Where results make sense

About us   |   Why use us?   |   Reviews   |   PR   |   Contact us

Category:Software engineering - Wikipedia, the free encyclopedia Software engineering is the application of computer sciences, project management, and other techniques to create software applications. Politically, software engineering does not claim to be part of engineering, which historically uses state certification in order to practice. Thus comparing software engineering and related fields has other criteria than certification. en.wikipedia.org /wiki/Category:Software_engineering   (84 words)

What is idempotence! In mathematics, an idempotent element (or simply an idempotent) is something that when multiplied by (for a function, composed with) itself, gives itself as a result. In particular, C header files are often designed to be idempotent, that is, if the header file is included more than once (as can easily happen with nested #includes), then nothing untoward happens - the effect is the same as if it had been included only once. Idempotent behaviour is the basis for the caching ability of the web; if the same request delivers the same response one can also work with a copy instead of requiring the original page. geekswithblogs.net /dthakur/archive/2004/11/19/15282.aspx   (308 words)

HotOS IX — Paper Since crashes are unavoidable, software must be at least as well prepared for a crash as it is for a clean shutdown. Many interesting operations in an Internet service are idempotent, or can easily be made idempotent by keeping track of sequence numbers or by wrapping requests in transactions; some large Internet services have already found it practical to do so [23]. Crash-only software is complementary to this approach and can help alleviate some of the complex and expensive management requirements for highly redundant hardware, because faster recovering software means less redundancy is required. www.usenix.org /events/hotos03/tech/full_papers/candea/candea_html   (4646 words)

Safe and Idempotent Methods   (Site not responding. Last check: 2007-11-05) Implementors should be aware that the software represents the user in their interactions over the Internet, and should be careful to allow the user to be aware of any actions they might take which may have an unexpected significance to themselves or others. Methods can also have the property of "idempotence" in that (aside from error or expiration issues) the side-effects of N > 0 identical requests is the same as for a single request. (A sequence is idempotent if a single execution of the entire sequence always yields a result that is not changed by a reexecution of all, or part, of that sequence.) For example, a sequence is non-idempotent if its result depends on a value that is later modified in the same sequence. www.ieinspector.com /httpanalyzer/manual/process44.htm   (315 words)

Information on idempotent A function f : D -> D is idempotent if f (f x) = f x for all x in D. I.e. Any value in the image of an idempotent function is a fixed point of the function. This term can be used to describe C header files, which contain common definitions and declarations to be included by several source files. www.wkonline.com /d/idempotent.html   (324 words)

Introduction to Econometrics - Matrix Algebra In our discussions we'll also always assume that these idempotent matrices are symmetric (which means that the element of the i-th row and the j-th column is equal to the element of the j-th row and the i-th column). Idempotent matrices are very important in order to write variables as deviations from the mean. All idempotent matrices have a root of 0 or 1. www.xycoon.com /matrix_algebra.htm   (1824 words)

thinking-out-loud: Idempotent Messaging One of the patterns, aptly titled "Idempotent Receiver" deals explicitly with idempotency in the context of messaging, and discusses both the use of unique message identifiers and idempotent interfaces. Second, it is difficult to ascertain what exactly most computer scientists, software engineers, hackers, whatever would consider the domain versus the range for a service, and what is an element of the range, and what does it mean to pass that element to the function? This operation is idempotent because the system ignores renewals where the passed in "current expiration date" is invalid. integralpath.blogs.com /thinkingoutloud/2004/05/idempotent_mess.html   (756 words)

I This is also heard from applications programmers trying to blame an obvious applications problem on an unrelated systems software change, for example a divide-by-0 fault after terminals were added to a network. Software that bypasses the defined OS interfaces to do things (like screen, keyboard, and disk I/O) itself, often in a way that depends on the hardware of the machine it is running on or which is nonportable or incompatible with other pieces of software. The list of all known software interrupt calls (both documented and undocumented) for IBM PCs and compatibles, maintained and made available for free redistribution by Ralf Brown . www.th-soft.com /zzJargon/I.htm   (3297 words)

Designing Web Services with the J2EETM 1.4 Platform: - Creating idempotent endpoints is one strategy a service can use to handle duplicate messages. Idempotent refers to a situation where repeated executions of the same event have the same effect as a single execution of the event. Because multiple service requests have the same effect as a single request, clients of a idempotent service can retry message requests until they are successful, without fear of causing duplicate actions. java.sun.com /blueprints/guidelines/designing_webservices/html/architecture7.html   (2133 words)

thinktecture - Ingo Rammer's Weblog: June 2002 Archives The thing is: as soon as two people who've spent some time with various software development projects come together, one topic inevitably turns up: funniest (or worst) experiences with other developers and managers. When you however decide to change an aspect of your software during the process, the cost of this change will probably be minimal. Software architects and developers aren't only engineers: we are also mathematicians and artists. www.thinktecture.com /staff/ingo/weblog/archives/2002_06.html   (1800 words)

