Amazon's EC2: Pay as You Grow Could Cut Your Costs in Half
Update: via ProductionScale, a nice Digital Web article on how to setup S3 to store media files and how Blue Origin was able to handle 3.5 million requests and 758 GBs in bandwidth in a single day for very little $$$. Also a Right Scale article on Network performance within Amazon EC2 and to Amazon S3. 75MB/s between EC2 instances, 10.2MB/s between EC2 and S3 for download, 6.9MB/s upload.
Now that Amazon's S3 (storage service) is out of beta and EC2 (elastic compute cloud) has added new instance types (the class of machine you can rent) with more CPU and more RAM, I thought it would be interesting to take a look out how their pricing stacks up.
The quick conclusion:the more you scale the more you save. A six node configuration in Amazon is about half the cost of a similar setup using a service provider. But cost may not be everything...
EC2 gets a lot of positive pub, so if you would like a few other perspectives take a look at Jason Hoffman of Joyent's blog post on Why EC2 isn't yet a platform for "normal" web applications and Hostingfu's
Short Comings of Amazon EC2. Both are well worth reading and tell a much needed cautionary tale.
The upshot is batch operations clearly work well within EC2 and S3 (storage service), but the jury is still out on deploying large database centric websites completely within EC2. The important sticky issues seem to be: static IP addresses, load balancing/fail over, lack of data center redundancy, lack of custom OS building, and problematic persistent block storage for databases. A lack of large RAM and CPU machines has been solved with the new instance types.
Assuming you are OK with all these issues, will EC2 cost less? Cost isn't the only issue of course. If dynamically scaling VMs is a key feature, SQS (message queue service) looks attractive, or S3's endless storage are critical, then weight accordingly.
My two use cases are my VPS, for selfish reasons, and a quote from a leading service provider for a 6 node setup for a startup. Six nodes is small, but since the architecture featured horizontal scaling, the cost of expanding was pretty linear and incremental.
Here's a quick summary of Amazon's pricing:
$0.16 per GB - next 40 TB / month data transfer out, $0.13 per GB - data transfer out / month over 50 TB. You don't pay for data transfer between EC2 and S3, so that's an advantage of using S3 within EC2.
You don't have to run these numbers by hand. To calculate the Amazon costs I used their handy dandy calculator. When performing calculations, per Amazon, I used 732 hours per month.
Single VPS Configuration
I was very curious about the economics of moving this simple site(http://highscalability.com) from a single managed VPS to EC2.
Currently my plan provides:
From Amazon:
Will I switch? Probably not. I don't know how well Drupal runs in EC2/S3 and it's not really worth it for me to find out. Drupal isn't horizontally scalable so that feature of EC2 holds little attraction. But the extra RAM and affordable disk storage are attractive.
So for very small deployments using your standard off the shelf software, there's no compelling reason to switch to EC2.
Six Node Configuration for Startup
This configuration is targeted at a real-life Web 2.0ish startup needing about 300GB of fast, highly available database storage. Currently there are no requirements for storing large quantities of BLOBs. There are 6 nodes overall: two database servers in failover configuration, two load balanced web servers, and two application servers.
From the service provider:
From Amazon:
The cost numbers really stand out. You pay half for a similar setup and the cost of incrementally scaling along any dimension is relatively inexpensive. You could in fact start much smaller and much cheaper and simply pay as you grow. The comparison is not apples to apples however. All the potential problems with EC2 have to be factored in as well. As someone said, architectecting for EC2/S3 takes a different way of thinking about things. And that's really true. Many of the standard tricks don't apply anymore.
Deploying customer facing production websites in a grid is not a well traveled path. If you don't want to walk the bleeding edge then EC2 may not be for you. For example, in the service provider scenario you have blisteringly fast disks in a very scalable RAID 10 setup. That will work. Now, how will your database work over S3? Is it even possible to deploy your database over S3 with confidence? Do you need to add a ton of caching nodes? Will you have to radically change your architecture in a way that doesn't fit your skill set or schedule? Will the extra care and monitoring needed by EC2 be unacceptable? Is the single data center model a problem? Does the lack of a hardware firewall and a load balancer seem like too big a weakness? Can you have any faith in Amazon as a grid provider?
Only the shadow may know the answers to these questions, but the potential cost savings and the potential ease of scaling make the questions worth answering.
