Google data centers are the large data center facilities Google uses to provide their services, which combine large amounts of digital storage (mainly hard drives and solid-state drives), compute nodes organized in aisles of racks, internal and external networking, environmental controls (mainly cooling and dehumidification), and operations software (especially as concerns load balancing and fault tolerance). This article describes the technological infrastructure behind Google's websites as presented in the company's public announcements.
There’s no official data on how many servers there are in Google data centers, but Gartner estimated in a July 2016 report that Google at the time had 2.5 million servers. This number is always changing as the company expands capacity and refreshes its hardware.
The locations of Google's various data centers are as follows:
The customization goal is to purchase CPU generations that offer the best performance per dollar, not absolute performance. How this is measured is unclear, but it is likely to incorporate running costs of the entire server, and CPU power consumption could be a significant factor. Servers as of 2009–2010 consisted of custom-made open-top systems containing two processors (each with several cores), a considerable amount of RAM spread over 8 DIMM slots housing double-height DIMMs, and at least two SATA hard disk drives connected through a non-standard ATX-sized power supply unit. The servers were open top so more servers could be fit into a rack. According to CNET and to a book by John Hennessy, each server had a novel 12-volt battery to reduce costs and improve power efficiency.
According to Google their global data center operation electrical power ranges between 500 and 681 megawatts. The combined processing power of these servers might have reached from 20 to 100 petaflops in 2008.
Details of the Google worldwide private networks are not publicly available, but Google publications make references to the "Atlas Top 10" report that ranks Google as the third largest ISP behind Level 3.
From this site, we can see that the Google network can be accessed from 67 public exchange points and 69 different locations across the world. As of May 2012, Google had 882 Gbit/s of public connectivity (not counting private peering agreements that Google has with the largest ISPs). This public network is used to distribute content to Google users as well as to crawl the Internet to build its search indexes.
The private side of the network is a secret, but a recent disclosure from Google indicate that they use custom built high-radix switch-routers (with a capacity of 128 × 10 Gigabit Ethernet port) for the wide area network. Running no less than two routers per datacenter (for redundancy) we can conclude that the Google network scales in the terabit per second range (with two fully loaded routers the bi-sectional bandwidth amount to 1,280 Gbit/s).
From a datacenter view, the network starts at the rack level, where 19-inch racks are custom-made and contain 40 to 80 servers (20 to 40 1U servers on either side, while new servers are 2U rackmount systems. Each rack has an Ethernet switch). Servers are connected via a 1 Gbit/s Ethernet link to the top of rack switch (TOR). TOR switches are then connected to a gigabit cluster switch using multiple gigabit or ten gigabit uplinks. The cluster switches themselves are interconnected and form the datacenter interconnect fabric (most likely using a dragonfly design rather than a classic butterfly or flattened butterfly layout).
From an operation standpoint, when a client computer attempts to connect to Google, several DNS servers resolve www.google.com into multiple IP addresses via Round Robin policy. Furthermore, this acts as the first level of load balancing and directs the client to different Google clusters. A Google cluster has thousands of servers, and once the client has connected to the server additional load balancing is done to send the queries to the least loaded web server. This makes Google one of the largest and most complex content delivery networks.
Google has numerous data centers scattered around the world. At least 12 significant Google data center installations are located in the United States. The largest known centers are located in The Dalles, Oregon; Atlanta, Georgia; Reston, Virginia; Lenoir, North Carolina; and Moncks Corner, South Carolina. In Europe, the largest known centers are in Eemshaven and Groningen in the Netherlands and Mons, Belgium. Google's Oceania Data Center is claimed to be located in Sydney, Australia. 
One of the largest Google data centers is located in the town of The Dalles, Oregon, on the Columbia River, approximately 80 miles (129 km) from Portland. Codenamed "Project 02", the $600 million complex was built in 2006 and is approximately the size of two American football fields, with cooling towers four stories high. The site was chosen to take advantage of inexpensive hydroelectric power, and to tap into the region's large surplus of fiber optic cable, a remnant of the dot-com boom. A blueprint of the site appeared in 2008.
In February 2009, Stora Enso announced that they had sold the Summa paper mill in Hamina, Finland to Google for 40 million Euros. Google invested 200 million euros on the site to build a data center and announced additional 150 million euro investment in 2012. Google chose this location due to the availability and proximity of renewable energy sources.
