65. elastic load balancing Flashcards
what is load balancing
- this service allow us to be more elastic on AWs
- it is known as elastic load balancing
what does load balancer do ?
it is a server that will forward the internet traffic down to multiple servre downstream
then there will be some EC2 instances
also called as backend EC2 instances
does elastic load balancing managed by AWS
yes elastic load balancing managed by AWS
is it good to expose load balancer publically
yes, we expose load balancer to our users
does we have EC2 behind load balancer
yes, behind load balancer there is multiple EC2
three EC2 instances
does load balancer direct traffic to EC2 instance
yes, if user goes, then it is redirected to EC2 instance
how user gets response
- ec2 will reply back with somethin and user will get the respose
what if second user gets in
load balancer will redirect second user to another ec2 instance
what if third user comes in
load balancer will redirect third user to third ec2 instance
does this thing help to scale backend better
yes, load balancing helps to scale backend in more better way
why would you use one?
we can spread the load across multiple downstream instances
we can expose single point of access, DNS host name, for our application
what if any downstream instance failed
if one of them is failing, load balancer will not direct traffic to that instance
so we can hide failure of any downstream instances / servers
can we provide SSL termination
we can provide SSL termination, so https for our website very easily
are we able to use load balancer across multiple availability zones
yes, we are able to use load balancer across multiple availability zones
does having load balancer among mulitple availability zones makes it more available
yes
what is ELB load balancer
ELB is a manager load balancer,
what is use of ELB load balancer
we dont need to be provisioning servers
does aws do it for us, ELB manager load balancer
yes, we dont have to be provisioning servers, aws will do it for us
does aws guarantee that it will be working
yes aws guarantee that load balancer, or other instances will be working
what are the things aws take care off
- aws will take care of all updates, maintenance, and high availability of that elastic load balancer
what are some things we have to take care of
we just have to configure few behavior of that load balancer
is it expensive or cheap to set up ELB load balancer on aws
it is cheap / less expensive
can we set up our own load balancer on ec2
yes we can set up our load balancer on ec2
what are some disadvantages of setting up our own load balancer on EC2`
in the end, we have to put extra effort, on maintenance, integration, maintaining and taking care of the OS, upgrades etc etc
