How to Configure CDN to Website

Configuring Azure CDN (Content Delivery Network) for your website involves several steps. Here's a step-by-step guide with an example:

Step 1: Create a CDN Profile in Azure

1. Log in to the Azure Portal.
2. Navigate to “Create a resource” and select “Networking” > “CDN”.
3. Fill in the details:

1. Name: Choose a unique name for your CDN profile.
2. Subscription: Select your Azure subscription.
3. Resource group: Create a new one or select an existing group.
4. Location: Choose the location closest to your user base.
5. Pricing tier: Select a pricing tier that suits your needs.

Step 2: Create a CDN Endpoint

1. After creating the CDN profile, create a new endpoint.
2. Configure the endpoint settings:

1. Name: Give your endpoint a descriptive name.
2. Origin type: Choose "Web App", "Cloud Service", "Storage", or "Custom origin".
3. Origin hostname: Enter the URL of your website (e.g., www.yourwebsite.com).
4. Path: Leave blank or specify a path to cache specific content.
5. Protocol: Select HTTPS, HTTP, or both.

Step 3: Configure Custom Domain (Optional)

1. In your CDN profile, go to the “Custom domains” section.
2. Add your domain (e.g., cdn.yourwebsite.com).
3. Verify the domain by adding a CNAME record to your DNS settings pointing to your CDN endpoint.

Step 4: Configure Caching Rules (Optional)

1. In your CDN endpoint, go to the “Caching rules” section.
2. Set global caching rules or create custom rules based on paths, file extensions, etc.

Step 5: Activate and Test

1. Once configured, the CDN endpoint will propagate. This process can take some time.
2. Test your CDN endpoint URL (e.g., https://yourcdnendpoint.azureedge.net).
3. Ensure that your website content is being delivered through the CDN.

Step 6: Update Website to Use CDN URLs

1. Update your website’s code to reference the CDN URLs for static content like images, CSS, and JavaScript files.
2. Example: Replace src="https://www.yourwebsite.com/images/logo.png" with src="https://yourcdnendpoint.azureedge.net/images/logo.png" in your HTML files.

Step 7: Monitor and Maintain

1. Regularly check the Azure portal for CDN metrics and logs.
2. Update CDN settings as needed based on performance and usage patterns.

Example

Imagine you have a website, www.example.com, hosted on Azure Web Apps. You want to use Azure CDN to deliver your static content like images and stylesheets faster to users.

1. Create a CDN Profile: Name it ExampleCDNProfile.
2. Create an Endpoint: Name it ExampleCDNEndpoint, set the origin to www.example.com.
3. Custom Domain (Optional): Set up cdn.example.com to point to ExampleCDNEndpoint.azureedge.net.
4. Configure Caching Rules: Set a global caching rule for a 7-day expiration for images and CSS files.
5. Activate and Test: Once the CDN is active, test accessing cdn.example.com/images/logo.png.
6. Update Website: Change references in your site's HTML to use CDN URLs for static content.
7. Monitor Performance: Regularly check performance through the Azure portal.

Remember, the actual steps might vary slightly based on the specifics of your website and Azure settings. Always refer to the latest Azure documentation for the most current information and best practices.

What's a CNAME is?

?CNAME mapping in DNS (Domain Name System) is a process used to create an alias from one domain name to another. This is particularly useful in situations where you want to manage all your traffic through a single domain or need to change the target addresses frequently without modifying the DNS settings for each client. Here's a more detailed explanation:

What is a CNAME Record?

• CNAME stands for Canonical Name Record. It's a type of resource record in DNS that maps one domain name (an alias) to another (the canonical name).
• Used for Aliasing: It's typically used to associate a subdomain with the domain's primary (canonical) domain name. For example, you could map www.example.com to example.com.

How Does CNAME Mapping Work?

1. DNS Query: When a user types in a URL in their browser, the DNS query is initiated.

CNAME Lookup: If the domain has a CNAME record, the DNS server looks up the canonical (actual) domain that the alias points to.

