CCP Revision Notes Flashcards
What acts as firewall rules around EC2 Instances?
Controlling Inbound and Outbound traffic?
Security Groups
How long can you reserve EC2 instances for?
1 & 3 years
What are EC2 spot-instances?
Allows the users to take advantage of unused EC2 instances at up to 90% discount rates.
Spot instances can be terminated if the on-demand price is higher than what the user has set as their max price that they are willing to pay for the instance.
If user is willing to pay $1/hr and the on-demand pricing is at $2 per hour, the customer paying $2/hr will get this instance.
What are EC2 on-demand?
Normal EC2 available for users to consume.
What is an EBS?
Elastic Block Store that attaches to EC2 while they run.
Similar to a USB stick
EBS are network attached storage and thus suffers latency.
Are EBS bound to availability zones?
Yes.
Replication to another AZ must be done through EBS snapshots.
What is AMI?
Amazon Machine Images are used when deploying EC2s.
What is Image Builder?
Image Builder automates the creation of base VM and container images.
Rather than spinning up and instance and installing software and tools and snapshotting that instance.
Image Builder allows users to define what software and packages needs to be included in the image and this will be a base image available for them.
What is EC2 Instance Store?
Instance Store is the physical storage drive attached to each EC2 instance.
Better performance than EBS - as EBS are network drives.
Instance Store data are lost when EC2s are terminated.
What is EFS?
Elastic File System is a shared network file system that can be used by multiple EC2 instances at a time.
Similar to a network file share.
How does EBS differ to EFS?
EBS is only attached and used by a single EC2 instance.
EFS can be used by multiple EC2 instances at a time.
What is AWS FSx
Offers 3rd party file share service in AWS to mimic the function of Elastic File Share (EFS)
Remember it as File Share xternal
What is Vertical Scaling?
The ability to scale the size of an instance.
From T2.Micro to T2.Large etc.
What is Horizontal Scaling?
The ability to increase the number of instances available for an application.
What is High Availability?
Highly available applications runs in multiple availability zones for fault tolerance and increase resilience.
What are ELBs?
Elastic load balancers are internet facing servers that forwards traffic downstream to EC2 instances.
Manages load of IFE applications.
EC2 instances are placed in “target groups” and ELB forwards traffic to the specified target groups.
If a target group has 4 instances, traffic is split 4-ways, unless stated otherwise
What are the 3 different types of ELBs?
Application LB - Layer 7
Network LB - Layer 4
Gateway LB - Layer 3
What is ASG?
Auto-Scaling Groups
What are the configuration requirements for ASGs?
Minimum Size
Desired Size
Max Size
What is Simple/Step Dynamic Scaling?
Addition or Removal of instances at set states.
If application CPU usage > 70% add 1 instance
If application CPU usage < 30% remove 1 instance
What is Target Dynamic Scaling?
Application scales to hit target CPU utilization.
If target is set at 50% CPU utilization, the application will scale or de-scale to try and hit this target.
What is Schedule Dynamic scaling?
Sets a schedule when the application will scale up and down.
Busy periods - Black Fridays, Pay Days etc.
Quiet Periods - Sundays, holidays etc.
What is Predictive Dynamic Scaling?
Scales based on ML findings and results.
Predictive = ML / AI
Does buckets have to have globally unique names regardless of regions and accounts?
Yes