EC2 Flashcards by Meg G

Pricing of On Demand EC2 Server

Fixed rate by hour (or second) with no commitment

Good for apps with short term spiky or unpredictable workflows

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Pricing of Reserved EC2 Server

Provide with capacity reservation getting a discount on hourly charge for instance.

Must set for 1-3 year terms

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Reserved Instance EC2 types and % discount

Standard RI
- up to 72% discount

Convertible RI
- up to 54% off
- feature capability to change attributes of RIs as long as exchange is equal or greater value

Scheduled RI
- Available to launch within time window you reserve.
- Good for predictable schedule

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What is a Spot Instance?

EC2 instance where you big price you want on instance capacity.

Great for apps with flexible start and end times

Up to 90% discount

Fluctuates based on supply and demand

Good for users w/ urgent need for large amounts of additional computing capacity

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What are EC2 Dedicated Hosts?

Most expensive EC2 Server (physical server).

But, it can help reduce cost by allowing you to use existing server bound software.

Can be purchased on demand (hourly) but is really expensive

Also can be purchased as a reservation for up to 70% off on demand price.

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What happens if your spot instance is terminated by EC2 half-way through the hour?

You will not be charged for a partial hour of usage

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What happens if you terminate a spot instance yourself (cost-wise)?

You will be charged for any hour in which the instance ran

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TRUE or FALSE: You can encrypt the root device volume?

TRUE

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TRUE or FALSE: Termination protection is enabled by default on EC2?

FALSE, must turn it on yourself

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What is default action of root EBS volume when EC2 instance is terminated?

Root volume is deleted, but other EBS volumes are NOT deleted

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What are the underlying hypervisors for EC2?

Zen and Nitro

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How can you access the private and public IP address of an EC2 Instance?

Use CURL or GET to access the instance metadata

URI: http://169.254.254/latest/meta-data/Instance

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How can you add metadata to an EC2 instance?

Use tags

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What is an EC2 Spot Fleet?

A group of Spot and optional On-Demand Instances. AWS will launch a number based on the specified target capacity. It will be fulfilled if the max price you picked exceeds current Spot Price.

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What is a EC2 Spot Block?

Stop your EC2 instance form being terminated even if Spot price goes over you max Spot price.

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What time interval can a Spot Block be set?

1-6 hours

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What are EC2 Spot Instances used for?

Big data and analytics
Containerized Workloads
CI/CD testing
Web services
Image and media rendering
High Performance Computing (HPC)

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What are EC2 Spot Instances NOT good for?

Persistent workloads
Critical jobs
Databases

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What items do you specify in an EC2 Spot request

Max price
Desired # instances
Launch specs
Request type: one-time | persistent

One-time (request once)
As soon as spot price goes over max price the spot instance is ended

Persistent
When spot goes over max then keeps going though cycle

Valid from, Valid until

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EC2 Spot Fleet Options

Capacity Optimized

Diversified

LowestPrices (default)

InstancePoolsToUseCount (spot instances distributed across a number of Spot Instance pools you specify. Param is valid only when used in-combination with lowestPrice

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What is EC2 Hibernate?

Hibernate EC2 instance.

Saves contents of RAM to EBS root volume allows for faster reboot

Resume and keeps save instance ID

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What is EC2 Hibernate useful for?

long-running processes
Servcies that take a long time to initialize

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Size of RAM needed to perform EC2 hibernate

less than 150GB

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Max amount of time an EC2 instance can be hibernated for?

60 days max

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EC2 Instance types that can be hibernated

On-Demand Reserved

EC2 instance families that can be hibernated

C, M, R 3-5

Perquisite of enabling hibernation on EC2 instance?

Root Volume must be ENCRYPTED

What is an EC2 Security Group?

You can attach a security group to an EC2 instance that acts like a virtual firewall. It can be used to control traffic (for 1 or more instance). These can be edited at any time and new rules will be applied immediately.

TRUE or FALSE: Security Groups are Stateful

True If create inbound rule, outbound rule is created automatically. (anything allowed in is also allowed out)

TRUE or FALSE: Security Groups can be used to Blacklist IP addresses

FALSE only NACLs can blacklist

Do EC2 Security Groups BLOCK, ALLOW, or BOTH

ALLOW Everything by default is blocked

What is an Elastic IP address?

