A common question we get is: can I add a node to my Galera Cluster without restarting the entire cluster? The simple answer is YES.

A lot worry about the fact that you do list servers that are part of the cluster within your my.cnf, and this file is not reloadable in a dynamic fashion. Fret not, though, because as long as your my.cnf has one active cluster member (the DONOR), you can have it be the JOINER.

If for example, you have 3 nodes: galera1: 159.223.105.21 galera2: 137.184.78.182 galera3: 137.184.65.171

The my.cnf line for wsrep_address should read as follows:

wsrep_cluster_address="gcomm://159.223.105.21,137.184.78.182,137.184.65.171"

It is then trivial for you to have your fourth server (say, galera4: 161.35.120.111), have a my.cnf that reads as follows:

wsrep_cluster_address="gcomm://159.223.105.21,137.184.78.182,137.184.65.171,161.35.120.111"

Now, …

During the early stages of my career, I was captivated by the theories and concepts surrounding foreign keys and how they empowered us to maintain data integrity. However, in practical application, I have found them to be quite challenging to manage. I am sure you’re a champion DBA, but I keep my distance from foreign keys.

With that short story as a background, this post aims to address the dilemma that arises when utilizing the pt-online-schema-change tool on tables that contain foreign keys.

We already know what one of the most used Percona tools pt-online-schema-change is and how pt-online-schema-change handles foreign keys.

When utilizing the pt-online-schema-change tool to alter a table, such as …

When using the MySQL Document Store API, we can use MySQL functions in the fields() method. In this post, we will talk about how you can use MySQL functions to return aggregate data from properties with simple values and how to use user-defined functions to return aggregate values from properties that are arrays.

OpenLiteSpeed is a lightweight and open-source version of the LiteSpeed Server developed by LiteSpeed Technologies. It supports Apache Rewrite rules, HTTP/2 and HTTP/3, TLS v1.3, and QUIC protocol.

Indexes are crucial for optimizing query execution times in databases, but having an excessive number of indexes, or redundant ones, can negatively impact performance. While pt-duplicate-key-checker is the go-to tool for identifying duplicate or redundant indexes in MySQL, it may not catch all duplicates.

In this blog post, we’ll put ourselves to the test and see if we can identify duplicate and redundant indexes in MySQL. Toward the end, we will identify what the pt-duplicate-key-checker doesn’t.

The unique quiz

Consider the following MySQL table definition. Let’s put our brains to work and note any of the duplicate or redundant indexes (play fair, don’t cheat):

CREATE TABLE `table_with_lot_of_trouble` (
`id` int NOT NULL,
`col1` varchar(1) DEFAULT NULL,
`col2` varchar(2) DEFAULT NULL,
`col3` varchar(3) …

Fossasia 2023

Codership is pleased to announce a new Generally Available (GA) release of the multi-master Galera Cluster for MySQL 5.7, consisting of MySQL-wsrep 5.7.41 (release notes, download) and MySQL-wsrep 8.0.32 (release notes, download). This release incorporates all changes to MySQL 5.7.41 and MySQL 8.0.32 respectively, adding a …

For a long time, MyDumper has been the fastest tool to take Logical Backups. We have been adding several features to expand the use cases. Masquerade was one of these features, but it was only for integer and UUID values. In this blog post, I’m going to present a new functionality that is available in MyDumper and will be available in the next release: we added the possibility to build random data based on a format that the user defines.

How does it work?

During export, mydumper sends SELECT statements to the database. Each row is written one by one as an INSERT statement. Something important that you might not know, is that each column of a row can be transformed by a function. When you execute a backup, the default function is the identity function, as nothing needs to be changed. The function, which can be configured inside the defaults file, will change the …

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In this blog, I will share the steps I took to debug an error ‘ERROR 1030 (HY000): Got error 168 – ‘Unknown (generic) error from engine’ from storage engine’ while…

The post How to fix 1030 Unknown generic error from engine in MySQL first appeared on Change Is Inevitable.