In 2013, the press revealed the existence of Google's floating data centers along the coasts of the states of California (Treasure Island's Building 3) and Maine. The development project was maintained under tight secrecy. The data centers are 250 feet long, 72 feet wide, 16 feet deep. The patent for an in-ocean data center cooling technology was bought by Google in 2009  (along with a wave-powered ship-based data center patent in 2008). Shortly thereafter, Google declared that the two massive and secretly-built infrastructures were merely «interactive learning centers, [...] a space where people can learn about new technology».
Most of the software stack that Google uses on their servers was developed in-house. According to a well-known Google employee, C++, Java, Python and (more recently) Go are favored over other programming languages. For example, the back end of Gmail is written in Java and the back end of Google Search is written in C++. Google has acknowledged that Python has played an important role from the beginning, and that it continues to do so as the system grows and evolves.
The software that runs the Google infrastructure includes:
Google has developed several abstractions which it uses for storing most of its data:
Most operations are read-only. When an update is required, queries are redirected to other servers, so as to simplify consistency issues. Queries are divided into sub-queries, where those sub-queries may be sent to different ducts in parallel, thus reducing the latency time.
Like most search engines, Google indexes documents by building a data structure known as inverted index. Such an index obtains a list of documents by a query word. The index is very large due to the number of documents stored in the servers.
The index is partitioned by document IDs into many pieces called shards. Each shard is replicated onto multiple servers. Initially, the index was being served from hard disk drives, as is done in traditional information retrieval (IR) systems. Google dealt with the increasing query volume by increasing number of replicas of each shard and thus increasing number of servers. Soon they found that they had enough servers to keep a copy of the whole index in main memory (although with low replication or no replication at all), and in early 2001 Google switched to an in-memory index system. This switch "radically changed many design parameters" of their search system, and allowed for a significant increase in throughput and a large decrease in latency of queries.
In June 2010, Google rolled out a next-generation indexing and serving system called "Caffeine" which can continuously crawl and update the search index. Previously, Google updated its search index in batches using a series of MapReduce jobs. The index was separated into several layers, some of which were updated faster than the others, and the main layer wouldn't be updated for as long as two weeks. With Caffeine the entire index is updated incrementally on a continuous basis. Later Google revealed a distributed data processing system called "Percolator" which is said to be the basis of Caffeine indexing system.
Close Coupled Cooling is a last generation cooling system particularly used in data centers. The goal of close coupled cooling is to bring heat transfer closest to its source: the equipment rack. By moving the air conditioner closer to the equipment rack a more precise delivery of inlet air and a more immediate capture of exhaust air is ensured.Council Bluffs, Iowa
Council Bluffs is a city in and the county seat of Pottawattamie County, Iowa, United States. The city is the most populous in Southwest Iowa, and forms part of the Omaha (Nebr.) Metropolitan Area. It is located on the east bank of the Missouri River, across from the city of Omaha. Council Bluffs was known, until at least 1853, as Kanesville. It was the historic starting point of the Mormon Trail. Kanesville is also the northernmost anchor town of the other emigrant trails, since there was a steam powered boat to ferry their wagons, and cattle, across the Missouri River.Council Bluffs' population was 62,230 at the 2010 census. The Omaha metropolitan region, of which Council Bluffs is a part, is the 59th largest in the United States, with an estimated population of 933,316 (2017).While Council Bluffs is more than a decade older than Omaha, the latter has grown to be a significantly larger city and the anchor of the bi-state metropolitan region.Data center
A data center (American English) or data centre (British English) is a building, dedicated space within a building, or a group of buildings used to house computer systems and associated components, such as telecommunications and storage systems.
Since IT operations are crucial for business continuity, it generally includes redundant or backup components and infrastructure for power supply, data communications connections, environmental controls (e.g. air conditioning, fire suppression) and various security devices. A large data center is an industrial-scale operation using as much electricity as a small town.Edward Snowden
Edward Joseph Snowden (born June 21, 1983) is an American fugitive, a former Central Intelligence Agency (CIA) employee, and former contractor for the United States government who copied and leaked highly classified information from the National Security Agency (NSA) in 2013. His disclosures revealed numerous global surveillance programs, many run by the NSA and the Five Eyes Intelligence Alliance with the cooperation of telecommunication companies and European governments.
In 2013, Snowden was hired by an NSA contractor, Booz Allen Hamilton, after previous employment with Dell and the CIA. On May 20, 2013, Snowden flew to Hong Kong after leaving his job at an NSA facility in Hawaii, and in early June he revealed thousands of classified NSA documents to journalists Glenn Greenwald, Laura Poitras, and Ewen MacAskill. Snowden came to international attention after stories based on the material appeared in The Guardian and The Washington Post. Further disclosures were made by other publications including Der Spiegel and The New York Times.
