Let's go through some important points when it comes the topics discussed in this section
This is an HTTP-based service that allows you to host web applications, REST API's and mobile back ends. You can develop a program in programming languages such as .NET, .NET Core, Java, Ruby, Node.js, PHP and Python.
Here you don't need to manage the underlying infrastructure. It allows you to focus on code development.
Each App service needs to be associated with an App Service Plan.
Each App service plan has an associated cost per month and also has specific features based on the plan you choose.
This service allows you to create and manage a group of identical load balanced virtual machines.
Here the number of Virtual Machine instances in the scale set can scale based on demand
This is the best service if you want to add scalability to your application
The Azure Load balancer is used to distribute incoming network traffic to a backend group of servers.
This service helps increase the availability of your entire application architecture
Here the Load Balancer would take the incoming requests from the users and direct the requests to virtual machines running in an Azure virtual network.
If you have a web application running on the backend virtual machines, the requests would be distributed across the virtual machines by the Azure Load Balancer.
You can use other tools to access and work with Azure resources
You can use PowerShell which can work on Windows, macOS and Linux
You can use the Azure command line interface which can work on Windows, macOS and Linux
You can use Azure cloud shell from the browser, which can then work on any operating system which has browser support
This service allows you to run small pieces of code as functions.
Here you just develop and upload the code to an Azure Function.
You only get billed for the amount of time the code is run.
You can use a variety of programming languages in Azure Functions.
C#, Java , JavaScript, PowerShell and Python.
You can use libraries by using NuGet and NPM packages.
Pricing plans available for Azure Functions
Consumption Plan Here you only pay for the time the code runs.
App Service Plan If you already have an App Service plan that runs a web application, you can reuse the same plan to run Azure Functions. This would save on cost if you already have an App Service Plan in place.
Premium Plan Here you get a number of pre-warmed instances that are always online and ready to run your functions. The plan also automatically adds more compute when required.
You can also invoke your functions via various triggers
This is a cloud service that helps you schedule, automate and orchestrate tasks , business processes and workflows.
How it works
You first design a workflow in Azure Logic Apps
Each workflow starts with a trigger.
The trigger is fired via a specific event
When the trigger is fired , the Logic App engine creates a logic app instance that runs the workflow.
Connectors for Azure Logic Apps
These connectors provide easy access to event, data and actions that are sent from external applications, services , systems or platforms.
You have built-in connectors that can connect to Azure services such as Azure functions, Azure API Apps etc.
You have Managed connectors that can connect to platforms such as Office 365, Microsoft Dynamics.
The Azure Traffic Manager service is a DNS-based traffic load balancer that distributes traffic across services that are distributed across different Azure regions.
The Traffic Manager service is used to direct client requests to the most appropriate service endpoint that is based on a traffic-routing method and the health of the endpoints.
The different traffic routing methods available for the Azure Traffic Manager are
Priority Route traffic to another endpoint in case the primary fails.
Weighted Route traffic to different endpoints based on weight.
Performance - you want end users to use the "closest" endpoint in terms of the lowest network latency.
Geographic - geographic location their DNS query originates from.
Multivalue Here different endpoints are sent to the client. The client then selects the endpoint to send the request to.
Subnet This maps a set of end-user IP address ranges to a specific endpoint within a Traffic Manager profile.
Below is an example of the Priority routing method that can be used with the Azure Traffic Manager service
Here we are assuming that a company has similar web applications , both are running using the Azure Web App service. One web application is running in the East US Region and the other is running in the West US Region.
1. Here we create a Traffic Manager profile and create two endpoints. Each endpoint points to each Azure Web app respectively. We assign a priority of 1 to the service endpoint attached to the Azure Web App running in the East US region and a priority of 2 to the other service endpoint.
1. Here users would make requests to the Traffic Manager service.
2. The requests could be initially be directed to an Azure Web App located in the East US region , since there is a priority of 1 to the service endpoint attached to this endpoint.
3. Now let's say there is an issue with the web application running in the East US region, Azure Traffic Manager would then understand that there is an issue with the web application running in this region.
It would then start redirecting user requests to the second endpoint which has the Priority of 2.
Hence over here you are adding a higher availability to your architecture by ensuring that user requests are always adhered to by redirecting requests if the primary service fails for any reason.
If you use the Weighted Routing method , you can actually load balance requests across multiple service endpoints
Over here , users requests would be directed or load balanced across both web applications running in different regions.
In the Performance routing method as shown below, users will be directed based on the least latency of an endpoint.
And then we have the Geographic routing method wherein users would be directed to an endpoint based on their geographic location
