DRBD:What is DRBD

DRBD® refers to block devices designed as a building block to form high availability (HA) clusters. This is done by mirroring a whole block device via an assigned network. DRBD can be understood as network based raid-1.

In the illustration above, the two orange boxes represent two servers that form an HA cluster. The boxes contain the usual components of a Linux™ kernel: file system, buffer cache, disk scheduler, disk drivers, TCP/IP stack and network interface card (NIC) driver. The black arrows illustrate the flow of data between these components.

The orange arrows show the flow of data, as DRBD mirrors the data of a high availably service from the active node of the HA cluster to the standby node of the HA cluster.

Failover and loadbalancer using keepalived (LVS) on two machines

Failover and loadbalancer using keepalived (LVS) on two machines
January 26th, 2009
28 comments

In this scenario, we have two machines and try to make the most of available resources. Each of the node will play the role of realserver, it will provide a service such as a web or a mail server. At the same time, one of the machines will loadbalance the requests to itself and to its neighbor. The node that is responsible of the loadbalancing owns the VIP. Every client connects to it transparently thanks to the VIP. The other node is also able to take over the VIP if it detects that current master failed but in nominal case only process requests forwarded by the loadbalancer.

Facebook, le Spray des années 2010 ?

"Facebook est-il une étape obligatoire pour tout acteur du web ? Oui, bien sûr que oui, surtout avec 500 millions de membres. Par contre il y a différentes façons d’exploiter Facebook et je vous recommande fortement de ne pas mettre tous vos oeufs dans le même panier (j’ai l’affreuse impression de me répéter au fil des mois). Souvenez-vous qu’à une époque pas si éloignée, Spray était l’acteur incontournable du web car c’était la destination à la mode (sa force reposait sur sa communauté). Aujourd’hui nous savons ce que Spray est devenu, il faut donc savoir en tirer les enseignements. Je suis intimement persuadé que Facebook sera le Spray des années 2010 : Une plateforme à la croissance fulgurante qui va exploser comme une supernova faute de fondamentaux viables."

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Posted by: marind

ickmull – XHTML vers Indesign

"Ickmull is an xslt transform and a testing framework to allow and encourage the evolution of a core set of functionality for taking basic prose text in XHTML format (from a blog or wiki, for instance) and converting it to the open, XML-based ICML format (a subset of the full IDML spec) so the content can be migrated automatically into Adobe InDesign layouts. "

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Posted by: marind

Netcase, workflow éditorial simplifié, ne nécessitant pas de formation

"netCase is a research group based out of Simon Fraser University working to produce a task-oriented, simple and flexible editorial workflow system using WordPress. We endeavour to create an intuitive system that can be easily implemented in small publishing operations, and can function in multiple editorial contexts. Our system (nEWS = netCase editorial workflow system) targets the user experience of small magazine publishers, their editorial staff, interns and volunteers, and their authors. We want to create an easily adoptable system that causes minimal complications during implementation, and requires little to no training for its users."

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Posted by: marind

« TBX (TermBase eXchange) : format XML pour décrire les « terminologies »

"TBX (TermBase eXchange) is family of XML-based languages for the interchange of terminological information (called TMLs, for Terminological Markup Language). All of TBX shares a core structure, in which information is represented on one of three structural levels: concept, language, and term. Concept entries contain language entries, which in turn contain entries for individual terms. The core structure also provides a set of generic elements for attaching descriptive and administrative information to these entries. These generic elements can be employed differently in different TMLs."

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Posted by: marind

Symposium sur la TEI et l’édition scientifique

"This symposium, to be held in conjunction with a meeting of the TEI Council, will explore such questions through a series of presentations outlining the current state of the art in institutional publishing operations such as those of universities in the UK, France, US, and Australia, from the point of view of private sector publishers (among which the NLM DTDs are increasingly adopted), and from international initiatives where interoperability has been identified as a major factor (e.g., PEER, which includes European research institutions, repositories, and STM publishers). The objective is to identify current difficulties in making publication systems interoperable and identify priority actions for the TEI to intervene in this arena."

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Posted by: marind

Powerpoint, voilà l’ennemi !

"“It’s dangerous because it can create the illusion of understanding and the illusion of control,” General McMaster said in a telephone interview afterward. “Some problems in the world are not bullet-izable.”

In General McMaster’s view, PowerPoint’s worst offense is not a chart like the spaghetti graphic, which was first uncovered by NBC’s Richard Engel, but rigid lists of bullet points (in, say, a presentation on a conflict’s causes) that take no account of interconnected political, economic and ethnic forces. “If you divorce war from all of that, it becomes a targeting exercise,” General McMaster said. "

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Posted by: marind