Elastic Load Balancing and Auto Scaling Flashcards
Auto Scaling responds to EC2 ______ checks and ________ metrics
Auto Scaling responds to EC2 status checks and CloudWatch metrics
Auto-scaling can be scaled based on _____ or on a _____
Auto-scaling can scale based on demand on a schedule
_______ policies define how to respond to _______ in demand
Scaling policies define how to respond to changes in demand
Auto Scaling groups define collections of EC2 instances that are ______ and _________ together
Auto Scaling groups define collections of EC2 instances that are scaled and managed together
What are the health check options available to EC2 instances? (2)
EC2 status checks
ELB uses the ELB health checks in addition to EC2 status checks
Auto Scaling - Monitoring:
How long is the granularity with Basic monitoring?
Is this a free service or are you charged?
5 minute granularity
No charge
Auto Scaling - Monitoring:
How long is the granularity with Detailed monitoring?
Is this a free service or are you charged?
- 1 minute granularity
- Charges apply
The Auto Scaling setting, known as Cooldowns, is used with a simple scaling policy to prevent Auto Scaling from __________ or ___________ instances before the effects of previous activities are _______.
The Auto Scaling setting, known as Cooldowns, is used with a simple scaling policy to prevent Auto Scaling from launching or terminating instances before the effects of previous activities are visible.
The Auto Scaling setting, known as Termination Policy, defines which instances to _________ first when a ______-__ event occurs
The Auto Scaling setting, known as Termination Policy, defines which instances to terminate first when a scale-in event occurs
The Auto Scaling setting, known as Termination Protection, prevents Auto Scaling from terminating ________ ________
The Auto Scaling setting, known as Termination Protection, prevents Auto Scaling from terminating protected instances
What is the reason for placing an instance from the “InService” state into the “Standby” state?
To update or troubleshoot the instance
Additional Scaling Settings:
A _________ ____ provides a specified amount of time to wait for the action to complete before the instance can _________ to the ____ _____
A lifecycle hook provides a specified amount of time to wait for the action to complete before the instance can transition to the next state
ELB Distributes incoming application traffic across multiple targets: What are they? (4)
- Amazon EC2 Instances
- Containers
- IP Addresses
- Lambda functions
ELB Provides _____ _________ for applications
ELB Provides Fault tolerance for applications
ELB distributes incoming traffic to a _____ __ or ________ __
ELB distributes incoming traffic to a Single AZ or Multiple AZs
In ELB, only ___ ______ per AZ can be enabled for each ELB
In ELB, only one subnet per AZ can be enabled for each ELB
Auto Scaling - Monitoring:
Group ______ provides data about the Auto Scaling Group (ASG).
Group metrics provide data about the Auto Scaling Group (ASG).
To ensure that your load balancer can scale properly, verify that each Availability Zone has a /___ subnet and at least __ IP addresses per subnet
To ensure that your load balancer can scale properly, verify that each Availability Zone has a /27 subnet and at least 8 IP addresses per subnet
ELB can be Internet facing or ____-____
Internal-only
Internet-facing ELB nodes have ______ IPs that Route traffic to ______ IP addresses of the EC2 instances
Internet-facing ELB nodes have public IPs that Route traffic to private IP addresses of the EC2 instances
________ only ELB nodes routes traffic to the ________ IP addresses of the EC2 instances
Internal only ELB nodes routes traffic to the private IP addresses of the EC2 instances
Application Load Balancer Use Cases: (2)
- Microservices architectures (e.g. Docker containers)
- Lambda targets
Gateway Load Balancer operates at which layer of the OSI model?
- Layer 3/ Networking
When Cross-Zone Load Balancing is enabled each load balancer ____ distributes traffic across all enabled ___
When Cross-Zone Load Balancing is enabled each load balancer node distributes traffic across all enabled AZs
With ___________ Load Balancers, cross-zone load balancing is enabled by default
With Application Load Balancers, cross-zone load balancing is enabled by default
With Network Load Balancers and Gateway Load Balancers, cross-zone load balancing is _____ by ______
With Network Load Balancers and Gateway Load Balancers, cross-zone load balancing is disabled by default
Gateway Load Balancer listens for packets on which ports?
Listens for all IP Packets on all ports
Gateway Load Balancer are used with Virtual Appliances such as: (3)
Firewalls
(IDS)/ (IPS)
Deep packet inspection systems (DPI)
Application Load Balancers listeners check for connection requests from clients using the _________ and ____ you configure
Application Load Balancers listeners check for connection requests from clients using the protocol and port you configure
Application Load Balancers ____ determine how to ____ requests to its __________ _______
Application Load Balancers rules determine how to route requests to its registered targets
A limitation of Application Load Balancers is that they only support
HTTP and HTTPS
To use an _____ listener with an Application Load Balancer, you must deploy at least one SSL/TLSS server __________ on your load balancer
To use an HTTPS listener with an Application Load Balancer, you must deploy at least one SSL/TLSS server certificate on your load balancer
Classic Load Balancer gives you a 504 error:
The gateway has ______ ___ which means the application is not __________ within the idle _______ period
The gateway has timed out, which means the application is not responding within the idle timeout period
When using an internet-facing ELB, you need one ______ ______ in each ___ where the ELB is defined
When using an internet-facing ELB, you need one public subnet in each AZ where the ELB is defined
Sticky sessions enable your users to ______ to the same ____ _________ every time they connect
Sticky sessions enable your users to stick to the same EC2 instance every time they connect
If you remove an instance from a pool, but the (ELB) continues to direct traffic to that EC2 instance. What is the fix?
Disable sticky sessions
When Deregistration Delay is enabled existing _____________ will remain ____ if the EC2 instance becomes _________
When Deregistration Delay is enabled existing connections will remain open if the EC2 instance becomes unhealthy
A use case for a lifecycle hook would be to run a script to download and install software after _________
or
- Pause an instance to process data before a _____-__
A use case for a lifecycle hook would be to run a script to download and install software after launching
or
- Pause an instance to process data before a scale-in(termination)
When Cross-Zone Load Balancing is _________, it only distributes traffic across the registered _______ in its ___
When Cross-Zone Load Balancing is disabled, it only distributes traffic across the registered targets in its AZ
Group metrics is an Auto Scaling Monitoring feature that is ___ _______ by default
Group metrics is an Auto Scaling Monitoring feature that is
not enabled by default
What is the default time period for the Auto Scaling setting, known as Cooldowns?
The default value for the Auto Scaling setting, known as Cooldowns is 300 sec or 5 min
When enabled what is the default time a lifecycle hook provides you?
When enabled what is the default time a lifecycle hook provides you? 1 hour by default
When Deregistration Delay is disabled existing ____________ is immediately _____ if the EC2 instance becomes __________
When Deregistration Delay is disabled existing connections is immediately closed if the EC2 instance becomes unhealthy
