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Memcached

What is Memcached?​

Memcached is a simple, high-performance in-memory key-value cache. Unlike Redis, it has no persistence and no built-in data structures (lists, sets, hashes), it's pure cache: store a value, get it back fast, let it expire. That simplicity makes it lighter and sometimes faster for pure caching workloads where you don't need Redis's extra features.

Start Memcached​

./laradock start memcached

The container's compose.yml declares depends_on: php-fpm, so starting memcached also starts php-fpm if it isn't running yet.

Stop Memcached​

Stopping just pauses the container; nothing to worry about since Memcached holds no data on disk anyway:

./laradock stop memcached

To delete the container entirely:

./laradock remove memcached

Configuration​

All settings live in memcached/defaults.env and can be overridden by adding the same line to your own .env:

VariableDefaultWhat it does
MEMCACHED_HOST_PORT11211Host-side port Memcached is published on (host:container), Memcached's standard port.

Use Memcached from Laravel​

  1. In your Laravel .env, set CACHE_DRIVER=memcached.
  2. In config/cache.php, point the memcached connection's host at the container name: 
    'memcached' => [
        'servers' => [
            [
                'host' => 'memcached',
                'port' => 11211,
                'weight' => 100,
            ],
        ],
    ],
  3. Laravel's Memcached driver requires the PHP memcached extension in php-fpm/workspace; make sure it's installed and enabled in those containers.

Check memory usage and stats​

Memcached speaks a simple text protocol, so you can query live stats with nc (netcat) from your host machine, no client library needed:

printf 'stats\r\n' | nc -w 1 localhost 11211

This prints counters like bytes (current memory used), limit_maxbytes (memory cap), curr_items (keys currently cached), get_hits/get_misses, and evictions (items dropped because memory ran out, a sign you need a bigger memory limit). Swap 11211 for your custom MEMCACHED_HOST_PORT if you changed it.

Flush all cached keys​

There's no per-key delete UI, but you can wipe the entire cache instantly:

printf 'flush_all\r\n' | nc -w 1 localhost 11211

A OK response confirms every key was invalidated immediately. Unlike Redis's FLUSHALL, this doesn't free memory back to the OS, Memcached just marks existing items expired, memory is reused as new keys come in.

Increase the memory limit​

Memcached's default in-memory cache size is 64MB (the -m flag, stock upstream default), which fills up fast under real traffic and starts evicting keys. Override the container's startup command in memcached/compose.yml to raise it:

services:
  memcached:
    command: memcached -m 256

Then apply it:

./laradock start memcached

Other useful flags you can add the same way: -c (max simultaneous connections, default 1024) and -I (max size of a single cached item, default 1MB).

Connect from your host machine​

Inside Laradock, other containers reach it by container name: memcached:11211. From your own machine, connect to localhost:11211 (or your custom MEMCACHED_HOST_PORT) with a Memcached client library, or use nc/telnet directly for the ad-hoc stats/flush_all commands shown above.

Common issues​

  • App can't connect but the container is running. Confirm the app's config uses memcached (the container name) as the host, not localhost or 127.0.0.1, those only work from your host machine, not from inside another container.
  • Cache writes silently fail. The PHP memcached extension isn't installed/enabled in php-fpm or workspace. Without it, Laravel's Memcached driver can't connect and cache operations no-op or throw depending on your error handling.
  • Port already in use on your host. Another local Memcached (or another Laradock project) is already bound to 11211. Change MEMCACHED_HOST_PORT in .env and restart: ./laradock restart memcached.
  • Cached data vanishes on restart. This is expected: Memcached has no persistence by design. If you need cached values to survive a restart, use Redis, Valkey, or Dragonfly instead.
  • No built-in authentication. Stock Memcached (what this image runs) accepts any connection that can reach its port, there's no username/password. Keep MEMCACHED_HOST_PORT off the public internet; it's meant to be reached from other containers or your local machine only.
  • Keys keep getting evicted under load. Check evictions in stats (see Check memory usage and stats above); a rising count means the memory limit is too small for your working set, see Increase the memory limit.

Need persistence or richer data structures? See Redis. New to Laradock? Start at Getting Started.