clearing the clouds understanding cloud computing ali khajeh-hosseini st andrews cloud computing...

Clearing the CloudsUnderstanding 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

2

Cloud computing

Clearing the clouds, November 2009

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 web


Service 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


Deployment 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



Cloud Service Consumers

Software as a ServiceSoftware as a Service

Platform as a ServicePlatform as a Service

Infrastructure as a ServiceInfrastructure as a Service

PublicCloudsPublicClouds

PrivateCloudsPrivateClouds

CommunityClouds

CommunityClouds

HybridCloudsHybridClouds

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?


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 costs


Costs

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


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...


Security

• 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 services


Legal 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


Effects 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


Company C (end users)

Company A (majoroil company)

Company B(IT solutionscompany)

TapeDrive

Database Server

Application Server

Firewall

Offshoreoil rig

Minutelydata

Amazon’sCloud

Company C

Company A Offshoreoil rig

Company B

Case 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 Issue

Interviews


• 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 cloud

Interviews


• 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…


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


Summary

clearing the clouds understanding cloud computing ali khajeh-hosseini st andrews cloud computing...

Documents

amazons cloud

cloud service providers

cloud bursting

staff costs cloud computing

stacc private cloud

organizations public

computing resources

organization community