PUBLIC MARKS from camel with tags linux & replication

This tutorial explains how you can set up MySQL master-master replication on four MySQL nodes (running on Debian Etch). The difference to a two node master-master replication (which is explained here) is that if you have more than two nodes, the replication goes in a circle, i.e., with four nodes, the replication goes from node1 to node2, from node2 to node3, from node3 to node4, and from node4 to node1. Since version 5, MySQL comes with built-in support for master-master replication, solving the problem that can happen with self-generated keys. In former MySQL versions, the problem with master-master replication was that conflicts arose immediately if node A and node B both inserted an auto-incrementing key on the same table. The advantages of master-master replication over the traditional master-slave replication are that you don't have to modify your applications to make write accesses only to the master, and that it is easier to provide high-availability because if the master fails, you still have the other master.

This short article explains how you can use a short script to check whether your MySQL master master replication is working as expected or not.

Voici quelques semaines qu’il en parlait sur les ml, alors il à fini par le coder. Ivan Voras (ivoras@) nous livre la première version d’un démon destiné à synchroniser deux systèmes de fichiers de manière plus économique et élégante que le classique rsync. Le principe est simple, basée sur kqueue (culture again), le démon adfs -c’est son nom- contrôle l’état des fichiers à répliquer et en fait une copie en “quasi” temps réel, lorsque ces derniers ont été modifiés. Bien que peu performant sur un très grand nombre de fichiers, cette application semble bien se comporter avec un petit nombre de fichiers (quelques dizaines de milliers ?!). Il est possible de récupérer la version courante du code, mais la version en ligne ne sera maintenue à jour que si des utilisateurs semblent intéressés. Avis aux amateurs.

Since version 5, MySQL comes with built-in support for master-master replication, solving the problem that can happen with self-generated keys. In former MySQL versions, the problem with master-master replication was that conflicts arose immediately if node A and node B both inserted an auto-incrementing key on the same table. The advantages of master-master replication over the traditional master-slave replication are that you don't have to modify your applications to make write accesses only to the master, and that it is easier to provide high-availability because if the master fails, you still have the other master.

This tutorial provides step-by-step instructions about how to create a highly available VMware Server environment on a Debian Etch system. With this tutorial, you will be able to create Virtual Machines that will be available on multiple systems with failover/failback capabilities.

Ce tutorial décrit comment configurer une réplication MySQL de maître à maître. Nous devons assurer la réplication de serveur pour obtenir la haute disponibilité. Dans mon cas, j'ai besoin de deux maîtres pour qu'ils soient synchronisés l'un avec l'autre : si l'un deux tombe, l'autre prend la relève, et aucune donnée n'est perdu. De même, lorsque le deuxième serveur revient, il sera capable de rattrapper le survivant.

This tutorial describes how to set up database replication in MySQL. MySQL replication allows you to have an exact copy of a database from a master server on another server (slave), and all updates to the database on the master server are immediately replicated to the database on the slave server so that both databases are in sync. This is not a backup policy because an accidentally issued DELETE command will also be carried out on the slave; but replication can help protect against hardware failures though.