We're looking into developing a product that would use Amazon's cloud tools (EC2, SQS, etc), and I'm curious what tips/gotchas/pointers people that have used these technologies have.

One tip/whatever per post, please.

+1  A: 

An important concept to grasp: the file system your EC2 instance lives on while it's running is not persistent. There are tools/services available that let you mount file systems backed by S3 storage, or you can upload to S3 or other storage service from the instance, but when an instance closes the associated file system is no more.

As for tools, I've found Amazon's tools to be great, but you should probably be comfortable with the command line if you're taking this route.

+1  A: 

We're interested in EC2 where i work. We don't care about web-serving or enterprisey stuff, just massive number crunching for physics, using python. This EC2 stuff had me befuddled, with most documentation oriented toward businessy applications and using C# or Java, but this slide show clarified much for me, especially for using python:

+4  A: 

Get a developer account at It's free and a god-send for a guy who hates remembering those dumb commands and arguments. If you only resort to Amazon-supplied tools, you're throwing away your human rights.

Melodramatic much?
Greg Hurlman
+5  A: 

The Elasticfox plug-in for Mozilla makes doing a lot of the EC2 stuff easier. It can be found at: Elasticfox Firefox Extension for Amazon EC2. This page has links specifically to download the Elasticfox plug-in and also the associated Sourceforge project. Well worth using...

Chris Markle
+1  A: 

As for SimpleDB, it has a very limited query language and it is very restrictive. If you planning on having lot of complex queries, you must first sit down and think how to organize your data to make those queries possible. One thing missing, but that will probably will be added, is the ability to count the results of a given query, much like SQL's COUNT.

Performance is ok, but I consider the latency maybe a little high.


For managing your EC2 instances, etc. Amazon also offers - in beta since a couple of days - the management console which has similar functionality to the Elasticfox Firefox plugin but is a pure web console.