PUBLIC MARKS from camel with tags replication & debian

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.

Ever had to make the same change on more than one Linux/unix server? Find it annoyingly painful to keep repeating the exact same commands again and again and again? This tool addresses exactly this problem. You run a utility (cssh) providing a number of server names as parameters, and then xterms opens up to each server with an extra “console” window. Anything typed into the console is replicated into each server window (so, for examples, you can edit the same file on N machines at the same time, or run the same commands with the same parameters across those servers). It is also possible to type into the server windows directly, or temporarily disable replication to one or more of the servers through the “Hosts” menu.

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.

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.

All versions of MySQL currently shipped with Debian Sarge lack support OpenSSL due to licensing issues. In order to enable support for SSL connections it is necessary recompile MySQL from source.