[Due for payment 2025-05-13] [$250] [quality] Explore smarter handling of cache key eviction

[mountiny]

Problem

To avoid local onyx data growing infinitely, we have implemented eviction logic to only allow a maximum of onyx keys in the db (maxCachedKeysCount). However, there seem to be bugs in the implementation of the eviction because we have found cases where the App gets into a weird state when the maximum is hit as for example here.

Solution

Develop a smarter key eviction strategy that will not influence the App functionality in a negative way while releasing resources that are not needed and keeping the App fast and responsive even for the largest accounts and heaviest users.

Issue Owner

Current Issue Owner: @muttmuure

Upwork Automation - Do Not Edit

• Upwork Job URL: https://www.upwork.com/jobs/~021915464098079907753
• Upwork Job ID: 1915464098079907753
• Last Price Increase: 2025-04-24

[melvin-bot]

Triggered auto assignment to @laurenreidexpensify (Bug), see https://stackoverflow.com/c/expensify/questions/14418 for more details. Please add this bug to a GH project, as outlined in the SO.

[kubabutkiewicz]

Update on that:
I am working on a solution for measuring the performance to onyx cache specifically and to spot issues related to eviction of the keys, so we could prepare the plan how we can improve it.

[kubabutkiewicz]

Update:
Shared a proposal internally with changing the approach when we are evicting keys from onyx cache based on the memory usage instead of hard coded key count limit, also working on automatic eviction of stale keys. Also shared a POC with the changes. Waiting for a internal review of that

[kubabutkiewicz]

Update:
Also found the root cause of data disappearing when we exceed the keys limit in cache. Working right now on the solution how to fix it.

[kubabutkiewicz]

H!
The plan for it now is:

1. Fix the issue which is causing the data disappearance. The issue is that the key eviction implementation is not respecting keys added to safeEvictionKeys.
2. Move logic related to key eviction directly to OnyxCache from OnyxUtils
3. Change name of the safeEvictionKeys config prop as its super confusing (even AI was confused by this name 😅 )
4. Add accurate unit tests for keys eviction and fix existing one.
5. Fix documentation for key eviction.