On June 21, 2013, the U.S. Department of Justice unsealed charges against Snowden of two counts of violating the Espionage Act of 1917 and theft of government property, following which the Department of State revoked his passport. Two days later, he flew into Moscow's Sheremetyevo Airport, but Russian authorities noted that his U.S. passport had been cancelled, and he was restricted to the airport terminal for over one month. Russia ultimately recognized his right of asylum, with a visa for residence for one year. Repeated extensions have permitted him to stay at least until 2020. In early 2016, he became the president of the Freedom of the Press Foundation, an organization that aims to protect journalists from hacking and government surveillance. As of 2017, he was living in an undisclosed location in Moscow.Five Eyes
The Five Eyes, often abbreviated as FVEY, is an anglophone intelligence alliance comprising Australia, Canada, New Zealand, the United Kingdom and the United States. These countries are parties to the multilateral UKUSA Agreement, a treaty for joint cooperation in signals intelligence.The origins of the FVEY can be traced back to the post–World War II period, when the Atlantic Charter was issued by the Allies to lay out their goals for a post-war world. During the course of the Cold War, the ECHELON surveillance system was initially developed by the FVEY to monitor the communications of the former Soviet Union and the Eastern Bloc, although it is now used to monitor billions of private communications worldwide.In the late 1990s, the existence of ECHELON was disclosed to the public, triggering a major debate in the European Parliament and, to a lesser extent, the United States Congress. As part of efforts in the ongoing War on Terror since 2001, the FVEY further expanded their surveillance capabilities, with much emphasis placed on monitoring the World Wide Web. The former NSA contractor Edward Snowden described the Five Eyes as a "supra-national intelligence organisation that does not answer to the known laws of its own countries". Documents leaked by Snowden in 2013 revealed that the FVEY have been spying on one another's citizens and sharing the collected information with each other in order to circumvent restrictive domestic regulations on surveillance of citizens.In spite of continued controversy over its methods, the Five Eyes relationship remains one of the most comprehensive known espionage alliances in history.
Since processed intelligence is gathered from multiple sources, the intelligence shared is not restricted to signals intelligence (SIGINT) and often involves defence intelligence as well as human intelligence (HUMINT) and geospatial intelligence (GEOINT). The following table provides an overview of most of the FVEY agencies involved in such forms of data sharing.Fourth Amendment Protection Act
The Fourth Amendment Protection Acts, are a collection of state legislation aimed at withdrawing state support for bulk data (metadata) collection and ban the use of warrant-less data in state courts. They are proposed nullification laws that, if enacted as law, would prohibit the state governments from co-operating with the National Security Agency, whose mass surveillance efforts are seen as unconstitutional by the proposals' proponents. Specific examples include the Kansas Fourth Amendment Preservation and Protection Act and the Arizona Fourth Amendment Protection Act. The original proposals were made in 2013 and 2014 by legislators in the American states of Utah, Washington, Arizona, Kansas, Missouri, Oklahoma and California. Some of the bills would require a warrant before information could be released, whereas others would forbid state universities from doing NSA research or hosting NSA recruiters, or prevent the provision of services such as water to NSA facilities. The bills are based on a model act provided by the Tenth Amendment Center and Offnow.Global surveillance
Global surveillance refers to the mass surveillance of entire populations across national borders. Its roots can be traced back to the middle of the 20th century when the UKUSA Agreement was jointly enacted by the United Kingdom and the United States, which later expanded to Canada, Australia, and New Zealand to create the present Five Eyes alliance. The alliance developed cooperation arrangements with several "third-party" nations. Eventually, this resulted in the establishment of a global surveillance network, code-named "ECHELON" (1971).Its existence, however, was not widely acknowledged by governments and the mainstream media until the global surveillance disclosures by Edward Snowden triggered a debate about the right to privacy in the Digital Age.Global surveillance disclosures (2013–present)
