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Fallacies Of Distributed Computing
The fallacies of distributed computing are a set of assertions made by L Peter Deutsch and others at Sun Microsystems describing false assumptions that programmers new to distributed applications invariably make. The fallacies The originally listed fallacies are # The network is reliable; # Latency is zero; # Bandwidth is infinite; # The network is secure; # Topology doesn't change; # There is one administrator; # Transport cost is zero; # The network is homogeneous; The effects of the fallacies # Software applications are written with little error-handling on networking errors. During a network outage, such applications may stall or infinitely wait for an answer packet, permanently consuming memory or other resources. When the failed network becomes available, those applications may also fail to retry any stalled operations or require a (manual) restart. # Ignorance of network latency, and of the packet loss it can cause, induces application- and transport-layer developer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L Peter Deutsch
L Peter Deutsch (born Laurence Peter Deutsch on August 7, 1946, in Boston, Massachusetts) is an American computer scientist and composer. He is the founder of Aladdin Enterprises and creator of Ghostscript, a free software PostScript and PDF interpreter. Deutsch's other work includes the Smalltalk implementation that inspired Java just-in-time compilation technology about 15 years later. Name Deutsch changed his legal first name from "Laurence" to "L" on September 12, 2007. His published work and other public references before that time generally use the name ''L. Peter Deutsch'' (with a dot after the ''L''). Early life Deutsch's father was the physicist Martin Deutsch, a professor at MIT. Contributions to computer science Deutsch wrote the PDP-1 Lisp 1.5 implementation and first REPL, Basic PDP-1 LISP, "while still in short pants" and finished it in 1963, when he was 17 years old. He collaborated with Calvin Mooers on the TRAC programming language and wrote its first impl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Topology
Network topology is the arrangement of the elements (Data link, links, Node (networking), nodes, etc.) of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and control radio networks, industrial Fieldbus, fieldbusses and computer networks. Network topology is the topological structure of a network and may be depicted physically or logically. It is an application of graph theory wherein communicating devices are modeled as nodes and the connections between the devices are modeled as links or lines between the nodes. Physical topology is the placement of the various components of a network (e.g., device location and cable installation), while logical topology illustrates how data flows within a network. Distances between nodes, physical interconnections, transmission rates, or signal types may differ between two different networks, yet their logical topologies may be identica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ResearchGate
ResearchGate is a European commercial social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a 2014 study by ''Nature'' and a 2016 article in ''Times Higher Education'', it is the largest academic social network in terms of active users, although other services have more registered users, and a 2015–2016 survey suggests that almost as many academics have Google Scholar profiles. While reading articles does not require registration, people who wish to become site members need to have an email address at a recognized institution or to be manually confirmed as a published researcher in order to sign up for an account. Articles are free to read by visitors, however additional features (such as job postings or advertisements) are accessible only as a paid subscription. Members of the site each have a user profile and can upload research output including papers, data, chapters, negative results, patents, r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microservices
In software engineering, a microservice architecture is an architectural pattern that organizes an application into a collection of loosely coupled, fine-grained services that communicate through lightweight protocols. This pattern is characterized by the ability to develop and deploy services independently, improving modularity, scalability, and adaptability. However, it introduces additional complexity, particularly in managing distributed systems and inter-service communication, making the initial implementation more challenging compared to a monolithic architecture. Definition There is no single, universally agreed-upon definition of microservices. However, they are generally characterized by a focus on modularity, with each service designed around a specific business capability. These services are loosely coupled, independently deployable, and often developed and scaled separately, enabling greater flexibility and agility in managing complex systems. Microservices architec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PACELC Design Principle
In database theory, the PACELC design principle is an extension to the CAP theorem. It states that in case of network partitioning (P) in a distributed computer system, one has to choose between availability (A) and consistency (C) (as per the CAP theorem), but else (E), even when the system is running normally in the absence of partitions, one has to choose between latency (L) and loss of consistency (C). Overview The CAP theorem can be phrased as "PAC", the impossibility theorem that no distributed data store can be both consistent and available in executions that contains partitions. This can be proved by examining latency: if a system ensures consistency, then operation latencies grow with message delays, and hence operations cannot terminate eventually if the network is partitioned, i.e. the system cannot ensure availability. In the absence of partitions, both consistency and availability can be satisfied. PACELC therefore goes further and examines how the system replicates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CAP Theorem
