Saturday 16 May 2009


I didn't get out to gather any map data today, maybe tomorrow. I have been looking at the stuff we mapped last week. The Osmarender view is nicely up-to-date, but the Mapnik view (which I prefer) is not. Under the old scheme I knew that I would have to wait until the next weekly render and when that ran the whole area would be refreshed. Now the Mapnik view is supposed to refresh more quickly, but in practice this just means I don't know when it will refresh, it can take more than a week, and some zoom levels are sometimes missed altogether for a small area; it rarely updates in less than a couple of days.

I know that the upheaval of the upgrade to API 0.6 has caused a lot of extra work and some things might not be working fully yet, so I guess things will get better but it is very off putting when your work doesn't appear. A new mapper near me, who has had some problems understanding how things work, has hacked his editings back and forth believing that the reason his work has not appeared is that he has done something wrong. He has made some mistakes - he hasn't joined roads together, he left gaps in streams where they go under bridges and he has used the wrong tags - all things a newbie might be expected to do, but it doesn't help that he can't see his work and I can't tell him when it will appear.

Maybe what is needed is a way to request that a Mapnik tile-set be refreshed, just like Information Freeway can request an Osmarender refresh, in fact why not use this to trigger both views to be updated?


- said...

View a tile, append /status to the URL to view it's status, or /dirty to force a re-render. It's untidy because it shouldn't be required.
A datestamp of zeroes means that it was requested by the auto-tile-dirtier, which is triggered by a minutely update.

I believe that with the weekly plenet imports, there's a fairly large queue that jumps up on Wednesdays, and is slowly reduced through the week.
Unfortunately, I cannot find a munin graph for tile queue, but there is one for CPU usage of that partiulcar server, which incicates that it's not been doing much (aqua colour) since Friday, but it's recently started doing more stuff this evening (blue), going to what appears to be a standard load.

Chris Hill said...

Thanks Thomas. I've checked a few tiles that need rendering. The ones that have changed recently and had not rendered had a status to match, not having been rendered for more than a month. I gave a tile a dirty tag and less than a minute later it had rendered. I'm going to try a couple more at different zoom levels to see what happens.