This blog post discusses how to use MySQL shell securely from Bash.

The Bourne shell is everywhere. It is part of the most basic Linux install. You will find it on the biggest SPARC machines down to a Raspberry Pi. It is nice to know it will always be there. Unlike other, more complex scripting environments such as Perl and Python, it doesn’t require any additional dependencies to be installed.

Anyone that has automated a MySQL task using a Bourne shell such as Bash will be familiar with the following message:

Warning: Using a password on the command line interface can be insecure.

This semi-ominous warning describes a security flaw in passing credentials on a process command line. Any unprivileged user on the system can use a command …

How does an application configure its database connection?  I find this to be a pretty interesting question. As the application moves from a developer’s workstation to a test harness, then to staging, and on to production, the database connection properties can change each time. …

In MySQL 5.7 we introduced JSON functionality into the MySQL Server. This work included the introduction of a JSON data type, virtual columns and a set of approximately 20 SQL functions that allow you to manipulate and search JSON data on the server side.…

I’m pleased to announce the newest MySQL Connector/J 5.1 Maintenance Release.

As usual, MySQL Connector/J 5.1 can be downloaded from the official distribution channels MySQL Downloads and The Central Repository. The commercially licensed version is available for download at My Oracle Support.

Please don’t forget to consult the CHANGES file in the download archive and/or the release notes page to know what is new and if there are any changes that might affect your applications.

MySQL Connector/J 5.1.40 is the official JDBC driver for MySQL …

Hello again, from day two of the sold out Percona Live Europe Open Source Database Conference! There is still much excitement here at the conference, and today looks to be just as busy as yesterday.

Day two of Percona Live Europe 2016 kicked off once again with a keynote presentation by Percona co-founder and CEO Peter Zaitsev on Percona Contributions to the Open Source Database Ecosystem, which highlighted Percona’s focus, approach and contributions to the open source database community. Peter talked about his passion for open source software, database technology and finding the best …

Percona announces the release of Percona Server 5.5.52-38.3 on October 5, 2016. Based on MySQL 5.5.52, including all the bug fixes in it, Percona Server 5.5.52-38.3 is now the current stable release in the 5.5 series.

Percona Server is open-source and free. You can find release details of the release in the 5.5.52-38.3 milestone on Launchpad. Downloads are available here and from the Percona Software Repositories.

Bugs Fixed: …

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The second MySQL tutorial session at Oracle Open World was “MySQL Group Replication in a Nutshell” by MySQL Community Manager Frederic Descamps. This is succinctly described as:

“Multi-master update anywhere replication for MySQL with built-in conflict detection and resolution, automatic distributed recovery, and group membership.”

MySQL Group Replication (GR) is a virtually synchronous replication solution which is an integral component of MySQL InnoDB Cluster announced at the MySQL keynote. You can download a labs version of MySQL InnoDB cluster which includes three components.

• MySQL Router …

Somebody recently asked, what they had to do, if they wanted to move their InnoDB-Logfiles back to the datadir. As a challenge, the servers were part of a Galera Cluster.

My first thought was:

The problem is not the Galera Cluster itself, it is the rsync-SST (wsrep_sst_method = rsync) that could cause trouble and destroy your InnoDB-Logfiles, by simply overwriting or deleting them.

So I tried to confirm my thought and realised, I was wrong. This works anyway, because the node just takes the dataset from the other node. (The backup plan was ready now.)

Preferably, the cluster does an IST, where it only fetches the missing write sets. This way you do not have the danger of losing the …

General query logs and slow query logs remain one of the most popular sources of auditing and diagnostic information in MySQL databases. Customers often ask about the cost of general and slow query logging so I went googling for existing research I could point them to. The data I found was not quite what I hoped for, which is why I decided to do some more testing.

Introduction Logging overhead is an obvious thing and it has been the topic of many blog posts before this one. Sure enough, my Google search returned multiple articles, however I wasn't fully satisfied the findings.
Perhaps the topic is so obvious that DBAs don't revisit it very often. In any case, most of the articles I found were several years old and that presents a few issues:

1. Most of the tests were run on MySQL 5.0 or 5.1.
2. Database hardware isn't what it used to be, which changes the perspective on database performance bottlenecks. …

    Recently we went through an exercise where we moved all of our database masters between data centers. We planned on doing this online with minimal user impact. Obviously when performing this sort of action there are a variety of considerations such as cache consistency and other pieces of shared state in stores like HBase, but the focus of this post will be primarily on MySQL.

    During this move we had a number of constraints. As mentioned above this was to be online when serving production traffic with minimal user impact. In aggregate we service hundreds of thousands of database queries per second. Additionally we needed to encrypt all data transferring between data centers. MySQL replication supports encryption, but connections to the servers themselves present several challenges. Specifically, from a performance standpoint the handshake to establish a connection across a WAN can impact latency if …