Compute Services Flashcards
What is EC2 (Elastic Compute Cloud)?
Not serverless because there is a server that you directly manage.
A web service that provides secure, resizable compute capacity in the cloud.
It is designed to make web-scale computing easier for developers.
Real world usage: Deploying a database or web application
Describe the On-Demand pricing option for EC2 (Elastic Compute Cloud)
You pay for compute capacity by the hour or the second depending on which instances you run.
No longer-term commitments or upfront payments are needed.
You can increase or decrease your compute capacity depending on the demands of your application and only pay the specified per hourly rates for the instance you use.
What is On-Demand pricing option for EC2 (Elastic Compute Cloud) recommended for?
Users that prefer low cost and flexibility without any up-front payment or long-term commitment.
Applications with short-term, spiky, or unpredictable workloads that cannot be interrupted
Applications being developed or tested on EC2 for the first time.
Describe the Spot pricing option for EC2 (Elastic Compute Cloud)
Available at up to a 90% discount compared to On-Demand prices and let you take advantage of unused Amazon EC2 capacity in the AWS Cloud.
You can significantly reduce the cost of running your applications, grow your application’s compute capacity and throughput for the same budget, and enable new types of cloud computing applications.
What is Spot pricing option for EC2 (Elastic Compute Cloud) recommended for?
Applications that have flexible start and end times
Applications that are only feasible at very low compute prices
Users with urgent computing needs for large amounts of additional capacity
Describe the Reserved Instances pricing option for EC2 (Elastic Compute Cloud)
Significant discount (up to 72%) compared to On-Demand Instance pricing.
You have the flexibility to change families, operating system types, and tenancies while benefitting from Reserved Instance pricing when you use Convertible Reserved Instances.
Describe the Dedicated Host pricing option for EC2 (Elastic Compute Cloud)
A flexible pricing model that offer low prices on EC2 and Fargate usage, in exchange for a commitment to a consistent amount of usage (measured in $/hour) for a one or three year term.
Allow you to use your existing per-socket, per-core, per-VM software licenses to help maintain license compliance.
This is similar to Dedicated Instances, but Dedicated Hosts provide more restrictive control over the server.
Describe the Dedicated Instances pricing option for EC2 (Elastic Compute Cloud)
Ensure your instance will run on a dedicated physical server due to licensing restriction that don’t allow for software to run on a shared tenancy model.
Describe the Savings Plans pricing option for EC2 (Elastic Compute Cloud)
A flexible pricing model that offer low prices on EC2 and Fargate usage, in exchange for a commitment to a consistent amount of usage (measured in $/hour) for a one or three year term.
How can you connect to an EC2 instance from a local machine?
Using secure shell (SSH) allows you to access an EC2 instance from your local laptop using a key pair, which consist of a private key and a public key.
A key pair is needed
Describe the Horizontal scaling feature for EC2 instances.
Scaling out adds or replaces instances
Describe the Vertical scaling feature for EC2 instances.
Scaling up upgrades an existing instance
Describe the Auto scaling feature for EC2 instances.
Helps you maintain application availability and allows you to automatically add or remove EC2 instances according to conditions you define.
You can use the fleet management features of Amazon EC2 Auto Scaling to maintain the health and availability of your fleet.
You can also use the dynamic and predictive scaling features of Amazon EC2 Auto Scaling to add or remove EC2 instances.
Dynamic scaling responds to changing demand and predictive scaling automatically schedules the right number of EC2 instances based on predicted demand.
Dynamic scaling and predictive scaling can be used together to scale faster.
o don’t confuse it with load balancing
How many compute hours do you receive on the Free Tier plan for EC2 instances?
750 compute hours
What are Elastic Load Balancers (ELB)?
Automatically distributes your incoming application traffic across multiple EC2 instances.
Classic
Application
Gateway
Network
Describe a Classic Elastic Load Balancer (ELB).
NOW Amazon Virtual Private Cloud (Amazon VPC)
Retired August 2022 and recommended to migrate to an Amazon Virtual Private Cloud (Amazon VPC).
VPC lets you provision a logically isolated section of the AWS Cloud where you can launch AWS resources in a virtual network that you define.
You have complete control over your virtual networking environment, including selection of your own IP address range, creation of subnets, and configuration of route tables and network gateways.
