AWS Certified Solution Architect – Points to remember (EC2)
Uptime SLA for EC2 and EBS within a region is 99.99%
Default cooling periodof a Autoscaling group is 5 mins.
Cooling period can be adjusted based on requirement.
AWS lambda scales automatically. No end-user actions required.
User Lambda Environment variables to pass parameters to function. For sensitive information you can use encrypted environment variables.
Remember that both EBS and EFS does not scale automatically.
EFS to expensive compared to EBS. So EBS is cost effective compared to EFS.
EBS volumes cannot be shared between different instances.
Since EFS is network file system, a latency is expected.
Use Lambda instead of EC2 where ever possible. Example there are simple computations to be done which does not need a big EC2 instance or a scenario where your computations should scale to millions of requests automatically.
Regional Reserved Instances do not provide a capacity reservation.
Standard and Convertible Reserved Instancesprovide a capacity reservation in a specific availability zone.
Application Load Balancer is the most comprehensive ELB available and most cost effective.