EC2 Flashcards
What are the instance types?
General purpose
Compute optimized
Memory optimized
Storage optimized
What workloads are general purpose EC2 instances good for?
Diverse workloads such as code repositories and web servers
What workloads are Compute optimized EC2 instances good for?
Compute-intensive tasks that require high performance
What workloads are Memory optimized EC2 instances good for?
Fast performance workloads that process large data sets in memory
What workloads are Storage optimized EC2 instances good for?
storage-intensive tasks that require high, sequential read and write access to large data sets on local storage
What is a security group?
Firewall around EC2 instances that controls how traffic is allowed into or out of EC2 instances
What do security groups regulate?
Access Ports
Authorized IP ranges
Inbound network traffic
Outbound network traffic
What should you do when an EC2 instance needs to access AWS?
Assign it a role
What are the EC2 purchasing options?
On-Demand Instances Reserved Instances Spot instances Dedicated Hosts Dedicated instances
What type of workloads are a good fit for On-Demand Instances?
Short term and uninterrupted workloads
What are key characters for On-Demand Instances?
Pay for what you use
Highest cost with no upfront payment
No long-term commitment
What type of workloads are a good fit for Reserved Instances?
Long term, steady-state usage applications (i.e database)
What are the reserved instance types?
Reserved Instances
Convertible Reserved Instances
Schedule Reserved Instances
What EC2 purchasing option is the most cost expensive?
Dedicated hosts
What EC2 purchasing option is the least cost expensive?
Spot instances
What are the savings when using spot instances compared to On-Demand?
90%
What are the savings when using reserved instances?
75% when compared to On-Demand instances
What is the contract commitment when using reserved instances?
1 to 3 years
What are dedicated hosts?
A dedicated physical server
Why use a dedicated host?
Government compliance requirements
What are characteristics of dedicate hosts?
single instance on a single dedicate physical server
Hardware is not shared by other instances
Control over instance placement
What are the dedicate hosts use cases?
Software that has complicated licensing model
Companies that have strong regulatory or compliance needs
How long can dedicates hosts be reserved?
3 years
What are dedicate instances?
One or more instances running on a dedicated physical server
What are characteristics of dedicate instances?
No control over instance placement (can’t move hardware after stop / start)
Automatic instance placement
All instances are on same physical server
What are strategies for handling spot instances?
Set max spot price
Spot Block
Know the type of instance needed
What is spot block?
Block spot instance during specified time frame without interruptions
What can be done to instances that exceed max spot price?
Stop or terminate the instance
How to terminate spot instances?
Cancel spot instance and then terminate it
What are Spot Fleets?
Set of spit instances + (optional) on-demand instances
What are strategies for allocating spot instances?
Lowest Price
Diversified
Capacity Optimized
What is the lowest price allocation strategy?
Spot instances are allocated from the pool with the lowest price (cost optimized, short workload)
What is the diversified allocation strategy?
Spot instances are distributed across all pools (great availability, long workloads)
What is the capacity optimized allocation strategy?
Spot instances are allocated from a pool with the optimal capacity for the number of instances
What are the placement group strategies?
Cluster
Spread
Partition
What are the characteristics of a cluster?
All instances are on the same hardware (rack)
What is a cluster strategy?
placement group strategy that places instances into low-latency group in single AZ
What are disadvantage(s) when using a cluster strategy?
If rack fails all instances fail
What are advantage(s) when using a cluster strategy?
offers low latency and high speed network
What is a spread strategy?
placement group strategy that spreads instances across underlying hardware
What are the characteristics of a spread strategy?
max 7 instances per group per Availability zone
What type of applications use the spread strategy?
critical applications that need high availability and in which failures are isolated
What are advantage(s) when using a spread strategy?
Located on different hardware
Spans across AZs
Reduced risk in case of failure
What are disadvantage(s) when using a spread strategy?
Limited to 7 instances per AZ per placement group
What is a partition strategy?
placement group strategy that spreads instances across different partitions (different sets of racks) within an AZ
What are advantage(s) when using a partition strategy?
Instances in different partitions are separated, in case of failure
Scales to hundreds of EC2 instances per group
Have up to 7 partitions per AZ in the same region
What type of applications use the partition strategy?
Big data applications
What is an Elastic Network Interfaces (ENI)?
Logical component in a VPC that represents a virtual network card
What are characteristics of an ENI?
Gives EC2 instances access to the network
Gives a private IPv4 and secondary IPv4 address
Gives one elastic IP per private IPv4
Has one or more security groups
Has a MAC address
What are an ENI’s limitation(s)?
Bound to a specific availability zone and single instance
What is EC2 Hibernate?
Service that preserves the state of an EC2 instances RAM
What are the advantages of using Hibernate?
Instance boot time is faster
What are Hibernate’s characteristics?
RAM state is written to a file in the root EBS volume
The root EBS volume must be encrypted
What type of applications use Hibernate?
Long-running processing
Need to save RAM state
Services that take time to initialize
What is EC2 Nitro?
Underlying platform for higher speed EBS volumes that need increased I/O operations
What are advantages of using EC2 Nitro?
Better networking options
Higher speeds EBS
Better underlying security
What is a vCPU?
A thread in a CPU
How many vCPUs per core?
2
What are the advantages of using EC2 capacity reservations?
Ensures you have EC2 capacity in advance when needed
What commitments are required for EC2 capacity reservations?
No commitments