Azure Cache for Redis - Commands & Configuration

Introduction

Sometimes your app needs to remember data quickly to work faster. Azure Cache for Redis helps by storing data in a fast place so your app can get it without waiting long.

When your website needs to show user info instantly without waiting for a database.

When you want to keep session data for users so they stay logged in smoothly.

When your app does many repeated calculations and you want to save results to avoid doing them again.

When you want to share data quickly between different parts of your app running on multiple servers.

When you want to reduce the load on your main database by caching frequent queries.

Config File - main.tf

main.tf

provider "azurerm" {
  features {}
}

resource "azurerm_resource_group" "example" {
  name     = "example-resources"
  location = "East US"
}

resource "azurerm_redis_cache" "example" {
  name                = "example-redis-cache"
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  capacity            = 1
  family              = "C"
  sku_name            = "Basic"
  enable_non_ssl_port = false
}

This Terraform file creates an Azure Redis Cache instance.

• provider: sets Azure as the cloud provider.
• resource_group: a container for your resources in Azure.
• redis_cache: the Redis cache instance with basic settings for testing or small apps.

Commands

This command prepares Terraform to work with Azure by downloading necessary plugins.

Terminal

terraform init

Expected Output

Initializing the backend...



Initializing provider plugins...

- Finding latest version of hashicorp/azurerm...

- Installing hashicorp/azurerm v3.64.0...

- Installed hashicorp/azurerm v3.64.0 (signed by HashiCorp)



Terraform has been successfully initialized!



You may now begin working with Terraform. Try running "terraform plan" to see

any changes that are required for your infrastructure. All Terraform commands

should now work.

This command creates the Redis Cache and resource group in Azure automatically without asking for confirmation.

Terminal

terraform apply -auto-approve

Expected Output

azurerm_resource_group.example: Creating...

azurerm_resource_group.example: Creation complete after 2s [id=/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/example-resources]

azurerm_redis_cache.example: Creating...

azurerm_redis_cache.example: Creation complete after 30s [id=/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/example-resources/providers/Microsoft.Cache/Redis/example-redis-cache]



Apply complete! Resources: 2 added, 0 changed, 0 destroyed.

→

-auto-approve - Skip manual approval to speed up deployment

This Azure CLI command checks the details of the Redis Cache to confirm it is running.

Terminal

az redis show --name example-redis-cache --resource-group example-resources

Expected Output

{

  "id": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/example-resources/providers/Microsoft.Cache/Redis/example-redis-cache",

  "location": "East US",

  "name": "example-redis-cache",

  "properties": {

    "provisioningState": "Succeeded",

    "hostName": "example-redis-cache.redis.cache.windows.net",

    "port": 6380,

    "sslPort": 6380

  },

  "resourceGroup": "example-resources",

  "sku": {

    "name": "Basic",

    "family": "C",

    "capacity": 1

  },

  "type": "Microsoft.Cache/Redis"

}

Key Concept

If you remember nothing else from this pattern, remember: Azure Cache for Redis stores data in memory to make your app faster by avoiding slow database calls.

Common Mistakes

Trying to connect to Redis without enabling the correct ports or SSL settings.

The connection will fail because Azure Redis Cache requires SSL by default and blocks non-SSL ports unless enabled.

Use the SSL port (usually 6380) and enable SSL in your client settings to connect securely.

Not creating or specifying the resource group before deploying Redis Cache.

Azure resources must belong to a resource group; deployment will fail without it.

Create a resource group first or include it in your deployment configuration.

Summary

Use Terraform to create an Azure Redis Cache instance with a resource group.

Run 'terraform init' to prepare the environment and 'terraform apply' to deploy the cache.

Verify the cache is running using Azure CLI with 'az redis show'.

Practice

1. What is the main purpose of Azure Cache for Redis?

easy

A. To permanently store large files

B. To host virtual machines

C. To replace Azure SQL Database

D. To store data in memory to speed up applications

Solution

1. Step 1: Understand Azure Cache for Redis function

   Azure Cache for Redis stores data in memory, which is much faster than disk storage.

2. Step 2: Identify the main benefit

   This in-memory storage helps speed up applications by reducing the time to access data.

