Tue, 2015-04-07 11:41guillaumelefranc

In the first blog of these series, we've done a rapid walkthrough on how to use Ansible and Vagrant to start a master/slave pair. In this second post, we will delve into the inner workings of Ansible, explaining how to set up server inventories, automate MariaDB deployments, use configuration templates and much more.

Setting up an Ansible inventory

Once Ansible is setup with your usual package manager, the first task should be to create passwordless SSH keys and to setup the servers you want to manage for passwordless access. Setting up SSH keys is extensively described on the internet so I won't get into any details in this post.

The second task is to create a server inventory. This is as …

Due to its synchronous nature, Galera performance can be limited by the slowest node in the cluster. So running heavy reporting queries or making frequent backups on one node, or putting a node across a slow WAN link to a remote data center might indirectly affect cluster performance. Combining Galera and asynchronous MySQL replication in the same setup, aka Hybrid Replication, can help. A slave is loosely coupled to the cluster, and will be able to handle a heavy load without affecting the performance of the cluster. The slave can also be a live copy of the Galera cluster for disaster recovery purposes.

We had explained the different steps to set this up in a previous post. With ClusterControl 1.2.9 …

Open Query is supporting the mysql-cli Kickstarter project (for MySQL and MariaDB) by Amjith Ramanujam who already successfully completed a similar tool for PostgreSQL.

It is a new MySQL client with Auto-Completion and Syntax Highlighting. From the info provided, it’s Python based, thus portable, and can be installed without root access. Could be a very useful tool. The good old mysql command line client does lack some things, yet a relatively low-level command line client is often useful for remote tasks (as opposed to graphical tools) so we reckon it’s good that this realm gets a bit of attention!

Two years ago Ovais Tariq had explained in detail what kinds of problems existed before MySQL introduced metadata locks in 5.5.3 and how these locks help to prevent them. Still, some implications of metadata locking in MySQL remain unclear for users – DBAs and even software developers that target recent MySQL versions. I’ve decided to include a slide or two into the presentation about InnoDB locks and deadlocks I plan to make (with my colleague Nilnandan Joshi) on April 16 at Percona Live 2015.

I decided to do this as …

MySQL Enterprise Firewall is a commercial extension, and is included with MySQL Enterprise Edition. This new SQL based firewall was just released in the MySQL 5.6.24 Enterprise Server! Let me tell you a bit more about how it reduces security vulnerabilities, how it works, and how to use it.

All too often, as statistics and daily headlines show, badly written applications continue to expose an organizations sensitive data to malicious attackers. These …

Every day hundreds of millions of dollars are wasted by allowing improperly tuned or misconfigured systems, misunderstood infrastructure, and inefficient IT operations to live and thrive in data centers around the globe. There are both direct and indirect costs associated with allowing these unhealthy systems to continue to exist. Let’s look at some.

The setup:

Let us start by using a small example. We will start by looking at a small database setup. This setup will have a single master-slave, with a database size of lets say 500GB. Traffic is steady and let’s say this translates into 500 IOPS on the master. You have chosen to host this on Amazon’s AWS. A common way of ensuring backups occur in AWS is to setup ebs snapshots of the slave. In terms of usage, let us assume your CPU is about 50% used and you have about 20GB of hot data that needs to stay in the memory for the database.

If we look at what this …

Below video will depict :

* How to set a login path

* How to use login path in mysql client

* How to use login path in mysqldump

* How to remove login path

You can download the slides from below URL

config_editor

Having big tables is one of the expected database problems, especially, for the fast growing database systems. In fact, big tables itself is not a problem but with big tables, the following problems are strongly expected:

1. Retrieving data from big tables is so slow.
2. It is a very hard job to maintain those tables like adding/removing an index, adding/dropping/modifying a column, … etc.
3. System resources, especially, the IO system might not be able to handle such huge traffic of writes and reads.
4. When it comes to the reporting queries, it might be a horrible nightmare!
5. Always cause disk space problem.

All the above problems will show up the need for scaling! So, let’s check out what are the possible solutions for that problem:

• MySQL Partitioning: Is a good solution but we will still face disk space and server resources problems. …

On a recent engagement I worked with a customer who makes extensive use of UUID() values for their Primary Key and stores it as char(36), and their row count on this example table has grown to over 1 billion rows.

The table is INSERT-only (no UPDATEs or DELETEs), and the bulk of their retrieval are PK lookups. Lookups by PK were performing acceptably, but they were concerned with the space usage by the table as we were approaching 1TB (running with innodb_file_per_table=1 and Percona Server 5.5).

This schema model presents an increasing burden for backups since they use Percona XtraBackup, and so the question was asked: does their choice of an effectively random Primary Key based on UUID() impact their on-disk storage, and to what extent? And as a neat trick I show towards the end of this post how you can calculate the …

The Ubuntu 12.04.3 LTS release only provides MySQL 5.1 and MySQL 5.5 using the default Ubuntu package manager.

Oracle (owners of the MySQL(tm)) now provide Debian/Ubuntu APT repositories for all GA and DMR versions of MySQL including supporting Ubuntu 12.04.

The following steps demonstrate upgrading from the Ubuntu 5.5 server package to the Oracle 5.6 server package.

Verify MySQL Packages

$ apt-cache search mysql-server
mysql-server - MySQL database server (metapackage depending on the latest version)
mysql-server-5.5 - MySQL database server binaries and system database setup
mysql-server-core-5.5 - MySQL database server binaries
auth2db - Powerful and eye-candy IDS logger, log viewer and alert generator
cacti - Frontend to rrdtool for monitoring systems and services
torrentflux - web based, feature-rich BitTorrent download manager

Verify …