mirror of https://github.com/dapr/docs.git
96 lines
2.7 KiB
Markdown
96 lines
2.7 KiB
Markdown
---
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type: docs
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title: "How-To: Share state between applications"
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linkTitle: "How-To: Share state between applications"
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weight: 400
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description: "Choose different strategies for sharing state between different applications"
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---
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## Introduction
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Dapr offers developers different ways to share state between applications.
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Different architectures might have different needs when it comes to sharing state. For example, in one scenario you may want to encapsulate all state within a given application and have Dapr manage the access for you. In a different scenario, you may need to have two applications working on the same state be able to get and save the same keys.
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To enable state sharing, Dapr supports the following key prefixes strategies:
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* **`appid`** - This is the default strategy. the `appid` prefix allows state to be managed only by the app with the specified `appid`. All state keys will be prefixed with the `appid`, and are scoped for the application.
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* **`name`** - This setting uses the name of the state store component as the prefix. Multiple applications can share the same state for a given state store.
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* **`none`** - This setting uses no prefixing. Multiple applications share state across different state stores.
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## Specifying a state prefix strategy
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To specify a prefix strategy, add a metadata key named `keyPrefix` on a state component:
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```yaml
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apiVersion: dapr.io/v1alpha1
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kind: Component
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metadata:
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name: statestore
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namespace: production
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spec:
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type: state.redis
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version: v1
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metadata:
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- name: keyPrefix
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value: <key-prefix-strategy>
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```
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## Examples
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The following examples will show you how state retrieval looks like with each of the supported prefix strategies:
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### `appid` (default)
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A Dapr application with app id `myApp` is saving state into a state store named `redis`:
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```shell
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curl -X POST http://localhost:3500/v1.0/state/redis \
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-H "Content-Type: application/json"
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-d '[
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{
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"key": "darth",
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"value": "nihilus"
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}
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]'
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```
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The key will be saved as `myApp||darth`.
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### `name`
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A Dapr application with app id `myApp` is saving state into a state store named `redis`:
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```shell
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curl -X POST http://localhost:3500/v1.0/state/redis \
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-H "Content-Type: application/json"
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-d '[
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{
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"key": "darth",
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"value": "nihilus"
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}
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]'
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```
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The key will be saved as `redis||darth`.
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### `none`
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A Dapr application with app id `myApp` is saving state into a state store named `redis`:
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```shell
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curl -X POST http://localhost:3500/v1.0/state/redis \
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-H "Content-Type: application/json"
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-d '[
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{
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"key": "darth",
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"value": "nihilus"
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}
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]'
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```
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The key will be saved as `darth`.
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