Redis®* on Render

Render provides fully managed Redis instances for high-throughput, low-latency key-value storage. In a multi-service architecture, a Redis instance often acts as a shared cache, message broker, or job queue.

Paid Redis instances include disk-backed persistence. All instances currently run Redis version 6.2.14.

Quickstarts

These Render quickstarts include steps for provisioning a Redis instance:

• Deploy a Celery background worker
• Deploy Rails with Sidekiq
• Rails caching with Redis
• Connecting to Redis with ioredis

Create your Redis instance

1. Go to dashboard.render.com/new/redis, or select New > Redis in the Render Dashboard.

   This form appears:

   

2. Provide a helpful Name for your instance.

   • You can change this value at any time.

3. Choose a Region to run your instance in.

   • Choose the same region as your services that will connect to the instance. This minimizes latency and enables communication over your private network.

4. Optionally change the instance’s Maxmemory Policy.

   • See details below.

5. Scroll down and select an instance type. This determines its available RAM and connection limit.

   Learn about Free instance type limitations.

   

6. Click Create Redis.

You’re all set! Your new instance’s status updates to Available in the Render Dashboard when it’s ready to use.

Connect to your Redis instance

Every Redis instance has two different URLs for incoming connections:

• An internal URL for connections from your other Render services running in the same region
• An external URL for connections from everything else
  • Before you can use the external URL, you must first enable external connections for your Redis instance.

Use the internal URL wherever possible. It minimizes latency by enabling communication over your private network.

Both URLs are available from the Connect menu in the top-right corner of your instance’s page in the Render Dashboard:

Internal connection examples

# Connect to your internal Redis instance using the REDIS_URL environment variable
# The REDIS_URL is set to the internal Redis URL e.g. redis://red-343245ndffg023:6379

Sidekiq.configure_server do |config|
    config.redis = {url: ENV.REDIS_URL}
end

Sidekiq.configure_client do |config|
    config.redis = {url: ENV.REDIS_URL}
end

# Simple example from https://github.com/mperham/sidekiq/wiki/Getting-Started
class HardJob
  include Sidekiq::Job

  def perform(name, count)
    # do something
  end
end

HardJob.perform_async('bob', 5)

Enabling external connections

By default, newly created Redis instances are not reachable at their external URL. To keep your instance secure, you can grant external access to specific sets of IPs.

In the Render Dashboard, go to your Redis instance’s Info page and scroll down to the Access Control section:

Here you can specify IP address blocks using CIDR notation. The example above grants access to the static outbound IPs for Render’s Ohio region.

If you attempt to connect from a disallowed IP address, your client will display an error like the following:

AUTH failed: Client IP address is not in the allowlist.

Connecting with redis-cli

The redis-cli is a useful administrative tool for exploring and manipulating data on your Redis instance. There are 2 ways you can use redis-cli with your Redis instance:

• If you have a running non-Docker service, redis-cli will be available as part of the environment and is accessible from the service’s Shell page. The service must be in the same region as the Redis instance. You can also SSH into that service and run redis-cli from there.

• You can run redis-cli locally on your machine. You first need to install redis-cli onto your machine. A copy and pastable redis-cli command is available in the External Access section of your Redis settings. Note that you first need to enable external connections for your Redis instance.

Once you have connected, you can set and get keys using various Redis commands.

oregon-redis.render.com:6379> set "render_is_cool" true
OK
oregon-redis.render.com:6379> get "render_is_cool"
"true"
oregon-redis.render.com:6379> KEYS r*
1) "render_is_cool"

Configure your Redis instance

Maxmemory policy

Your Redis instance’s maxmemory policy determines which data it evicts to free space when it reaches its memory limit. You select a policy on instance creation and can change it later.

• For caching use cases, we recommend using allkeys-lru.
• For job queues, we recommend using noeviction to ensure that queued jobs are not lost.
• For other use cases, select a policy from the table below based on your requirements.

You can select any of the following policies:

Changing instance types

You can upgrade your Redis instance to a larger instance type with more RAM and a higher connection limit.

1. In the Render Dashboard, open your instance’s Info page and scroll down to the Redis Instance section.

2. Under Instance Type, click Update.

3. Select a new instance type and click Save Changes.

Blueprint configuration

As with your other services, you can manage your Redis instances with Blueprints, Render’s infrastructure-as-code model. For details and examples, see the Blueprint YAML Reference.

Data persistence

Paid Redis instances on Render write their state to disk once per second via the configuration appendfsync everysec. If a paid instance experiences an interruption (or if you upgrade your instance type), you might lose up to one second of writes.

Free Redis instances do not persist data to disk.

Metrics

Metrics for memory usage, CPU load, and active connections are available for Redis instances in the Render Dashboard.

The default metrics granularity shown is 12 hours, which can be adjusted from 5 minutes to 1 week.