---
type: docs
title: "Azure Service Bus"
linkTitle: "Azure Service Bus"
description: "Detailed documentation on the Azure Service Bus pubsub component"
aliases:
  - "/operations/components/setup-pubsub/supported-pubsub/setup-azure-servicebus/"
---

## Component format
To setup Azure Service Bus pubsub create a component of type `pubsub.azure.servicebus`. See [this guide]({{< ref "howto-publish-subscribe.md#step-1-setup-the-pubsub-component" >}}) on how to create and apply a pubsub configuration.

### Connection String Authentication

```yaml
apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: servicebus-pubsub
  namespace: default
spec:
  type: pubsub.azure.servicebus
  version: v1
  metadata:
  - name: connectionString # Required when not using Azure Authentication.
    value: "Endpoint=sb://{ServiceBusNamespace}.servicebus.windows.net/;SharedAccessKeyName={PolicyName};SharedAccessKey={Key};EntityPath={ServiceBus}"
  # - name: timeoutInSec # Optional
  #   value: 60
  # - name: handlerTimeoutInSec # Optional
  #   value: 60
  # - name: disableEntityManagement # Optional
  #   value: "false"
  # - name: maxDeliveryCount # Optional
  #   value: 3
  # - name: lockDurationInSec # Optional
  #   value: 60
  # - name: lockRenewalInSec # Optional
  #   value: 20
  # - name: maxActiveMessages # Optional
  #   value: 2000
  # - name: maxActiveMessagesRecoveryInSec # Optional
  #   value: 2
  # - name: maxConcurrentHandlers # Optional
  #   value: 10
  # - name: prefetchCount # Optional
  #   value: 5
  # - name: defaultMessageTimeToLiveInSec # Optional
  #   value: 10
  # - name: autoDeleteOnIdleInSec # Optional
  #   value: 3600
  # - name: maxReconnectionAttempts # Optional
  #   value: 30
  # - name: connectionRecoveryInSec # Optional
  #   value: 2
  # - name: publishMaxRetries # Optional
  #   value: 5
  # - name: publishInitialRetryInternalInMs # Optional
  #   value: 500
```

> __NOTE:__ The above settings are shared across all topics that use this component.

{{% alert title="Warning" color="warning" %}}
The above example uses secrets as plain strings. It is recommended to use a secret store for the secrets as described [here]({{< ref component-secrets.md >}}).
{{% /alert %}}

## Spec metadata fields

| Field              | Required | Details | Example |
|--------------------|:--------:|---------|---------|
| connectionString   | Y  | Shared access policy connection-string for the Service Bus  | "`Endpoint=sb://{ServiceBusNamespace}.servicebus.windows.net/;SharedAccessKeyName={PolicyName};SharedAccessKey={Key};EntityPath={ServiceBus}`"
| timeoutInSec       | N  | Timeout for sending messages and management operations. Default: `60` |`30`
| handlerTimeoutInSec| N  |  Timeout for invoking app handler. # Optional. Default: `60` | `30`
| disableEntityManagement | N  | When set to true, topics and subscriptions do not get created automatically. Default: `"false"` | `"true"`, `"false"`
| maxDeliveryCount      | N  |Defines the number of attempts the server will make to deliver a message. Default set by server| `10`
| lockDurationInSec     | N  |Defines the length in seconds that a message will be locked for before expiring. Default set by server | `30`
| lockRenewalInSec      | N  |Defines the frequency at which buffered message locks will be renewed. Default: `20`. | `20`
| maxActiveMessages     | N  |Defines the maximum number of messages to be buffered or processing at once. Default: `10000` | `2000`
| maxActiveMessagesRecoveryInSec | N  |Defines the number of seconds to wait once the maximum active message limit is reached. Default: `2` | `10`
| maxConcurrentHandlers | N  |Defines the maximum number of concurrent message handlers  | `10`
| prefetchCount         | N  |Defines the number of prefetched messages (use for high throughput / low latency scenarios)| `5`
| defaultMessageTimeToLiveInSec | N  |Default message time to live. | `10`
| autoDeleteOnIdleInSec | N  |Time in seconds to wait before auto deleting idle subscriptions. | `3600`
| maxReconnectionAttempts | N  |Defines the maximum number of reconnect attempts. Default: `30` | `30`
| connectionRecoveryInSec | N  |Time in seconds to wait between connection recovery attempts. Defaults: `2` | `2`
| publishMaxRetries | N  | The max number of retries for when Azure Service Bus responds with "too busy" in order to throttle messages. Defaults: `5` | `5`
| publishInitialRetryInternalInMs | N  | Time in milliseconds for the initial exponential backoff when Azure Service Bus throttle messages. Defaults: `500` | `500`
| namespaceName| N | Parameter to set the name of the Service Bus namespace. Required if using AAD authentication. | `"namespace"` |

### Azure Active Directory (AAD) authentication
The Azure Service Bus pubsub component supports authentication using all Azure Active Directory mechanisms. For further information and the relevant component metadata fields to provide depending on the choice of AAD authentication mechanism, see the [docs for authenticating to Azure]({{< ref authenticating-azure.md >}}).

#### Example Configuration
```yaml
apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: servicebus-pubsub
  namespace: default
spec:
  type: pubsub.azure.servicebus
  version: v1
  metadata:
  - name: namespaceName # Required when using Azure Authentication.
    value: "servicebusnamespace"
  - name: azureTenantId
    value: "***"
  - name: azureClientId
    value: "***"
  - name: azureClientSecret
    value: "***"
```

## Message metadata

Azure Service Bus messages extend the Dapr message format with additional contextual metadata. Some metadata fields are set by Azure Service Bus itself (read-only) and others can be set by the client when publishing a message.

### Sending a message with metadata

To set Azure Service Bus metadata when sending a message, set the query parameters on the HTTP request or the gRPC metadata as documented [here](https://docs.dapr.io/reference/api/pubsub_api/#metadata).

- `metadata.MessageId`
- `metadata.CorrelationId`
- `metadata.SessionId`
- `metadata.Label`
- `metadata.ReplyTo`
- `metadata.PartitionKey`
- `metadata.To`
- `metadata.ContentType`
- `metadata.ScheduledEnqueueTimeUtc`
- `metadata.ReplyToSessionId`

> **NOTE:** The `metadata.MessageId` property does not set the `id` property of the cloud event and should be treated in isolation.

### Receiving a message with metadata

When Dapr calls your application, it will attach Azure Service Bus message metadata to the request using either HTTP headers or gRPC metadata.
In addition to the [settable metadata listed above](#sending-a-message-with-metadata), you can also access the following read-only message metadata.

- `metadata.DeliveryCount`
- `metadata.LockedUntilUtc`
- `metadata.LockToken`
- `metadata.EnqueuedTimeUtc`
- `metadata.SequenceNumber`

To find out more details on the purpose of any of these metadata properties, please refer to [the official Azure Service Bus documentation](https://docs.microsoft.com/rest/api/servicebus/message-headers-and-properties#message-headers).

## Create an Azure Service Bus

Follow the instructions [here](https://docs.microsoft.com/azure/service-bus-messaging/service-bus-quickstart-topics-subscriptions-portal) on setting up Azure Service Bus Topics.

## Related links
- [Basic schema for a Dapr component]({{< ref component-schema >}})
- [Pub/Sub building block]({{< ref pubsub >}})
- Read [this guide]({{< ref "howto-publish-subscribe.md#step-2-publish-a-topic" >}}) for instructions on configuring pub/sub components