Static IPv4 address for dynamic cloud computing. You can remap the address to another instance in your account if there is an instance failure. You will need this if you do not auto-assign a public IP address.

Is there a Limit to # of Elastic IP addresses you can have?

Yes, there is a limit of 5 per region.

How can you distribute traffic among instances?

Use and Elastic Load Balancer

Memory utilization disk swap utilization disk space utilization page file utilization Note CloudWatch Agent must be installed on EC2 server

How to retrieve user data from running instance?

http://169.254.169.254/latest/user-data

What happens if you stop an instance, modify its user data, and start the instance?

Modified user data is lost.

EC2 User Data Size limit

16KB

What is the EC2 User Data used for?

After instance is started, runs auto configuration tasks and scripts

What is an EC2 placement group?

It determines how instances are placed on underlying hardware

List strategies for EC2 placement groups

Cluster - puts instances into a low-latency group in a single AZ Spread - spreads instances across underlying hardware Partition - each partition has own set of racks. No 2 partitions have same rack. Makes it easier to isolate impact failures.

How to detach a EBS root volume from an EC2 instance?

Stop instance and then detach the volume

When to use Cluster EC2 Placement Group

Want all instances in 1 AZ Need low-latency high throughput or both Only CERTAIN instances can be launched into Cluster placement Group

When to use Spread EC2 Placement Group

Want EC2 to all be put on separate hardware Ex. want DB instance and app server on different machines/hardware Recommended for apps with small # of critical instances that should be kept separate from each other Can be in multiple AZ zones all in 1 region INDIVIDUAL critical instances (1 instance on each rack)

For EC2 Placement groups is there a max # of instances per AZ?

Yes 7 per AZ

What EC2 Placement Group(s) should you use if you want to put EC2s in multiple AZs in 1 region

Spread or Partitioned

When to use Partitioned EC2 Placement Group

Can have multiple EC2 instances in a partition Each partition is on own set of racks Isolate impact of hardware failures HDFS, HBase and Cassandra cluster Can be multiple AZ zones all in 1 region MULTIPLE EC2 Instances (on each rack)

TRUE or FALSE: you can merge EC2 placement groups

FALSE

TRUE or FALSE: you can move STOPPED instances to a placement group using AWS Console

FALSE Can only move them with AWS CLI or AWS SDK

How are Windows EC2 Servers Billed?

By the Hour

What are 2 recommended strategies for having the best experience in terms of availability for Spots instances?

Use Proactive capacity rebalancing Use capacity optimized allocation

Standard network card for EC2 instance

ENI (Elastic Network Interface) . Use multiple ENI for each network.

High Performance Networking for EC2 with Single Root IO Virtualization and high preformance

EN (Enhanced Networking)

What EC2 Networking is needed for rates of 10 GBps - 100 GBps

EN (Enhanced Networking)

Options for EN Networking

ENA (Elastic Network Adapter) - always use Intel VFA

Networking for EC2 needed for HPC and Machine Learning

EFA (Elastic Fabric Adapter)

Which Networking adapters uses OS By-pass

EFA (Elastic Fabric Adapter) only supported in LINUX

For a Spot Instance: How long do you have to either stop or terminate your instance if it goes above the max Spot price?

2 minutes

How to extend your private VMware Cloud into public AWS

VCenter on AWS Cloud ordered through VMware

When to use Outpost Racks

You have a datacenter (large deployments)

When to use Outpost Servers

Small space requirements for local compute and networking

How to extend AWS to your datacenter

Outposts

TRUE or FALSE, the default NACL can be updated

TRUE

TRUE or FALSE, the default SG can be deleted?

FALSE, but you can update it

TRUE or FALSE, you can remove the default * astrick rule in a NACL

FALSE, it also cannot be updated

TRUE or FALSE, launch configurations allow for versioning

FALSE, use launch templates if you need versions

Default Cool down period of ASG

300 seconds (5 minutes)

How to setup setup disaster recovery solution on AWS using VMware servers?

Contact your VMware representative to provision dedicated hardware within AWS in which you can deploy vCenter yourself.

Your boss is concerned about over-provisioning resources when an Auto Scaling event occurs. Which dynamic scaling policy should be used to prevent this

Target tracking scaling