Amazon EC2

• CFN-INIT is a powerful desired-state-like configuration engine which is part of the CFN suite of products.

• It allows you to set a state for things like packages, users, groups, sources and files within resources inside a template - and it will make that change happen on the instance, performing whatever actions are required.

• Creation policies create a 'WAIT STATE' on resources .. not allowing the resource to move to CREATE_COMPLETE until signalled using the cfn-signal tool.

• EC2 Instance roles and Instance Profiles are how applications running on an EC2 instance can be given permissions to access AWS resources on your behalf.

• Short Term Temporary credentials are available via the EC2 Instance Metadata and are renewed automatically by the EC2 and STS Services.

• Dedicated hosts are EC2 Hosts which support a certain type of instance which are dedicated to your account.

• You can pay an on-demand or reserved price for the hosts and then you have no EC2 instance pricing to pay for instances running on these dedicated hosts.

• Generally dedicated hosts are used for applications which use physical core/socket licensing

• Enhanced networking is the AWS implementation of SR-IOV, a standard allowing a physical host network card to present many logical devices which can be directly utilized by instances.

• This means lower host CPU usage, better throughput, lower and consistent latency

• EBS optimisation on instances means dedicated bandwidth for storage networking - separate from data networking.