Azure Cosmos DB is a globally distributed, multi-model database service that allows you to manage various data forms at scale, with equally suitable options for a wide range of industries and applications. For a person preparing for the DP-420 Designing and Implementing Native Applications Using Microsoft Azure Cosmos DB exam, understanding how to provision and manage Azure Cosmos DB resources via Azure Resource Manager (ARM) templates is essential.
Why Use ARM Templates For Azure Cosmos DB?
ARM templates are definition files written in JSON data syntax. These templates allow for declarative and repeatable deployments, which leads to reduced human error because of their predictability and consistency. They contain the information required to generate resources such as the properties of the resources, dependencies, and permissions.
When you aim to manage Azure Cosmos DB resources using ARM templates, you are embracing principles such as Infrastructure as Code and DevOps practices, which improve productivity, guarantee repeatability, and make resource management more effective.
Creating an ARM Template for Azure Cosmos DB
Creating an ARM template generally involves defining your resources and the associated properties within the structure of an ARM template, which is a JSON object. Here is a simple example of defining a Cosmos DB account with shared throughput.
{
"$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {...},
"variables": {...},
"resources": [
{
"type": "Microsoft.DocumentDB/databaseAccounts/apis/databases",
"name": "[concat(variables('accountName'), '/sql/', parameters('databaseName'))]",
"apiVersion": "2020-04-01",
"dependsOn": [...],
"properties": {
"resource": {
"id": "[parameters('databaseName')]"
},
"options": {
"throughput": "[parameters('databaseThroughput')]"
}
}
}
],
"outputs": {...}
}
In this example, the name of the resource is defined by concatenating the account name with ‘sql’ and the database name. The desired throughput for the database is defined as a parameter (‘databaseThroughput’).
Managing Azure Cosmos DB Resources with ARM Templates
With an ARM template in place, common tasks such as deploying, updating, and deleting Cosmos DB resources become more straightforward and repeatable. ARM templates support deploying resources to multiple regions, enabling you to scale your applications globally.
Deploying Azure Cosmos DB Resources:
You can deploy an ARM template via Azure Portal, Azure PowerShell, Azure CLI, or REST APIs. The deployment process reads and validates the template, then provisions and configures your resources.
Updating Azure Cosmos DB Resources:
When the state of your application changes, you can update your resources with an ARM template. The Resource Manager compares the state defined in your template with the current state of resources in Azure, and then modifies the resources to match the desired state.
Deleting Azure Cosmos DB Resources:
Should you wish to remove your resources, you can use the “az group delete” command if you’re using Azure CLI or the “Remove-AzResourceGroup” cmdlet if you are using Azure PowerShell.
Azure Cosmos DB and ARM templates offer a powerful combination for developers and DevOps professionals working on cloud applications. By following these steps, you would be able to use ARM templates to provision and manage Azure Cosmos DB resources efficiently and effectively, which would be crucial knowledge for passing the DP-420 exam.
Practice Test
True/False: Azure Resource Manager templates (ARM templates) can be used to automate the deployment of Azure Cosmos DB instances.
- True
- False
Answer: True
Explanation: ARM templates are designed to automate deployments on the Azure platform. This includes creating and managing instances of Azure Cosmos DB.
Which of the following languages are used to write ARM templates?
- a) JSON
- b) Python
- c) JavaScript
- d) C#
Answer: a) JSON
Explanation: ARM templates are written in JSON (JavaScript Object Notation). While it’s commonly used with JavaScript, it is a language-independent data format.
True/False: You can automate the provisioning of Azure Cosmos DB accounts using ARM templates.
- True
- False
Answer: True
Explanation: Using ARM templates, you can automate the creation and configuration of resources across multiple Azure subscriptions and resource groups.
What are the key elements of an ARM template in respect to Azure Cosmos DB deployment?
- a) Databases
- b) Containers
- c) Triggers
- d) Indexing policy
- e) Conflict resolution policy
Answer: a) Databases, b) Containers, d) Indexing policy, e) Conflict resolution policy
Explanation: An ARM template for Azure Cosmos DB contains multiple elements. They include databases, containers, indexing policies, and the conflict resolution policy. Triggers are not a key part of the template.
True/False: You can specify the consistency level for your Cosmos DB account using ARM templates.
- True
- False
Answer: True
Explanation: Consistency level can be specified when creating Azure Cosmos DB accounts through ARM templates. It can be set to Strong, Bounded staleness, Session, Consistent prefix, or Eventual.
The ARM Template does not support which of the following Azure Cosmos DB APIs?
- a) SQL
- b) MongoDB
- c) Gremlin
- d) None of the above
Answer: d) None of the above
Explanation: The ARM template supports provisioning resources for all Azure cosmos DB APIs, including SQL, MongoDB, and Gremlin.
