docs: describe what the volatile-lru eviction policy actually evicts

[Daniel Kirkland (d-kirkland)]

Summary

• Five Redis/Valkey pages describe the volatile-lru eviction policy as one that "only automatically deletes data that is expired" (or "carts that are expired"). That is not what the policy does: per the Redis documentation, volatile-lru evicts the least recently used keys that have an expiration (TTL) set, when the memory limit is reached. Such keys do not have to be expired.
• The docs contradict themselves: redis.md L34 and caches.md L164 already say it correctly ("keeps evicting least recently used keys that have a TTL set", "it will only evict keys that have a TTL").
• Rewrites the six sentences to say what the policy does (evicts keys that have a TTL, least recently used first, when the memory limit is reached). redis.md L53 ("a key eviction policy that will not delete data that is not expired") now says it never evicts keys without a TTL and can still evict least recently used keys that have one.

Related links

Docs (at origin/main 70b7d45), changed lines:

• redis.md L29
• redis.md L53
• caches.md L114
• cart-storage.md L80
• increment.md L70
• number-ranges.md L54

Docs lines that state it correctly (not changed): redis.md L34, caches.md L164.

Redis documentation (the semantics come from here, not from the platform source): https://redis.io/docs/latest/develop/reference/eviction/ : "volatile-lru: Evict the least recently used keys that have an associated expiration (TTL)."; and the volatile-xxx policies behave like noeviction if no keys have an expiration.

Platform context (tag v6.7.15.1): carts are stored with a TTL (RedisCartPersister.php L118: $options = [self::EXPIRES_IN_SECONDS => $this->expireDays * 86400];), which is why volatile-lru can evict them in cart-storage.md. Also: compose.yaml L67 runs the cache service with --maxmemory-policy volatile-lfu. This is context only; this PR does not change which policy is recommended.

Checklist

• I reviewed affected links, code samples, and cross-references, including PageRef references where relevant. (Every changed sentence was compared with the Redis documentation; the pages' own correct statements were left alone.)
• I added or updated redirects in .gitbook.yaml if pages were moved, renamed, or deleted. (N/A, no page moved.)
• I updated .wordlist.txt (and sorted it) if spellcheck flags new legitimate terms. (No new prose words outside code spans; checked against .wordlist.txt; the docker spellcheck image could not be run locally.)
• Any required dependent changes in downstream modules have already been merged and published. (N/A)
• This pull request is ready for review.

Notes

• This PR was fully AI generated (Claude Code) and requires human review. It has not been merged, approved or reviewed by the AI session. Please verify the claims and the changed text against the linked source.
• Scope: main (Shopware 6.7) only. Checked against the platform tag v6.7.15.1 (the latest 6.7 tag when this was written). Older versions have their own docs branches and are not touched here.
• Not changed on purpose: session.md L121 (allkeys-lru, "deletes the last recently used entries when Redis reaches max memory consumption") is correct. Which policy is recommended for which instance is not touched: that is the open question in the draft PR [Owner decision needed] docs: Redis maxmemory-policy recommendations contradict each other (volatile-lfu vs volatile-lru) #2590 (volatile-lru vs volatile-lfu, guides/hosting/index.md L25). [Owner decision needed] docs: Redis maxmemory-policy recommendations contradict each other (volatile-lfu vs volatile-lru) #2590 has no line overlap with this PR; if its owner decides to recommend volatile-lfu, the lines changed here would be rewritten for that policy.
• Limit: the Redis semantics are taken from the Redis documentation URL above; the platform source does not define them.

🤖 Generated with Claude Code

[shopware-dev-docs-connector]

Developer Docs healthcheck

Status: Completed with success.
Repository: shopware/docs
Commit: 4593b6d
Preview: https://developer-documentation-etvj3he6q-shopware-frontends.vercel.app
Workflow run: #5632

[shopware-dev-docs-connector]

Developer Docs healthcheck

Status: Running.
Repository: shopware/docs
Commit: 4191f44
Preview: Waiting for workflow logs.