How-To: Share state between applications

Dapr provides different ways to share state between applications.

Different architectures might have different needs when it comes to sharing state. In one scenario, you may want to:

• Encapsulate all state within a given application
• Have Dapr manage the access for you

In a different scenario, you may need two applications working on the same state to get and save the same keys.

To enable state sharing, Dapr supports the following key prefixes strategies:

Specifying a state prefix strategy

To specify a prefix strategy, add a metadata key named keyPrefix on a state component:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: statestore
  namespace: production
spec:
  type: state.redis
  version: v1
  metadata:
  - name: keyPrefix
    value: <key-prefix-strategy>

Examples

The following examples demonstrate what state retrieval looks like with each of the supported prefix strategies.

appid (default)

In the example below, a Dapr application with app id myApp is saving state into a state store named redis:

curl -X POST http://localhost:3500/v1.0/state/redis \
  -H "Content-Type: application/json"
  -d '[
        {
          "key": "darth",
          "value": "nihilus"
        }
      ]'

The key will be saved as myApp||darth.

name

In the example below, a Dapr application with app id myApp is saving state into a state store named redis:

curl -X POST http://localhost:3500/v1.0/state/redis \
  -H "Content-Type: application/json"
  -d '[
        {
          "key": "darth",
          "value": "nihilus"
        }
      ]'

The key will be saved as redis||darth.

none

In the example below, a Dapr application with app id myApp is saving state into a state store named redis:

curl -X POST http://localhost:3500/v1.0/state/redis \
  -H "Content-Type: application/json"
  -d '[
        {
          "key": "darth",
          "value": "nihilus"
        }
      ]'

The key will be saved as darth.