[No title] Administrative software is used to provide a consistent view of shared operating system resources across nodes. In the case of software errors, such as a kernel panic, it may be possible to reboot the node, and resume communication with the node, possibly performing some recovery actions. It is important that this failover be transparent to the users of the resource, and in particular, the expected semantics of any operations that were in progress at the time of the failure must be preserved. www.usenix.org /publications/library/proceedings/sd96/full_papers/kittur.txt   (5129 words)

Chapter 5 Developing Web Applications idempotent request is one that does not cause any change or inconsistency in an application when retried. To configure idempotent URL response, specify the URLs that can be safely retried in idempotent-url-pattern elements in the sun-web.xml file. In effect, retrying an idempotent URL should not cause values to change on the server or in the database. docs.sun.com /source/819-0217/dgwebapp.html   (5044 words)

Re: Idempotent from Harald.T.Alvestrand@uninett.no on 1995-09-04 (ietf-http-wg-old@w3.org from September to ... If the request is idempotent and a >>>> GET or HEAD response is cached, the proxy may return the cached message if it passes any restrictions in the Expires header field. This allows the client software to represent other methods, such as POST, in a special way so that the user is made aware of the fact that an non-idempotent action is >>>>>> an action that may have side effects being requested. These are the only four examples of the word "idempotent" in the document; I think we don't need it. lists.w3.org /Archives/Public/ietf-http-wg-old/1995SepDec/0038.html   (542 words)

Citations: Using Weaves for Software Construction and Analysis - Gorlick, Razouk (ResearchIndex)   (Site not responding. Last check: 2007-11-05) allow the software architecture to be dynamically changed during program execution, by inserting, removing, or changing the interconnections between elements of the application. As a general rule, instrumented connectors are non invasive and idempotent. Non invasive means that their presence in a connector s implementation is undetectable; idempotent means that any number of intermediaries can be chained because their import and export interfaces are the same and that.... citeseer.ist.psu.edu /context/14196/0   (2303 words)

[No title] I can't think of a possible case where your object implementation would want to lie to the client and claim that it wasn't involved in the outcome, unless your purpose was to defraud your client, and that could get you in more trouble than breaking the CORBA spec. In an RPC system, an operation is idempotent if performing it more than once has the same effect as performing it once. So even for idempotent operations, the client needs to know if the operation actually was invoked or not. www.omg.org /issues/issue1315.txt   (4481 words)

Design Issues for HTTP (For example, the NFS protocol is idempotent, but the FTP and NNTP protocols are not.) In the case of FTP the state information consists of authorisation, which is not trivial to establish every time but could be, and current directory and transfer mode which are basically trivial. The problem is that to use them in an idempotent way requires the re-evaluation of the intermediate result sets at each query. In an idempotent world, this information would be included in the GET command. www.w3.org /Protocols/DesignIssues.html   (943 words)

report on S1 One of the recurrent mathematical framework is that of idempotent semirings. The original software was written in C by Champarnaud and Hansel [6]. The functionalities already implemented (with some original algorithms) are (given the generators of the semigroup): list of the elements, relations, idempotents, computation of the minimal ideal, of Green's classes, of the inverses, of local subsemigroups, of the representative of an element, variety tests: commutativity, nilpotence, idempotence, aperiodicity, and so on. www.cs.rug.nl /~rein/alapedes/S1.html   (3181 words)

thinking-out-loud: Software Architecture Luke Hohmann has a book title Beyond Software Architecture in the AW Martin Fowler Signature series of books that addresses some of the topics around Product and Marketing Management. That dimension is usually load, concurrent number of client request, etc. Rich doesn't create a situation that describe a scalability problem, and the solution is couched in terms of increased performance (throughput, response time, network efficiency, and so on). You can dig into the software looking for ways to reduce the session duration in the name of scalability, or you can go with the more naive [and probably faster and easier to implement and test] solution of throwing more hardware at it (horizontal scalability). integralpath.blogs.com /thinkingoutloud/software_architecture   (2752 words)

John Reynolds's Blog: Why is so much software so bad? Bemoaning the sorry state of software quality is a complaint that comes back like clockwork and ironically often comes from industry veterans who, by their experience and time in the industry, should hold themselves at least partially responsible for it's current state. Fortunately software is not the first technology that has worked through these growing pains. Your use of this web site or any of its content or software indicates your agreement to be bound by these Terms of Participation. weblogs.java.net /blog/johnreynolds/archive/2005/02/why_is_so_much.html   (3138 words)

