Redis to Valkey: Configuring Magento 2 Cache and Sessions

If your store runs the latest patch of Magento 2.4.6, 2.4.7 or 2.4.8, Adobe's system requirements now list Valkey 8.1 for cache and sessions and mark Redis as not supported. Magento 2.4.9 requires Valkey 9, and its setup commands change as well.

Valkey is an open-source fork of Redis that speaks the same protocol, so the move is mostly configuration rather than code. If you want the background on what Magento stores in its cache and sessions first, start with the Redis, RabbitMQ and indexing lesson (Arabic, with English code).

Which Magento versions need Valkey?

How do you configure cache and sessions on 2.4.8 and earlier?

The options are still named redis; point them at your Valkey server:

bin/magento setup:config:set --cache-backend=redis --cache-backend-redis-server=127.0.0.1 --cache-backend-redis-db=0
bin/magento setup:config:set --page-cache=redis --page-cache-redis-server=127.0.0.1 --page-cache-redis-db=1
bin/magento setup:config:set --session-save=redis --session-save-redis-host=127.0.0.1 --session-save-redis-log-level=4 --session-save-redis-db=2

Each type gets its own database number: 0 for the default cache, 1 for the page cache and 2 for sessions. The commands write the settings to app/etc/env.php. If Varnish handles your full page cache, you can skip the page cache line; see setting up Varnish full page cache.

How do you configure them on Magento 2.4.9?

bin/magento setup:config:set --cache-backend=valkey --cache-backend-valkey-server=127.0.0.1 --cache-backend-valkey-db=0
bin/magento setup:config:set --page-cache=valkey --page-cache-valkey-server=127.0.0.1 --page-cache-valkey-db=1
bin/magento setup:config:set --session-save=valkey --session-save-valkey-host=127.0.0.1 --session-save-valkey-db=2

Magento 2.4.9 moved its cache layer to Symfony Cache, which changed the shape of the env.php configuration. Don't copy an old snippet from another article or project: run the commands and read the file they generate. According to Adobe, using igbinary with Symfony Cache makes cache entries about 45% smaller and 5–10% faster.

Which settings make a performance difference?

• Separate cache from sessions: different database numbers at minimum, and a dedicated instance for each where you can.
• Persist sessions only: enable RDB or AOF on the session instance. Cache can be rebuilt, so it doesn't need persistence.
• Memory: size the cache instance at least as large as your var/cache directory.
• Lua: keep use_lua=0 and use_lua_on_gc=1. Enabling use_lua on 2.4.7 and 2.4.8 can corrupt the cache.
• Session concurrency: on large clusters, set max_concurrency to at least 10% of your PHP processes.
• Several web nodes: use the L2 cache (RemoteSynchronizedCache) and preload keys such as GLOBAL_PLUGIN_LIST and SYSTEM_DEFAULT with preload_keys, including your store's id_prefix.

Adobe's recommended Valkey server settings:

lazyfree-lazy-eviction yes
lazyfree-lazy-expire yes
lazyfree-lazy-server-del yes
lazyfree-lazy-user-del yes
replica-lazy-flush yes

Where this cache sits in a larger store's architecture, next to the database and message queues, is covered in the e-commerce system design lesson (Arabic). Magento's own cache types are explained in the database and performance lesson (Arabic).

How do you move a live store from Redis to Valkey?

1. Provision the Valkey version your Magento release requires, and rehearse the switch on staging.
2. Pick a low-traffic window: existing sessions don't carry over, so signed-in customers will need to log in again.
3. Run the setup:config:set commands for your version.
4. Flush the cache with bin/magento cache:flush.
5. Confirm connectivity with valkey-cli ping, and watch traffic with valkey-cli monitor for a few seconds only, since it is expensive on a busy server.
6. Watch page load times and error logs for the first few hours.

Valkey migration checklist

• The Valkey version matches your Magento release's requirements
• Cache, page cache and sessions use separate databases or instances
• Persistence is enabled on the session instance only
• use_lua=0 and use_lua_on_gc=1
• env.php was reviewed after running the commands, not copied from an old source
• The switch ran in a low-traffic window after a staging rehearsal
• cache:flush has run and valkey-cli ping returns PONG