Quickstart: State Management

Pre-requisites

For this example, you will need:

• Dapr CLI and initialized environment.
• Latest Node.js installed.

• Docker Desktop

Step 1: Set up the environment

Clone the sample provided in the Quickstarts repo.

git clone https://github.com/dapr/quickstarts.git

Step 2: Manipulate service state

In a terminal window, navigate to the order-processor directory.

cd state_management/javascript/sdk/order-processor

Install dependencies, which will include the dapr-client package from the JavaScript SDK:

npm install

Verify you have the following files included in the service directory:

• package.json
• package-lock.json

Run the order-processor service alongside a Dapr sidecar.

dapr run --app-id order-processor --components-path ../../../components/ -- npm run start

The order-processor service writes, reads, and deletes an orderId key/value pair to the statestore instance defined in the statestore.yaml component. As soon as the service starts, it performs a loop.

  const client = new DaprClient(DAPR_HOST, DAPR_HTTP_PORT);

  // Save state into the state store
  client.state.save(STATE_STORE_NAME, [
      {
          key: orderId.toString(),
          value: order
      }
  ]);
  console.log("Saving Order: ", order);

  // Get state from the state store
  var result = client.state.get(STATE_STORE_NAME, orderId.toString());
  result.then(function(val) {
      console.log("Getting Order: ", val);
  });

  // Delete state from the state store
  client.state.delete(STATE_STORE_NAME, orderId.toString());    
  result.then(function(val) {
      console.log("Deleting Order: ", val);
  });

Step 3: View the order-processor outputs

Notice, as specified in the code above, the code saves application state in the Dapr state store, reads it, then deletes it.

Order-processor output:

== APP == > order-processor@1.0.0 start
== APP == > node index.js
== APP == Saving Order:  { orderId: 1 }
== APP == Saving Order:  { orderId: 2 }
== APP == Saving Order:  { orderId: 3 }
== APP == Saving Order:  { orderId: 4 }
== APP == Saving Order:  { orderId: 5 }
== APP == Getting Order:  { orderId: 1 }
== APP == Deleting Order:  { orderId: 1 }
== APP == Getting Order:  { orderId: 2 }
== APP == Deleting Order:  { orderId: 2 }
== APP == Getting Order:  { orderId: 3 }
== APP == Deleting Order:  { orderId: 3 }
== APP == Getting Order:  { orderId: 4 }
== APP == Deleting Order:  { orderId: 4 }
== APP == Getting Order:  { orderId: 5 }
== APP == Deleting Order:  { orderId: 5 }

statestore.yaml component file

When you run dapr init, Dapr creates a default Redis statestore.yaml and runs a Redis container on your local machine, located:

• On Windows, under %UserProfile%\.dapr\components\statestore.yaml
• On Linux/MacOS, under ~/.dapr/components/statestore.yaml

With the statestore.yaml component, you can easily swap out the state store without making code changes.

The Redis statestore.yaml file included for this quickstart contains the following:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: statestore
spec:
  type: state.redis
  version: v1
  metadata:
  - name: redisHost
    value: localhost:6379
  - name: redisPassword
    value: ""
  - name: actorStateStore
    value: "true"

In the YAML file:

• metadata/name is how your application talks to the component (called DAPR_STORE_NAME in the code sample).
• spec/metadata defines the connection to the Redis instance used by the component.

Pre-requisites

For this example, you will need:

• Dapr CLI and initialized environment.
• .NET SDK or .NET 6 SDK installed.

• Docker Desktop

Step 1: Set up the environment

Clone the sample provided in the Quickstarts repo.

git clone https://github.com/dapr/quickstarts.git

Step 2: Manipulate service state

In a terminal window, navigate to the order-processor directory.

cd state_management/csharp/sdk/order-processor

Recall NuGet packages:

dotnet restore
dotnet build

Run the order-processor service alongside a Dapr sidecar.

dapr run --app-id order-processor --components-path ../../../components/ -- dotnet run

The order-processor service writes, reads, and deletes an orderId key/value pair to the statestore instance defined in the statestore.yaml component. As soon as the service starts, it performs a loop.

var client = new DaprClientBuilder().Build();

// Save state into the state store
await client.SaveStateAsync(DAPR_STORE_NAME, orderId.ToString(), order.ToString());
Console.WriteLine("Saving Order: " + order);

// Get state from the state store
var result = await client.GetStateAsync<string>(DAPR_STORE_NAME, orderId.ToString());
Console.WriteLine("Getting Order: " + result);

// Delete state from the state store
await client.DeleteStateAsync(DAPR_STORE_NAME, orderId.ToString());
Console.WriteLine("Deleting Order: " + order);

Step 3: View the order-processor outputs

Notice, as specified in the code above, the code saves application state in the Dapr state store, reads it, then deletes it.

