AWS Elastic Load Balancer

What is AWS ELB?

Amazon web services elastic load balancer distributes traffic equally among multiple EC2 instances or servers.ELB thus acts as a single point of contact for all the clients. With the feature of ELB, clients can either increment or decrement multiple EC2 instances across one or more availability zones without interrupting the information flow.Amazon employed the ELB technique because of numerous benefits like fault tolerance, and users can actively monitor their data flow.

ELB integrates with Auto scaling and provides enough back-end capacity to meet varying traffic levels.
When any of the EC2 instances fails, AWS ELB automatically sends the traffic to other healthy running EC2 instances, and when a failed EC2 instance works, it reroutes the traffic to that instance.
ELB supports the following load balancers: application load balancers, network load balancers, gateway load balancers, and classic load balancers. You can select the load balancer that best suits your requirements depending on your application requirements.

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Why Elastic Load Balancer?

Load balancers are virtual machines provided by Amazon web services used to distribute web traffic equally on all servers without overloading any server. AWS elastic load balancing also helps distribute web traffic across multiple targets in multiple availability zones, thereby improving the performance of applications.

ELB acts as a virtual machine by accepting incoming web traffic and routing requests to healthy targets. With ELB you can add or delete EC2 instances as your needs without interrupting the information flow. The vital feature of ELB is even if you delete ELB, you can't delete the instances registered to it.
Developers can also protect their applications by enabling delete protection that helps stop accidental deletion of your load balancer.
The main advantage of the Elastic load balancer is that it helps continuously monitor the health of Amazon EC2 instances. Supports both internet protocol version (IPv4) and internet protocol version (IPv6).Developers can develop end-to-end traffic applications that use secure HTTPS/SSL connections.

How does an AWS ELB work?

Amazon web services elastic load balancer distributes traffic equally among multiple EC2 instances or servers.
ELB thus acts as a single point of contact for all the clients. With the feature of ELB, clients can either increment or decrement multiple EC2 instances across one or more availability zones without interrupting the information flow.
Amazon employed the ELB technique because of numerous benefits like fault tolerance, and users can actively monitor their data flow.
ELB integrates with Auto scaling and provides enough back-end capacity to meet varying traffic levels.
When any of the EC2 instances fails, AWS ELB automatically sends the traffic to other healthy running EC2 instances, and when a failed EC2 instance works, it reroutes the traffic to that instance.
ELB supports the following load balancers: application load balancers, network load balancers, gateway load balancers, and classic load balancers. You can select the load balancer that best suits your requirements depending on your application requirements.

Types of AWS Elastic Load Balancers :

Load balancers are servers that accept multiple connection requests from multiple sources and distribute the load equally among all multiple targets. There are four different types of load balancers provided by Amazon web services that include:

Gateway load balancer:

Gateway load balancers help clients deploy, scale, and manage third-party virtual appliances effectively by providing a gateway that equally distributes the traffic among all multiple virtual appliances, thereby decreasing the points of failure and enhancing your network availability.

Amazon web services allow you to buy these virtual appliances directly from third-party vendors through the AWS marketplace.
The main benefits of gateway load balancers are that users can deploy third-party virtual appliances quickly and users can work with their favored partners for security services.
Users can scale virtual appliances up or down based on the demand, and you can pay only for the services you have used. The cost depends on two main factors: how much time the gateway load balancer runs and the number of load balancer capacity units (LCU) used by the gateway load balancer per hour.

Network load balancer :

The network load balancer accepts multiple connection requests per second from different users and maintains ultra-low latencies for latency-sensitive applications. It usually operates on an open system interconnection layer of four levels and routes the connections to targets Amazon EC2 instances, containers, and microservices.

Amazon handles sudden and volatile traffic patterns effectively using a single static IP address per AZ. The network load balancer combines other popular AWS services like Auto Scaling, Amazon cloud formation, AWS Certificate Manager (ACM), and Amazon EC2 Container Service (ECS).The critical feature of network load balancers is they are known for providing sticky sessions as they route requests from the client to the same target (i.e., it tells how much time an IP spends on a particular website). Amazon route 53 will direct traffic to other healthy load balancer nodes when a network load balancer node is unhealthy in a specific zone.
The cost depends on two main factors: how much time the network load balancer runs and the number of load balancer capacity units (LCU) used by the network load balancer per hour.

Application load balancer :

An application load balancer functions at the seventh layer of the open system interconnection (OSI) model. In the digital era, access to web applications has increased dramatically, and sometimes heavy traffic may cause web services to slow down.The application load balancer solves this problem by distributing the traffic to healthy targets within the Amazon cloud services. The application load balancer also integrates with other Amazon web services such as AWS Auto Scaling, AWS Cloud Formation, AWS Code Deploy, AWS Elastic Container Service, and AWS Certificate Manager.
The cost of using the application load balancer is charged hourly, and load balancer capacity units (LCUs) determine the number of active connections occurring per second. The rate is usually $0.008 per LCU per hour. The cost of using an application load balancer is less when compared with a classic load balancer.

Classic load balancer :

Classic load balancer functions at layer seven and layer 4 of the open system interconnection model. This serves the purpose of load balancing across multiple Amazon EC2 instances and is generally applied to applications built within the classic EC2 network. But when the client uses a virtual private network, it is recommended to use an application load balancer for layer seven and a network load balancer for layer four traffic.

