setting up the new SCHOLIA

[pfps]

I was thinking about what it would take to set up a reasonable SCHOLIA based on QLever.

My view is that the current target is to get to a semi-production SCHOLIA based on QLever, i.e., one that doesn't have all the characteristics of a production system but is expected to work at least as well as the current version of SCHOLIA when it is not down and is also expected to not be down much.

What it takes to get there, in my opinion:

1/ A semi-production QLever Wikidata server that supports SCHOLIA

I think that the current version of QLever more than meets the requirement for performance. As far as down-time goes, it would be nice to have some sort of watchdog that checks every few seconds that QLever hasn't crashed and, if so, restarts it. QLever doesn't crash much, but I can make it crash reliably in my (admitedly unusual) benchmark setup.

I don't know what changes had to be made to QLever to support SCHOLIA, but the version that is being used for testing appears to be adequate.

2/ A semi-production process to push updates to the server.

I think that the current wikidata-update process is adequate for this. It isn't very optimized, but works well so long as the QLever server doesn't crash. If the server does crash, it can lose some data, which isn't great but is acceptable for semi-production. This part of QLever is being improved considerably and going with the current updater is more than fine for a short time.

3/ SCHOLIA queries that work as well with QLever as SCHOLIA works with the WDQS

I think that this is already the case for everything except author. There are some problems remaining but there are also problems with SCHOLIA on the WDQS.

4/ A semi-production SCHOLIA server that works with these queries

I think that the current server is adequate for this purpose. There is still the problem of missing labels defaulting to the IRI instead of the id, but that's minor.

So perhaps it is now time to "officially" get a semi-production QLever Wikidata service set up so that SCHOLIA can cut over to using it by the deadline. The next step would be to set up the semi-production SCHOLIA server, but may be just updating the one on toolforge would be a good way to go.