Google дерек орталықтарының құрылысы мен жұмыс принципі

Facilities containing Google servers

Google data centers are the large data center facilities Google uses to provide their services, which combine large drives, computer nodes organized in aisles of racks, internal and external networking, environmental controls (mainly cooling and humidification control), and operations software (especially as concerns load balancing and fault tolerance). There is no official data on how many servers 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 changing as the company expands capacity and refreshes its hardware.

As of 2014, Google has used a heavily customized version of Debian Linux. They migrated from a Red Hat based system incrementally in 2013. 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 The servers were open top so more servers could fit into a rack. According to CNET and 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. In order to run such a large network, with direct connections to as many ISPs as possible at the lowest possible cost, Google has a very open peering policy. 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). These custom switch routers are connected to DWDM devices to interconnect data centers and point of presences (PoP) via dark fiber. 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.

To support fault tolerance, increase the scale of data centers and accommodate low radix switches, Google has adopted various modified Clos topologies in the past.

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 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." Google halted work on the barges in late 2013 and began selling off the barges in 2014.

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. 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.

In October 2013, The Washington Post reported that the U. S. National Security Agency intercepted communications between Google's data centers, as part of a program named MUSCULAR. This wiretapping was made possible because, at the time, Google did not encrypt data passed inside its own network. This was rectified when Google began encrypting data sent between data centers in 2013.

Google's most efficient data center runs at using only fresh air cooling, requiring no electrically powered air conditioning. In December 2016, Google announced that—starting in 2017—it would purchase enough renewable energy to match 100% of the energy usage of its data centers and offices. The commitment will make Google "the world's largest corporate buyer of renewable power, with commitments reaching 2.6 gigawatts (2,600 megawatts) of wind and solar energy".