How are teams handling caching of `named caches` in CI We ad

Question

How are teams handling caching of `named caches` in CI We added it to the cache but on BitBucket the cache is only written the first time it is missed That means if it s written on a CI run that doesn t touch most of the repo it will be fairly incomplete We used to be on Gitlab where the cache could be updated after each run so it would continuously expand but then we had the problem that it would eventually grow too big and the cost of downloading it exceeded the benefit Is anyone implementing their own cache system using something like S3

witty-crayon-22786 · Answer

gt We added it to the cache but on BitBucket the cache is only written the first time it is missed are you able to choose the cache key if so would suggest choosing it based on a hash of any requirements files you have

clean-city-64472 · Answer

BitBucket doesn t support dynamic cache keys unfortunately The other problem is it has 1gb max cache size and our named caches is 1 5gb

witty-crayon-22786 · Answer

the named caches effectively only contain PIP PEX artifacts

witty-crayon-22786 · Answer

mm yea so it s entirely possible that it is faster for you not to cache that directory then and then only re fetch it if someone misses the native cache

clean-city-64472 · Answer

but we are spending 7minutes resolving contraints txt

witty-crayon-22786 · Answer

in every build or only in builds where you ve changed requirements

clean-city-64472 · Answer

seems to be every build

witty-crayon-22786 · Answer

hm interesting will follow up with you elsewhere

witty-crayon-22786 · Answer

to close the loop here the `named caches` are only relevant for Python resolves when you miss Pants process cache stored locally in `~ cache pants lmdb store` or you should only miss the process cache if you ve changed the input requirements or if they have been garbage collected aren t large enough if you are comfortable re running resolves from scratch when you change your requirements using saving only the process cache in CI environments might work well for you to make the size of the process cache much easier to manage

witty-crayon-22786 · Answer

i ll likely add some of this to <https www pantsbuild org docs using pants in ci> but if anyone has any questions feedback before i do would love to hear them

happy-kitchen-89482 · Answer

Also for future readers we solved the growth without bound problem of CI caches by purging them when they get too large but that is obviously clunky

powerful-boots-1234 · Answer

gt but we are spending 7minutes resolving contraints txt edited is resolution here using pip The most recent versions of pip take far long to resolve deps <https github com pypa pip issues 9187>

clean-city-64472 · Answer

I believe so There is a separate issue where the output we get from Pants is a bit confusing once that s resolved we ll have a clearer picture of exactly where the time is spent

witty-crayon-22786 · Answer

yes it s pip underneath

witty-crayon-22786 · Answer

to get output from PEX and pip can set ` pex verbosity=1` but i think that in < clean city 64472> s case the resolve is large enough that it isn t worth digging into