In this exam cram we're going to cover a elastic load balancing and auto scaling.
So like I said before most of the information you need to know for the exam in terms of Elastic Load
Balancing is on this screen is probably goes a little bit further than you need. So elastic load balancers
in terms of the three types you've got the application, the network, and the classic load balancer.
So classic is old school it's deprecated, network and application load balancers are new generation. The
application load balancer is all about hate HTTP traffic.
Whereas the network load balancer is more about TCP and these other protocols but mainly TCP if anything
comes up on the exam.
So we've got the request level and the connection level.
So you don't need to know much more than that for the exam but let's just go over these so just remember
the purpose of load balancer is to automatically distribute incoming application traffic across multiple targets
and those targets can be EC2 instances, containers, and IP addresses. ELB can handle varying load
of you application traffic.
So that means as your the number of EC2 instances increases or decreases the ELB can respond to
that and it can do that across Availability Zones.
So that gives you high availability automatic scaling and helps you with fault tolerance. So the three
types application load balances. Layer 7 content and the request is the key thing here.
The Network load balancers routes connections based on IP protocol data.
So it's more about TCP and the classic load balancer is the old one. For auto scaling
this is about horizontal scaling. Auto Scaling is about elasticity and scalability so it can scale
and change the number of instances you have by launching new ones and terminating when
you don't need them anymore. It automates the process of scaling up.
That's adding instances or removing instances and that's scaling down based on the demand for your application.
So it helps you make sure you got the right number of instances to be cost optimized.
when you create a collection of EC2 instances for auto scaling it's known as an auto scaling group
and you can specify the minimum, maximum, and desired capacity as well as using scaling policies. So just
as a summary
This is what we built out in the hands on labs and this is what it's all about.
So the application load balancer helps to distribute connections to different EC2 instances and the
instances themselves are launched and terminated by the auto scaling group to make sure that the
right number exist at any time.