Currently, interwiki template transclusions are cached in the transcache table. This implementation has several drawbacks:
- There is no garbage collection logic - the transcache table will continue to grow in size as the wiki evolves
- Large templates can cause a database error depending on settings, if they do not fit into the transcache table
- In a multi-wiki environment, responses for the same template are cached and duplicated on each wiki
I'd like to propose to generify caching of interwiki transclusion logic, and provide an alternative backend, such as one based on the ObjectCache implementation configured for the wiki (while keeping the original implementation available). Having an ObjectCache based transclusion cache fits the purpose of the transclusion cache being an actual cache, and will solve the aforementioned issues with cache garbage collection and duplicate entries.