New EC2 instance types

[Clint Byrum]

Excerpts from Gustavo Niemeyer's message of Thu Mar 08 06:48:03 -0800 2012:
> This is great for juju:
> 
> http://aws.typepad.com/aws/2012/03/ec2-updates-new-instance-64-bit-bit-ubiquity-ssh-client.html
> 
> We may even switch the default instance type to m1.small 64bit.
> 

This is truly exciting news, and I think the m1.medium is a great
addition.

Other than the single-AMI issue, what benefit would using 64-bit on
m1.small gain us? 64-bit pointers end up taking up more RAM, and with
some pointer-heavy workloads (like PHP) this can be significant. Also
CPU cache pressure is increased because of increased code size, so even
heavy computation code can suffer if it doesn't actually need to work
with 64-bit numbers.

In short, if you don't need to address large sections of memory or do
64-bit arithmetic, 64-bits is a wash in terms of trade-offs.

Does seem like we should add 'arch' to the ec2 provider since we can no
longer infer it from the instance type.

Side note.. MindTerm brings back *old* memories of a startup I worked at
in 2000 where we used it to let people click on a link which would lead
to us gaining access to their database server (via SSH reverse tunnel)
to download all their transactions and run a live demo of our business
intelligence tools. Amazing that All these years later Amazon is making
use of it. ;)