This morning, I received a newsletter from the Windows Azure Platform Team. Besides the fact that it’s formatting is horrible as usual since all German umlauts are displayed as some weird unreadable symbol, it contained a lot of new and exciting features for Windows Azure. Also be sure to check out this video which provides a fast overview of new features for Windows Azure.
Extra Small Instances
This is one of the features I was really waiting for. Before this announcement, the smallest instance size was Small, having a price tag of $0.12 per hour. Now there is an Extra Small instance size with $0.05 / hour.
I went ahead and replicated the table from this Microsoft web site to have the most current overview on my blog. This should come in handy, at least for me because I will keep forgetting this stuff.
|Compute Instance Size||CPU||Memory||Instance Storage||I/O Performance||Cost per hour|
|Extra Small||1.0 GHz||768 MB||20 GB||Low||$0.05|
|Small||1.6 GHz||1.75 GB||225 GB||Moderate||$0.12|
|Medium||2 x 1.6 GHz||3.5 GB||490 GB||High||$0.24|
|Large||4 x 1.6 GHz||7 GB||1,000 GB||High||$0.24|
|Extra large||8 x 1.6 GHz||14 GB||2,040 GB||High||$0.96|
As explained in this video, Extra Small Instances share resources (CPU, memory) with other VMs on the same node. Furthermore, the network bandwidth is capped at around 5 Mbps. This is not the case with larger instance sizes, where CPU and memory are not shared and your service can leverage unused bandwidth.
I believe this is a very good idea. Amazon’s smallest Windows instance (Micro Instance) is available at a cut-price $0.03 per hour, but we can’t compare these offerings 1:1 because Azure offers more functionality. We don’t have to pay extra for load balancing services and we don’t have to worry about OS updates etc. Besides, Azure’s Extra Small instance has 155MB more RAM, which could make a lot of difference.
This is why I like this new instance size so much: It means that it just got easier to get a small service running without downtime. By that I mean that I can now pay 2 extra small instances for a small service which gives me the ability to enable rolling upgrades without downtime. This includes automatic OS updates as well as my own updates to my service when delivering new features. This is still cheaper than having one small instance without all these benefits. I would expect this to activate the SLAs also, but I’m not sure about that. This won’t be the case while this feature is still in beta.