Cloud services are by definition remote, so you have to be able to connect to them over a network connection. There are multiple potential points of failure, including issues with your home network, your Internet service provider, the cloud provider's network or even their own ISP, not to mention obvious things like your power going out or your computer dying. If any one of these things goes down, you are out of luck getting to your data or applications.
Network congestion will also affect how quickly and easily you can upload or download via the cloud. Extreme slowness can be just as bad as an outage when you're trying in vain to get to data you need right away to finish that last-minute presentation or paper.
Sometimes catastrophic disruptions occur over entire data centers, or portions of data centers. Services can be interrupted by a weather event or other natural disaster, a power outage, equipment failure or simply unscheduled downtime for repairs or maintenance. While cloud hosts strive for 100 percent uptime, this is a lofty goal. Things happen, even to the big players.
Amazon, an early pioneer in the cloud service area, has had several highly publicized outages from 2011 to 2013. Some of them took down or impaired well-known sites including Reddit, Netflix, Coursera, Foursquare, Instagram, Pinterest, Flipboard, Vine and even Amazon itself. They have been attributed to thunder storms, power outages, human error and even a glitch in a single networking device in one case.
Microsoft's Windows Azure service had an approximately 10-hour disruption in February 2012 caused by a leap day-related software bug. Google had an outage of only a few minutes in August 2013 that took out all of their services, including the search engine, Gmail and YouTube, and reportedly cost them around half a million dollars [source: Bloomberg]. According to the analytics firm GoSquared, the outage also reduced global Web traffic by 40 percent [source: Bloomberg, Mack].
For a person at home trying to watch a movie on Netflix, outages can be an annoyance. But for a business, even short disruptions can have a major impact on revenue. It's a lesson that anyone relying on the cloud should spread their service over multiple data centers, or even multiple providers, if possible. Backing up data regularly in some automated fashion is also a good idea. Redundancy is key. It comes with a price tag, but it may be worth it if you need constant access to your data and services.
Author's Note: 5 Factors That Affect Cloud-based Data Upload and Retrieval
I gradually -- without even noticing at first -- moved many of my activities to the cloud. My e-mail is entirely Web-based. I haven't had a physical photo album in years. And I'm even reading most of my books via Kindle's cloud. I've also switched to writing most of my articles and other documents in Google Drive -- including this one.
But I have a slow computer and a finicky cable modem that I have to reset a lot, so I make it a habit of downloading my work frequently. And I occasionally move it to a thumb drive for good measure. I'm sort of half on and half off the cloud anytime I'm on the computer. The cloud is incredibly useful when it works, and most of the time it does -- but it's always good to have a backup plan.
- Babcock, Charles. "Amazon Cloud Outage Causes Customer to Leave." InformationWeek. July 6, 2012. (Nov. 3, 2013) http://www.informationweek.com/cloud-computing/infrastructure/amazon-cloud-outage-causes-customer-to-l/240003249
- Babcock, Charles. "Amazon's Dec. 24th Outage: A Closer Look." InformationWeek. January 4, 2013. (Nov. 3, 2013) http://www.informationweek.com/cloud-computing/infrastructure/amazons-dec-24th-outage-a-closer-look/240145533
