Redis by Upstash

Redis by Upstash is a fully-managed, Redis-compatible database service offering global read replicas for reduced latency in distant regions. Upstash databases are provisioned inside your Fly organization, ensuring private, low-latency connections to your Fly applications.

See the What you Should Know section for more details about this service.

Create and manage a Redis database

Creating and managing databases happens exclusively via the Fly CLI. Install it, then signup for a Fly account.

Create and get status of a Redis database

flyctl redis create

? Select Organization: fly-apps (fly-apps)
? Choose a primary region (can't be changed later) Madrid, Spain (mad)
? Optionally, choose one or more replica regions (can be changed later): Amsterdam, Netherlands (ams)
? Select an Upstash Redis plan Free: 100 MB Max Data Size

Once created, check the list of Redis databases.

flyctl redis list

ID              NAME                ORG             PLAN    PRIMARY REGION  READ REGIONS
aaV829vaMVQGbi5 late-waterfall-1133 fly-apps        Free    mad             ams

Note the database ID, then fetch its status.

fly redis status aaV829vaMVDGbi5

Redis
  ID             = aaV829vaMVDGbi5
  Name           = late-waterfall-1133
  Plan           = Free
  Primary Region = mad
  Read Regions   = ams
  Private URL     = redis://password@fly-magical-javelin-30042.upstash.io

Connect to a Redis database

fly redis connect
? Select a database to connect to empty-water-3291 (sjc) 200M
Proxying local port 16379 to remote [fdaa:0:6d6b:0:1::3]:6379
127.0.0.1:16379> set foo bar
OK
127.0.0.1:16379> get foo
"bar"
127.0.0.1:16379>

By connecting a database, you can run Redis commands on redis-cli.

Update a Redis database

Upstash Redis instances can’t change their primary region or name, but the following may change:

• Read regions
• Pricing plan
• Eviction settings

Use flyctl redis update and follow the prompts. Changing region settings should not cause downtime.

Delete a Redis database

Deleting a Redis database can’t be undone. Be careful!

fly redis delete my-redis-db

Your Redis database my-redis-db was deleted

What you should know

Once provisioned, the database primary region cannot be changed.

Traffic routing

Upstash Redis is available in all Fly regions via a private IPv6 address restricted to your Fly organization. Traffic is automatically routed to the nearest replica, or in the absence of nearby replicas, to the primary instance.

If you plan to deploy in a single region, ensure that your database is deployed in the same region as your application.

Writing to replica regions

Replicas forward writes to the primary. Replicas can’t be written to. Writes are synchronous, and synchronous writes over geographical distance experience latency. Plan for this latency in your application design.

If you’re using Redis as region-local cache and don’t require a shared cache, setup separate databases per-region and enable object eviction.

Memory limits and object eviction policies

By default, Upstash Redis will disallow writes when the max data size limit has been reached. If you enable eviction during creation on update, Upstash Redis will evict keys to free up space.

First, keys marked with a TTL will be evicted at random. In the absence of volatile keys, keys will be chosen randomly for eviction. This is roughly the combination of the volatile-random and allkeys-random eviction policies available in standard Redis.

Note that items marked with an explicit TTL will expire accurately, regardless of whether eviction is enabled.

Pricing

More plans may be added in the future. Get in touch on our community forum with feedback and suggestions for improvements.