EC2 Flashcards
What is EC2 ?
It is a web service that provides re-sizable compute capacity in the cloud.
* economic game changer.
EC2 Options ?
On-demand - allows you to pay a fixed rate (hour, second) with no commitment.
Reserved - provides you with a capacity reservation. (1-3 years contract). Significant discount.
Spot - enables you to bid whatever price you want for instance capacity. (Great if your apps have flexible start and finish times (like a stock market))
Dedicated hosts - Physical ECX2 server dedicated for your use. *Can use your own server bound licenses (VMWare, SQL, BYOL)
What are the 4 EC2 options ?
1) On Demand
2) Reserved
3) Spot
4) Dedicated Hosts
On-Demand - Use cases
1) Perfect for users that want the low cost and flexibility of Amazon EC2 without any upfront payments.
2) Applications with short term, spikey or unpredictable workloads that cannot be interrupted.
3) Applications being developed or tested for the first time. (Great for learning)
Reserved - Use Cases;
1) Applications with steady state requirements.
2) Applications with predictable usage.
3) Users can make upfront payments.
What are the three reserved instance (RI) types?
1) Standard RI
2) Convertible RI
3) Scheduled RI
Discounts on RI ?
Standard RI - 75% discount off (3-year contract)
Convertible RI 54% discount off (3-year contract)
What is a scheduled RI ?
An EC2 instance that is only available to launch within the time window you reserve.
* It allows you to match your capacity reservation to a predictable recurring schedule that only requires a fraction of a day, month or year.
Use Cases for Spot Instances?
1) Applications that have flexible start/finish time.
2) Applications that are only feasible at very low compute prices.
3) Users with an urgent need for large amounts of additional computing capacity.
Use Cases for dedicated hosts?
1) Useful for customers and licenses who are not eligible to support multi-tenant virtualisation
2) Can be purchased on demand (hourly)
3) can be purchased as a reservation for up to 70% off the on-demand price.
EC2 Instances Types: FightDrMcPX
F = FPGA I = IOPS G = Graphics H = High Disk Throughput T = Cheap General Purpose D = Density R = Ram M= Main choice for general purpose apps: C = Compute P = Graphics (Pics) X = Xtreme Memory
Spot Instance Termination - When are you charged?
If a spot instance is terminated by AWS EC2 then you are not charged for the partial hour of usage. If you terminate the instance yourself then you will be charged for the complete hour in which the instance ran.
What does the status system check mean on an EC2 instance?
This check verifies that your instance is reachable. We test that we are able to get network packets to your instance.
* similar to a hypervisor check.
What does the instance system check mean on an EC2 instance?
This check verifies that your instance’s operating system is accepting traffic.
Termination Protection
This is turned on by default and you must turn it off into to terminate an instance.
EBS root volume encryption?
1) It cannot be natively encrypted on implementation.
2) It can be encrypted if you copy the AMI and encrypt the copied AMI’s root volume.
3) It can be encrypted by third-party tools.
Role assignment
Roles can be assigned on creation or post creation.
Check an EC2 metadata
curl http://169.254.169.254/latest/meta-data/
What is an EC2 clustered placement group?
A group of instances within a single availability zone.
- Recommended for: Low network latency.
- Recommended for high network throughput.
What is an EC2 spread placement group?
A group of instances that are placed on distinct hardware. Recommended for applications that have a number of critical instances that should be kept separate from each other.
* Can span multiple availability zones.
Placement group naming
Must be unique to your account.
Only certain types of instances can be launched in a placement group.
Compute optimised
GPU
Memory optimised
Storage optimised
Placement groups merges and movements
You cannot merge a placement group.
You cannot move an existing instance into a placemenr group.
You can create an AMI from an existing instance then launch a new instance from the AMI into a placement group.
