Posts Tagged Dedicated Instances

AWS Dedicated Instances are Architecturally Insignificant

AWS’s announcement of dedicated instances is important for enterprise CIOs, compliance officers and others that get the willies when thinking about the big, bad and unsecure public cloud.

For everyone else? These aren’t the droids you’re looking for… You can go about your business… Move along…

It seems that all that dedicated instances give you is the guarantee that no other virtual machine will run on the same physical piece of tin as your virtual machine. The single tenant hardware being referred to is limited to, I assume, local disk, processor and memory. The network, non-ephemeral storage and other key bits are obviously (to me at least) shared, never mind that AWS without ELB, EBS, SQS and a host of other AWS services is, well, not particularly interesting.

I see very few use cases where dedicated instances can actually be used in a compliance restricted environment. You will have to encrypt all the data that you move to the machine and will have to roll your own failover with local and volatile storage (if your regulations can cope with data being left lying around on an instance after it has failed). Perhaps intensive and brief data processing tasks that need to run on rapidly scaled up compute nodes will find a sweet spot with dedicated instances and maybe that is a big enough market for AWS to approach. At the very least it makes AWS look more prepared and capable to take on the regulatory and compliance issues that their customers are asking them about.

What would be interesting is if we could get dedicated storage in addition to dedicated instances order to architect solutions that, as well as being more secure, could be used for higher performing disk I/O. That would allow the building of data tiers (NoSQL as well as RDBMS) that do not have to deal with latency and throughput variations that are experienced with EBS backed databases. Dedicated storage on AWS, however, starts to look and smell a lot like a SAN and then may become too difficult, complicated or expensive to do at scale.

So the AWS dedicated instances are an interesting and useful little tweak to the AWS hypervisor that at least gives credibility to AWS’s security credentials and helps woo the enterprise. It doesn’t offer anything that will change how we architect solutions on AWS and doesn’t offer enough for the regulatory jittery enterprise. But it is a start.

Simon Munro



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