Distributed computing

Not to be confused with Decentralized computing.

Distributed computing is a field of computer science that studies distributed systems, defined as computer systems whose inter-communicating components are located on different networked computers.[1][2]

The components of a distributed system communicate and coordinate their actions by passing messages to one another in order to achieve a common goal. Three significant challenges of distributed systems are: maintaining concurrency of components, overcoming the lack of a global clock, and managing the independent failure of components.[1] When a component of one system fails, the entire system does not fail.[3] Examples of distributed systems vary from SOA-based systems to microservices to massively multiplayer online games to peer-to-peer applications. Distributed systems cost significantly more than monolithic architectures, primarily due to increased needs for additional hardware, servers, gateways, firewalls, new subnets, proxies, and so on.[4] Also, distributed systems are prone to fallacies of distributed computing. On the other hand, a well designed distributed system is more scalable, more durable, more changeable and more fine-tuned than a monolithic application deployed on a single machine.[5] According to Marc Brooker: "a system is scalable in the range where marginal cost of additional workload is nearly constant." Serverless technologies fit this definition but the total cost of ownership, and not just the infra cost must be considered.[6]

A computer program that runs within a distributed system is called a distributed program,[7] and distributed programming is the process of writing such programs.[8] There are many different types of implementations for the message passing mechanism, including pure HTTP, RPC-like connectors and message queues.[9]

Distributed computing also refers to the use of distributed systems to solve computational problems. In distributed computing, a problem is divided into many tasks, each of which is solved by one or more computers,[10] which communicate with each other via message passing.[11]

  1. ^ a b Tanenbaum, Andrew S.; Steen, Maarten van (2002). Distributed systems: principles and paradigms. Upper Saddle River, NJ: Pearson Prentice Hall. ISBN 0-13-088893-1. Archived from the original on 2020-08-12. Retrieved 2020-08-28.
  2. ^ "Distributed Programs". Texts in Computer Science. London: Springer London. 2010. pp. 373–406. doi:10.1007/978-1-84882-745-5_11. ISBN 978-1-84882-744-8. ISSN 1868-0941. Systems consist of a number of physically distributed components that work independently using their private storage, but also communicate from time to time by explicit message passing. Such systems are called distributed systems.
  3. ^ Dusseau & Dusseau 2016, p. 1–2.
  4. ^ Ford, Neal (March 3, 2020). Fundamentals of Software Architecture: An Engineering Approach (1st ed.). O'Reilly Media. pp. 146–147. ISBN 978-1492043454.
  5. ^ Monolith to Microservices Evolutionary Patterns to Transform Your Monolith. O'Reilly Media. ISBN 9781492047810.
  6. ^ Building Serverless Applications on Knative. O'Reilly Media. ISBN 9781098142049.
  7. ^ "Distributed Programs". Texts in Computer Science. London: Springer London. 2010. pp. 373–406. doi:10.1007/978-1-84882-745-5_11. ISBN 978-1-84882-744-8. ISSN 1868-0941. Distributed programs are abstract descriptions of distributed systems. A distributed program consists of a collection of processes that work concurrently and communicate by explicit message passing. Each process can access a set of variables which are disjoint from the variables that can be changed by any other process.
  8. ^ Andrews (2000). Dolev (2000). Ghosh (2007), p. 10.
  9. ^ Magnoni, L. (2015). "Modern Messaging for Distributed Sytems (sic)". Journal of Physics: Conference Series. 608 (1): 012038. doi:10.1088/1742-6596/608/1/012038. ISSN 1742-6596.
  10. ^ Godfrey (2002).
  11. ^ Andrews (2000), p. 291–292. Dolev (2000), p. 5.