Ongoing news reports in the international media have revealed operational details about the United States National Security Agency (NSA) and its international partners' global surveillance of both foreign nationals and U.S. citizens. The reports mostly emanate from a cache of top secret documents leaked by ex-NSA contractor Edward Snowden, which he obtained whilst working for Booz Allen Hamilton, one of the largest contractors for defense and intelligence in the United States. In addition to a trove of U.S. federal documents, Snowden's cache reportedly contains thousands of Australian, British and Canadian intelligence files that he had accessed via the exclusive "Five Eyes" network. In June 2013, the first of Snowden's documents were published simultaneously by The Washington Post and The Guardian, attracting considerable public attention. The disclosure continued throughout 2013, and a small portion of the estimated full cache of documents was later published by other media outlets worldwide, most notably The New York Times (United States), the Canadian Broadcasting Corporation, the Australian Broadcasting Corporation, Der Spiegel (Germany), O Globo (Brazil), Le Monde (France), L'espresso (Italy), NRC Handelsblad (the Netherlands), Dagbladet (Norway), El País (Spain), and Sveriges Television (Sweden).These media reports have shed light on the implications of several secret treaties signed by members of the UKUSA community in their efforts to implement global surveillance. For example, Der Spiegel revealed how the German Foreign Intelligence Service (German: Bundesnachrichtendienst; BND) transfers "massive amounts of intercepted data to the NSA", while Swedish Television revealed the National Defence Radio Establishment (FRA) provided the NSA with data from its cable collection, under a secret treaty signed in 1954 for bilateral cooperation on surveillance. Other security and intelligence agencies involved in the practice of global surveillance include those in Australia (ASD), Britain (GCHQ), Canada (CSEC), Denmark (PET), France (DGSE), Germany (BND), Italy (AISE), the Netherlands (AIVD), Norway (NIS), Spain (CNI), Switzerland (NDB), Singapore (SID) as well as Israel (ISNU), which receives raw, unfiltered data of U.S. citizens that is shared by the NSA.On June 14, 2013, United States prosecutors charged Edward Snowden with espionage and theft of government property. In late July 2013, he was granted a one-year temporary asylum by the Russian government, contributing to a deterioration of Russia–United States relations. On August 6, 2013, U.S. President Barack Obama made a public appearance on national television where he told Americans that "We don't have a domestic spying program" and that "There is no spying on Americans". Towards the end of October 2013, the British Prime Minister David Cameron warned The Guardian not to publish any more leaks, or it will receive a DA-Notice. In November 2013, a criminal investigation of the disclosure was being undertaken by Britain's Metropolitan Police Service. In December 2013, The Guardian editor Alan Rusbridger said: "We have published I think 26 documents so far out of the 58,000 we've seen."The extent to which the media reports have responsibly informed the public is disputed. In January 2014, Obama said that "the sensational way in which these disclosures have come out has often shed more heat than light" and critics such as Sean Wilentz have noted that many of the Snowden documents released do not concern domestic surveillance. The US & UK Defense establishment weigh the strategic harm in the period following the disclosures more heavily than their civic public benefit. In its first assessment of these disclosures, the Pentagon concluded that Snowden committed the biggest "theft" of U.S. secrets in the history of the United States. Sir David Omand, a former director of GCHQ, described Snowden's disclosure as the "most catastrophic loss to British intelligence ever".Google
Google LLC is an American multinational technology company that specializes in Internet-related services and products, which include online advertising technologies, search engine, cloud computing, software, and hardware. It is considered one of the Big Four technology companies, alongside Amazon, Apple and Facebook.Google was founded in 1998 by Larry Page and Sergey Brin while they were Ph.D. students at Stanford University in California. Together they own about 14 percent of its shares and control 56 percent of the stockholder voting power through supervoting stock. They incorporated Google as a privately held company on September 4, 1998. An initial public offering (IPO) took place on August 19, 2004, and Google moved to its headquarters in Mountain View, California, nicknamed the Googleplex. In August 2015, Google announced plans to reorganize its various interests as a conglomerate called Alphabet Inc. Google is Alphabet's leading subsidiary and will continue to be the umbrella company for Alphabet's Internet interests. Sundar Pichai was appointed CEO of Google, replacing Larry Page who became the CEO of Alphabet.
