Hi!
Just in case anybody finds it interesting/useful, I've made a quick performance analysis on the update service we're running on wdqs-beta, in order to catch up with the wikidata updates:
https://www.mediawiki.org/wiki/Wikibase/Indexing/Updater_performance_analysi...
May be useful for evaluation which hardware we may need if we want for updates to coexist with production loads.