Microsoft Azure - Finding the Right Load Balancing Service

Pre-requisite: AZURE 

We can divide incoming application traffic among many targets, such as Virtual Machines (VMs), containers, and IP addresses in our VPC, using Azure load balancer. The load balancer can increase the high availability of applications and decrease the latency for end users. Azure load balancer supports TCP and UDP protocols as well as HTTP/HTTPS and we can route the traffic to Private and Public IP addresses.

Types Of Load Balancers In AZURE 

Microsoft Azure offers several load-balancing services that can help distribute traffic across multiple servers or resources, ensuring high availability and performance. Here are some of the load balancing services available in Azure and how to choose the right one:

Azure Load Balancer: This is a basic load-balancing service that distributes traffic across multiple virtual machines (VMs) or instances of an application. It can be used for TCP/UDP traffic and provides health probes to ensure that traffic is directed only to healthy instances. This is a good choice for simple scenarios where basic load balancing is sufficient.

Azure Application Gateway: This is a layer 7 load balancer that is designed for web applications. It provides features such as SSL offloading, URL-based routing, and session affinity. It can also perform application-level health checks to ensure that traffic is directed only to healthy instances. This is a good choice for web applications that require advanced load-balancing features.

Azure Traffic Manager: This is a DNS-based load balancer that can distribute traffic across multiple endpoints based on DNS queries. It can be used to route traffic to different regions, availability zones, or data centers, based on proximity or performance. This is a good choice for global applications that need to route traffic based on location or performance.

Azure Front Door: This is a layer 7 load balancer that provides advanced traffic management features such as SSL offloading, URL-based routing, and session affinity. It can also perform application-level health checks and provides features such as a web application firewall and content delivery network (CDN) integration. This is a good choice for complex applications that require advanced traffic management and security features.

Uses of Azure Load Balancer

1. The load balancer will distribute the incoming traffic equally to the VMs.
2. A load balancer will be useful as a proxy server. Which makes our application more secure.
3. We can route the traffic to the required VM based on our requirements. 
4. The load balancer can help us to maintain the high availability of our application. 

Characteristics of an Azure load balancer

1. The load balancer will perform health checks on our VMs.When the health check fails it will automatically route the traffic to the server on which the health check is successful.
2. If any additional VM is added to the target pool the load balancer will automatically recognize the VM and it will route the traffic to that particular server or VM.
3. We can attach the Security group to the Application Load balancer where we can control the inbound and outbound traffic. 
4. Routing of the traffic is very easy because of Host-based and Path-based routing. With the help of load-balancing rules.
5. The load balancer can be placed on a public server and the application on a private server can expose the load balancer to the public by this our application is more secure. 

Advantages of Azure Load Balancer

1. As it enables us to disperse traffic across numerous backend servers, the Azure load balancer is a financially sensible solution for traffic management.
2. The Azure load balancers are simple to set up since they are user-friendly. 
3. There are many configuration options available for the Azure load balancer, including HTTP and HTTPS as well as TCP AND UDP, where the flexibility is more.
4. We can achieve high availability with the aid of Azure load balancing, ensuring the availability and responsiveness of our application. 
5. We may scale out our application with Azure load balancer by dividing the traffic among several physical or virtual servers.

Finding the Right Load Balancing Service

When choosing the right load-balancing service in Azure, it is important to consider factors such as the type of traffic being load balanced, the application architecture, and the required features. It is also important to consider factors such as cost, scalability, and ease of management. Here we will discuss how to choose the right load-balancing solution for you in the Azure Portal. We know that load balancing can always be difficult to know which one of the many services is right for you can always be a difficult challenge, so we have this new solution. If you start searching for load balancing, you'll notice that we have this new load balancing help me choose a feature. 

Now off the bat in this feature, Azures wanted the customer to be able to identify what are the different options, load balancing options in Azure today, and from a high level, what are the differences between them. And that's what Azure tries to capture in these tiles with the three bullet notes just below the title. Now if you want to learn more about any one of these resources, a great place to start is by just clicking on the title. You'll notice that Azure has a plethora of links available for you, including a link to the high-level documentation itself, but also highlighting the key features for this particular service, security, and monitoring since that’s essential to the lifecycle of a product, some reference architecture, so you can essentially see how this service might fit into your architecture, and pricing, since Azure know that's always important.

 Now you can essentially start answering the question about hey what service are you trying to create? So, does your application use HTTP/HTTPS? You'll notice if you select yes, we’ll remove some of the actual tile options available to really start filtering down to what your particular environment needs. So as you continue answering this question, like is your application public,? Let's say your application is public. It’s also deployed in multiple regions. Performance acceleration is always important to both customers and you.

Do you want SSL offloading or application layer processing per request? Now, at this point,  if these questions ever become a little bit too technical or you actually don't know potentially what SSL offloading is, for example, what you can always do is actually click on these services themselves. And if Aurzes are going to ask you a question about it, most likely Azure will actually have some links to the documentation here. So if you want to go learn more about SSL offloading, you can always click on this feature or for the front door this feature.

So, if you click to know what your application is about you can click no and move forward. And is your application hosted on PaaS? If you click yes in this question, at that point, you'll notice that we have recommended a particular service and this is a great opportunity for you to go click on reference architecture to go see how this particular service might fit in your global environment.

Now, let's say that you find this guided view a little bit helpful, but you actually want to dig in a little bit deeper and actually see what the differences are between the four different services available. And that's where the service comparison comes in. 

The service comparison is a grid comparing the different services across some of the most important features. So, again for load balancing, some of the high-level things, so there can support protocols for your application. Does it provide private load balancing or global load balancing? So as new features come in, Azures also start updating this list as well to make sure that you will always be able to differentiate which one of these services does well. Now if, you want to go learn more about these services, but want a bit more of a guided experience versus the experience today where you can just go click on the documentation. That's where the tutorial comes in. So, here you will notice that we have a bunch of different MS Learn courses available that will give a more guided experience and will be a little bit more in-depth.

So if you want to go learn about application gateway, you can always come here and to the MSR resource and just go ahead and actually start this module.

Now the final thing you'll notice is that Azure has different load-balancing services. And if you select any one of them, you'll notice that this is the browse experience.

Limitations of the Azure load balancer 

1. The Azure load balancer operates at layer 4 of the OSI model and does not support layer 7 load balancers.
2. We are unable to redirect traffic to multiple regions that are only accessible from a few specific locations.
3. The Azure load balancer doesn't support SSL we have to perform SSL operations at the backend.
4. Only a few monitoring features are supported by Azure load balancing.