Re: Outreachy: Timeline tasks

[Luciana Lima Brito <lubrito@posteo.net>]

On Wed, 28 Apr 2021 19:17:51 +0100
Christopher Baines <mail@cbaines.net> wrote:

> So, there's already some code for timing different parts of the data
> loading process, if you look in the job output and search for ", took
> " you should see timings printed out.
> 
> These timings being printed out does help, but having the information
> in the log doesn't make it easy to figure out which part is the
> slowest for example.
> 
> I'd also not consider this a "one off" thing, the data loading code
> will continue to change as Guix changes and it's performance will
> probably change too.
> 
> I've been wondering about visualisations, I remember systemd had a
> feature to plot the systems boot as a image which made seeing which
> parts are slow much easier (here's an example [1]).
> 
> 1: https://lizards.opensuse.org/wp-content/uploads/2012/07/plot001.gif

This is interesting! In fact, one of the things that attracted me was
the possibility to work with visualizations, as I saw that on the
roadmap there is one task related to provide statistics over time). 
My master degree is on Information Visualization, so I would appreciate
very much if I could help with that.

In this matter, we should determine what else, other than time, would
be interesting to see. The visualization should be clear enough about
timing but should also provide information about what could be related
to the delays, such as size of the queries, complexity, the return it
gives... So, first I think we should determine what information we want
to see, then depending on the variables, we choose a suitable way to
present the visualization.

About implementing, I'm kind of new to guile and I never built a
visualization in guile, so I don't know which libraries it would take to
build a visual work like that. Depending on what we have,
interactions could be compromised, and instead we would have to work
with charts (static visualizations). Can you tell me more about that?

And one last thing, a visualization can be simple or can be very
complex.The time for that should be carefully taken into account in
order to not impair the main goal which is the improvements of the slow
parts.

> 
> > About the improvements on the performance of slow parts, it is a
> > little bit abstract for me to see now how to break it in smaller
> > tasks. I do believe that it would require to reformulate some parts
> > of the queries, and as their result may change a bit, tweaks could
> > be required on the code too. My point is, how would I propose an
> > improvement approach if I don't even know what exactly is to be
> > improved? But I imagine that work on this second task is more
> > demanding than the first and will take most of the time of the
> > internship.  
> 
> As I said before, this part is dependent on deciding where the areas
> for improvement are. Maybe have a look through one of the job logs on
> data.guix.gnu.org and see if you can spot some slow parts?

I'll look into that and get back to you.

-- 
Best Regards,

Luciana Lima Brito
MSc. in Computer Science