The main feature of the classic load balancer is it supports both internet protocol versions 4 AND 6 (IPv4 and IPv6) for EC2 classic networks. Clients are charged hourly for each GB of data transferred from your load balancer.

AWS Elastic Load Balancing Components

• Load Balancer : A load balancer helps distribute incoming traffic across multiple targets like EC2 instances and multiple availability zones (AZs), thereby increasing the efficiency of web pages.
• Listener or VSRX instance : The listener refers to validating requests from clients using the port and protocol you have configured, and it forwards connection requests to one or more target groups based on the rules the client has defined.

• Target Groups or VSRX Application Workloads :  When creating a vSRX instance as a listener rule, the client must specify vSRX applications and conditions. When the rules are met, traffic is directed to appropriate vSRX applications. You can also use different vSRX applications for different needs, like creating one vSRX application for formal requests and another vSRX for microservice requests for your application.

• Load balancers in AWS ELB : Clients can prefer any load balancer depending on their deployed and maintained applications. The four types of load balancers are classic, application, gateway, and network.

How do you create a Load Balancer?

•  Application load balancing :
  Step 1 : Create a target group used for request routing.
  Step 2 : Select your load balancer.
  Step 3 : To create a network load balancer, you must configure the load balancer and listener.
  Step 4 : Verify whether it is sending traffic to your EC2 instances.
  Step 5 : delete your load balancer if you no longer use it.
• Classic load balancer :
  Step 1 : To create a classic load balancer, first open the Amazon EC2 console at https://console.aws.amazon.com/ec2/
  Then on the navigator, select the same region for your load balancer that you chose already for the EC2 instance.
  

  Under load balancing, click on create load balancers.
  Step 2 : Give your load balancer a name that can have a maximum of 32 characters.
  To create LB inside, choose the same network you selected for the EC2 instance.
  If you opt for default VPC and want to choose subnets, click on Enable advanced VPC configuration.
  For available subnets, select at least one public subnet using the add icon.
  

  Step 3: Allocate security groups to your load balancer in a VPC.
  Step 4: Configure health checks for your EC2 instances.
  Step 5: After that, register EC2 instances with your load balancer.
  Step 6: Tag your load balancer and click on review and create.
  Step 7: Review the settings once again before creating your load balancer and verify if it is sending traffic to your EC2 instances.
  Step 8: delete your load balancer if you no longer use it.
  
  

•  Network load balancing:  
  Step 1: Create a target group used for request routing.
  Step 2: Select your load balancer.
  Step 3: To create a network load balancer, you must configure the load balancer and listener.
  Step 4: Verify whether it is sending traffic to your EC2 instances.
  Step 5: delete your load balancer if you no longer use it.

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Features of Elastic Load Balancing :

Security :

With ELB, you can distribute traffic to multiple target locations that work on the same load balancer.

TLS termination :

SSL termination CPU is offloaded, and SSL settings are well managed at the core.

Health checks :

ELB checks the servers' health and diverts the traffic to the healthy server if one server fails to operate.

Layer 4 and Layer 7 balancing :

Layer 7 and layer four load can be balanced by HTTP/HTTPS applications.

Operational Monitoring:

System Administrators can monitor the traffic in real-time with Amazon cloud watch metrics.

Product comparisons :

Clients can choose the load balancers depending on the applications they are building; they may choose an application load balancer or a classic load balancer.

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What are the benefits of load balancing?   

Following are some of the crucial benefits of load balancing that include :

High performance and speed :

It is a well-known fact that no customer wants a slow-running website; in that case, you should meet your customer's demand by increasing the speed of your website. But sometimes, your server will be overburdened with many people coming across a single website. To overcome this problem, Amazon applied the load balancing concept that distributes customers to multiple targets.

IT flexibility :

Load balancing relieves IT staff from now they can turn off the servers for maintenance or for other issues and redirect the traffic to another server.

Scalability :

The load balancer is highly scalable in managing the sudden spikes in your website traffic by distributing the traffic to multiple servers without slowing down the website.

Redundancy :

Whenever a hardware failure or excess traffic is visiting your website, your server may be out of action temporarily. So, it would be best if you are looking for good backup and redundancy strategies to increase the performance and speed of your servers.

How can AWS help with load balancing?

Load balancers are servers that accept multiple connection requests from multiple sources and distribute the load equally among all multiple targets. There are four different types of load balancers provided by Amazon web services that include gateway, application, and classic and network load balancers. Clients choose any of the load balancers depending on the purpose of their applications. Amazon web services allow you to buy these virtual appliances directly from third-party vendors through the AWS marketplace. In the digital era, access to web applications has increased dramatically and sometimes heavy traffic may cause web services to slow down. Load balancer solves this problem by distributing the traffic to healthy targets within the Amazon cloud services. The load balancer also integrates with other Amazon web services such as AWS Auto Scaling, AWS Cloud Formation, AWS Code Deploy, AWS Elastic Container Service, and AWS Certificate Manager.
The cost of using a load balancer is charged hourly, and load balancer capacity units (LCUs) determine the number of active connections occurring per second. The rate is usually $0.008 per LCU per hour.

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Conclusion:

We hope our article on "AWS ELB how it works" has given the answer you are searching for. This article clearly explained in detail how elastic load balancing helps customers access WebPages faster. So, here is the end of our article.

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