Thin client

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Layer architecture of client servers
A computer terminal in a public library

As a thin client , lean client or slim client ( english thinner, leaner and leaner client ) is usually a computer called that a network with a server is connected and uses its resources.

description

The idea of ​​the thin client comes from the field of terminals from the days of mainframes , where "stupid" terminals were used. These terminals were directly connected to the system. Thin clients are more intelligent and require an infrastructure (network cabling, network protocols, ...) so that they can connect to the server. Terminal software must run on the server, e.g. B. Terminal server from Microsoft , xendesktop from citrix or Virtual Desktop Infrastructure . The operating system of a thin client is reduced to the bare essentials, since the hardware only displays and passes on inputs. The operating system and the hardware allow the use of connected hardware e.g. B. a printer or the playback of audio or video data.

In special areas of industry, thin clients are used as "terminal extensions" or industrial monitors in order to reduce dangers in the IECEx area.

Manufacturer-dependent terms would be Cloud Client , Zero Client , Universal Desktop or Clever Client .

Demarcation

In contrast to the fat client ( english fat client ), including Full Client ( full-fledged client ) supported by its hardware and software is built so can process that he compute- and resource-intensive tasks.

Thin client operating systems

Typical thin client operating systems are based on Linux, Windows CE, Windows Embedded Standard (Win32) or Windows Embedded 7 and are protected against manipulation by users or viruses and the like by write filters. Most manufacturers have a management platform that enables the system configuration to be made available centrally, for example to configure device drivers, background images etc. and to install them if necessary.

Special devices that are intended for the operation of thin client applications are often referred to as thin clients. There is no clear definition for these thin clients. As a rule, this refers to desktop computers without their own mass storage device (hard drive, CD drives) that can be configured and managed using central management software.

Concept history

The term thin client comes from Sun Microsystems . The Sun Ray was called a thin client . Microsoft's RDP protocol is implemented on the Sun-Ray server and the finished screen content is sent to the Sun-Ray devices.

Manufacturers such as Hewlett-Packard and Wyse have made microcomputers that they have also referred to as thin clients . In this case, Microsoft's RDP protocol is converted into screen content on the devices from a graphic card. An operating system runs on these devices and thus these devices are normal computers, but without a hard drive. As a result, Sun Microsystems renamed the Sun Ray devices as ultra thin clients .

Thin client manufacturer

Hewlett-Packard Thin Client (Model T5700)

According to an IDC study from 2006, the global market for thin client workstation devices is dominated by Wyse Technology (acquired by Dell in 2012 ) and Hewlett-Packard . These two companies have a market share of over 70%. Other manufacturers of thin clients are Sun Microsystems , Igel Technology (market leader in Germany), ViewSonic , Chip PC, VXL Instruments, Hako Computing, Rangee, Devon IT, Athena or Statodesk (formerly LISCON), Fujitsu Technology Solutions , LuniLogic and others.

advantages

The biggest advantage of thin clients over fat clients is that they are easier to operate. Only the software that is required for access to centrally operated applications runs on the thin clients. This basic software can be operated uniformly independently of the applications that are actually used. One approach to this is to use configuration images which, after they have been created, are distributed to the thin clients to be configured. This also enables very simple management through centralized or decentralized control systems. In addition, because they do not have moving parts, thin clients are often less expensive. Added to this is the greatly reduced administrative effort, as an almost unlimited number of thin clients can be managed by simply assigning configurations. The fast connection and disconnection of applications for the end user leads to a clear service advantage, especially with distant clients and lengthy installations. As a rule, thin client models with around 10 to 20 watts require significantly less electrical power than standard desktop PCs, because the multi-core CPUs of the PCs alone are 40 to 120 watts without peripherals. Since less waste heat is generated than with standard desktop PCs, air conditioning systems in office buildings are generally less stressed, even if the higher expenditure or additional consumption of the corresponding server system has to be taken into account.

The average useful life of a thin client is seven years, a conventional desktop is used three to four years.

Thin clients always give a user the same access to their personal user interface, configuration, directories and installed programs, regardless of which physical thin client workstation they log on to. This means that there is no need to assign workplaces to users. A user can work at a different workplace every day without restrictions.

Framework contracts can be concluded with manufacturers of thin clients, these are then preconfigured, so that the thin client only has to be connected to a functioning network at the user.

disadvantage

Graphics-intensive applications cannot be executed sensibly with many server / client solutions if the network cannot process the amount of data quickly enough or if applications require accelerated graphics cards, which are rarely available on thin clients. Most applications are programmed for fat clients. The operation of applications on servers is often forbidden by license regulations and requires additional and usually costly permits from the software manufacturer, which are not always granted. Thin clients cannot be used without a network connection. They can therefore only be used to a limited extent by mobile users.

Due to new technologies on the server side and the increasingly better virtualization technology, however, it is foreseeable that the market share of thin clients will steadily increase. Ultimately, this is also favored by increasing cost pressure and increasingly complex work environments in companies. The thin client is therefore a real alternative to a normal PC in standardized work environments with a large number of workstations.

In addition, a thin client can usually hardly recognize peripheral devices; only a mouse, keyboard and monitor are accepted without any problems. In practice, a network printer is required in addition to the server.

Zero clients

For some time now, some manufacturers have been using the term zero client , but these devices can for the most part be assigned to the group of thin clients. The idea is primarily to give potential buyers a limited function (e.g. only one possible service such as Citrix XenDesktop, VMWare View or IBM Virtual Desktop for Smart Business) with a simple, primitive and more or less secure management (e.g. via DHCP options). The definition is flexible depending on the manufacturer. Despite the manufacturer's statements to the contrary, you can find firmware (Linux-based or completely separate OS), RAM and a CPU in almost every zero client. However, the firmware was limited to a minimal range of functions. Short boot times are achieved, among other things, by switching to suspend mode , giving the user the impression that it is a "zero client" with short start times.

See also

Web links

Commons : Thin Clients  - collection of images, videos and audio files

Individual evidence

  1. ↑ VersaView 5100 Industrial Monitors. Retrieved April 3, 2020 .
  2. ↑ R. STAHL | HMI | Thin clients. Retrieved April 3, 2020 .
  3. ↑ IECEx. Retrieved April 3, 2020 .
  4. ↑ Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT (Ed.): Ecological comparison of thin client workstation devices . 2008 ( PDF ( Memento of February 12, 2013 in the Internet Archive )).
  5. ↑ International Data Corporation (Ed.): IDC Enterprise Thin Client Q-View, Q4 2005 . 2006 ( PDF ( Memento from July 20, 2008 in the Internet Archive )). Note: In 2007, HP took over competitor Neoware
  6. ^ Euan Davis: Green Benefits Put Thin-Client Computing Back On The Desktop Hardware Agenda . Ed .: Forrester Research. 2008.