Clearing the Clouds
Understanding cloud computing
Ali Khajeh-Hosseini
ST ANDREWS
CLOUD COMPUTING CO-LABORATORY
• There are many definitions and they all differ • Simply put, cloud computing is a model for delivering IT as a Service. Clouds refer to the actual data centres that house the hardware and software • US National Institute of Standards and Technology working definition: Cloud computing has • Five characteristics • Three service models • Four deployment models
Cloud computing
1. On‐demand self‐service: you can start using computing resources at anytime without needing human interaction with cloud service providers. Computing resources can be storage, processing, memory, network bandwidth, VMs... 2. Broad network access: you can access those resources over the network using laptops, mobiles phones etc. 3. Resource pooling: the computing resources are shared by multiple users (multi‐tenancy) 4. Rapid elasticity: you can scale up or down the amount of resources that you’re using very quickly 5. Measured service: resource usage is metered by measuring your storage, CPU hours, bandwidth usage etc. Clearing the clouds, November 2009 3
Characteristics
•
Infrastructure as a Service
– Low level of abstraction, most flexible, dealing with virtual machines•
Platform as a Service
– High level of abstraction, less flexibility, dealing with your application code and your provider’s APIs•
Software as a Service
– Using software that others have developed and offer as a service over the webService Models
•
Private cloud: controlled and used by one
organization
•
Community cloud: used by several organizations
•
Public cloud: available to the general public
•
Hybrid cloud: mixture of the above, allows cloud
bursting
Clearing the clouds, November 2009 5Deployment Models
•
St Andrews Cloud Computing Co‐laboratory
launched in April 09
•
Local investment of about £0.5 million covering
– PhD Studentships – Experimental hardware platform – Technical support•
Our aim was to explore the research potential of
CC bringing together researchers in distributed
systems, high‐performance computing and
systems engineering
StACC
•
The StACC private cloud is now operational
– 10 servers (Cloud controller, storage server, 8 * 4 core general purpose servers) – Running Eucalyptus open source software•
Objectives
– To understand what’s involved in setting up and running a cloud (more than you might think!) – To provide an experimental platform that we can measure – To provide us with a platform that we can extend (and break)StACC Experimental Cloud
Clearing the clouds, November 2009 7
Cloud Service Consumers
Software as a Service Software as a Service Platform as a Service Platform as a Service Infrastructure as a Service Infrastructure as a Service Public Clouds Public Clouds Private Clouds Private Clouds Community Clouds Community Clouds Hybrid Clouds Hybrid Clouds Is it cheaper? Is it secure? How will it effect my work? • We did an extensive literature survey to see if we can find out the answers...
• Should I lease or buy? • Walker modelled the cost of a CPU hour when purchased as part of a server cluster and compared it with Amazon EC2 • 2 scenarios, purchasing: – a 60,000 core HPC cluster – a compute blade rack consisting of 176 cores • Model showed that it’s cheaper to buy in both scenarios assuming that CPU utilization is very high and electricity is cheap • Good first step but far too narrow in scope, what about costs of housing the infrastructure, installation and maintenance, staff, storage and networking? Clearing the clouds, November 2009 9
Costs
E. Walker, The Real Cost of a CPU Hour, 2009 • Deelman et al. used simulation to calculate the cost of running a data‐intensive astronomy application on Amazon’s cloud • Highlighted the potentials of using cloud computing as a cost‐ effective deployment option for data‐intensive scientific application • Assumed the cost of running instances on AWS EC2 are calculated on a dollar‐per‐CPU‐second basis, i.e. they normalised the costs • But, AWS charge on a dollar‐per‐CPU‐hour basis and charge for a full hour even for partial hours. So launching 100 instances for 5 minutes would cost 100 CPU hours • Makes a significant difference in costsCosts
E. Deelman, G. Singh, M. Livny, B. Berriman, J. Good, The cost of doing science on the cloud: the Montage example, 2008• Kondo et al. investigated the costs of using cloud computing for desktop grid projects such as SETI@Home • They found that deploying the servers used for the SETI@Home project on Amazon’s cloud would cost 40% less than using their university’s data centre • Didn’t include upfront server purchasing costs or staff costs • Cloud computing would look even more attractive if they did Clearing the clouds, November 2009 11
Costs
D. Kondo, B. Javadi, P. Malecot, F. Cappello, D. P. Anderson, Cost‐benefit analysis of Cloud Computing versus desktop grids, 2009•
So is it really cheaper?
