CLOUD

CLOUDDemystifying

the

Jesse DunietzSASS Talk

A Survey of Cloud Computing

Cloud service = unified-looking, network-accessible resource pool

Cloud service looks like single, locale-independent entity

Room for on-demand increase of resources

Large, homogeneous resource pool

Self-monitoring for provider and consumer

Ubiquitous access over network

On-demand self-service

The central ideas of CC are not new.• The grand vision: J.C.R. Licklider’s “intergalactic

computer network” (1963)• Utility computing

• “If computers of the kind I have advocated become the computers of the future, then computing may someday be organized as a public utility just as the telephone system is a public utility…The computer utility could become the basis of a new and important industry.”

--John McCarthy (1961)

• Mainframes desktop computing utility/cloud

Grid computing: an intermediate step• Grid is “a system that:

• coordinates resources that are not subject to centralized control

• using standard, open, general-purpose protocols and interfaces

• to deliver nontrivial qualities of service” (--Ian Foster)• Distributed, parallelised computation• Loosely coupled• Extension of clustering• Computing as accessible as the electric grid• E.g. Folding@Home, SETI@Home (BOINC)

Grid computing: an intermediate step

Recent years have seen an explosion of cloud-like services.

• 1999: salesforce.com

• 2002: Amazon Web Services

• 2005: Zoho Office

• 2006: Amazon EC2

• 2007: Gmail/Google Apps

• 2009: Chrome OS announced

Recent years have seen an explosion of cloud-like services.

Cloud computing depends on many recent software technologies.• Late 1990’s: widespread broadband Internet

• Late 1990’s: OS virtualisation

• Xen hypervisor developed at Cambridge CL!

• 2005-2006: Intel/AMD offer hardware-assisted virtualization

• Server farm management (scaling)

“As a service” (XaaS) is the new computing paradigm.

InfrastructurePlatformSoftware

Google Docs,Photoshop ExpressJ2EE, Google App Engine

Amazon EC2, GoGrid,Microsoft Azure

Cloud deployments come in all shapes and sizes.

• Private cloud• Public cloud

• e.g. Amazon

• Community cloud• e.g.

http://www.scienceclouds.org

• Hybrid

CC has obstacles, but offers many benefits.

Disadvantages

Privacy

Reliability

Migration

Legal issues

Account security

Lock-in (loss of control)

Advantages

Cost savings

HW/OS independence ([S|I]aaS)

Server security

“Thin” clients for wimpy devices

Update speed

New uses for cloud technology are constantly popping up.

• Rich web applications• Computing as a utility (IaaS)• New “back office”

functionality applications• E.g. Apple Push

Notification Service• Anywhere, anytime

computing

Not everyone’s head is in the clouds.

• A few treasures from Richard Stallman:• “[The] term [‘cloud computing’] is too nebulous to refer to anything in

particular. If it has any meaning, it can only be, ‘Don't pay attention to who controls your data or your computing. Just trust every company.’”

• “The issue I've raised is about a more specific kind of scenario: Software as a Service. We can avoid it, and avoiding it is the only way to maintain our freedom.”

• Another from Oracle CEO Larry Ellison:• Cloud computing has been defined as “everything that we currently do” and

will have no effect except to “change the wording on some of our ads”

• Recent outages reduced trust in reliability• Greenpeace has complained about energy usage

CC is still full of unsolved problems.

• Interoperability, generic design blueprint

• Making sporadic self-healing converge on consistency• Formal models for “loose

coupling” vs. brokenness

“Everything we think of as a computer today is really just a device that connects to the big computer that we are all collectively building.”

-- Tim O’Reilly, CEO, O’Reilly Media