What's installed on your Redis server?
- Redis Open Source from the official Redis repository, on the latest version at install time
- A required password set with requirepass and generated at install
- AOF persistence turned on (appendonly yes)
- Remote connections on port 6379
- The vm.overcommit_memory = 1 setting that Redis's documentation recommends
- Firewall with only ports 22 and 6379 open, plus fail2ban for SSH
What size do you need for Redis?
Redis keeps all your data in RAM, so the size of your data decides the size of your server. The administration docs give no fixed figure, but they warn that a write-heavy instance can use up to twice its normal memory while saving an RDB file or rewriting the AOF. As a rule of thumb, 1 GB suits a small cache or session store, and for larger data you should choose about twice its size in RAM. If it isn't enough, scale up from your panel, and your data and IP address stay the same.
| Use | Size | Price | Choose |
|---|---|---|---|
| Starter | 1 GB RAM · 1 vCore · 25 GB NVMe | $2.58/mo | |
| Medium | 2 GB RAM · 1 vCore · 40 GB NVMe | $4.01/mo | |
| Powerful | 4 GB RAM · 2 vCore · 60 GB NVMe | $6.89/mo |
Who is it for?
- Several app servers that need a shared cache or session store
- Laravel, Django, Rails or Node.js queues moving to a Redis of their own
- Apps using in-memory structures such as pub/sub, counters or leaderboards
- Developers who want a remote Redis for development and testing
What happens after you order?
- Set the size and complete your payment.
- Your server starts and Redis installs itself. On the Overview tab, wait for the App row to say Redis is ready.
- Copy the Connection address and Password rows. There's no Login row, because the password belongs to Redis's default user.
- Test the connection: redis-cli -h IP -a PASSWORD ping
- Give your app the connection string: redis://:PASSWORD@IP:6379/0
- If you're using it as a cache, set maxmemory-policy allkeys-lru, then limit port 6379 to your own addresses.
With every server
- Daily backups included in the price
- Unlimited traffic
- Full root access
- Scale RAM and CPU up or down later, and grow the disk
- Location: Istanbul · IST-1.
Good to know
- Port 6379 is open to the internet and has no TLS, so the password and data travel unencrypted. Limit it: ufw delete allow 6379/tcp, then ufw allow from YOUR_IP to any port 6379.
- maxmemory is set to about three quarters of the RAM during installation. At the limit, Redis refuses new writes. If you resize your server, raise the value in /etc/redis/redis.conf.
- Redis 8 and later is distributed under RSALv2, SSPLv1 or AGPLv3. If you plan to offer Redis to others as a service, read the terms.
- Redis comes from its own repository and doesn't update itself. You install new versions with apt.
Redis questions and answers
How do I connect to my Redis server?
Your connection string is redis://:PASSWORD@IP:6379/0. From the command line, run redis-cli -h IP -a PASSWORD. A connection without the password gets a NOAUTH error, so every remote command has to authenticate first.
How much RAM does Redis need?
The size of your data decides how much RAM Redis needs, and there's no fixed official figure. As a rule of thumb, 1 GB is a start for a small cache or session store. Memory can double during saves on a write-heavy instance, so choose about twice your data size in RAM.
Does Redis lose data when it restarts?
No. Redis has AOF persistence on in this install, so each write is appended to disk and the data comes back from that file after a restart. The default fsync policy runs once a second, which means an unexpected outage can lose at most the last second of writes.
What happens when Redis runs out of memory?
This install sets maxmemory to about three quarters of the RAM, and at the limit Redis refuses new writes. For a cache, add maxmemory-policy allkeys-lru to /etc/redis/redis.conf and run systemctl restart redis-server. Redis then evicts old keys by itself at the limit.
Is my Redis connection encrypted?
Redis connections have no TLS at install, so the password and data travel unencrypted. Limit access to your own IP address or open an SSH tunnel with ssh -L 6379:127.0.0.1:6379 root@IP. An app on the same server connects to 127.0.0.1, so its traffic never leaves the machine.
Can I create a separate Redis user for my app?
Yes, through Redis ACLs. For example: ACL SETUSER uygulama on >STRONG_PASSWORD allkeys +@all -@dangerous. Then save it to the settings file with CONFIG REWRITE. The connection string becomes redis://uygulama:STRONG_PASSWORD@IP:6379/0.