What is a Load Balancer and why do you need it?

Intro

Key element of the cloud environment, load balancer plays an important role in maintaining the availability of your cloud-based applications to customers, employees and end users. This blog will look at what load balance is and how it contributes to the overall health and robustness of your cloud infrastructure.

What is a load balancer?

Load balancing is the process of distributing workloads through multiple servers (also known as a server cluster). The main purpose of the load balance is to prevent any server from overloading and even crashing. In other words, the load balancer increases the availability of cloud services and prevents downtime.

Also, when the amount of workload an individual server receives is at acceptable levels, the requests will in turn have sufficient computing resources (e.g., CPU, RAM) to operate during acceptable response times. Fast response time is important to end user satisfaction and productivity.

Importance of load balancing in a cloud environment.

Due to the features mentioned earlier, load balancers are very useful for cloud infrastructure where mass workloads can easily affect a server, and high levels of service availability and response times are important for certain work processes or mandatory by SLAs.

Load balancing also plays a key role in scaling a cloud infrastructure. By nature, cloud infrastructure is designed to expand easily for any ups or downs in traffic. When a cloud "scales", it rotates many virtual servers and launches multiple application instances. Among these new examples, the main network component responsible for traffic distribution is load balancers.

 Without load balancers, new rotating virtual servers cannot receive incoming traffic in a coordinated manner or at all. Some virtual servers can even be managed with zero traffic, while others can be overloaded.

 Load balancers can also detect non-existent servers and redirect traffic to those that are still running. If you subscribe to one of the major cloud service providers (such as AWS) and activate the required feature, your cloud infrastructure can cover many geographical areas.

 Thus, if a region becomes operational due to a natural disaster, such as a catastrophic earthquake, flood, or tsunami, load balancers can divert traffic to areas not affected by the disaster.

 Depending on the load balancing algorithms they support, load balancers can determine the probability of overloading a particular server (or set of servers) and redirect traffic to other nodes that are considered healthier. Such proactive capabilities can significantly reduce the chances of your cloud services becoming inaccessible.

 As you provide more services with your cloud infrastructure, you can reach out to a variety of customers - employees, trading partners, customers, suppliers, and more. You can expect an exponential increase in traffic, which does not count from time to time and seasonal increase in demand. You need to make sure you include load balancing work in your cloud efforts to support your growing demand and expand your infrastructure to maintain an acceptable level of response and availability. Application Load Balancer vs Classic Load Balancer

When you search for the Load Balancer service, you may encounter 2 types – Application Load Balancer and Classic Load Balancer. These 2 types are very popular and differ from each other because of their functions according to the needs of the users. So, let's take a closer look at each and its features.

Classic Load Balancer: It operates at both Layer 4 and 7, and routes traffic between clients and backend servers based on IP address and TCP port.

Application Load Balancer:  It operates at Layer 7 of the OSI model and allows traffic distribution toward backend instances based on the information inside the HTTP requests header.

Thus, as the application load balancer works at layer 7, enabling it to inspect application-level content, not just IP and port, it can route more complex rules than with the Classic Load Balancer. For instance, unlike classic load balancer, application one can route requests to many ports on a single target.

Now, let's introduce ALB-A, AZCLOUD's high - quality application load balancer product.

AZCLOUD ALB-A 

AZCLOUD Load Balancer is AZCLOUD service that provides distribution of incoming traffic across multiple targets, such as Azcloud VMs instances, containers, microservices, containers and IP addresses.

ALB-A automatically distributes incoming application traffic across multiple targets, such as ACS instances, containers, and IP addresses. Additionally, layer 7 load balancer that routes connections based on the content of the request.

Further below is brief characteristics of AZCLOUD ALB-A. 