The company's rapid growth since incorporation has triggered a chain of products, acquisitions, and partnerships beyond Google's core search engine (Google Search). It offers services designed for work and productivity (Google Docs, Google Sheets, and Google Slides), email (Gmail/Inbox), scheduling and time management (Google Calendar), cloud storage (Google Drive), social networking (Google+), instant messaging and video chat (Google Allo, Duo, Hangouts), language translation (Google Translate), mapping and navigation (Google Maps, Waze, Google Earth, Street View), video sharing (YouTube), note-taking (Google Keep), and photo organizing and editing (Google Photos). The company leads the development of the Android mobile operating system, the Google Chrome web browser, and Chrome OS, a lightweight operating system based on the Chrome browser. Google has moved increasingly into hardware; from 2010 to 2015, it partnered with major electronics manufacturers in the production of its Nexus devices, and it released multiple hardware products in October 2016, including the Google Pixel smartphone, Google Home smart speaker, Google Wifi mesh wireless router, and Google Daydream virtual reality headset. Google has also experimented with becoming an Internet carrier (Google Fiber, Project Fi, and Google Station).Google.com is the most visited website in the world. Several other Google services also figure in the top 100 most visited websites, including YouTube and Blogger. Google is the most valuable brand in the world as of 2017, but has received significant criticism involving issues such as privacy concerns, tax avoidance, antitrust, censorship, and search neutrality. Google's mission statement is "to organize the world's information and make it universally accessible and useful", and its unofficial slogan was "Don't be evil" until the phrase was removed from the company's code of conduct around May 2018.Hamina
Hamina (Finnish pronunciation: [ˈhɑminɑ]; Swedish: Fredrikshamn, [freːdrɪksˈhamːn]) is a town and a municipality of Finland. It is located approximately 145 km (90 mi) east of the country's capital Helsinki, in the Kymenlaakso region, and formerly the province of Southern Finland. The municipality's population is 20,280 (31 January 2019) and covers an area of 1,155.14 square kilometres (446.00 sq mi), of which 545.66 km2 (210.68 sq mi)
is water. The population density is
33.27 inhabitants per square kilometre (86.2/sq mi). The population of the central town is approximately 10,000. Hamina is unilingually Finnish speaking.
Valtatie 7 is the town's road connection to Helsinki, after it was upgraded to a continuous motorway in September 2014. Hamina is also one of the most important harbors of Finland. The port specializes in forest products and transit cargo to Russia. One of Google's three European data centers is situated in Hamina.Hyperscale computing
In computing, hyperscale is the ability of an architecture to scale appropriately as increased demand is added to the system. This typically involves the ability to seamlessly provision and add compute, memory, networking, and storage resources to a given node or set of nodes that make up a larger computing, distributed computing, or grid computing environment. Hyperscale computing is necessary in order to build a robust and scalable cloud, big data, map reduce, or distributed storage system and is often associated with the infrastructure required to run large distributed sites such as Facebook, Google, Microsoft, Amazon, or Oracle. Companies like Ericsson, Advanced Micro Devices and Intel provide hyperscale infrastructure kits for IT service providers.MUSCULAR (surveillance program)
MUSCULAR (DS-200B), located in the United Kingdom, is the name of a surveillance program jointly operated by Britain's Government Communications Headquarters (GCHQ) and the U.S. National Security Agency (NSA) that was revealed by documents released by Edward Snowden and interviews with knowledgeable officials. GCHQ is the primary operator of the program. GCHQ and the NSA have secretly broken into the main communications links that connect the data centers of Yahoo! and Google. Substantive information about the program was made public at the end of October 2013.Mechanical, electrical, and plumbing
Mechanical, electrical and plumbing (MEP) refers to these aspects of building design and construction. In commercial buildings, these elements are often designed by a specialized engineering firm. MEP design is important for planning, decision making, accurate documentation, performance- and cost-estimation, construction, and operating/maintaining the resulting facilities.