- Babcock, Charles. "Azure Outage Caused By False Failure Alarms: Microsoft." InformationWeek. March 12, 2012. (Nov. 3, 2013) http://www.informationweek.com/cloud-computing/infrastructure/azure-outage-caused-by-false-failure-ala/232602382
- Barton, Mike. "Cloud Downtime's Cost: $70M Since 2007, Give or Take..." Wired. June 19, 2012. (Oct. 26, 2013) http://www.wired.com/insights/2012/06/cloud-downtime-cost/
- Binning, David. "Top five cloud computing security issues." Computer Weekly. April 24, 2009. (Oct. 25, 2013) http://www.computerweekly.com/news/2240089111/Top-five-cloud-computing-security-issues
- Bloomberg Businessweek. "Google Outage Said to Cost Company $545K in Revenue." Aug. 19, 2013. (Nov. 03, 2013) http://www.businessweek.com/videos/2013-08-19/google-outage-said-to-cost-company-545k-in-revenue
- CNBC. "Companies Climbing to the Cloud." 2011. (Nov. 2, 2011) http://www.cnbc.com/id/43250952
- Collier, Kevin. "How to avoid triggering the new Copyright Alert System." Daily Dot. Feb. 25, 2013. (Nov. 1, 2013) http://www.dailydot.com/news/copyright-alerts-how-to-download-upload-hide/
- Computer Weekly. "Google mail collapses." Feb. 24, 2009. (Nov. 1, 2013) http://www.computerweekly.com/news/2240088530/Google-mail-collapses
- Gallagher, Ryan. "Bandwidth-Throttling Copyright Enforcement System Launches Across U.S." Slate. Feb. 25, 2013. (Nov. 3, 2013) http://www.slate.com/blogs/future_tense/2013/02/25/six_strikes_copyright_enforcement_system_launches_will_throttle_your_bandwidth.html
- Google. "Google Developers - Google Cloud Storage." (Nov. 4, 2013) https://developers.google.com/storage/pricing
- Gray, Patrick." Legal issues to consider with cloud computing." Tech Republic. March 5, 2013. (Oct. 25, 2013) http://www.techrepublic.com/blog/tech-decision-maker/legal-issues-to-consider-with-cloud-computing/
- Hashizume, Keiko, David G. Rosado, Eduardo Fernandez-Medina and Eduardo B. Fernandez. "An analysis of security issues for cloud computing." Journal of Internet Services and Applications. 2013. (Nov. 2, 2013) http://download.springer.com/static/pdf/375/art%253A10.1186%252F1869-0238-4-5.pdf?auth66=1383621448_61651d08a71d785305ae219d2d3e6a5d&ext=.pdf
- Hewlett-Packard. "HP Cloud Pricing." (Nov. 4, 2013) http://www.hpcloud.com/pricing
- Hurwitz, Judith, Robin Bloor, Marcia Kaufman and Fern Halper. Cloud Computing for Dummies. "Cloud Computing Cheat Sheet." November 2009. (Nov. 1, 2013) http://www.dummies.com/how-to/content/cloud-computing-cheat-sheet.html
- Hurwitz, Judith, Robin Bloor, Marcia Kaufman and Fern Halper. Cloud Computing for Dummies. "Comparing Public, Private, and Hybrid Cloud Computing Options." November 2009. (Nov. 3, 2013) http://www.dummies.com/how-to/content/comparing-public-private-and-hybrid-cloud-computin.html
- Hurwitz, Judith, Robin Bloor, Marcia Kaufman and Fern Halper. Cloud Computing for Dummies. "Grasping the Fundamentals." November 2009. (Nov. 1, 2013) http://media.wiley.com/product_data/excerpt/05/04704847/0470484705.pdf
- Huth, Alexa and James Cebula. "The Basics of Cloud Computing." United States Computer Emergency Readiness Team. 2011. (Oct. 25, 2013) https://www.us-cert.gov/sites/default/files/publications/CloudComputingHuthCebula.pdf
- IBM. "What is cloud?" (Nov. 2, 2013) http://www.ibm.com/cloud-computing/in/en/what-is-cloud-computing.html
- Ingram, Mathew. "What Happens When the Cloud Meets a Bandwidth Cap." Gigaom. May 4, 2011. (Nov. 3, 2013) http://gigaom.com/2011/05/04/what-happens-when-the-cloud-meets-a-bandwidth-cap/
- Koba, Mark. "Cloud Computing 101: Learning the Basics." CNBC. June 2, 2011. (Oct. 25, 2013) http://www.cnbc.com/id/43077233
- Ludwig, Sean. "Amazon cloud outage takes down Netflix, Instagram, Pinterest, & more." VentureBeat. June 29, 2012. (Nov. 3, 2013) http://venturebeat.com/2012/06/29/amazon-outage-netflix-instagram-pinterest/
