redis will not work with Silverstripe

[sunnysideup]

Have a look: silverstripe/silverstripe-framework#6383... From what I can gather Redis caching will not actually work with Silverstripe 3.5

[patricknelson]

Hello from 3yrs in the future 👋

It's worth noting here that this only applies if you're using Redis caching for the aggregate named back-end. So, if you configure Redis to cache everything via any, you'll encounter the bug. For example:

// Bug!
SS_Cache::pick_backend('primary_redis', 'any', 10);

// No bug.
SS_Cache::pick_backend('primary_redis', 'cacheblock', 10);

This is because DataObject clearing everything emerges from calling ->flushCache() that then calls Aggregate::flushCache() which then specifically fetches the back-end caching mechanism for aggregate which then finally looks for tag compatibility and then ends up clearing the entire cache (bad!). So a good fix is just to configure the Redis back-end for those things which you specifically want to leverage Redis for.

This should obviously not be an issue in SS v4 as noted in that thread.