1. Resolution to IP Address: The DNS server then resolves the canonical domain name to its IP address.
2. User is Directed: Finally, the user is directed to the IP address corresponding to the canonical domain name.

Usage in Azure CDN and Websites

• Linking CDN to Custom Domain: For example, in Azure CDN, you might create a CNAME record to map a custom subdomain like cdn.example.com to the Azure CDN endpoint URL, like examplecdnendpoint.azureedge.net.
• Seamless Integration: This allows users to access content via the custom domain while Azure CDN serves the content. The process is transparent to the end user.

Example of CNAME Mapping

• Original Setup: Your website www.example.com is hosted on Azure, and you set up an Azure CDN with the endpoint examplecdnendpoint.azureedge.net.
• CNAME Record: In your domain's DNS settings, you add a CNAME record where cdn.example.com points to examplecdnendpoint.azureedge.net.
• Result: When someone visits cdn.example.com, they are seamlessly served content from the Azure CDN endpoint.

Points to Note

• CNAME Flattening: Some DNS providers offer CNAME flattening to handle CNAMEs at the root domain level, as traditionally CNAMEs are not allowed at the root (e.g., example.com directly).
• TTL Settings: The Time To Live (TTL) setting in DNS determines how long the CNAME record is cached by DNS servers and browsers.
• Limitations: A domain with a CNAME record cannot have other record types (like A or MX records) simultaneously.

How CDN endpoints works on server content?

When you create a CDN (Content Delivery Network) for a website like example.com, the CDN needs to know what content it should serve. This is determined by the configuration of the CDN, specifically the setup of the CDN endpoint. Here's how it works:

1. Setting Up the Origin

• Origin Definition: The origin is the primary source of the content that the CDN will distribute. In the case of example.com, the origin would be the server where example.com is hosted.
• Types of Origins: The origin can be a web server, a cloud storage bucket, or even another CDN. For a website, it's typically the web server hosting the site.

2. Configuring the CDN Endpoint

• Endpoint Creation: When you create a CDN, you define an endpoint. This endpoint specifies where the CDN should pull the content from.
• Specifying the Origin: You'll specify example.com or its IP address as the origin for the CDN endpoint. This tells the CDN that example.com is the source of the content it needs to cache and serve.

3. Content Caching

• Initial Request: The first time a user requests a piece of content (like an image or a CSS file) from example.com, the CDN fetches it from the origin server.
• Caching the Content: The CDN then caches this content at its edge locations (servers located closer to the end-users).
• Subsequent Requests: When another user requests the same content, the CDN serves it from the cached copy at the edge location, rather than fetching it again from the origin server.

4. CDN and DNS

• CNAME Mapping: You might use a CNAME record in DNS to point a subdomain (like cdn.example.com) to the CDN endpoint. This makes the CDN transparent to users, as they can access CDN-served content using a domain name associated with your website.
• DNS Resolution: When a request is made to cdn.example.com, DNS resolves this to the CDN endpoint, and the CDN serves the cached content.

5. Content Delivery

• Load Balancing: The CDN automatically selects the nearest edge server to the user making the request, ensuring faster delivery of content.
• Dynamic and Static Content: While static content (like images, CSS, JavaScript files) is cached, dynamic content (like user-specific pages) might be fetched from the origin server each time, depending on the CDN's configuration.

6. Content Update and Expiry

• TTL (Time to Live): The CDN's cache has a TTL for each cached item. Once the TTL expires, the CDN will fetch the latest version of the content from the origin server.
• Manual Purging: You can also manually purge the CDN's cache if you need to force it to update its cached content.

Example Scenario

• Website: example.com hosts a range of content including HTML pages, images, and style sheets.
• CDN Setup: You configure the CDN endpoint to point to example.com.
• User Requests: When users across the globe access example.com, the CDN serves the content from the nearest edge server, reducing latency and improving load times.