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Database Cluster Management - Manual vs Automation via ClusterControl

In a previous blog, we looked at the efficiency gains when automating the deployment of a Galera cluster for MySQL. In this post, we are going to dive into cluster management. Should we manage our cluster manually, or does it make sense to automate the procedures ? What do we gain with automation?

Cluster management involves a number of tasks:

  • Node management:
    • Restart service (per node or rolling restart)
    • Bootstrap cluster
    • Stop cluster
    • Reboot server
    • Rebuild node
    • Recover cluster/node
    • Find most advanced node (i.e. node with latest data)
  • Configuration management:
    • Centrally manage configuration files
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Optimizing and repairing MySQL databases with mysqlcheck

In this post, we will talk about mysqlcheck which is a maintenance command line tool that allows you to check, analyze, repair, and optimize MySQL/MariaDB tables and databases. Check one table in the database The following command will check the table posts in the database blog: $ mysqlcheck -c blog posts blog.posts OK If your database is protected by a password add -u root -p at the end of the command: $ mysqlcheck -c blog posts -u root -p Enter password: blog.posts OK Analyze all tables in a database The following command will check the table posts in the database […]

Install cx_Oracle for Python

This shows you how to install the cx_Oracle library for Python 2.7 on Fedora Linux. If Fedora has it on the server you can download it with the following yum command:

yum install -y cx_Oracle-5.2.1-11g-py27-1.x86_64.rpm

Currently, you’ll get the following failure because it’s not available in the Fedora repository:

Loaded plugins: langpacks, refresh-packagekit
mysql-connectors-community                                      | 2.5 kB  00:00:00     
mysql-tools-community                                           | 2.5 kB  00:00:00     
mysql56-community                                               | 2.5 kB  00:00:00     
pgdg93                                                          | 3.6 kB  00:00:00     
updates/20/x86_64/metalink                                      | 2.3 kB  00:00:00     
No package …
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Upgrading to MySQL 5.7? Beware of the new STRICT mode

This blog post discusses the ramifications of STRICT mode in MySQL 5.7.

In short

By default, MySQL 5.7 is much “stricter” than older versions of MySQL. That can make your application fail. To temporarily fix this, change the




 (same as in MySQL 5.6):


MySQL 5.7, dates and default values

The default


 in MySQL 5.7 is:


That makes MySQL operate in “strict” mode for transactional tables.

“Strict …

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MySQL Downgrade Caveats

In this blog, we’ll discuss things to watch out for during a MySQL downgrade.

Previously, I wrote the blog MySQL upgrade best practices. Besides upgrading your MySQL version, sometimes you need to downgrade. When it comes to downgrading MySQL, there are two types of downgrade methods supported:

  1. In-Place Downgrade: In this method, you use the existing data directory and replace MySQL binaries, followed by a
     execution. This type of downgrade is supported within the same release series. For example, in-place downgrades are supported when moving from 5.7.12 to 5.7.10.
  2. SQL Dump Downgrade: An SQL dump is another …
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MySQL Query Tuning Trilogy: Working with optimizer and SQL tuning (3rd and final part)

Join us on Tuesday, October 25th, for the third and final part of our webinar trilogy on MySQL Query Tuning, in which we look at the query tuning process and tools to help with that. So far in this trilogy we’ve covered topics such as SQL tuning, indexing, the optimizer and how to leverage EXPLAIN to gain insight into execution plans.

For Part 3, Krzysztof Książek, Senior Support Engineer at Severalnines, will now take a look at working with the optimizer as well as SQL tuning. This will include a discussion on how execution plans are calculated and a closer look at InnoDB statistics, how to hint optimizer and finally, how to optimize SQL.

MySQL Query Tuning (III): Working with optimizer and SQL tuning

Tuesday, October 25th

Sign up for the webinar

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Evolving MySQL Compression - Part 1

Pinterest Infrastructure engineers are the caretakers of more than 75 billion Pins–dynamic objects in an ever-growing database of people’s interests, ideas and intentions. A Pin is stored as a 1.2 KB JSON blob in sharded MySQL databases. A few years back, as we were growing quickly, we were running out of space on our sharded MySQL databases and had to make a change. One option was to scale up hardware (and our spend). The other option–which we chose–was using MySQL InnoDB page compression. This cost a bit of latency but saved disk space. However, we thought we could do better. As a result, we created a new form of MySQL compression which is now available to users of Percona MySQL Server 5.6.

JSON is efficient for developers, not machines

As a small start-up, Pinterest built and scaled its MySQL …

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Percona Server 5.6.33-79.0 is now available

Percona announces the release of Percona Server 5.6.33-79.0 on October 18th, 2016. Download the latest version from the Percona web site or the Percona Software Repositories.

Based on MySQL 5.6.33, including all the bug fixes in it, Percona Server 5.6.33-79.0 is the current GA release in the Percona Server 5.6 series. Percona Server is open-source and free – this is the …

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MySQL 8.0 Labs: [Recursive] Common Table Expressions in MySQL (CTEs), Part Two – how to generate series

Here is the second in a series of posts about CTEs, a new feature of MySQL 8.0, available in this Labs release. The first post ended with:

Inside the recursive CTE definition (the part in AS (…)), some syntax constraints must be respected […]

  • a recursive SELECT mustn’t contain GROUP BY, aggregate functions
    (like SUM), ORDER BY, LIMIT, DISTINCT (this rule doesn’t apply to the non-recursive/anchor/seed SELECT)
  • a recursive SELECT must reference the CTE only once and only in its
    FROM clause, not in any subquery.

MySQL Connector/Node.JS 1.0.4 now on

MySQL Connector/Node.JS 1.0.4 was recently released as a development milestone release. This is the first version available via is the central registry for Node.JS packages. This and potential future official MySQL packages can be found using the @mysql organisation. For this to work we had to change the package name to contain that prefix and have chosen the name @mysql/xdevapi as this package provides the implementation of our X DevAPI for Node.JS and we have a free namespace for potential future libraries as part of our Connector/Node.JS product.

Given an existing Node.JS project we can easily install the library:

$ npm install --save @mysql/xdevapi …
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