The multi master plugin for MySQL is here. MySQL Group Replication ensures virtual synchronous updates on any node in a group of MySQL servers, with conflict handling and failure detection. Distributed recovery is also in the package to ease the process of adding new nodes to your server group.

How do you start? Just sit back, download MySQL Group Replication from http://labs.mysql.com/ and then let us begin this journey into the world of multi master MySQL.

Pre requisites

Under its hood, the multi master plugin is powered by a group communication toolkit. This is what decides which nodes belong to the server group, performs failure detection and orders server messages. This last being the magic thing that allows the data to be consistent across all nodes.

As of now we rely on the Corosync Cluster …

MySQL Group Replication is here and with it comes the need to install and configure the underlying group communication toolkit that supports it: Corosync. Corosync is a well known and reliable Group Communication System that is used in such applications as Pacemaker.

In term of support, we develop MySQL Group Replication based on Corosync version 1.4.6, so this tutorial is based on this version. Regardless of this, no known problems are know to exists when using newer versions, but no extensive testing has been done on those.

Along with Corosync we also encourage the use of NSS to better secure your data that is transmitted in the group.

Installing

To install Corosync, you can rely on your packet manager for most distributions or compile it from source.

==> From the package manager

• Debian distributions

$ sudo apt-get install corosync …

The new addition to the MySQL planet, MySQL Group Replication is now on Labs Release for you to try it! It offers you update everywhere capabilities on any group of normal, out of the box, MySQL servers. Concurrent updates on a setup of several MySQL servers is now possible and this with our trademark: the ease of use.

In fact we ship MySQL Group Replication in such a way that for you to form a group and add new nodes, all that is needed is to configure the servers with your unique group id and just press start. In this post we show you the “behind the scenes” of this process, on how the node catches up with the remaining servers through distributed recovery.

The basics about Distributed Recovery

If we were to summarize what distributed recovery is, we could describe it as the process through which a new server gets missing data from a live node, while paying attention to what happens in the group, eventually catching …

Introduction

The multi master plugin for MySQL is here. MySQL Group Replication ensures virtually synchronous updates on any node in a group of MySQL servers, with conflict handling and failure detection. Distributed recovery is also in the package to ease the process of adding new nodes.

For a better understanding on how things work, we go under the hood in this post and you will have a better understanding about the communication layer functionality and implementation.

Group Communication concepts Figure 1 – Plugin Architecture

As the architecture shown in Figure 1, Group Replication is a classic modular and layered piece of software and the bottom two layers comprise the communication module. But, it is not a regular …

The first preview  release of MySQL Group Replication, a MySQL plugin that brings multi-master update everywhere to MySQL, is available on labs. This plugin ties together concepts and technologies from distributed systems, such as group communication, with traditional database replication. The ultimate result is a seamlessly distributed and replicated database over a set of MySQL servers cooperating together to keep the replicated state strongly consistent.

Introduction

Before diving into the details of MySQL Group Replication, lets first introduce some background concepts and an overview of how things work. These will provide some context to help understand what this is all about and what are the differences between traditional MySQL replication and the one implemented in this new plugin.

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Friend and former colleague Roland Bouwman has written an excellent update on the GROUP BY implementation in MySQL.

MySQL’s implementation of GROUP BY has historically been quirky. Sometimes that quirkiness has been useful, but often it causes grief as SQL authors can make mistakes that are executed but don’t produce the results they want (or expect).

Simple example:

SELECT cat, COUNT(val) as cnt, othercol FROM tbl GROUP BY cat

The ‘cat‘ column is in the GROUP BY clause, the COUNT(val) is an aggregate, but the ‘othercol‘ column is … well… neither. What used to effectively happen is that the server would pick one othercol value from within each group. As I noted before, sometimes useful but often a pest as the server wouldn’t know if …

MySQL Fabric 1.5.2 is out. In this release, you will find fixes for some bugs and, specially, new exciting features:

New interface using the MySQL Protocol

Now MySQL Fabric mimics to some extent a MySQL Server. This will foster the MySQL Fabric adoption by other connectors as they will not have to use a XML-RPC protocol.

import mysql.connector

cnx = mysql.connector.connect(host='localhost', port=32275, user='admin', password='adminpasswd')

cur = cnx.cursor()

cur.execute("CALL dump.servers(patterns=%)", multi=True)
print cur.column_names
for row in cur.fetchall():
print "Row", row

Provisioning command group

We have started to make MySQL Fabric Cloud Aware and exploit the easiness to spawn new machines in a cloud environment. There is a long road ahead and this is just the beginning.

$ mysqlfabric provider register my_provider user passwd \ …

We are very happy to introduce a new MySQL utility named “mysqlbinlogmove“, which is used to relocate binary log files. This utility is one of two new utilities included in MySQL Utilities release-1.6.0 Alpha. The other utility is “mysqlgrants“, which is used to display the privileges (grants) of database objects.

Note: I use “binary log” to refer to both “kinds” of binary log files (binlog and relay log files) in general, and use “binlog” to refer specifically to those that are not “relay log” files.

The mysqlbinlogmove utility allows you to move binary log files to a new location taking care of correctly updating the respective index file for you. This utility can be very useful if you want to change the location to store the binlog file and you want to move all of the binary log files. It is also handy to archive older binary log files to a new location thereby saving disk …

We are happy to announce mysqlgrants, a new utility that allows users to display the privileges of grantees over database objects. Together with mysqlbinlogmove, these are the new utilities included in MySQL Utilities release-1.6.0 Alpha.

Mysqlgrants allows you to know which users have access to a specific object or list of objects. Furthermore, it can also show the list of privileges that each user has over said object(s). In short, mysqlgrants simplifies the task of monitoring grants in MySQL helping you ensure users do not have more permissions than necessary, thus keeping data more secure.

Main Features

Below is a summary of the main features of the mysqlgrants utility:

• Helps DBAs to see which users have what level of access for each object listed.
• Supports several types of reporting: list just the grantees, the grantees and their respective grants or the …

Cloud service provider Backblaze has updated its earlier study of hard drive failure rates (Nov 2013) in its own infrastructure – from 27,000 to more than 34,000 drives, and the new report (Sep 2014) is quite informative. Hitachi comes out pretty high, Western Digital has produced some good drives, but Seagate tends to come out worst. Each brand does have good and not-so-good models so there’s no single right answer, and for any new model you’ll always be dealing with an unknown factor.

Backblaze also found that consumer drives actually perform well compared to enterprise grade drives, and once price is taking into account the enterprise drives just …