How to prepare for load balacing? - amazon-web-services

I am a little confused on how to prepare an elastic load balancer. Suppose I have a web application written in node.js and a frontend written in react.js Would I have the node.js/react.js code duplicated on multiple EC2 instances? Then hook those instances up to the load balancer so it can be distributed? In that case, if a change were to be made, it would have to be updated on each of the servers, correct?

Would I have the node.js/react.js code duplicated on multiple EC2
instances? Then hook those instances up to the load balancer so it can be distributed?
Yes, that's how load balancing works. It balances the load across multiple servers.
In that case, if a change were to be made, it would have to be updated
on each of the servers, correct?
Correct
I suggest you look into using Elastic Beanstalk, which will handle most of this for you. You would push a change to Elastic Beanstalk and it will handle deploying that change to each of the load balanced servers.

Elastic Beanstalk would be a perfect choice for your scenario where it handles the deployment of the code to the multiple numbers of EC2 instances.
Another workaround is to use an Autoscaling group, which will sit behind a load balancer.

Related

Elastic Load Balancer (Elastic Beanstalk) vs NGINIX

I am pretty new to AWS deployment (please send any helpful guides). And I read that it comes with an elastic load balancer but I've also heard that a lot of people put NGINX on an EC2 to use as a load balancer.
Do people commonly use either or? Having two seems redundant.
Nginx on an EC2 instance for load balancing would be a single point of failure, if the EC2 instance went down your app would be down. An AWS Load Balancer is actually multiple load balancer nodes distributed across multiple AWS availability zones to provide high availability. The EC2 instance would also be something for you to have to manage, where an AWS Load Balancer is managed for you by Amazon.
You mention Elastic Beanstalk in your question title. Elastic Beanstalk will use both. It uses a Load Balancer for distributing traffic across multiple instances, and it uses Nginx on each instance as a reverse proxy to your application.

How to install a program on the load balancer

I've created a web application using Beanstalk. I want to install a program on the load balancer. It's Zerotier (a program that enable you to create a local network over the internet). However, I'm not able to find a way to login to the load balancer server to do that. I know that I can install the program directly in the EC2 instance but the problem here is that the program will stop working when auto scaled.
install and add the program by making a deployment or service, not in the load balancer but in the cluster, your load balancer will help you to divide the work equally. on AWS its automatically provide you with the Load Balancer.
A load balancer serves as the single point of contact for clients. The load balancer distributes incoming application traffic across multiple targets, such as EC2 instances, in multiple Availability Zones. This increases the availability of your application. You add one or more listeners to your load balancer.
source

How to handle classic load balancer with Elastic Beanstalk after redeploy

We have an ELB which can scale up and down from 1 to 4 instances. When we deploy a new verison of the server it spins up a new instance.
Because we need 256 bit encryption on our HTTPS we've been forced to use the classic load balancer (the only one where we can force clients, in our case android and iphone apps). What we noticed is that the load balancer is strictly associated to a specific instance. So when the server is re-deployed then the load balancer stops working b/c the instance it was associated with does not exist anymore.
Is there any way to handle this? Or is there a way where we can use a application load balancer and still get 256 bit encryption?
You could use rolling updates with Elastic Beanstalk. During an update a new instance will be added first. The new instance should be associated with the Load Balancer. When the new instance is up and running, the old one is stopped and removed from the Load Balancer. New instances should be associated with the Load Balancer automatically. If this doesn't happen, there must be something happening with your Elastic Beanstalk Environment.
You can definitely use 256 encryption with a Network Load Balancer. You will have to terminate SSL at the EC2 instances.

How to deploy a single web application(nodejs+reactjs) on two EC2 server for load balancing and autoscaling?

My client is asking me to deploy web application (nodejs backend+reactjs frontend) on two EC2 servers. Inorder to achieve good load balancing and autoscaling based on traffic,
Note: client doesn't want to go for single server of high version
There are multiple ways of achieving a satisfying architecture for this problem. If we are looking into using EC2 instances we can do the following:
Deploy your back-end into Target Group for an Auto Scaling Group and put an Application Load Balancer in front of it. Instances can automatically register to the load balancer, which can distribute traffic between them.
Deploy your static front-end application into an S3 bucket, if necessary, use a CloudFront distribution for caching and faster loads.
Assuming the front-end is a SPA (browser-generated HTML), then host the React part on S3 + CloudFront
Regarding deploying Node on EC2:
Use CloudFormation to setup the infrastructure (the EC2 machines, ASG, and Load Balancer)
Then use CodeDeploy to deploy / update the application
Here is a post on deploying Node.js using CodeDeploy: https://hub.packtpub.com/deploy-nodejs-apps-aws-code-deploy/
You might find it easier to use Elastic Beanstalk though

Does Elastic Load Balancing is required to run a simple dynamic application in aws?

I am new to aws. I hosted my .net website on aws last month via Elastic Beanstalk. Its a simple 5 page .net core website and do not have any database. The users are also too few.
Now the problem is I got the bill of the month where elastic load balancing charge is very high(almost 95%). My question is:
Do I need elastic load balancing service to run my website? Can't it be done without it.
If I will delete the elastic load balancing than what happen? Is there a way to disable it for a while and check?
If elastic load balancing is necessary than how can I control its use to minimum level or optimize it for low cost?
Ok, now the below answers partially resolved my problem. Now when I am changing my instance to single instance I am getting the below error:
Do I need elastic load balancing service to run my website? Can't it be done without it.
Yes, you can change your EB environment from load-balanced, to single-instance type. The single-instance does not use load balancer. It is only a single instance with elastic IP.
If I will delete the elastic load balancing than what happen? Is there a way to disable it for a while and check?
Thinks will break if you delete it manually. The correct way is to use EB configuration options to change from load-balanced to single-instance. What happens then, it depends on what you use the load balancer for? For example, if you use it for SSL certificates, you will loose HTTPs, and will have to set it up differently.
If elastic load balancing is necessary than how can I control its use to minimum level or optimize it for low cost?
Its not necessary. That's why single-instance EB environment exists.
Do I need elastic load balancing service to run my website? Can't it be done without it.
Ofcourse your website can run without a load balancer, load balancer is used when you have too many traffic on your website and you don't want to overload your single instance. In such a case load balancer evenly balances the load across different instance.
it provides a single dns name for your website through which all traffic enters ( another reason why people use load balancer)
If I will delete the elastic load balancing than what happen? Is there a way to disable it for a while and check?
if you a provision load balancer through beanstalk then deleting it manually will definitely break things, instead change your environment configuration to single instance, and as #marcin pointed out other things will also be taken like https,load balancer health of ec2 instances,stickiness with cookies.
https://docs.aws.amazon.com/elasticbeanstalk/latest/dg/using-features-managing-env-types.html
If elastic load balancing is necessary than how can I control its use to minimum level or optimize it for low cost?
Totally depends on the traffic on your website and the capacity of your instance. if your instance is big enough in terms of computing, memory no need of load balancer.( if its big ,naturally your instance will be free to cater all the request).