True/False: ARM templates can be used to automate the creation of Azure Cosmos DB collections.
- True
- False
Answer: True
Explanation: ARM templates support automation of the entire resource creation process on Azure, including Azure Cosmos DB collections.
How can you improve the performance of Azure Cosmos DB for read-heavy workloads using ARM templates?
- a) Throughput optimization
- b) Index optimization
- c) Partitioning
- d) All of the above
Answer: d) All of the above
Explanation: You can enhance the performance through throughput optimization, index optimization, and by partitioning the containers appropriately.
True/False: Azure ARM templates can manage any Azure resource, not just Azure Cosmos DB resources.
- True
- False
Answer: True
Explanation: ARM templates are designed to handle all Azure resources, not just Azure Cosmos DB resources.
Which one of the following cannot be configured using an ARM template for Azure Cosmos DB?
- a) Database ID
- b) Container ID
- c) Partition Key
- d) Database size
Answer: d) Database size
Explanation: Database size is managed dynamically by Azure Cosmos DB and cannot be configured using an ARM template. Others like Database ID, Container ID, and Partition Key can be configured.
Interview Questions
What are Azure Resource Manager templates (ARM templates)?
Azure Resource Manager templates (ARM templates) are JavaScript Object Notation (JSON) files that define the infrastructure and configuration for your project. The template uses declarative syntax, which lets you simply describe your intention for deploying the resources.
What is the purpose of using ARM Templates with Azure Cosmos DB?
ARM Templates allow Cosmos DB users to automate the deployment and management of Azure Cosmos DB resources. They can define the infrastructure for applications in a declarative manner, which allows them to repeatedly deploy an application throughout the application lifecycle and across different environments with confidence that the resources are deployed in a consistent state.
How can you use ARM Templates to scale Azure Cosmos DB resources?
ARM templates allow you to define throughput settings that you would like your Azure Cosmos DB resources to have upon creation. You can set these properties by specifying the “throughput” property of your database or container resources in the ARM template.
Can you monitor activities on your Azure Cosmos DB using ARM templates?
Unfortunately, you can’t directly monitor activity with ARM templates. However, the resources such as metrics and diagnostic settings could be defined by ARM templates, which could indirectly help in monitoring.
Can you create MongoDB and Cassandra API accounts using ARM templates in Azure Cosmos DB?
Yes, you can define MongoDB and Cassandra API accounts in your ARM template by setting the “kind” property to MongoDB or GlobalDocumentDB (Cassandra) when creating a Cosmos DB account in the ARM template.
How do you specify the consistency level of Azure Cosmos DB in ARM template?
When you create a Cosmos DB account in an ARM template, you can specify the consistency level by setting the “defaultConsistencyLevel” property.
Can you update resource properties using ARM templates in Azure Cosmos DB?
Yes, you can modify some properties of Cosmos DB resources using ARM templates by re-deploying the template with the updated properties.
How do you deploy an ARM Template for Azure Cosmos DB?
You can either use Azure CLI, Azure PowerShell or deploy directly through Azure Portal. You need to run appropriate commands in Azure CLI or PowerShell, or use the Template deployment option in Azure Portal.
Can ARM Templates manage multiple Cosmos DB Resources at once?
Yes, the ARM template allows the simultaneous management of multiple Azure resources in a single, coordinated operation.
Can you manage the index policy of Cosmos DB containers using ARM templates?
Yes, you can define the index policies for the containers of your Cosmos DB in an ARM template by specifying the “indexingPolicy” property of your container resources.
How secure is the deployment of Azure Cosmos DB resources using ARM templates?
ARM templates are highly secure as they support Azure’s role-based access control (RBAC) authorization. This ensures that only authorized users can deploy resources.
How do you specify the partition key path for a Cosmos DB container in an ARM template?
You can specify the partition key path when creating cosmos db container by adding a “partitionKey” section under the properties, and add a “paths” array underneath it.
How do you set up failover priorities for regions using ARM templates in Cosmos DB?
You can set up failover for your Cosmos DB account in an ARM template by defining the “locations” property and adjusting their “failoverPriority” as desired.
Can ARM templates help with Azure DevOps for Cosmos DB?
Yes, ARM Templates are a critical tool for infrastructure as code (IaC) and can be used with Azure DevOps pipelines to automate deployment and ensure consistent application environments.
How do you specify the network rules for a Cosmos DB account in an ARM template?
You can define the network rules by specifying the “virtualNetworkRules”, “ipRules”, and “isVirtualNetworkFilterEnabled” properties in the ARM template.
extutorials.com