We are looking at moving to Vector tiles after the deployment of openstreetmap raster tiles is completed. We need to look at the performance closely though because on some devices it was slower with Vector tiles. I think we still want to go that direction we just have to quantify some of the performance.
You can render raster on the fly from a vector based tileserver, and optionally use vector maps for clients where it makes sense (mobile for example).
I've been running a large OSM raster rendering stack for a while, for the whole planet. Moving on to a vector based stack right now, which is what you should do if you are starting today. The reason being the server, with vector tiles pre-rendered, can very quickly render raster tiles on the fly. It's fast enough that for most cases, there is no need to cache them. Once I get the new stack fully burned in, we'll swap our raster rendering stack out for the new vector stuff and do raster on the fly. I might cache the rasters depending on throughput, but from what I can tell it should be basically a non-issue.
The difference between raster tiles and vector tiles is that in raster tiles the rendering (conversion to actual images) is done on your server (either when each tile is loaded for the first time or you may initialize a bunch of zoom levels for your area yourself; this may take hours to days depending on your area size) while for vector tiles you just send the descriptions/shapes and the inages are created on the client side. It is expected that the client performance won't be as good as with raster tiles and slow clients like mobile phones will struggle while trying to render the images.
One interesting idea would be to have both raster and vector tiles; then in your client side code you could detect if the client is a mobile device or a desktop pc (I am not sure if you can detect more things about how speedy the device would be) and serve the corresponding tileset (ie the vector tileset if the device is desktop or the raster one if it is mobile). This way you will definitely decrease the load on your server and most clients won't have performance problems!
In any case, the clients will get faster as the time passes so after some years vector tiles would probably be the norm because they have the huge advantage that it is very easy to style them on-the-fly in any way you like (while, to style raster images you need to re-create them all from scratch).
This results in having a tile server that generates & serves raster tiles using:
* carto to generate a proper stylesheet
* mapnik to create the tiles
* apache with the mod_tile module to serve the tiles
* renderd to be used as a bridge between apache/mod_tile and mapnik
* Postgres/PostGIS as a database to host the data
The actual data is an OpenStreetMap pbf file downloaded from http://download.geofabrik.de/ which is inserted to the database through osm2pgsql.
The above are used for the raster tile server only.
In addition to this, I am using geoserver (http://geoserver.org/) which is a Java web app (runs in tomcat) that is used to view/edit and (mainly) serve geospatial data. What I usually do is that when I need to display a new shape (shp) file I use shp2pgsql to insert it to a table in my PostGIS database (using something like this shp2pgsql -s SRID SHAPEFILE.shp SCHEMA.TABLE | psql -h HOST -d DATABASE -U USER) also another good tool is ogr2ogr which can convert between various formats (it also supports kml, for example ogr2ogr -f "PGDump" koko.sql test.kml).
After the shp file is inserted to the database, I can create a datasource for this dataset from GeoServer and publish this dataset to the web (i.e the dataset will have a URL of the form http://1.2.3.4:8080/geoserver/Dataset/wms); it can then be consumed by client applications (in javascipt) using leaflet or openlayers. Notice that GeoServer can easily publish various file formats for example an SHP directly (you don't need to insert it to the PostGIS; this is something I do for better control of my datasources).
PostGIS is the component that supports the vector tiles (http://docs.geoserver.org/latest/en/user/extensions/vectorti...) so I want to integrate it the OpenStreetMap data that is hosted in my PostGIS (which is used for the raster tiles); I haven't found the time yet though.
I think it's a great setup and it works great for the needs of the organization I work for; actually, I like it so much that I want (for a long time) to write a rather comprehensive tutorial on how to set ip up along with some notes on how to do various PostGIS things but I don't know when (and if) I'll find the time for something so large :/
