Cloud Concepts #1
EC2 Auto Scaling and ELB for demand tracking and high availability
'Automatic scaling of the instance count' and 'replacing unhealthy instances' point to EC2 Auto Scaling. Combined with a load balancer (ELB), it is the classic pattern for 'demand-following + high availability'.
Standard availability pattern: Multi-AZ distribution plus Auto Scaling
The standard way to raise availability is multi-AZ distribution + load balancer + Auto Scaling. Conversely, 'single-server consolidation', 'no backups', and 'disabling health checks' are classic anti-patterns that create single points of failure or unrecoverable loss.
Loose coupling with a queue versus tight coupling
'Insert a queue', 'isolate failures', and 'keep going even if one side stops' point to loose coupling. SQS / SNS are representative. It is contrasted with tight coupling (direct dependency), which risks cascading failures.
The 7 Rs of migration and where rehosting fits
The migration R's: Rehost (no change = lift & shift) / Replatform (slight optimization) / Refactor (rebuild) / Repurchase (different product = SaaS) / Relocate (move as-is). 'No change' and 'lift & shift' mean rehost.
The six perspectives of the AWS CAF for cloud adoption
The six CAF perspectives = business / people / governance / platform / security / operations. It is 'adoption guidance' that addresses not only technology but also organizational and people change. Note that its role differs from the Well-Architected Framework (design guidance).