Can EC2 20 instance limit be bypassed by use of multiple accounts?

Just a simple question, say I on a research team with 10 members and we want to deploy a project that will require on-demand leasing of 200 开发者_StackOverflow社区EC2 instances. Can we virtually bypass the 20 instances limit by creating 10 AWS accounts (one each) and then lease on demand up to 200 instances?

You can do that - you can have as many accounts, with their appropriate payment details, as you like. You then have the standard 20-instance limit associated with each account.

Bear in mind though, that these accounts are all separate and have their own sets of access keys. Any technology you deploy to span instances across these accounts will need to be aware of that, since your 'pool' manager will need the appropriate key for the account it is attempting to launch an instance in. You may also encounter complexities with EBS sharing, Security Group access (if, for example, you have a Domain Controller in one account, VMs in the other accounts will not be able to see it), and Load Balancing and VPC are likely to be difficult at best.

Amazon are usually fairly quick to respond to limit increase requests - after all, the more instances you're using, the more money they're making. They obviously want to ensure they have capacity for your requirement, which is why they manually 'vet' requests, but provided you have a reasonable business case they're fairly accomodating.

http://aws.amazon.com/ec2/faqs/#How_many_instances_can_I_run_in_Amazon_EC2

You are limited to running 20 On-Demand or Reserved Instances, and running 100 Spot Instances per region. Cluster GPU Quadruple Extra Large instances and High I/O Quadruple Extra Large instances are limited to running 2 On-Demand instances per region [...].

Increase your limit with http://aws.amazon.com/contact-us/ec2-request

Bid the 'on-demand price' for a bunch of spot instances. You will never end up paying full price, but will rarely have your spot instances terminated. See http://aws.amazon.com/ec2/spot-instances/ and deciding on your spot bidding strategy