but sometimes.
I cannot always really correlate this to certain servers  being slow at the time in question.
That is the reason I really would like to have a reference measurement application that graphs me how long it took.
So the idea would be to have an application that is called via web server, makes a database query on every
host, records, how long it took and measures how long the application took to complete.
The measurements could be written out to rrd files so it is easy to graph afterwards.

Do you think it would be sufficiant to measure the time of a simple select and an insert or would a more complex
query be sensible?
Do you already a tool that does this?

What do you think about this?

Cheers
 	nosy

headers

Jeremy Baron | 27 Jun 2012 18:01

Re: What is slow

Hi Nosy,

On Wed, Jun 27, 2012 at 5:42 AM, Marlen Caemmerer
<marlen.caemmerer <at> wikimedia.de> wrote:
> I sometimes get complaints that toolserver was slow. This regards web
> applications and it is not always slow but sometimes.
> I cannot always really correlate this to certain servers  being slow at the
> time in question.
> That is the reason I really would like to have a reference measurement
> application that graphs me how long it took.
> So the idea would be to have an application that is called via web server,
> makes a database query on every host, records, how long it took and measures
> how long the application took to complete.
> The measurements could be written out to rrd files so it is easy to graph
> afterwards.
>
> Do you think it would be sufficiant to measure the time of a simple select
> and an insert or would a more complex query be sensible?
> Do you already a tool that does this?
>
> What do you think about this?

For slow queries you could just use the built in mysql slow query log.
(the threshold for "slow" can be tweaked. apparently at least to
1/100th of a sec) or also add pt-query-digest and do a periodic sample
like at WMF cluster. or maybe you're interested in pt-stalk?

https://gerrit.wikimedia.org/r/gitweb?p=operations%2Fpuppet.git&a=search&h=17a2407dbcd4571c8aed098842578e5485eb231d&st=grep&s=tcpdump
https://ishmael.wikimedia.org/ <-- requires a labs account. you really
should get one! in the meantime any of the wikidata team can show you

(Continue reading)