Upgrading to SDL Web 8 and Publication URLs

Question

@Quirijn added the following comment on mappings to my previous question (Web Application vs Web site in Topology Manager ).

Just one extra thing I found: if you use a server-relative publication url (starting with the slash) AND a mapping with a context path, they have to match or the mapping will fail. So if my publication property says ' /en' and my context mapping is anything other than 'en', I won't be able to create the mapping.

Is this for backwards compatibility?

It seems you could:

1. Upgrade to SDL Web 8
2. Leave existing Publication urls alone (or at least make them "server-relative" by adding a slash?)
3. Set up Topology Manager to match the same urls in the context paths.
4. Later (optionally) change the mappings Publication URLs to be context relative (empty in this case as Rick explains).

Am I missing anything?

Edit: fixed #4--Rick caught that I really meant Publication URLs instead of mappings.

Answer 1

Indeed, that is for backwards compatibility and to support gradual migrations as you mentioned.

If you use old-style server-relative Publication URLs, then these URLs may (often will) overlap with the Web Application Context URL and/or Mapping Relative URL as maintained in Topology Manager.

If you switch completely to Topology Manager based publishing, it is best to get rid of the overlap by making the Publication URL context-relative (which typically means: make it empty).

If you also still want to use Publication Target based publishing (for gradual migration purposes), you can keep using server-relative Publication URLs, but we don't allow you to put conflicting information in Topology Manager.

So, regarding your points:

1. Yes, please :-)
2. Leave them alone means: keep them server-relative
3. Topology Manager will prevent you from creating conflicting mappings
4. You won't change the Mappings, but the Publication URLs. This is indeed an optional step, but I would highly recommend it; it's inconvenient to maintain this in two subsystems and have the system complain if they get out-of-sync.

Also note that with context-relative Publication URLs you can achieve URL mappings that were not possible before (with server-relative Publication URLs): you can have different mappings on different CD Environments (e.g. Staging vs. Live). For example, you could use a single website/app with multiple distinct Mapping Relative URLs on Staging, but use multiple distinct websites (distinct domain names) on Live.