Limit local cache size (cache eviction)

[mehulkar]

Discussed in #1264

^{Originally posted by maxburs May 18, 2022}
I'm caching the /node_modules/.turbo folder in CI. This is causing problems because of its size. I've seen it get as large at 4.5gb. Is there a good way to limit the size of the cache?

_TURBO-2071

[anthonyshew]

We just spoke on this amongst the team and we've settled on that this is something that we should do. We have it on our board and we will get it prioritized at some point in the future. We're not sure when at the moment but having controls around cache eviction is something we're interested in being a feature.

[EloB]

@anthonyshew An idea would be to track when you actually hit a cache in like a json file with a key map of cache key and unix timestamp in the .cache/turbo folder like hits.json. So you can present how many unused/rarely used cache files you have at the moment.

Than maybe have the possibility to clean up unused files with a command for instance turbo cache clean --unused or something similar.

turbo build

...

 Tasks:    A successful, B total
Cached:    C cached, D total
Unused:    E caches since F ago, remove by "turbo cache clean --unused"
  Time:    Gs >>> FULL TURBO

[mehulkar]

That's a good idea and we want a mapping of [code ref] -> [turbo hash] for other reasons also.