Sql Server 2018
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The use of the word server in computing comes from queueing theory,[4] where it dates to the mid 20th century, being notably used in Kendall (1953) (along with "service"), the paper that introduced Kendall's notation. In earlier papers, such as the Erlang (1909), more concrete terms such as "[telephone] operators" are used.
In computing, "server" dates at least to RFC 5 (1969),[5] one of the earliest documents describing ARPANET (the predecessor of Internet), and is contrasted with "user", distinguishing two types of host: "server-host" and "user-host". The use of "serving" also dates to early documents, such as RFC 4,[6] contrasting "serving-host" with "using-host".
Strictly speaking, the term server refers to a computer program or process (running program). Through metonymy, it refers to a device used for (or a device dedicated to) running one or several server programs. On a network, such a device is called a host. In addition to server, the words serve and service (as verb and as noun respectively) are frequently used, though servicer and servant are not.[a] The word service (noun) may refer to the abstract form of functionality, e.g. Web service. Alternatively, it may refer to a computer program that turns a computer into a server, e.g. Windows service. Originally used as "servers serve users" (and "users use servers"), in the sense of "obey", today one often says that "servers serve data", in the same sense as "give". For instance, web servers "serve [up] web pages to users" or "service their requests".
The role of a server is to share data as well as to share resources and distribute work. A server computer can serve its own computer programs as well; depending on the scenario, this could be part of a quid pro quo transaction, or simply a technical possibility. The following table shows several scenarios in which a server is used.
The name server is used both for the hardware and software pieces. For the hardware servers, it is usually limited to mean the high-end machines although software servers can run on a variety of hardwares.
Since servers are usually accessed over a network, many run unattended without a computer monitor or input device, audio hardware and USB interfaces. Many servers do not have a graphical user interface (GUI). They are configured and managed remotely. Remote management can be conducted via various methods including Microsoft Management Console (MMC), PowerShell, SSH and browser-based out-of-band management systems such as Dell's iDRAC or HP's iLo.
Large traditional single servers would need to be run for long periods without interruption. Availability would have to be very high, making hardware reliability and durability extremely important. Mission-critical enterprise servers would be very fault tolerant and use specialized hardware with low failure rates in order to maximize uptime. Uninterruptible power supplies might be incorporated to guard against power failure. Servers typically include hardware redundancy such as dual power supplies, RAID disk systems, and ECC memory,[14] along with extensive pre-boot memory testing and verification. Critical components might be hot swappable, allowing technicians to replace them on the running server without shutting it down, and to guard against overheating, servers might have more powerful fans or use water cooling. They will often be able to be configured, powered up and down, or rebooted remotely, using out-of-band management, typically based on IPMI. Server casings are usually flat and wide, and designed to be rack-mounted, either on 19-inch racks or on Open Racks.
These types of servers are often housed in dedicated data centers. These will normally have very stable power and Internet and increased security. Noise is also less of a concern, but power consumption and heat output can be a serious issue. Server rooms are equipped with air conditioning devices.
A server farm or server cluster is a collection of computer servers maintained by an organization to supply server functionality far beyond the capability of a single device. Modern data centers are now often built of very large clusters of much simpler servers,[15] and there is a collaborative effort, Open Compute Project around this concept.
A mobile server has a portable form factor, e.g. a laptop.[16] In contrast to large data centers or rack servers, the mobile server is designed for on-the-road or ad hoc deployment into emergency, disaster or temporary environments where traditional servers are not feasible due to their power requirements, size, and deployment time.[17] The main beneficiaries of so-called "server on the go" technology include network managers, software or database developers, training centers, military personnel, law enforcement, forensics, emergency relief groups, and service organizations.[18] To facilitate portability, features such as the keyboard, display, battery (uninterruptible power supply, to provide power redundancy in case of failure), and mouse are all integrated into the chassis.
On the Internet, the dominant operating systems among servers are UNIX-like open-source distributions, such as those based on Linux and FreeBSD,[19] with Windows Server also having a significant share. Proprietary operating systems such as z/OS and macOS Server are also deployed, but in much smaller numbers. Servers that run Linux are commonly used as Webservers or Databanks. Windows Servers are used for Networks that are made out of Windows Clients.
In 2010, data centers (servers, cooling, and other electrical infrastructure) were responsible for 1.1-1.5% of electrical energy consumption worldwide and 1.7-2.2% in the United States.[21][needs update] One estimate is that total energy consumption for information and communications technology saves more than 5 times its carbon footprint[22] in the rest of the economy by increasing efficiency.
Global energy consumption is increasing due to the increasing demand of data and bandwidth. Natural Resources Defense Council (NRDC) states that data centers used 91 billion kilowatt hours (kWh) electrical energy in 2013 which accounts to 3% of global electricity usage.[needs update]
Ubuntu Server brings economic and technical scalability to your data centre, public or private cloud. Whether you want to deploy an OpenStack cloud, a Kubernetes cluster or a 50,000-node render farm, Ubuntu Server delivers the best value scale-out performance available.
It doesn't matter whether you want to deploy a NoSQL database, web farm or cloud. Certified by leading hardware OEMs and with comprehensive deployment tools, so you can get the most from your infrastructure.
Our regular release cycle means access to the latest and most performant open source. A lean initial installation along with integrated deployment and application modelling technologies make Ubuntu Server a great solution for simple deployment and management at scale.
Long-term support (LTS) releases of Ubuntu Server receive standard security updates for around 2,500 packages in the Ubuntu Main repository for five years by default. Every six months, interim releases bring new features, while hardware enablement updates add support for the latest machines to all supported LTS releases.
Ubuntu is the most popular guest operating system on public clouds, the foundation for private cloud implementation and the platform of choice of developers according to the 2020 HackerEarth Developer Survey.
With the option of a command line or browser-based interface, Juju enables you to design and deploy entire workloads in just a few clicks. It works on public clouds like AWS and Microsoft Azure, private clouds built on OpenStack and even directly on bare metal, via MAAS.
MAAS is a time-saving provisioning system that makes it quick and easy to set up the physical hardware to deploy complex services, like Ubuntu's OpenStack cloud infrastructure. Just plug in your servers, connect them to the network and let MAAS do the rest.
Ubuntu Pro offers a single, per-node packaging of the most comprehensive software, hardening and security in the industry. With the Base OS, OpenStack, Kubernetes and Applications security maintanance included, Ubuntu Pro delivers everything you need to future-proof your data centre.
Want to talk to other Ubuntu users straightaway? Share ideas and get advice and help from our large, active community of IT professionals. As a community, we set high standards for friendliness and tolerance, we welcome your questions and contributions!
The Apache HTTP Server Project is an effort to develop and maintain anopen-source HTTP server for modern operating systems including UNIX andWindows. The goal of this project is to provide a secure, efficient andextensible server that provides HTTP services in sync with the current HTTPstandards.
The Apache HTTP Server Project had long committed to provide maintenancereleases of the 2.2.x flavor through June of 2017. The final release 2.2.34was published in July 2017, and no further evaluation of bug reports orsecurity risks will be considered or published for 2.2.x releases.
A server is a computer program or device that provides a service to another computer program and its user, also known as the client. In a data center, the physical computer that a server program runs on is also frequently referred to as a server. That machine might be a dedicated server or it might be used for other purposes.
In the client/server programming model, a server program awaits and fulfills requests from client programs, which might be running in the same, or other computers. A given application in a computer might function as a client with requests for services from other programs and as a server of requests from other programs.
The term server can refer to a physical machine, a virtual machine or to software that is performing server services. The way that a server works varies considerably depending on how the word server is being used.
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