Using the CloudConsiderations for adopting Cloud servicesMatt Johnson, Eduserv
Forget everything you know already… Cloud services ≠ Colocation Cloud services ≠ Dedicated hosting Cloud services ≠ Managed services(although service management can be layered on top)
Cloud services are about Scale Commodity Tiered services Low (or no) cost-of-sale
Common Cloud “FUD” issues Security Privacy ControlBut there are other considerations as well…
SLAs are fundamentally differentAmazon EC2’s SLA of “99.95%” looks good – but: Measurements based on rolling year Assumed 100% uptime prior to contractOnly covers entire service outages – not single VMs Maximum service credit of 10% of monthly spend
“Long-term” means 1 month But don’t always count on it – read the T&Cs:“We may change, discontinue or add Service Level Agreements from time to time.”“We may terminate this Agreement for any reason by providing you 30 days advance notice.”
Even the T&Cs are short-term“We may change, discontinue, or deprecate any of the Service Offerings (including the Service Offerings as a whole) or change or remove features or functionality of the Service Offerings from time to time.” “We may modify this Agreement (including any Policies) at any time by posting a revised version on the AWS Site...”
By the way……the quotes above were from Amazon Web Services, the World’s biggest Cloud IaaS provider. They’re not unusual.
Cloud services can disappear……and do so more often than you might think:
You are now a small fish in a big pond Rackspace has 70,000+ physical servers Amazon has 460,000+ physical servers Microsoft has 350,000+ physical servers How many do you have?
Above all, Cloud services are commodities When did you last negotiate on price at a supermarket? When did you last change the T&Cs of your gas bill?When did you last get a refund because your bus was late?
Given all this, why use the Cloud?Lots of reasons (which are not covered here), but primarily: Flexibility Speed Cost So, how do you overcome the drawbacks?
Know what you want, and what you need You have to know your own service requirements the cloud provider doesn’t (and shouldn’t) care
Understand how your cloud provider operates Cloud services often work in different ways:By default, Amazon instances disappear when powered off… …as does all of your changed data
Build good cloud applications… …that are designed for failure: Assume your infrastructure is non-resilientAllow your applications to control the infrastructure Google “Chaos Monkey” for more info
Walk before you run Make use of free trial services Start with non-critical servicesLearn how to break (and fix) things
Stay on your toes Shop around for the best pricing / performance Design your services to be provider agnostic Avoid lock-in to specific technologiesJust like other hosting, (including in-house), Cloud services can go wrong!
Plan your exit...Can you export configuration/data/virtual machines? What are the T&Cs relating to notice periods? Can you move the services elsewhere? Will you move the services elsewhere?
Final thoughts… Who manages and operates your services? Do they “get” the benefits of Cloud computing? Do your applications scale (up and down)?Many cloud providers will disappear before you do!
Thanks – any questions? Matt Johnson Head of Research, EduservE: Matt.Johnson@eduserv.org.uk, T: @mhj_workwww.eduserv.org.uk/hosting/cloud-computing