Durable Event Storage for AI Event Sourcing with Azure Event Hubs

Question

Pulumi · Accepted Answer

To create a durable event storage solution for AI event sourcing using Azure, we'll take advantage of Azure Event Hubs. Event Hubs is a fully managed, real-time data ingestion service that’s highly scalable and capable of streaming millions of events per second. Events can be stored for later processing or real-time analytics. We will use Pulumi's infrastructure as code approach to define and deploy our resources to Azure.

We'll define an Event Hubs Namespace, an Event Hub, and configure the Event Hub to ensure it retains events for a durable period (which can be up to 7 days on the standard tier), and enable the Capture feature to automatically save the streaming data to a blob storage for long-term retention.

Here's a basic overview of the components we’ll set up:

- **Event Hubs Namespace**: A namespace is a scoping container for multiple Event Hubs.
- **Event Hub**: Where the events are sent. Each Event Hub corresponds to a consumer group or category of related events.
- **Capture Feature**: An automated way to save the incoming events to a Blob storage or an Azure Data Lake service.

Below is a Python program that uses Pulumi to set up these resources. We will define the necessary components using `azure-native` package, which is the Pulumi provider for Azure. Ensure you have the Pulumi CLI and Azure provider set up before running this program.

```python
import pulumi
import pulumi_azure_native.eventhub as eventhub
import pulumi_azure_native.resources as resources
import pulumi_azure_native.storage as storage

# Create an Azure Resource Group
resource_group = resources.ResourceGroup('eventhub-rg')

# Create an Azure Storage Account for long-term storage
storage_account = storage.StorageAccount('storacc',
    resource_group_name=resource_group.name,
    kind=storage.Kind.STORAGE_V2,
    sku=storage.SkuArgs(name=storage.SkuName.STANDARD_LRS))

# Create an Azure Storage Blob Container where the captured data will be stored
blob_container = storage.BlobContainer('eventcontainer',
    account_name=storage_account.name,
    resource_group_name=resource_group.name,
    public_access=storage.PublicAccess.NONE)

# Create an Event Hubs Namespace
event_hub_namespace = eventhub.Namespace('eventhubnamespace',
    resource_group_name=resource_group.name,
    sku=eventhub.SkuArgs(
        name=eventhub.SkuName.STANDARD
    ))

# Create an Event Hub with Capture enabled for long-term storage
event_hub = eventhub.EventHub('eventhub',
    resource_group_name=resource_group.name,
    namespace_name=event_hub_namespace.name,
    message_retention_in_days=7,
    partition_count=2,
    capture_description=eventhub.CaptureDescriptionArgs(
        enabled=True,
        encoding=eventhub.EncodingCaptureDescription.AVRO,
        interval_in_seconds=300,
        size_limit_in_bytes=314572800,  # 300 MB
        destination=eventhub.DestinationArgs(
            name="EventHubArchive.AzureBlockBlob",
            blob_container=blob_container.name,
            archive_name_format="{Namespace}/{EventHub}/{PartitionId}/{Year}/{Month}/{Day}/{Hour}/{Minute}/{Second}",
            storage_account_resource_id=storage_account.id
        )
    ))

# Exporting the Event Hub connection string and Storage Account name
primary_connection_string = pulumi.Output.all(resource_group.name, event_hub_namespace.name) \
    .apply(lambda args: eventhub.list_namespace_keys(resource_group_name=args[0], namespace_name=args[1])) \
    .apply(lambda list_keys: list_keys.primary_connection_string)

pulumi.export('Primary Event Hub Connection String', primary_connection_string)
pulumi.export('Storage Account Name', storage_account.name)
```

In the program above, the `pulumi_azure_native.eventhub.Namespace` and `pulumi_azure_native.eventhub.EventHub` are used to create the namespace and event hub respectively. We've enabled the Capture feature on the Event Hub to save the data to Azure Blob storage created using `pulumi_azure_native.storage.StorageAccount` and `pulumi_azure_native.storage.BlobContainer`.

We’ve also exported the primary connection string of the Event Hub namespace, which you may need to send events to your Event Hub, and the name of the storage account being used for long-term retention.

To deploy these resources, save the program into a file, for example `main.py`. Run `pulumi up` and follow the prompts to authenticate with Azure if you haven't already done so.

Remember to destroy the resources with `pulumi destroy` when you no longer need them to avoid incurring unnecessary costs.