- Ludwig, Sean. "Amazon cloud outage takes down Reddit, Airbnb, Flipboard, Coursera, & more." VentureBeat. Oct. 22, 2012. (Oct. 26, 2013) http://venturebeat.com/2012/10/22/amazon-cloud-outage-takes-down-reddit-airbnb-flipboard-more/
- Mack, Eric. "Google outage reportedly caused big drop in global traffic." CNET. Aug. 16, 2013. (Nov. 3, 2013) http://news.cnet.com/8301-17938_105-57598978-1/google-outage-reportedly-caused-big-drop-in-global-traffic/
- McKay, Dimitri. "The Three Categories of Cloud Computing: What's Your Flavor?" Security Week. March 21, 2011. (Oct. 25, 2013) http://www.securityweek.com/three-categories-cloud-computing-whats-your-flavor
- Microsoft. "Cloud Basics - Entering the Cloud." (Oct. 25, 2013) http://www.microsoft.com/industry/government/guides/cloud_computing/1-entering.aspx
- Pavolotsky, John. "Top Five Legal Issues For The Cloud." Forbes. April 13, 2010. (Oct. 25, 2013) http://www.forbes.com/2010/04/12/cloud-computing-enterprise-technology-cio-network-legal.html
- Rackspace. "Pay-as-you-go pricing." (Nov. 4, 2013) http://www.rackspace.com/cloud/public-pricing/
- Rackspace. "Rackspace Cloud Servers." (Nov. 4, 2013) http://www.rackspace.com/cloud/servers/
- Rackspace Knowledge Center. "Understanding the Cloud Computing Stack: SaaS, PaaS, Iaas." Oct. 22, 2013. (Nov. 2, 2013) http://www.rackspace.com/knowledge_center/whitepaper/understanding-the-cloud-computing-stack-saas-paas-iaas
- RickG. "Database-as-a-Service and Platform-as-a-Service." Oracle. July 31, 2013. (Nov. 2, 2013) https://blogs.oracle.com/realworldcloudplatform/entry/database_as_a_service_and
- RickG. "Varieties of Cloud Computing." Oracle. July 22, 2013. (Oct. 25, 2013) https://blogs.oracle.com/realworldcloudplatform/entry/varieties_of_cloud_computing
- Roettgers, Janko. "AT&T's New Bandwidth Cap Is Bad News for Netflix." Gigaom. March 14, 2011. (Nov. 3, 2013) http://gigaom.com/2011/03/14/att-bandwidth-cap-netflix/
- Shontell, Alyson. "10 Things You Should Know About Tech But Were Too Afraid To Ask." Business Insider. Aug. 16, 2011. (Oct. 25, 2013) http://www.businessinsider.com/what-is-cloud-computing-9-basic-tech-questions-2011-8?op=1
- Spangler, Todd. "Sony 4K TV Internet Video Service Will Bump Into Bandwidth Caps." Variety. Sept. 4, 2013. (Nov. 4, 2013) http://variety.com/2013/digital/news/sony-4k-tv-internet-video-service-will-bump-into-bandwidth-caps-1200598969/
- Stone, Brad. "Another Amazon Outage Exposes the Cloud's Dark Lining." Bloomberg Businessweek. Aug. 26, 2013. (Oct. 26, 2013) http://www.businessweek.com/articles/2013-08-26/another-amazon-outage-exposes-the-clouds-dark-lining
- TestInternetSpeed.org. "What is a Bandwidth Cap?" Oct. 22, 2013. (Nov. 3, 2013) http://testinternetspeed.org/blog/what-is-a-bandwidth-cap/
- Verge, Jason. "Network Issues Cause Amazon Cloud Outage." Data Center Knowledge. Sept. 13, 2013. (Oct. 25, 2013) http://www.datacenterknowledge.com/archives/2013/09/13/network-issues-cause-amazon-cloud-outage/
- Verstraete, Christian. "Cloud computing: 1 concept, 3 types and 2 business models." HP Cloud Source Blog. May 9, 2012. (Nov. 4, 2013) http://h30507.www3.hp.com/t5/Cloud-Source-Blog/Cloud-computing-1-concept-3-types-and-2-business-models/ba-p/112787#.UnYUS5SjiQl
- Whittaker, Zack. "Amazon Web Services suffers outage, takes down Vine, Instagram, others with it." ZDNet. Aug. 26, 2013. (Oct. 26, 2013) http://www.zdnet.com/amazon-web-services-suffers-outage-takes-down-vine-instagram-flipboard-with-it-7000019842/
- Woods, Ben. "Virgin throttles broadband for high-speed customers." ZDNet. April 2, 2012. (Nov. 4, 2013) http://www.zdnet.com/virgin-throttles-broadband-for-high-speed-customers-3040154946/
Google is redesigning the way we use email. HowStuffWorks delves into the changes.