CPSC 4820 - DAY 6
FEBRUARY 8, 2018

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ELASTICITY AND MANAGEMENT TOOLS
-------------------------------

Elastic Load Balancing - distributes traffic across multiple EC2 instances
Supports health checks.

Application Load Balancer - works with target group and contains rules and 
listeners.

+-------------------------------------+--------------------------------------+
| Classic Load Balancer		      | ALB				     |
+-------------------------------------+--------------------------------------+
| EC2-Classic			      | Path-based routing		     |
| VPC				      | Routing requests to multiple 	     |
| TCP and SSL Listeners		      | Containerized applications	     |
| Sticky sessions		      | Monitoring health of each service    |
| OSI Layer 4			      | OSI Layer 7			     |
+-------------------------------------+--------------------------------------+


Auto scaling can scale your EC2 capacity automatically.  Well suited for
applications that experience variability.

Benefits of Auto Scaling

	-Better Fault Tolerance
	-Better Availability
	-Better Cost Management

Launch configuration is a template that an auto scaling group uses to launch
EC2 instances.

Contains a collection of EC2 instances that share similar characteristics.

Instances in Auto scaling group are treated as a logical grouping for the 
purpose of instance scaling and management.

Dynamic Scaling - create a scaling policy that uses cloudwatch alarms to
determine when your auto scaling group should scale in/out.

AWS Trusted Advisor

Four pillars of a well architected cloud

	-Cost optimization
	-Security
	-Fault tolerance
	-Performance improvement.