Working with an index alias in Azure AI Search

Introduction

According to the official Microsoft documentation, in Azure AI Search, an index alias is a secondary name that can be used to refer to an index for querying, indexing, and other operations.

You can set up an alias that links to a search index and use the alias name in place of the index name. This provides added flexibility, allowing you to switch the index your application uses without altering the references throughout your application. Instead of modifying each reference, you only need to adjust the alias mapping.

Let's take a look at how we can implement this.

Preparation

To follow along, you should already have an Azure AI Search instance, and an index created.

Working with the index without an alias

Initially, let's see how we run a simple query on an existing index using Postman.

In the URL to which we will send our requests to, I specify the index name, which in my case is single-product-index:

https://itt-search.search.windows.net/indexes/<your-index-name>/docs/search?api-version=2024-05-01-preview        

Sending the HTTP POST request returns the following response:

Using the index name is not wrong, but it can make it harder for us to manage our indexes.

For instance, if we need to modify an existing index definition, such as incorporating a new analyzer, we must establish a new search index since current search indexes cannot be altered.

This implies that we either have to delete and reconstruct the index ?? or generate a new index and transition our application to use the updated one.

Instead of doing any of these, we can use an index alias to solve the issue.

Creating and using an index alias

Let's now create an alias for the index. Go to the Azure portal and open the Azure AI Search instance you are using.

Next, go to 'Aliases' from the left menu and select '+ Add alias'.

Decide a proper name for your index alias and specify the search index you want to use it for.

After creating it, you should see the alias in your list. Please wait a couple of seconds for the update to propagate through the system.

Finally, open Postman, and in the same URL, switch the index name with the alias name, in my case single-product-alias.

https://itt-search.search.windows.net/indexes/<your-index-alias>/docs/search?api-version=2024-05-01-preview        

Submit the HTTP POST request and observe that the response remains the same as when we used the index name.

Conclusion

If you plan to modify a production index, use an alias instead of the index name in your client-side application!

With the existing architectural design, when you need to direct your application to a new index, you only have to adjust the alias mapping.

Thanks for sticking to the end of another article from 'Iliev Talks Tech'.

Next steps:

• Load balancing between multiple Azure OpenAI instances using Azure API Management
• Import an Azure OpenAI API as a REST API into Azure API Management
• Azure AI Search - Data Deletion and Change Detection Policies
• Azure AI Search - Create Index from Multiple Data Sources