You can use both IPv4 and IPv6 in your VPC for secure and easy access to resources and applications.
You can easily customize the network configuration for your VPC. For example, you can create a public facing subnet for your web servers that has access to the Internet, and place your backend systems, such as databases or application servers, in a private-facing subnet with no Internet access.
You can leverage multiple layers of security (including security groups and network access control lists) to help control access to EC2 instances in each subnet.
You can create a hardware virtual private network (VPN) connection between your corporate data center and your VPC and leverage the AWS Cloud as an extension of your corporate data center.
Describe an Application Elastic Load Balancer (ELB).
Is best suited for load balancing of HTTP and HTTPS traffic and provides advanced request routing targeted at the delivery of modern application architectures, including microservices and containers.
Operating at the individual request level (Layer seven), Application Load Balancer routes traffic to targets within Amazon Virtual Private Cloud (Amazon VPC) based on the content of the request.
Describe a Gateway Elastic Load Balancer (ELB).
Makes it easy to deploy, scale, and run third-party virtual networking appliances.
Providing load balancing and auto scaling for fleets of third-party appliances, Gateway Load Balancer is transparent to the source and destination of traffic.
This capability makes it well suited for working with third-party appliances for security, network analytics, and other use cases.
Describe a Network Elastic Load Balancer (ELB).
Is best suited for load balancing of TCP traffic where extreme performance is required. Operating at the connection level (Layer four), Network Load Balancer routes traffic to targets within Amazon Virtual Private Cloud (Amazon VPC) and is capable of handling millions of requests per second while maintaining ultra-low latencies.
Optimized to handle sudden and volatile traffic patterns.
What is Lambda?
Lets you run code without provisioning or managing servers.
You pay only for the compute time you consume—there is no charge when your code is not running.
You can run code 26 Overview of Amazon Web Services AWS Whitepaper AWS Serverless Application Repository for virtually any type of application or backend service—all with zero administration. Just upload your code, and Lambda takes care of everything required to run and scale your code with high availability.
You can set up your code to automatically trigger from other AWS services, or you can call it directly from any web or mobile app.
Times out after 15 minutes and are not recommended for processes that run longer than that.
What is the Lambda pricing model?
Always free, even after the free-usage tier expired, you’ll have access to 1 million free Lambda calls each month.
What are the responsibilities for Lambda?
Your responsibility – you are only responsible for your application code.
AWS responsibility – AWS manages servers, coding environment, and language support.
What is Fargate?
Considered serverless and is used to manage containers.
Is a compute engine for Amazon ECS that allows you to run containers without having to manage servers or clusters.
With AWS Fargate, you no longer have to provision, configure, and scale clusters of VMs to run containers.
This removes the need to choose server types, decide when to scale your clusters, or optimize cluster packing.
Removes the need for you to interact with or think about servers or clusters.
Lets you focus on designing and building your applications instead of managing the infrastructure that runs them.
What are the two modes for Amazon ECS?
Fargate launch type
and
EC2 launch type
Describe the Fargate launch type.
All you have to do is package your application in containers, specify the CPU and memory requirements, define networking and IAM policies, and launch the application.
Describe the EC2 launch type.
Allows you to have server-level, more granular control over the infrastructure that runs your container applications.
You can use Amazon ECS to manage a cluster of servers and schedule placement of containers on the servers. Amazon ECS keeps track of all the CPU, memory and other resources in your cluster, and also finds the best server for a container to run on based on your specified resource requirements.
What are the responsibilities for Fargate?
You are responsible for provisioning, patching, and scaling clusters of servers.
You can decide which type of server to use, which applications and how many containers to run in a cluster to optimize utilization, and when you should add or remove servers from a cluster.
EC2 launch type gives you more control of your server clusters and provides a broader range of customization options, which might be required to support some specific applications or possible compliance and government requirements.
What is Lightsail?
Is a compute service that is used to quickly launch preconfigured applications for small projects.
Is designed to be the easiest way to launch and manage a virtual private server with AWS.
Lightsail plans include everything you need to jumpstart your project – a VM, SSD-based storage, data transfer, DNS management, and a static IP address – for a low, predictable price.
What is Outposts?
Supports a hybrid deployment model.
Bring native AWS services, infrastructure, and operating models to virtually any data center, co-location space, or on-premises facility.
