Cache improvement: ListFlags

[AyWa]

Describe the bug

• ListFlags should be cache by flipt when cache is enable. Right now it will always call the storage
• When a key is not in storage, it seems we defer to the underlying storage, so if there is a lot of req/s, we might call the db multiple times. I would suggest that we try to call the db only once

Version Info

main branch

[markphelps]

Thanks @AyWa ! Im actually working on improving caching currently as well as introducing Redis support for cache. I'll take this on as part of that work after that work is complete #633.

My only concern with caching the List Flags response would be the number of flags that could potentially be returned which could cause the cache to 'overflow'. Perhaps setting a default + max batch size for the list flags request would help solve this? I just realized we arent enforcing a default or max limit for listing flags today 🙈

[AyWa]

@markphelps Sounds good !

My only concern with caching the List Flags response would be the number of flags that could potentially be returned which could cause the cache to 'overflow'.

Yeah thats true that it could be a problem, I agree that setting a default + max batch size might help to ensure we dont overflow the cache !

[erka]

@markphelps do you actually want do to this? I believe ListFlags probably isn't called a lot of times(web ui/import/export). Web UI should cache the list for some time, export/import one time operation. Could you guide me please where I have blind spot?

[markphelps]

Yeah I think I agree. Going to close this for now