MEP specifically encompasses the in-depth design and selection of these systems, as opposed to a tradesperson simply installing equipment. For example, a plumber may select and install a commercial hot water system based on common practice and regulatory codes. A team of MEP engineers will research the best design according to the principles of engineering, and supply installers with the specifications they develop. As a result, engineers working in the MEP field must understand a broad range of disciplines, including dynamics, mechanics, fluids, thermodynamics, heat transfer, chemistry, electricity, and computers.PRISM (surveillance program)
PRISM is a code name for a program under which the United States National Security Agency (NSA) collects internet communications from various U.S. internet companies. The program is also known by the SIGAD US-984XN. PRISM collects stored internet communications based on demands made to internet companies such as Google LLC under Section 702 of the FISA Amendments Act of 2008 to turn over any data that match court-approved search terms. The NSA can use these PRISM requests to target communications that were encrypted when they traveled across the internet backbone, to focus on stored data that telecommunication filtering systems discarded earlier, and to get data that is easier to handle, among other things.PRISM began in 2007 in the wake of the passage of the Protect America Act under the Bush Administration. The program is operated under the supervision of the U.S. Foreign Intelligence Surveillance Court (FISA Court, or FISC) pursuant to the Foreign Intelligence Surveillance Act (FISA). Its existence was leaked six years later by NSA contractor Edward Snowden, who warned that the extent of mass data collection was far greater than the public knew and included what he characterized as "dangerous" and "criminal" activities. The disclosures were published by The Guardian and The Washington Post on June 6, 2013. Subsequent documents have demonstrated a financial arrangement between the NSA's Special Source Operations division (SSO) and PRISM partners in the millions of dollars.Documents indicate that PRISM is "the number one source of raw intelligence used for NSA analytic reports", and it accounts for 91% of the NSA's internet traffic acquired under FISA section 702 authority." The leaked information came to light one day after the revelation that the FISA Court had been ordering a subsidiary of telecommunications company Verizon Communications to turn over to the NSA logs tracking all of its customers' telephone calls.U.S. government officials have disputed some aspects of the Guardian and Washington Post stories and have defended the program by asserting it cannot be used on domestic targets without a warrant, that it has helped to prevent acts of terrorism, and that it receives independent oversight from the federal government's executive, judicial and legislative branches. On June 19, 2013, U.S. President Barack Obama, during a visit to Germany, stated that the NSA's data gathering practices constitute "a circumscribed, narrow system directed at us being able to protect our people."The Dalles, Oregon
The Dalles is the county seat and largest city of Wasco County, Oregon, United States. The population was 13,620 at the 2010 census, and is the largest city on the Oregon side along the Columbia River outside the Portland Metropolitan area.Timeline of global surveillance disclosures (2013–present)
This timeline of global surveillance disclosures from 2013 to the present day is a chronological list of the global surveillance disclosures that began in 2013. The disclosures have been largely instigated by revelations from the former American National Security Agency contractor Edward Snowden.Yahoo!
Yahoo! is a web services provider headquartered in Sunnyvale, California and owned by Verizon Media. The original Yahoo! company was founded by Jerry Yang and David Filo in January 1994 and was incorporated on March 2, 1995. Yahoo was one of the pioneers of the early Internet era in the 1990s.It provides or provided a Web portal, search engine Yahoo! Search, and related services, including Yahoo! Directory, Yahoo! Mail, Yahoo! News, Yahoo! Finance, Yahoo! Groups, Yahoo! Answers, advertising, online mapping, video sharing, fantasy sports, and its social media website. At its height it was one of the most popular sites in the United States. According to third-party web analytics providers Alexa and SimilarWeb, Yahoo! was the most widely read news and media website – with over 7 billion views per month – ranking as the sixth-most-visited website globally in 2016.Once one of the largest internet companies, Yahoo! slowly declined starting in the late 2000s, and in 2017 Verizon Communications acquired most of Yahoo's Internet business for $4.48 billion, excluding its stakes in Alibaba Group and Yahoo! Japan, which were transferred to Yahoo's successor company Altaba. Despite its decline from prominence, Yahoo! domain websites are still one of the most popular, ranking 8th in the world according to the Alexa rankings as of January 2019.Zettabyte Era
The Zettabyte Era is a period of human and computer science history that started in one of two ways: the global IP traffic first exceeded that of one zettabyte, which happened in 2016; or the amount of digital data in the world first exceeded a zettabyte, which happened in 2012. A zettabyte is a multiple of the unit byte that measures digital storage, and it is equivalent to 1,000,000,000,000,000,000,000  bytes.According to Cisco Systems, an American multinational technology conglomerate, the global IP traffic achieved an estimated 1.2 zettabytes (or an average of 96 exabytes (EB) per month) in 2016. Global IP traffic refers to all digital data that passes over an IP network which includes, but is not limited to, the public Internet. The largest contributing factor to the growth of IP traffic comes from video traffic (including online streaming services like Netflix and YouTube).The Zettabyte Era can also be understood as an age of growth of all forms of digital data that exist in the world which includes the public Internet, but also all other forms of digital data such as stored data from security cameras or voice data from cell-phone calls. Taking into account this second definition of the Zettabyte Era, it was estimated that in 2012 upwards of 1 zettabyte of data existed in the world and that by 2020 there would be more than 40 zettabytes of data in the world at large.The Zettabyte Era translates to difficulties for data centers to keep up with the explosion of data consumption, creation and replication. In 2015, 2% of total global power was taken up by the Internet and all its components, so energy efficiency with regards to data centers has become a central problem in the Zettabyte Era.