Redis memory leak with Statamic nocache regions?

[JorisOrangeStudio]

We're experiencing a Redis memory leak on our Statamic websites (8GB server). Memory usage increases by ~0.5-1GB daily, eventually maxing out. Clearing the application cache of the websites temporarily resolves the issue.

• Using Static half page caching via Redis
• Redis is the main memory consumer (in the graph below, redis was using 4-5GB from the 8GB on the 14th of August)
• Numerous nocache::region.* keys present (300-600 KB each, no TTL set) and amount of keys keeps increasing

Are we missing out on some invalidation for these nocache regions? Or what could be the reason of the increasing memory

Any insights or solutions would be greatly appreciated.

[ryanmitchell]

You should use the select="xx" param on the nocache tags if you aren't already: https://statamic.dev/tags/nocache#performance.
This will ensure the region only includes the data you actually need and prevents these sorts of build ups.

[ryanmitchell]

Yep. You could use url too I guess

[martyf]

There you go, learn something new every day - thanks for that Ryan.

[JorisOrangeStudio]

Thanks Ryan, so id is just there to scope down the region, since the current entry ID is not used by the collection loop either?

One more question regarding this:

Theres no TTL as such, they exist until the static cache is cleared.

I've enabled cache expiry (6 hours) on the half page caching like this:

        'half' => [
            'driver' => 'application',
            'expiry' => 360,
        ],

For the static-cache:responses:* keys there is actually a TTL for 6 hours added, but the nocache::region.* keys don't have this. That means that only on manual static:clear it will clear the indefinite growth regions right?

[ryanmitchell]

Not sure on that, probably one for @jasonvarga to answer

[JorisOrangeStudio]

I've looked into the NoCache source, not sure if this is the correct place, but it indeed looks like the regions are set forever:

cms/src/StaticCaching/NoCache/Session.php

Line 153 in dfa5e1d

StaticCache::cacheStore()->forever('nocache::region.'.$region->key(), $region);

Is this done with a reason🤔 I can image that after invalidating within a certain time and requesting the region again will result in a RegionNotFound exception? I'm not sure about the 'lookup/get' behaviour of regions.

[jasonvarga]

Do you use nocache on pages that aren't statically cached?

[JorisOrangeStudio]

No, we don't have any exclusions set up in the static cache config

[JorisOrangeStudio]

I was wondering if there is any update on this. Over the past 5 days I noticed that the same occurred (Now it is around ±6GB in nocache regions on Redis). Let me know if I need to create an issue for it :)

[jasonvarga]

Keep an eye on #10671