Welcome to our series on AWS concepts. Alot lies in store for you ahead. Enjoy the read.
Application Load Balancer
As mentioned earlier, the application load balancer is one of the 3 types of elastic load balancer in AWS.
So what is the application load balancer?
It adds the following over and above what is offered by classic load balancers. Some newly enhanced features are:
- Supported protocols eg HTTP/2, WebSockets
- Enhanced cloudwatch metrices eg load balancer metrices
- Access logs
- Enhanced granular health checks
There are also new features namely:
- AWS WAF (Web Application Firewall) integration
- Deletion protection
- Path and host based routing
- Dynamic ports
- IPv6 support on
- Request tracking
Application load balancers can be used if you are using containers within one instance for different services. One can then use a single load balancer that routes requests to the different containers by examining the port number of the traffic routed to it.
There are important terms to note in reference to application load balancers. This include:
- Target group
A target is a destination for traffic based on the established listener rules. It can be registered with multiple target groups.
Every target group routes requests to one or more targets using the protocol and port specified.
This is a process that checks for connection requests. After that it determines how the load balancer routes the request to the backend targets in one or more target groups according to the rules set.
Procedure for setup of a Load Balancer
NOTE: As mentioned earlier, we are assuming that you already know how to create an AWS account and that the account is already setup. But if it is not yet set up, you will need a debit card with at least $1 for the initial account setup at AWS. Thereafter, the account can have multiple users and and multiple setups.
For this load balancer guide, we will assume that you have an EC2 instance running with containers listening on different ports or multiple EC2 instances with services running on different ports.
- Login to the console
- Navigate to the EC2 console
- Scroll down to LOAD BALANCING in the side navigation pane.
- Click on Load Balancers
- Click Create Load Balancer
- Select Application Load Balancer
- We will then input details for the load balancer
1. The name you put here will be the name that will be propagated to to the DNS endpoint for this load balancer.
2. Ensure you add the ports under the listener section
3. You will need to select at least 2 availability zones for the application load balancers. This can be the same as the ones your VPC’s subnet are in.
4. If you are not using SSL skip the tab below and go to the security group configuration.
5. After that, configure the backend routing for the redirects. Create a new target group if you have not created a target group already.
The healthcheck path will be path of the page to redirect to.
6. Finally, you will register the target. You will select the instance(s) first then click Add to registered tab above the list of instances.
Once you fill in all the details necessary as per your implementation needs in all pages, the last tab will have the create tab after the review page.
7. Once you have created the LB with one target you can create and add the other targets under the target group tab.
Finally, verify that configs are ok.
To be continued shortly …….
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