This post was written by Seppo Jaakola, CEO of Codership. There appears to be great misunderstanding as to what MySQL transaction isolation levels Galera CLuster actually supports and how. This blog post tries to give answer to those uncertainties. Galera Cluster provides SNAPSHOT ISOLATION between transactions running on separate cluster nodes. Transactions running on the […]

Codership is pleased to announce the release of Galera Cluster 5.5.42 and 5.6.25 with Galera Replication library 3.12, implementing wsrep API version 25. Galera Cluster is now available as targeted packages and package repositories for a number of Linux distributions, including Ubuntu, Debian, Fedora, CentOS, OpenSUSE and SLES. Obtaining packages using a package repository removes […]

In this post, we will describe the Primary Component, a central concept in how Galera ensures that there is no opportunity for database inconsistency or divergence between the nodes in case of a network split. What is the Primary Component? The Primary Component is that set of Galera nodes that can communicate with each other […]

Introduction A question frequently asked is how much latency does Galera have in geo-distributed environments. After all, snail mail can also be used for database replication, but the latency will not be acceptable. Let’s see how Galera performs. A Two-Datacenter Setup We start by creating a two-node cluster using a pair of Amazon EC2 regions […]

Introduction With Galera you can construct database clusters where each node is located in a different physical or even geographical location. In this blog post we will show some of the benefits from having such a geo-distributed cluster and the specific Galera features that enable practical replication across WAN links. Benefits From Geo-Distribution Geo-distribution allows […]

Galera Cluster has the ability to add new nodes to the cluster by handling internally the transfer of the entire dataset to the new node. The same procedure, called State Snapshot Transfer (SST), applies to nodes that are rejoining the cluster after being down for a longer period of time. A lot of operations happen […]