Order-processor output:

== APP == Saving Order: Order { orderId = 1 }
== APP == Getting Order: Order { orderId = 1 }
== APP == Deleting Order: Order { orderId = 1 }
== APP == Saving Order: Order { orderId = 2 }
== APP == Getting Order: Order { orderId = 2 }
== APP == Deleting Order: Order { orderId = 2 }
== APP == Saving Order: Order { orderId = 3 }
== APP == Getting Order: Order { orderId = 3 }
== APP == Deleting Order: Order { orderId = 3 }
== APP == Saving Order: Order { orderId = 4 }
== APP == Getting Order: Order { orderId = 4 }
== APP == Deleting Order: Order { orderId = 4 }
== APP == Saving Order: Order { orderId = 5 }
== APP == Getting Order: Order { orderId = 5 }
== APP == Deleting Order: Order { orderId = 5 }

statestore.yaml component file

When you run dapr init, Dapr creates a default Redis statestore.yaml and runs a Redis container on your local machine, located:

• On Windows, under %UserProfile%\.dapr\components\statestore.yaml
• On Linux/MacOS, under ~/.dapr/components/statestore.yaml

With the statestore.yaml component, you can easily swap out the state store without making code changes.

The Redis statestore.yaml file included for this quickstart contains the following:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: statestore
spec:
  type: state.redis
  version: v1
  metadata:
  - name: redisHost
    value: localhost:6379
  - name: redisPassword
    value: ""
  - name: actorStateStore
    value: "true"

In the YAML file:

• metadata/name is how your application talks to the component (called DAPR_STORE_NAME in the code sample).
• spec/metadata defines the connection to the Redis instance used by the component.

Pre-requisites

For this example, you will need:

• Dapr CLI and initialized environment.
• Java JDK 11 (or greater):
  • Oracle JDK, or
  • OpenJDK
• Apache Maven, version 3.x.

• Docker Desktop

Step 1: Set up the environment

Clone the sample provided in the Quickstarts repo.

git clone https://github.com/dapr/quickstarts.git

Step 2: Manipulate service state

In a terminal window, navigate to the order-processor directory.

cd state_management/java/sdk/order-processor

Install the dependencies:

mvn clean install

Run the order-processor service alongside a Dapr sidecar.

dapr run --app-id order-processor --components-path ../../../components -- java -jar target/order-processor-0.0.1-SNAPSHOT.jar

The order-processor service writes, reads, and deletes an orderId key/value pair to the statestore instance defined in the statestore.yaml component. As soon as the service starts, it performs a loop.

try (DaprClient client = new DaprClientBuilder().build()) {
  for (int i = 1; i <= 10; i++) {
    int orderId = i;
    Order order = new Order();
    order.setOrderId(orderId);

    // Save state into the state store
    client.saveState(DAPR_STATE_STORE, String.valueOf(orderId), order).block();
    LOGGER.info("Saving Order: " + order.getOrderId());

    // Get state from the state store
    State<Order> response = client.getState(DAPR_STATE_STORE, String.valueOf(orderId), Order.class).block();
    LOGGER.info("Getting Order: " + response.getValue().getOrderId());

    // Delete state from the state store
    client.deleteState(DAPR_STATE_STORE, String.valueOf(orderId)).block();
    LOGGER.info("Deleting Order: " + orderId);
    TimeUnit.MILLISECONDS.sleep(1000);
  }

Step 3: View the order-processor outputs

Notice, as specified in the code above, the code saves application state in the Dapr state store, reads it, then deletes it.

Order-processor output:

== APP == INFO:root:Saving Order: {'orderId': '1'}
== APP == INFO:root:Result after get: b"{'orderId': '1'}"
== APP == INFO:root:Deleting Order: {'orderId': '1'}
== APP == INFO:root:Saving Order: {'orderId': '2'}
== APP == INFO:root:Result after get: b"{'orderId': '2'}"
== APP == INFO:root:Deleting Order: {'orderId': '2'}
== APP == INFO:root:Saving Order: {'orderId': '3'}
== APP == INFO:root:Result after get: b"{'orderId': '3'}"
== APP == INFO:root:Deleting Order: {'orderId': '3'}
== APP == INFO:root:Saving Order: {'orderId': '4'}
== APP == INFO:root:Result after get: b"{'orderId': '4'}"
== APP == INFO:root:Deleting Order: {'orderId': '4'}

statestore.yaml component file

When you run dapr init, Dapr creates a default Redis statestore.yaml and runs a Redis container on your local machine, located:

• On Windows, under %UserProfile%\.dapr\components\statestore.yaml
• On Linux/MacOS, under ~/.dapr/components/statestore.yaml

With the statestore.yaml component, you can easily swap out the state store without making code changes.

