High Availability and Scaling Flashcards
automatically distributes your incoming traffic across multiple targets, such as EC2 instances, containers, and IP addresses, in one or more Availability Zones.
Elastic Load Balancer
First load balancer that is now out of date and not recommended
Classic Load Balancer (CLB)
Load balancer functions at layer 7 of OSI model, Supports HTTP/S/WebSocket
Application Load Balancer (ALB)
Load balancer functions at the fourth layer of the Open Systems Interconnection (OSI) model. It can handle millions of requests per second. Supports TCP, TLS, UDP
Network Load Balancer (NLB)
Each ELB is configured with an A record which points to the ELB nodes placed across the chosen AZs.
True
ELB Nodes with public IPs AND private IPs
Internet-Facing
ELB Nodes with private IP
Internal-Facing
Controls what protocols and ports will be accepted by the ELB nodes
Listeners
Can an internet-facing ELB connect to both public and private EC2 instances?
Yes
Suggested size by AWS of IP’s for ELBs in order for scale
/27 or larger
Ability to distribute or load balance across all instances in all AZ
Cross-Zone Load Balancing
Will nodes scale automatically if the load increases?
Yes
Are CLB capable of scaling?
No
ALB must have SSL certifications installed if HTTPS is used
True
Are ALB slower than NLB?
Yes
Direct the connections which arrive at a listener in an ALB
Rules
Forwarding encrypted connections without terminating them requires Network Load balancer
True
Can you detailed health checking with a network load balancer?
No
Can NLB have static IPs for whitelisting?
Yes
Can NLB forward TCP to instances with unbroken encryption
Yes
NLB are used with privatelink to provide services to other VPCs
True
Specifies instance configuration information that can be used to easily provision instances in the same configuration
Launch Templates
Used for automatic scaling and self-healing for Ec2 using launch templates/configurations
Auto Scaling Groups
Keeps running instances at the desired capacity by provisioning or termination instances
Auto Scaling Groups