You can use the same APIs, the same tools, the same hardware, and the same functionality across on-premises and the cloud to deliver a truly consistent hybrid experience.
Can be used to support workloads that need to remain on-premises due to low latency or local data processing needs.
What are the two variants of AWS Outposts?
VMware Cloud:
Allows you to use the same VMware control plane and APIs you use to run your infrastructure.
AWS-native variant:
Allows you to use the same exact APIs and control plane you use to run in the AWS Cloud, but on-premises.
What are the responsibilities for AWS Outposts infrastructure?
Is fully managed, maintained, and supported by AWS to deliver access to the latest AWS services.
How to get started with AWS Outposts infrastructure?
You simply log into the AWS Management Console to order your Outposts servers, choosing from a wide range of compute and storage options.
You can order one or more servers, or quarter, half, and full rack units.
What is Batch?
Is a compute service that is used to process large workloads in smaller batches
Enables developers, scientists, and engineers to easily and efficiently run hundreds of thousands of batch computing jobs on AWS.
Dynamically provisions the optimal quantity and type of compute resources (such as CPU or memory-optimized instances) based on the volume and specific resource requirements of the batch jobs submitted.
What are the benefits of Batch?
There is no need to install and manage batch computing software or server clusters that you use to run your jobs, allowing you to focus on analyzing results and solving problems.
Plans, schedules, and runs your batch computing workloads across the full range of AWS compute services and features, such as Amazon EC2 and Spot Instances.
You have a variable and intermittent workload, so you want to use a compute service that allows you to pay only for the compute resources you use, without paying for compute time when your code isn’t running. Which AWS services should you use?
Lambda
Lambda allows you to run a variable and intermittent code without paying for compute time when your code isn’t running. https://aws.amazon.com/lambda/
When monitoring the health of their application, a company notices one of their EC2 instances seems to handle a lot more traffic than the other instances. How can the company evenly distribute the traffic across all of its servers so that one server is not overwhelmed with requests?
Elastic Load Balancing
The company can utilize Elastic Load Balancing to evenly distribute incoming traffic across all their EC2 instances.
A company is considering a serverless architecture and wants to build and run applications without having to manage infrastructure. Which AWS services should the company consider using when building applications?
DynamoDB: Serverless is a way to build and run applications without having to manage infrastructure. DynamoDB is considered serverless.
Fargate: Serverless is a way to build and run applications without having to manage infrastructure. Fargate is considered serverless.
Lambda: Serverless is a way to build and run applications without having to manage infrastructure. Lambda is considered serverless.
S3: Serverless is a way to build and run applications without having to manage infrastructure. S3 is considered serverless.
When configuring an Application Load Balancer (ALB), what step should you take to ensure a highly available architecture?
Configure the load balancer to serve traffic to multiple Availability Zones.
You would set up the load balancer to deliver traffic across multiple Availability Zones.
You need to set a number range of EC2 instances to be made available to handle the load for your application. Which AWS service should you use?
AWS Auto Scaling: will ensure you have the optimal number of EC2 instances to handle your application’s load, based on rules you specify. The other services mentioned can help distribute load amongst existing resources, but they do not have the ability by themselves to create new resources.
What is S3 a suitable storage solution?
Documents: S3 is object storage suitable for the storage of “flat” files like documents, photos, etc. Use cases that require very atomic or consistent reading and writing, such as databases and operating systems, are more suited to EBS (Elastic Block Store) storage.
Pictures: S3 is object storage suitable for the storage of “flat” files like documents, photos, etc. Use cases that require very atomic or consistent reading and writing, such as databases and operating systems, are more suited to EBS (Elastic Block Store) storage.
By default, what can a private subnet communicate with?
Other private subnets in the same VPC: By default, a private subnet can only communicate with other subnets in the same VPC, be they private or public. In order to communicate to the internet, a NAT gateway and internet gateway are required, and to enable communication between subnets in different VPCs, the VPCs must first be peered.
Public subnets in the same VPC: By default, a private subnet can only communicate with other subnets in the same VPC, be they private or public.
What allows you to make entire buckets (like 1 hosting an S3 website) public?
Bucket policies: allow you to control access to entire buckets, whereas access control lists let you control access to individual objects within an S3 bucket.
Which of the following is TRUE when considering subnets in a VPC?
By default, all subnets within a VPC can communicate with each other, without needing any other resources or configuration.