3. Final Answer:

   To store data in memory to speed up applications -> Option D

4. Quick Check:

   In-memory cache = speed up apps [OK]

Hint: Remember: Redis cache is for fast memory storage [OK]

Common Mistakes:

• Thinking Redis stores large files permanently
• Confusing Redis with database replacement
• Assuming Redis hosts virtual machines

2. Which property sets the pricing tier when creating an Azure Cache for Redis instance?

easy

A. sku_name

B. resource_group

C. location

D. capacity

Solution

1. Step 1: Identify pricing tier property

   The pricing tier is controlled by the SKU name, which defines features and cost.

2. Step 2: Differentiate from other properties

   Capacity sets size, location sets region, resource group organizes resources.

3. Final Answer:

   sku_name -> Option A

4. Quick Check:

   Pricing tier = sku_name [OK]

Hint: Pricing tier is set by sku_name, not capacity [OK]

Common Mistakes:

• Confusing capacity with pricing tier
• Using location or resource group as pricing tier
• Mixing sku_name with capacity

3. Given this snippet to create Azure Cache for Redis in ARM template:

{
  "type": "Microsoft.Cache/Redis",
  "name": "myRedisCache",
  "apiVersion": "2023-04-01",
  "location": "eastus",
  "properties": {
    "sku": { "name": "Standard", "family": "C", "capacity": 2 },
    "enableNonSslPort": false
  }
}

What does setting enableNonSslPort to false do?

medium

A. Disables the non-SSL port, forcing SSL connections

B. Enables non-SSL port for faster connections

C. Sets the cache size to 2 GB

D. Changes the cache location to westus

Solution

1. Step 1: Understand enableNonSslPort property

   This property controls if clients can connect without SSL (non-secure).

2. Step 2: Interpret false value

   Setting it to false disables non-SSL port, so only secure SSL connections are allowed.

3. Final Answer:

   Disables the non-SSL port, forcing SSL connections -> Option A

4. Quick Check:

   enableNonSslPort false = SSL only [OK]

Hint: False disables non-SSL port, secure only [OK]

Common Mistakes:

• Thinking false enables non-SSL port
• Confusing capacity with enableNonSslPort
• Assuming location changes with this property

4. You try to create an Azure Cache for Redis with this JSON snippet:

{
  "type": "Microsoft.Cache/Redis",
  "name": "cache1",
  "apiVersion": "2023-04-01",
  "location": "eastus",
  "properties": {
    "sku": { "name": "Standard", "family": "C", "capacity": 0 },
    "enableNonSslPort": true
  }
}

What is the problem with this configuration?

medium

A. enableNonSslPort cannot be true for Basic SKU

B. Capacity cannot be zero; it must be at least 1

C. Location eastus is invalid

D. Missing resource group property

Solution

1. Step 1: Check capacity value

   Capacity defines cache size and must be a positive integer starting at 1.

2. Step 2: Validate other properties

   enableNonSslPort can be true, eastus is valid location, resource group is set outside this snippet.

3. Final Answer:

   Capacity cannot be zero; it must be at least 1 -> Option B

4. Quick Check:

   Capacity ≥ 1 required [OK]

Hint: Capacity must be 1 or more, zero is invalid [OK]

Common Mistakes:

• Assuming zero capacity is allowed
• Thinking enableNonSslPort is restricted by SKU
• Confusing location validity

5. You want to reduce database load by caching user session data using Azure Cache for Redis. Which combination of settings is best to ensure fast response and cost efficiency?

hard

A. Use Basic SKU with capacity 10 and enableNonSslPort false

B. Use Premium SKU with capacity 5 and enableNonSslPort true

C. Use Standard SKU with capacity 3 and enableNonSslPort false

D. Use Standard SKU with capacity 1 and enableNonSslPort false

Solution

1. Step 1: Balance performance and cost

   Standard SKU offers good performance at moderate cost; capacity 3 provides enough memory for sessions without overspending.

2. Step 2: Ensure secure connections

   Disabling non-SSL port (false) ensures secure data transfer, important for user sessions.

3. Step 3: Evaluate other options

   Basic SKU with high capacity is less performant; Premium SKU with high capacity is costly; enabling non-SSL port reduces security.

4. Final Answer:

   Use Standard SKU with capacity 3 and enableNonSslPort false -> Option C

5. Quick Check:

   Standard SKU + moderate capacity + secure port = best balance [OK]

Hint: Pick Standard SKU, moderate size, secure port for best balance [OK]

Common Mistakes:

• Choosing too large capacity increasing cost
• Using Basic SKU for heavy session caching
• Enabling non-SSL port reducing security