[OSM-talk] New History tab for openstreetmap.org (beta)

[Paweł Paprota]

On 01/04/2013 10:13 AM, Alex Barth wrote:
> Pawel -
>
> This is great.
>
> What would it take to make this blazing fast?

There is still a lot challenges ahead with performance such as:

* On high zoom levels OWL API response time is acceptable most of the 
time but I only tested it with 1.5M changesets. Will it scale to 10 
times that? I think it will (on high zoom levels) without major changes 
but if it doesn't then database schema needs to be adjusted (SP-GiST 
indexing maybe).

* On low zoom levels there is a known issue with performance because a 
lot of changesets match and they need to then be sorted by timestamp to 
select the latest ones and the sorting right now does not use the index. 
I spoke with a Postgres guru on IRC and he gave me some hints which I 
still need to try out.

* Client-side performance is still a challenge - I managed to kill 
Firefox a couple of times with the amount of changes that the code tried 
to show. There should probably be a limit of geometry features to be 
shown (plus it should be based on the browser you use) and some kind of 
warning and/or filtering of changes just like the "Browse map data" 
feature does it currently.

* Another performance challenge is with processing history data and 
creating tiles. It used to take a long time but I optimized the hell out 
of the tiler code and now it can process about 500k changesets per 24 
hours so in a month we would have the whole history (in theory, don't 
try this at home...). That's on the zark server with two cores. More 
core = more tiling jobs that can run efficiently so it should not be 
that bad after all (unless the database blows up).

So to answer your question - mostly more testing and development is 
needed, for that I need time.

>
> Echoing Christian: where should we file bugs/suggestions?
>

I enabled Issues on my fork of openstreetmap-website repo:

https://github.com/ppawel/openstreetmap-website/issues

Paweł