In database theory, the CAP theorem, also named Brewer's theorem after computer scientist Eric Brewer (scientist), Eric Brewer, states that any distributed data store can provide at most Inconsistent triad, two of the following three guarantees: ; Consistency model, Consistency: Every read receives the most recent write or an error. Note that consistency as defined in the CAP theorem is quite different from the consistency guaranteed in ACID database transactions. ; Availability: Every request received by a non-failing node in the system must result in a response. This is the definition of availability in CAP theorem as defined by Gilbert and Lynch. Note that availability as defined in CAP theorem is different from high availability in software architecture. ; Network partitioning, Partition tolerance: The system continues to operate despite an arbitrary number of messages being dropped (or delayed) by the network between nodes. When a network partition failure happens, it must be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java (programming Language)
Java is a High-level programming language, high-level, General-purpose programming language, general-purpose, Memory safety, memory-safe, object-oriented programming, object-oriented programming language. It is intended to let programmers ''write once, run anywhere'' (Write once, run anywhere, WORA), meaning that compiler, compiled Java code can run on all platforms that support Java without the need to recompile. Java applications are typically compiled to Java bytecode, bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax (programming languages), syntax of Java is similar to C (programming language), C and C++, but has fewer low-level programming language, low-level facilities than either of them. The Java runtime provides dynamic capabilities (such as Reflective programming, reflection and runtime code modification) that are typically not available in traditional compiled languages. Java gained popularity sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Gosling
James Arthur Gosling (born 19 May 1955) is a Canadian computer scientist, best known as the founder and lead designer behind the Java (programming language), Java programming language. Gosling was elected a member of the National Academy of Engineering in 2004 for the conception and development of the architecture for the Java programming language and for contributions to windowing systems. Early life Gosling was born in Calgary, Calgary, Alberta, to Joyce Morrison and Dave Gosling. He is of English, Welsh, Scottish, and Icelandic descent. Gosling attended William Aberhart High School. While in high school, he wrote some of the software to analyze data from the ISIS (satellite), ISIS 2 satellite, working for the University of Calgary physics department. He received a Bachelor of Science from the University of Calgary and his M.A. and Ph.D. from Carnegie Mellon University, all in computer science. He wrote a version of Emacs called Gosling Emacs (Gosmacs) while working toward ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bill Joy
William Nelson Joy (born November 8, 1954) is an American computer engineer and venture capitalist. He co-founded Sun Microsystems in 1982 along with Scott McNealy, Vinod Khosla, and Andy Bechtolsheim, and served as Chief Scientist and CTO at the company until 2003. He played an integral role in the early development of BSD UNIX while being a graduate student at Berkeley, and he is the original author of the vi text editor. He also wrote the 2000 essay " Why The Future Doesn't Need Us", in which he expressed deep concerns over the development of modern technologies. Joy was elected a member of the National Academy of Engineering (1999) for contributions to operating systems and networking software. Early career Joy was born in the Detroit suburb of Farmington Hills, Michigan, to William Joy, a school vice-principal and counselor, and Ruth Joy. He earned a Bachelor of Science in electrical engineering from the University of Michigan and a Master of Science in electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellow
A fellow is a title and form of address for distinguished, learned, or skilled individuals in academia, medicine, research, and industry. The exact meaning of the term differs in each field. In learned society, learned or professional society, professional societies, the term refers to a privileged member who is specially elected in recognition of their work and achievements. Within institutions of higher education, a fellow is a member of a highly ranked group of teachers at a particular college or university or a member of the governing body in some universities. It can also be a specially selected postgraduate student who has been appointed to a post (called a fellowship) granting a stipend, research facilities and other privileges for a fixed period (usually one year or more) in order to undertake some advanced study or research, often in return for teaching services. In the context of medical education in North America, a fellow is a physician who is undergoing a supervised, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subnetwork
A subnet, or subnetwork, is a logical subdivision of an IP network. Updated by RFC 6918. The practice of dividing a network into two or more networks is called subnetting. Computers that belong to the same subnet are addressed with an identical group of its most-significant bits of their IP addresses. This results in the logical division of an IP address into two fields: the ''network number'' or ''routing prefix'', and the ''rest field'' or ''host identifier''. The ''rest field'' is an identifier for a specific host or network interface. The ''routing prefix'' may be expressed as the first address of a network, written in Classless Inter-Domain Routing (CIDR) notation, followed by a slash character (''/''), and ending with the bit-length of the prefix. For example, is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Packet Loss
Packet loss occurs when one or more packets of data travelling across a computer network fail to reach their destination. Packet loss is either caused by errors in data transmission, typically across wireless networks, or network congestion.Kurose, J.F. & Ross, K.W. (2010). ''Computer Networking: A Top-Down Approach''. New York: Addison-Wesley. Packet loss is measured as a percentage of packets lost with respect to packets sent. The Transmission Control Protocol (TCP) detects packet loss and performs retransmissions to ensure reliable messaging. Packet loss in a TCP connection is also used to avoid congestion and thus produces an intentionally reduced throughput for the connection. In real-time applications like streaming media or online games, packet loss can affect a user's quality of experience (QoE). Causes The Internet Protocol (IP) is designed according to the end-to-end principle as a best-effort delivery service, with the intention of keeping the logic routers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
