What is the hierarchical namespace in Azure Data Lake Storage in TypeScript

Question

Pulumi · Accepted Answer

Azure Data Lake Storage Gen2 (ADLS Gen2) is a widely-used data storage service that is part of Microsoft Azure's cloud platform. It's built on top of Azure Blob storage and enhanced by additional capabilities to make it suitable for big data analytics. One of the main features of ADLS Gen2 is its hierarchical namespace.

The hierarchical namespace organizes objects/files into a hierarchy of directories for efficient data access. This is different from the flat namespace used in typical blob storage where everything is organized as objects in containers with no directory structure. By enabling the hierarchical namespace, Azure Data Lake Storage Gen2 allows you to perform operations on directories and subdirectories (like rename or delete) which is not possible in the flat namespace, while also improving performance for directory operations.

To enable hierarchical namespace in ADLS Gen2 as part of a Pulumi program, you would typically create an Azure storage account first with the hierarchical namespace activated. Here's a TypeScript program using Pulumi to create such a storage account:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as storage from "@pulumi/azure-native/storage";

// Create an Azure Resource Group
const resourceGroup = new storage.ResourceGroup("my-resource-group");

// Create a Storage Account with hierarchical namespace enabled (ADLS Gen2)
const storageAccount = new storage.StorageAccount("mystorageaccount", {
  resourceGroupName: resourceGroup.name,
  kind: "StorageV2", // ADLS Gen2 is available in "StorageV2" kind
  sku: {
    name: "Standard_LRS"
  },
  location: "East US",
  // Enabling hierarchical namespace for the account
  isHnsEnabled: true
});

// Export the connection string for the storage account
export const connectionString = storageAccount.primaryConnectionString;

// Export the primary endpoint of the Data Lake Storage account
export const dataLakeEndpoint = storageAccount.primaryEndpoints.apply(endpoints => endpoints.dfs);
```

In this program:

- We import required Pulumi libraries for the Azure provider.
- We create a new Azure resource group to contain our resources.
- We create a new Azure Storage account of `kind: "StorageV2"` which is necessary for ADLS Gen2.
- The `sku` defines the performance/replication of the storage account where `Standard_LRS` stands for "Standard Locally-Redundant Storage".
- We're located in the "East US" region, but you should choose a region that's appropriate for your use case.
- The `isHnsEnabled` property is set to `true` to enable the hierarchical namespace, transforming the storage account into an ADLS Gen2 account.
- We then export the connection string and the primary DFS endpoint for the account, which can be useful for connecting analytics services or applications to the data lake.

After running your Pulumi program, you can use this storage account as an ADLS Gen2 account with a hierarchical namespace. Remember to replace `"my-resource-group"` and `"mystorageaccount"` with the actual names you would like to use for your resource group and storage account.