Connecting

PHP

On each connection, the first command sent to the server must authenticate by issuing a set with username password as the value. The proxy responds STORED on success or CLIENT_ERROR invalid credentials on failure. The key name (shown here as _auth) is ignored by the proxy — any value works. This is the default Memcached authentication mechanism and does not require SASL support, which not every client or hosting environment has properly compiled in.

Use mc1.public.gra1.ovh.velstash.io to connect to your instance. We recommend using TLS (port 11212) for connections over the public Internet, since traffic between you and this region (cached values as well as credentials) may be easier to intercept if travelling unencrypted. We reserve the right to introduce usage-based pricing for disproportionate external traffic in the future, with advance notice.

Installing the extension

You need ext-memcached — not ext-memcache (no "d"). The two are different, unmaintained-vs-maintained PHP extensions, and only ext-memcached is used in the examples below.

# Debian/Ubuntu
sudo apt install php-memcached

# via PECL
pecl install memcached

# Docker (Debian-based images)
RUN apt-get update && apt-get install -y php-memcached

Plain TCP

PHP's ext-memcached is used here — no TLS variant is shown below, see the note underneath.

// The callback runs once when the persistent connection is first established.
// Subsequent requests reuse the connection without re-authenticating.
$mc = new Memcached('myapp', function (Memcached $mc) {
    $mc->setOption(Memcached::OPT_BINARY_PROTOCOL, false);
    $mc->addServer('mc1.public.gra1.ovh.velstash.io', 11211);
    $mc->set('_auth', 'your-username your-password')
        or throw new Exception('auth error');
});

TLS

PHP's ext-memcached has no native TLS support. If you need to connect over the public Internet and want traffic encrypted, run stunnel alongside your application as a local TLS-terminating proxy, and point ext-memcached at 127.0.0.1 on the local plaintext port stunnel exposes.

# stunnel.conf
[velstash]
client = yes
accept = 127.0.0.1:11212
connect = mc1.public.gra1.ovh.velstash.io:11212

Then point ext-memcached at 127.0.0.1:11212 instead of the public host directly.

Reading and writing

<?php
$mc->set('user:123:profile', $data, 3600); // 3600s TTL

$value = $mc->get('user:123:profile');
if ($mc->getResultCode() === Memcached::RES_NOTFOUND) {
    // not a cache hit — false alone isn't enough, since false
    // can also be a legitimately stored value
}

Common pitfalls

• Items over 1MB (the default max item size) fail silently on set — check the result code or error your client returns if a value doesn't seem to be sticking.
• Prefixing keys with : (e.g. user:123:profile) is what makes the dashboard's top-keys/prefixes view group things meaningfully — worth doing from day one.
• The auth set authenticates the underlying TCP connection, not the client object — it only needs to run once per connection (that's why each example above issues it right after connecting, not before every request). If your client library pools connections or silently reopens them, make sure new connections authenticate too before you rely on them.