Load Sharing - Sharing the processing workload among a group of servers rather than relying on a single server prevents Azcloud VMs from being overwhelmed by requests

Network Flexibility - You will be able to change your backend infrastructure without affecting the availability of your services, enabling seamless horizontal scaling, rolling deployments, large architecture redesigns, and more

TLS Offloading - With ALB-A customers can create an HTTPS listener, which uses encrypted connections (also known as SSL offload). This feature enables traffic encryption between your load balancer and the clients that initiate SSL or TLS sessions. This enables you to offload TLS termination tasks to the load balancer while preserving the source IP address for your back-end applications

Network Elasticity - Automatically scale up storage capacity

Network Security - ALB enables to create and manage security groups associated with load balancing to provide additional networking and security options

Layer-7 Load Balancing - ALB can load balance HTTP/HTTPS traffic to targets – Azcloud VMs based on request attributes (such as X-Forwarded-Proto, X-Forwarded-Port, or X-Forwarded-For headers)

Comparison of various cloud providers’ LBs

In a cloud environment, many “Load Balancer” providers compete with each other for high market share by offering a variety of load balancer features, benefits, and “fair” pricing models to stick in users’ minds. Some of these popular providers are AWS ELB, GCP Load Balancing, and Azure Load Balancer. These providers have been around for a long time and have been able to seize some of the market shares because of highly essential benefits that Load Balancer includes. Benefits such as Load sharing, TLS Offload, Layer – 7 Load Balancing play a key role in Load Balancer and demonstrate the quality of the product. We would like to point out that all these important benefits are also included in AZCLOUD ALB-A, which means that with these benefits and features, AZCLOUD ALB-A is strong enough to compete with other popular providers. Moreover, in terms of pricing and price calculation simplicity, AZCLOUD ALB-A is the most preferable and cost-effective than others. From the table below, you can see the price comparison of application load balancer providers:

 It is obvious that AZCLOUD ALB-A prices are cheaper than Azure and AWS. The main reason why other providers are so high is the extra fees they add to the price of the product. For instance:

Note: Digital Ocean doesn’t have Application gateway

Another main advantage of AZCLOUD ALB-A is its price calculation simplicity, which allows users to calculate the price of an item easily and directly. Below you can see the pricing calculation for each provider.

• Azure - you should calculate data processing, data transfer, and outbound traffic from regions
• AWS – you should calculate processed bytes (Lambda functions as targets), processed bytes (EC2 Instances and IP addresses as targets), average number of new connections per ALB, average connection duration, average number of requests per second per ALB, average number of rule evaluations per request.
• AZCLOUD ALB-A - you should calculate only maximum number of simultaneous connections.

For more information about AZCLOUD ALB-A prices, you can visit the link below:

https://azcloud.az/en/services/network/alb-a#bundles

The truth is that although other providers try to offer high-quality application load balancers with great benefits and features, still some minor shortcomings can pose a threat to the product. Such as most of the users complain that it is a bit confusing when using the product due to unclear information on how to use it correctly without the need for technical knowledge. However, AZCLOUD ALB-A, taking into account the convenience of users, provides them with “use cases” and additional documentation, which contains all the detailed and clear information on the correct use of ALB-A. Thanks to the “use cases” and the informative document, users can now use the Load Balancer without the need for any professional technical infrastructure. In addition, you can also check out the use cases mentioned below.

• Legacy applications that implement custom protocol
• Database clusters
• High performance queue servers (ActiveMQ, RabbitMQ, ZeroMQ etc.).
• A cluster of FTPS or SFTP servers with common storage media
• Business critical applications
• For horizontal scaling infrastructure
• WEB Application

You can get acquainted with the instructions in the document from the link below and start using ALB-A safely from now on:  https://docs.azcloud.az

Also, while other providers offer one type of Application Load Balancer, AZCLOUD ALB-A offers users 3 types of ALB-A at different prices for each - ALB-A Standard, ALB-A Ultra, and ALB-A turbo. Check the list below and see the prices and features of each type up close:

1. ALB-A Standard: 

• The best choice for Static websites and blogs with low to moderate traffic.
• Simultaneous connections to the ALB Standard instance up to 10000
• 29 AZN per month

1. ALB-A Ultra:

• The best choice for transaction-driven sites or services with traffic moderation.
• Simultaneous connections to the ALB Turbo instance up to 20000
• 49 AZN per month

1. ALB-A Turbo:

• The best choice Busy sites, services, or endpoints where high performance is a must
• Simultaneous connections to the ALB Turbo instance up to 40000
• 95 AZN per month

Basically, this difference (multiple product variants) helps to make one main point clear, such as what feature of the product costs a certain price. Check out the link below to get to know the ALB-A types and prices closely and enjoy! 

https://azcloud.az/en/services/network/alb-a