updating the other projects sidebar shouldn't require a full parse.
We just need the connected item id, lookup the site links and stash it somewhere that it accessible when rendering the sidebar.
I'm not so sure if the parser output is the best place. And for pages that don't yet have the other projects in the parser output, I am not convinced that invalidateCache is a good approach. We should rethink this.
Version: unspecified
Severity: critical
Whiteboard: u=dev c=backend p=2 s=2014-09-09