Overpass popup patch

[Roland Olbricht]

Thank you for the fast answer.

I'll set the patch it up in its own Rails Port branch this evening.

> The big issue here as regards deployment however is going to be that we 
> would normally want, for operational reasons, to have this running off 
> an instance of overpass that was running on our servers. We'd also need 
> to discuss issues of scalability and what resources such an api might 
> need before being exposed on the home page.

I offer to do support and maintance for an instance on osm.org.

Concerning hardware: The current instances are disk bound and benefit from more RAM. Overpass API runs with 4 GB RAM and 250 GB disk space, but with 32 or 64 GB RAM and 750 GB disk space it is more performant and easier to maintain.

Concerning scalability: The current instance has in live tests accomplished about 100 database requests per second with requests similar to the requests we expect. I expect that this is an order of magnitude more than we will need when exposed on the home page. Even if this doesn't suffice, further instances simply multiply the capacity, because there are no interdependencies between multiple instances.

> Design wise we would need to think about how this behaviour should be 
> triggered as currently it looks like you are capturing every click on 
> the map which doesn't sound like it would be a reasonable thing to do.

Thank you for the feedback. I assume from the description that a mouse click anywhere on the map should open a popup, or do we want to restrict it somehow further? What other event can the action be bound to? 

Cheers,

Roland