If you design a distributed application for easy scale-out, or you just want to make use of any of the new “cloud computing” offerings by Amazon, Google or Microsoft, there are some typical concepts or components you usually end up using:

• distributed blob storage (aka S3)
• asynchronous, durable message queues (aka SQS)
• non-Relational-/non-transactional databases (like SimpleDB, Google BigTable, Azure SQL Services)
• distributed background worker pool
• load-balanced, edge-service processes handling user requests (often virtualized)
• distributed caches (like memcached)
• CDN (content delivery network like Akamai)

Now when it comes to design and sketch an architecture that makes use of such patterns, are there any commonly used symbols I could use? Or even a download with some cool Visio stencils? :)

It doesn’t have to be a formal system like UML but I think it would be great if there were symbols that everyone knows and understands, like we have commonly used shapes for databases or a documents, for example. I think it would be important to not mix it up with traditional concepts like a normal file system (local or network server/SAN), or a relational database.

Simply speaking, I want to be able to draw some conclusions about an application’s scalability or data consistency issues by just looking at the system architecture overview diagram.

Update: Thank you very much for your answers. I like the idea of putting a small "cloud symbol" on the traditional symbols. However I leave this thread open just in case someone will find specific symbols (maybe in a book or so) - or uploaded some pimped up Visio stencils ;)