•
Not really sure, it all depends on the specific
scenario and what you include in your
calculations
•
We’re developing a tool to help users decide
for themselves...
Costs
•
Security concerns are often mentioned in cloud
computing but not much research has been done to
address them
•
The Cloud Security Alliance has published a set of
security guidelines in the form of problem statements
and issues that need to be considered by users
•
Most concerns are about loss of control over physical
hardware which then lead on to legal issues...
Clearing the clouds, November 2009 13Security
• Most legal issues are related to the cloud’s physical location, which determine its jurisdiction • Amazon have data centres in 2 regions (US and Europe) so they can deal with these issues • But the cloud’s nature means that users don’t know (or care) about this information: “it’s all in the cloud” • Location is important because cloud computing increases the control of governments and corporations over resources*. Cloud computing brings together vast amounts of data and computing resources in centralised data centres, compared to how they are currently hosted in geographically dispersed locations • It’s unlikely that these jurisdiction issues will stop the use of cloud servicesLegal Issues
* P. T. Jaeger, J. Lin, J. M. Grimes, S. N. Simmons, Where is the cloud? Geography, economics, environment, and jurisdiction in cloud computing, 2009•
How will cloud computing effect the work of
IT departments?
•
Their authority has been diminishing over the
last few decades, from mainframes to PCs
•
Cloud computing is going to decrease their
authority further
•
Users are turning into “choosers”
*who can
replace the services provided by the IT
department with service offered in the cloud
Clearing the clouds, November 2009 15Effects on Work
* R. Yanosky, From Users to Choosers: The Cloud and the Changing Shape of Enterprise Authority, 2008•
To study these issues, we performed a case study
examining the relative costs of migrating from a
locally provided host to a host provided on Amazon
•
The system studied was a fairly small data
acquisition IT system from the Oil & Gas industry.
The system had a contract value of £104,000 and
was deployed in a local data centre
•
Our focus was socio‐technical – what are the human
and organisational issues that influence such
decisions
Case Study
Case Study
Clearing the clouds, November 2009 17 Company C (end users) Company A (major oil company) Company B (IT solutions company) Tape Drive Database Server Application Server Firewall Offshore oil rig Minutely data Amazon’s Cloud Company C Company A Offshore oil rig Company BCase Study
•
Infrastructure costs over 5 years
•
Around 55% cheaper
•
218 support calls over 5 years
•
20% of them would be eliminated
• Backup, power and network issues would be Amazon’s responsibility In‐house Cloud £57,000 £25,000 Support IssueInterviews
Clearing the clouds, November 2009 19 • We took these findings and presented them to various people in the company and interviewed them • Technical manager: – It looks attractive – We would lose leverage over support contracts – Concerned about security and protection of virtual machines – Some corporations veto data going over port 80 • Support staff: – Very negative about cloud computing – Feel threatened – Don’t want to lose control over hardware•
Project manager:
– Hard to sell this idea, there’s no data centre to show clients – Difficult to alter corporate security policies – Easier to manage cash flow – Reduces required skill‐set and overheads•
Business development manager:
– We are under pressure to reduce electricity usage – It presents new opportunities for us, e.g. running training courses in the cloudInterviews
• Cloud computing has sparked a huge interest in the IT industry • Many organizations are thinking about migrating their systems to the cloud. During this period, many migration decisions need to be made, what to keep in‐house, what to migrate • These aren’t simple decisions and there are a range of issues that need to be considered when making these decisions: economic, technical, organizational, risks etc. • We are developing a decision support system to help people make those decisions… Clearing the clouds, November 2009 21
Decision Support System
•
Cloud computing is still in its early days
•
We are currently at the start of a transition
period, the shift towards cloud computing
could take many years
•
Not much research has been done about
issues effecting cloud service consumers