The Redis statestore.yaml file included for this Quickstart contains the following:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: statestore
spec:
  type: state.redis
  version: v1
  metadata:
  - name: redisHost
    value: localhost:6379
  - name: redisPassword
    value: ""
  - name: actorStateStore
    value: "true"

In the YAML file:

• metadata/name is how your application talks to the component (called DAPR_STORE_NAME in the code sample).
• spec/metadata defines the connection to the Redis instance used by the component.

Pre-requisites

For this example, you will need:

• Dapr CLI and initialized environment.
• Latest version of Go.

• Docker Desktop

Step 1: Set up the environment

Clone the sample provided in the Quickstarts repo.

git clone https://github.com/dapr/quickstarts.git

Step 2: Manipulate service state

In a terminal window, navigate to the order-processor directory.

cd state_management/go/sdk/order-processor

Install the dependencies and build the application:

go build app.go

Run the order-processor service alongside a Dapr sidecar.

dapr run --app-id order-processor --components-path ../../../components -- go run app.go

The order-processor service writes, reads, and deletes an orderId key/value pair to the statestore instance defined in the statestore.yaml component. As soon as the service starts, it performs a loop.

  client, err := dapr.NewClient()

  // Save state into the state store
  _ = client.SaveState(ctx, STATE_STORE_NAME, strconv.Itoa(orderId), []byte(order))
  log.Print("Saving Order: " + string(order))

  // Get state from the state store
  result, _ := client.GetState(ctx, STATE_STORE_NAME, strconv.Itoa(orderId))
  fmt.Println("Getting Order: " + string(result.Value))

  // Delete state from the state store
  _ = client.DeleteState(ctx, STATE_STORE_NAME, strconv.Itoa(orderId))
  log.Print("Deleting Order: " + string(order))

Step 3: View the order-processor outputs

Notice, as specified in the code above, the code saves application state in the Dapr state store, reads it, then deletes it.

Order-processor output:

== APP == dapr client initializing for: 127.0.0.1:53689
== APP == 2022/04/01 09:16:03 Saving Order: {"orderId":1}
== APP == Getting Order: {"orderId":1}
== APP == 2022/04/01 09:16:03 Deleting Order: {"orderId":1}
== APP == 2022/04/01 09:16:03 Saving Order: {"orderId":2}
== APP == Getting Order: {"orderId":2}
== APP == 2022/04/01 09:16:03 Deleting Order: {"orderId":2}
== APP == 2022/04/01 09:16:03 Saving Order: {"orderId":3}
== APP == Getting Order: {"orderId":3}
== APP == 2022/04/01 09:16:03 Deleting Order: {"orderId":3}
== APP == 2022/04/01 09:16:03 Saving Order: {"orderId":4}
== APP == Getting Order: {"orderId":4}
== APP == 2022/04/01 09:16:03 Deleting Order: {"orderId":4}
== APP == 2022/04/01 09:16:03 Saving Order: {"orderId":5}
== APP == Getting Order: {"orderId":5}
== APP == 2022/04/01 09:16:03 Deleting Order: {"orderId":5}

statestore.yaml component file

When you run dapr init, Dapr creates a default Redis statestore.yaml and runs a Redis container on your local machine, located:

• On Windows, under %UserProfile%\.dapr\components\statestore.yaml
• On Linux/MacOS, under ~/.dapr/components/statestore.yaml

With the statestore.yaml component, you can easily swap out the state store without making code changes.

The Redis statestore.yaml file included for this Quickstart contains the following:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: statestore
spec:
  type: state.redis
  version: v1
  metadata:
  - name: redisHost
    value: localhost:6379
  - name: redisPassword
    value: ""
  - name: actorStateStore
    value: "true"

In the YAML file:

• metadata/name is how your application talks to the component (called DAPR_STORE_NAME in the code sample).
• spec/metadata defines the connection to the Redis instance used by the component.