Amazon just announced two big improvements to EC2:
- Multiple Locations
Amazon EC2 now provides the
ability to place instances in multiple locations. Amazon EC2 locations
are composed of regions and Availability Zones. Regions are
geographically dispersed and will be in separate geographic areas or
countries. Currently, Amazon EC2 exposes only a single region.
Availability Zones are distinct locations that are engineered to be
insulated from failures in other Availability Zones and provide
inexpensive, low latency network connectivity to other Availability
Zones in the same region. Regions consist of one or more Availability
Zones. By launching instances in separate Availability Zones, you can
protect your applications from failure of a single location.- Elastic IP Addresses
Elastic IP addresses
are static IP addresses designed for dynamic cloud computing. An
Elastic IP address is associated with your account not a particular
instance, and you control that address until you choose to explicitly
release it. Unlike traditional static IP addresses, however, Elastic IP
addresses allow you to mask instance or Availability Zone failures by
programmatically remapping your public IP addresses to any instance in
your account. Rather than waiting on a data technician to reconfigure
or replace your host, or waiting for DNS to propagate to all of your
customers, Amazon EC2 enables you to engineer around problems with your
instance or software by quickly remapping your Elastic IP address to a
replacement instance.
Datacenters and geographic regions are Single Points of Failure (SPOF) too. Failure Happens, and it’s far better (and cheaper) to build services that are resilient to failure than to try to prevent them from happening. This is a big step in the right direction.
Update: RightScale posted an excellent overview of how this works.