EC2 - Solutions Architect Associate Level Flashcards
An IP address that can be reached on the internet
Public IP
An IP address that can only be used to locate a machine on a private network
Private IP
An IP address assigned to your AWS account that allows you to have a fixed IP address for ephemeral resources
Elastic IP
What are two alternatives to using an Elastic IP address for your EC2 instances?
- Use a random public IP and register a DNS name to it
- Use a load balancer and no public IP for the EC2
By default, what sorts of IPs do a new EC2 instance come with?
Public and private IP
To SSH into an EC2 instance that is NOT in your private network (or VPC), you must connect using which IP address?
Public IP address
True/False - If you stop an EC2 instance and start it up again, it will retain the same public IP address
False - The public IP address could change unless it is assigned an Elastic IP
True/False: Elastic IP addresses only incur charges if they are not associated with an active EC2 instance or network interface
True
A logical way to place EC2 instances to meet the needs of specialized workloads
Placement Group
What are the three types of placement strategies available for a placement group?
- Cluster
- Partition
- Spread
Placement group strategy that packs instances close together inside an Availability Zone. This strategy enables workloads to achieve the low-latency network performance necessary for tightly-coupled node-to-node communication that is typical of HPC applications
Cluster
Placement group strategy that spreads your instances across logical partitions such that groups of instances in one partition do not share the underlying hardware with groups of instances in different partitions. This strategy is typically used by large distributed and replicated workloads, such as Hadoop, Cassandra, and Kafka.
Partition
Placement group strategy that strictly places a small group of instances across distinct underlying hardware to reduce correlated failures
Spread
True/False: An Elastic Network Interface (ENI) is bound to the specific AZ that it is created in
True
A logical networking component in a VPC that represents a virtual network card
Elastic Network Interface (ENI)
A common use case for this component is the creation of management networks. This allows you to have public-facing applications like web servers in a public subnet but lock down SSH access down to a private subnet on a secondary network interface
Elastic Network Interface (ENI)
True/False: Multiple Elastic Network Interfaces (ENI) can be attached to a single EC2 instance
True
True/False: Unattached Elastic Network Interfaces (ENIs) incur an hourly cost
False - ENIs do not cost anything
Alternate EC2 state that shuts down the instance, but preserves the in-memory (RAM) state by saving it in a file on an encrypted EBS volume
EC2 Hibernate
True/False: EC2 Hibernate allows you to restart EC2 instances faster than you could start a Stopped instance
True
A set of Spot Instances and optionally On-Demand Instances that is launched based on criteria that you specify
Spot Fleet
Which placement group should if you want to ensure your EC2 instances have the highest networking performance while communicating with each other?
Cluster Placement Group
If you have a critical application hosted on a fleet of EC2 instances in which you want to achieve maximum availability when there’s an AZ failure, which EC2 Placement Group should you choose?
Spread Placement Group
In an EC2 spread placement group, how many instances can you have per Availability Zone?
7
True/False: A launch configuration is used to specify instance configuration information
False - This is called a launch template. Launch configurations are only used by Auto Scaling groups and are slated for deprecation.
AWS-owned physical servers that allow you to use your own software licenses (e.g. Microsoft and Oracle) on EC2
EC2 Dedicated Hosts
This type of spot instance is designed to not be interrupted and will run continuously for the duration you select
Spot block
If you want to cancel a persistent Spot request and terminate its instances, what two actions must you do?
- Cancel the spot request
- Terminate the spot instances manually
This attribute defines how EC2 instances are distributed across physical hardware and affects pricing
Tenancy
What are the three tenancy options available to an EC2 instance?
Shared (default)
Dedicated Instance (dedicated)
Dedicated Host (host)
Tenancy option where multiple AWS accounts may share the same physical hardware
Shared (default)
Tenancy option where your instance runs on single-tenant hardware
Dedicated Instance (dedicated)
Tenancy option where your instance runs on a physical server with EC2 instance capacity fully dedicated to your use with an isolated server with configurations you can control
Dedicated Host (host)
True/False: A launch configuration can be used to configure default, dedicated, and host tenancy for your EC2s
False - A launch configuration can only configure default and dedicated
After launching an EC2 instance, which two tenancy options can you switch between?
Dedicated and Host
Which is the correct IPv4 for the the Instance Metadata Service (IMDS)? 169.254.169.254 or 254.169.254.169?
169.254.169.254
