- Let's talk about Amazon Elastic Compute Cloud or EC2.
With Amazon Elastic Compute Cloud,
what we get are virtual machines and we call them instances
so one virtual machine would be an instance of EC2.
These are based on the Xen hypervisor
and they come with sort of a price-fixed menu you could say
of CPU, memory, disk and network IO.
We don't really get to control CPU and memory
and disk or network IO individually,
but Amazon has done a really good job
of creating a collection of machines,
various types of EC2 instances,
for different types of workloads.
And they come with various degrees
of CPU, memory, disk and of course network IO.
With EC2 we can launch from one EC2 instance
to thousands of instances if we need to.
Now it's important to understand
that there are service limits.
Typically from the start your account is initially
limited to a certain number of instances
depending on the instance type.
That's considered a soft limit,
meaning that you can submit a support ticket request
to lift that limit.
They put that in place just as a way
to limit resource consumption in the case
where people might have runaway scripts
or maybe they aren't paying attention to what they're doing.
So with EC2 instances,
we have very powerful range of compute options
for various types of workloads.
It's important to understand
that this is a very different paradigm
than what we might be used to.
In traditional IT where we had long living servers
that we assumed would be there for years on end
in a rack somewhere,
that is not the case anymore.
We're getting away from that paradigm
and we're assuming a paradigm
where our EC2 instances are disposable,
where if there's something wrong with it,
we throw it away and start anew.
And we have systems that we'll talk about later
that can help that machine bootstrap and configure
and so to have it right back up and running
where it should be
simply by throwing it away and recreating it.