Distributed computing is a word from computer science, about using many computers to solve a big problem. One way to solve a big problem is to use a very fast computer called a supercomputer. Supercomputers are very expensive, and many scientists can not buy them. A cheaper way to solve a big problem is to split it into smaller problems, when possible. These smaller problems can then be solved by different computers (or processors), which talk to each other over a computer network. Because many computers work together, this makes them as powerful as a supercomputer. One example where distributed computing is used is the Great Internet Mersenne Prime Search.
Distributed computing
Classifications
Usually a distinction is made between
- Client-server system: Many clients access one or more servers.
- Distributed application: Programming the application creates the distributed system.
- Distributed operating system: The operating system itself is distributed, this is not visible to users and applications.
Reasons for the use of distributed systems
With distributed systems, true concurrency can be realized; that is, multiple processes can be genuinely executed simultaneously. In addition, a distributed system is also usually more scalable than a single computer, since you can easily increase performance by adding more machines.
A frequently encountered scenario is also the provision of remote resources, as is the case with Wikipedia. In addition, distributed systems are used to increase fail-safety by offering certain functionalities from several computers (redundancy), so that if one computer fails, the same functionality is offered by another computer.
In many cases, there are also economic reasons for networking inexpensive computers instead of purchasing an expensive supercomputer. This is exploited, for example, by volunteer computing projects such as SETI@home, which use idle computing power from stand-alone computers to solve complex problems. After one of the first and largest public volunteer distributed system projects SETI@home announced its end on March 31, 2020, and due to increased interest from the COVID-19 pandemic, the distributed system Folding@home will be the first computing system to achieve an exaFLOPS. The system simulated protein folding for research on COVID-19 and reached a speed of about 2.43 x86 exaFLOPS on April 13 - several times faster than the previous record holder, supercomputer Summit.
Other reasons:
- Remote access to certain resources (printer, ...)
- Cooperation (Computer Supported Cooperative Work)
- Load distribution