The latest from the MySQL community

One new feature in Percona XtraDB Cluster (PXC) in recent releases was the inclusion of the ability for an existing cluster to auto-bootstrap after an all-node-down event.  Suppose you lose power on all nodes simultaneously or something else similar happens to your cluster. Traditionally, this meant manually re-bootstrapping the cluster, but not any more.

How it works

Given the above all-down situation, if all nodes are able to restart and see each other such that they all agree what the state was and that all nodes have returned, then the nodes will make a decision that it is safe for them to recover PRIMARY state as a whole.

This requires:

• All nodes went down hard — that is; a kill -9, kernel panic, server power failure, or similar event
• All nodes from the last PRIMARY component are restarted …

In the MySQL team, we are currently discussing deprecating the ability to change the collation_database and character_set_database settings. As part of our plan, mysql clients will still be able to access these variables, but they will be read-only.

Introduction

The MySQL manual summarizes these two variables as saying:

This option is dynamic, but only the server should set this information. You should not set the value of this variable manually.

This is to say that usage is already discouraged, but these two variables originally had a purpose of allowing a DBA to change the default character-set temporarily for the current session only. For example:

SET SESSION character_set_database=latin5;
LOAD DATA infile 'foo.txt' ... ;
-- foo.txt is interpreted as if it was in latin5 …

Tue, 2014-12-02 12:19anatoliydimitrov

Puppet is a powerful automation tool that helps administrators manage complex server setups centrally. You can use Puppet to manage MariaDB — let's see how.

With Puppet, you describe system states that you want the Puppet master server [to enforce] on the managed nodes. If you don't have Puppet installed and configured yet, please check the official Puppet documentation.

Before you can use Puppet to manage MariaDB, you must install a Puppet module that sets the proper repository corresponding to your operating system and version of MariaDB. For Red Hat-based distros, including CentOS, you can use the …

This post is a follow-up to my November 19 webinar, “Tips from the Trenches: A Guide to Preventing Downtime for the Over-Extended DBA,” during which I described some of the most common reasons DBAs experience avoidable downtime. The session was aimed at the “over-stretched DBA,” identified as the MySQL DBA short of time or an engineer of another discipline without the depth of the MySQL system. The over-stretched DBA may be prone to making fundamental mistakes that cause downtime through poor response time, operations that cause blocking on important data or administrative mishaps through the lack of best practice monitoring and alerting. (You can download my slides and view the recorded webinar here.)

Monitor the things
One of the aides to keeping the system up and …

Podcasts Learning Performance

This episode we start a 2-part series on MaxScale, a scaling proxy for MySQL. Ear Candy is OS Query and At the Movies is about MaxScale.

Relational databases aren’t very well suited to time-series data in some ways, but MySQL is powerful and flexible. At VividCortex, we have found that it’s a good storage engine to support a large-scale, high-velocity time-series database in the AWS cloud.

Join us next Tuesday, December 9, at 2 PM EST (7 PM GMT) as Baron Schwartz, our CEO and Founder discusses our unique time-series data requirements. He will explain the following:

• How we built a solution using MySQL and additional components such as Redis
• Why we needed more than just MySQL to meet the requirements
• The good and bad aspects of our architecture
• Performance statistics
• Thoughts for the future of our time-series data architecture

You will leave the talk with a greater understanding of MySQL’s capabilities related to time-series data. Please register …

Podcasts Learning Performance

This episode we start a 2-part series on MaxScale, a scaling proxy for MySQL. Ear Candy is OS Query and At the Movies is about MaxScale.

Amazon recently announced RDS Aurora a new addition to their database as a service offerings. Here’s Mark Callaghan’s take on what’s happening under the hood and thoughts from Fusheng Han. Amazon is uniquely positioned with RDS to take on offerings like Clustrix. So it’s definitely worth reading Dave Anselmi’s take on Aurora. Join 28,000 others […]

1) Is mysqldump text backup or binary backup
It is a text backup . If you open the backup file you will see all the statements that can be used to recreate databases and objects . It also has the insert statements to populate the tables with data

2) What is the syntax for mysqldump ?
mysqldump -u [uname] -p[pass] –databases [dbname][dbname2] > [backupfile.sql]

3) How to backup all databases using mysqldump ?
mysqldump -u root -p –all-databases > backupfile.sql

4) How to backup specific databases using mysqldump ?
mysqldump -u root -p –databases school hospital > backupfile.sql

5) How to backup specific tables using mysqldump ?
mysqldump –user=root –password=mypassword -h localhost databasename table_name_to_dump table_name_to_dump_2 > dump_only_two_tables_file.sql

The Perfect Server - CentOS 7 x86_64 (nginx, Dovecot, ISPConfig 3)

This tutorial shows how to prepare a CentOS 7 x86_64 server for the installation of ISPConfig 3, and how to install ISPConfig 3 on it. ISPConfig 3 is a webhosting control panel that allows you to configure the following services through a web browser: nginx web server, Postfix mail server, MySQL, BIND nameserver, PureFTPd, SpamAssassin, ClamAV, Mailman, and many more. Since version 3.0.4, ISPConfig comes with full support for the nginx web server in addition to Apache; this tutorial covers the setup of a server that uses nginx, not Apache. The ISPConfig 3 apache perfect server tutorial is available here.