Project Writers of client software should make sure make that any actions taken by their software are safe and otherwise idempotent. The actual user of the software should be completely aware of any actions that may be taken by the software they are running. How to restrict a robot (An automated software that surfs the net, for indexing, etc.) from accessing a server and what to do if a robot is affecting your server in a negative manner (Reads file over and over again, for example). www2.rad.com /networks/1997/security/internetsecurity.htm   (2468 words)

software engineering history - UWB Software UWBSoftware.com   (Site not responding. Last check: 2007-11-05) An early history of software engineering by Robert L. Glass The following article is a condensation of the ideas of Robert L. Glass in his book "In the Beginning: Recollections of Software Pioneers... Software Engineering History Computers were invented in the 1940’s Then - computing programming languages were invented Eventually - program language training was developed However, training was... Brief History of Software Engineering Software is a collection of computer programs, procedures, rules, associated documentation and data. www.uwbsoftware.com /software-engineering-history   (252 words)

Citebase - A unifying approach to software and hardware design for scientific calculations and idempotent mathematics   (Site not responding. Last check: 2007-11-05) A unifying approach to software and hardware design generated by ideas of Idempotent Mathematics is discussed. After an overview of `Idempotent Mathematics' with an emphasis on matrix theory, interval analysis over idempotent semirings is developed. In this paper, we present an algebraic approach to idempotent functional analysis, which is an abstract version of idempotent analysis. citebase.eprints.org /cgi-bin/citations?id=oai%3AarXiv%2Eorg%3Amath%2F0101069   (1338 words)

Tea Leaves: More Software Engineering Terms An operation is "idimpotent" if it should be idempotent, but instead it brings your system to a crashing halt if you try it twice. Unit tests - Pieces of software that thoroughly exercise, at a bare minimum, at least 5% of a given software component. Other useful software engineering terms can be found here. www.tgr.com /weblog/archives/000240.html   (301 words)

Talk Abstracts for Digital Libraries: Digital Asset Management The approach uses and separates the roles of science, subjective judgment and mathematics using ``pixel predictors" P:D->D, idempotent filters Q:D->D and indexing (compression) functions C:D->Z respectively, where D is a space of files representing digital images, and Z denotes the integers. We incorporate the thesaurus directly into the search software, so that both cataloguers and users are free to use any terms in English that accurately describe their media. This paper describes the natural language processing elements of the search software, discusses how to represent hierarchical relationships efficiently, and considers the use and limitations of XML as a metadata tagging solution. www.ima.umn.edu /multimedia/abstract/2-12abs.html   (2234 words)

Synchronizing REST Resources With Asynchronous Notification: A Practical Proposal - CommerceNet Wiki   (Site not responding. Last check: 2007-11-05) The first desideratum for distributed systems (http://research.sun.com/techrep/1994/abstract-29.html) is that communications between failure domains be either side-effect-free or idempotent (http://citeseer.ist.psu.edu/lampson83hint.html). A notification that a particular web page is in a particular state is idempotent, so that would be a reasonable thing to send. There is a possible race condition if the subscriber polls the current state of the resource and establishes the subscription to be notified of future states in two separate messages. labs.commerce.net /wiki/index.php/Synchronizing_REST_Resources_With_Asynchronous_Notification:_A_Practical_Proposal   (1627 words)

G. Landini's Software If no specific copyright notice is included, then consider the plugin as free software: you can redistribute it and/or modify it under the terms of the GNU General Public license as published by the Free Software Foundation; either version 2 of the license, or (at your option) any later version. The centroid of an object with a hole is a ring, otherwise it is a point. The reconstruction algorithm is: iterated 8-neighbour geodesic dilations of the seed UNDER the mask image until stability is reached (the idempotent limit). www.dentistry.bham.ac.uk /landinig/software/software.html   (4069 words)

The TCP/IP Guide - HTTP Methods A method is said to be idempotent if repeating the same method request numerous times causes the exact same results as if the method were issued only once. The POST method is not idempotent because each instance of a POST request causes the receiving server to process the data in the request's body. A GET request for a simple document is idempotent, but a GET for a script can change files on the server and therefore is not idempotent. www.tcpipguide.com /free/t_HTTPMethods-4.htm   (646 words)

I An operation is idempotent if its results do not affect the results of any operation. The input/output device, usually a fixed disk or diskette, from which the system software is loaded when the machine is turned on. A continuing cycle of reciprocal action between a user and one or more software applications through input devices (a keyboard, mouse, file server, and so on) and output devices (a display, printer, file server, and so on). www.unet.univie.ac.at /aix/aixuser/glossary/I.htm   (5192 words)

Try your search on: Qwika (all wikis)

About us   |   Why use us?   |   Reviews   |   Press   |   Contact us   Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.