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10 Newer Entries Showing entries 151 to 160 of 35724 10 Older Entries
Exploring Metadata Locks with gdb - First Steps
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Metadata locks are used in MySQL since version 5.5.3 and are available in GA MySQL versions for 6 years already. Still they are far from clearly documented (even less their implementation is documented in details - try to find anything about metadata locks in current MySQL Internals manual) and often causes "unexpected" problems for users.

Only since MySQL 5.7.3 (and only for a few months in GA releases since 5.7.9) we have an easy, official and documented …

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Getting Started with WP-CLI on Ubuntu 15.10
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WP-CLI is a tool to provide a command line interface to install and manage a WordPress site. This tutorial explains the installation of Wordpress on a LEMP (Linux + Nginx + MySQL + PHP) server with WP-CLI and shows how to install plugins and themes with WP-CLI on the command line.

How to Deploy a Cluster
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In this blog post I will talk about how to deploy a cluster, the methods I tried and my solution to resolving the prerequisites problem.

I’m fairly new to the big data field. Learning about Hadoop, I kept hearing the term “clusters”, deploying a cluster, and installing some services on namenode, some on datanode and so on. I also heard about Cloudera manager which helps me to deploy services on my cluster, so I set up a VM and followed several tutorials including the Cloudera documentation to install cloudera manager. However, every time I reached the “cluster installation” step my installation failed. I later found out that …

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MySQL Performance Troubleshooting Crash Course. A Story Of One Sneaky MySQL Performance Bug
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What better way to learn the basics of MySQL Performance Troubleshooting, than by observing a MySQL expert troubleshoot a nasty MySQL 5.7 performance bug, that a team of DBAs were chasing for weeks before giving up and calling in an external consultant for help.

The bug was causing roughly 2 minute long lock-ups for all MySQL write queries at seemingly random 20-30 hour intervals and it took me (the external consultant) only 4 hours to uncover the issue (and a couple more to find and showcase a solution).

Once upon a time…

Wait. Before we start with the story, I would like to share a couple of basic principles I obey when …

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Version Tokens in MySQL 5.7
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In MySQL 5.7.8 we added support for version tokens. This is a new feature that enables you to prevent accessing incorrect or out-of-date data, and stray modifications executing on the wrong server.

For some backstory

When there are multiple MySQL instances running on a Linux machine, there is a reasonable chance that clients could connect to the wrong instance.…

New in MariaDB Connector/C 3.0 – Part I: SSL
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New SSL alternatives SSL connections in previous versions of MariaDB Connector/C based on the OpenSSL library. The OpenSSL heartbleed bug, licensing problems and the lack of supporting different transport layers were the main reasons that we decided to offer SSL alternatives. In addition to OpenSSL the following SSL libraries are supported in Connector/C 3.0: GnuTLS […]

The post New in MariaDB Connector/C 3.0 – Part I: SSL appeared first on

grouping_operation, duplicates_removal: EXPLAIN FORMAT=JSON has all details about GROUP BY
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In the previous EXPLAIN FORMAT=JSON is Cool! series blog post, we discussed the  


  member (which is child of

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The performance of TLS with MySQL Connector/Python
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I've ran a simple test to see the performance impact of TLS on MySQL connections with MySQL Connector/Python

The test results are in this Jupyter notebook.


  • Try to reuse connections if you use TLS
  • Establishing TLS connections is expensive (server & client)
  • Improved performance might be possible in the future by using TLS Tickets

Not tested:

  • Difference between YaSSL and OpenSSL
  • Difference between Ciphersuites
  • Performance of larger resultsets and queries
How to Install Magento with Nginx on Ubuntu 15.10
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Magento is an open source e-commerce software and content management system for e-commerce websites based on the PHP Zend Framework. It uses MySQL or MariaDB as database backend. The Magento development has been started in 2008 by Varien. Inc. In this tutorial, I will show you how to install Magento 2 with Nginx, PHP-FPM, and MariaDB as the database. I will use ubuntu 15.10 (Wily Werewolf) as a basis for the installation.

New Year Wishes for Providers of MySQL Support Services
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Three years ago I shared my wishes for customers of Oracle's MySQL Support Services. There I basically asked them to report any problem that they suspect to be caused by the bug in MySQL software at year I want to share wishes mostly for myself (and other providers of MySQL Support services).

I have a job of MySQL Support Engineer for almost 10.5 years. I did it in MySQL AB, Sun, Oracle and Percona. I had enough opportunities to see …

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10 Newer Entries Showing entries 151 to 160 of 35724 10 Older Entries

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