This blog post will focus on failover and recovery scenarios inside the InnoDB Cluster and ClusterSet environment. To know more about the deployments of these topologies, you can refer to the manuals – InnoDB Cluster and Innodb ClusterSet setup.

In the below snippet, we have two clusters (cluster1 and cluster2), which are connected via an async channel and combined, known as a ClusterSet topology. We are going to use the below topology in all of our cases.

MySQL  127.0.0.1:3308 ssl  JS > myclusterset.status({extended: 1})
{
    "clusters": {
        "Cluster1": {
            "clusterRole": "PRIMARY", …

In InnoDB, the undo log and the redo log are two indispensable components that play a vital role in maintaining data integrity and ensuring transactional consistency. Both logs are crucial in the ACID (Atomicity, Consistency, Isolation, Durability) properties of database systems. Additionally, they are essential for the Multi-Version Concurrency Control (MVCC) mechanism. In this blog post, we will delve into the differences between the InnoDB undo log and redo log, exploring their significance and providing code examples to illustrate their usage.

InnoDB Undo Log

The undo log, also known as the rollback segment, is a crucial part of the InnoDB storage engine. Its primary purpose is to support transactional consistency and provide the ability to …

This blog was originally published in July 2017 and was updated in August 2023.

It’s a pretty common question around here, so let’s see what we can do about that.

So, What is MySQL Partitioning?

Partitioning is a way in which a database (MySQL in this case) splits its actual data down into separate tables but still gets treated as a single table by the SQL layer.

When partitioning in MySQL, it’s a good idea to find a natural partition key. You want to ensure that table lookups go to the correct partition or group of partitions. This means that all SELECT, UPDATE, and DELETE should include that column in the WHERE clause. Otherwise, the storage engine does a scatter-gather and queries ALL partitions in a UNION that is not concurrent.

Generally, you must add the partition key into the primary key along …

Fragmentation is a common concern in some database systems. Highly fragmented tables can affect performance and resource allocation. But reducing fragmentation often involves rebuilding the table completely. This blog post will discuss fragmentation and its impact on InnoDB.

What is fragmentation?

We say that something is fragmented when it is formed by parts that are separate or placed in a different order than the natural one. In databases, we can experiment with different types of fragmentation:

• Segment Fragmentation: segments are fragmented; they are stored not following the order of data, or there are empty pages gaps between the data pages.
• Tablespace Fragmentation: the tablespace is stored in non-consecutive filesystem blocks.
• Table Fragmentation: data is stored not following the primary key order (heap tables), …

Learn how Multi-Valued Indexing in MySQL 8.0 can enhance query performance by efficiently indexing and querying JSON arrays. Discover the benefits, implementation steps, and considerations for optimizing your MySQL database.

1. Multi-Valued Indexing in MySQL 8.0
2. Understanding Multi-Valued Indexes and their benefits
3. Creating Multi-Valued Indexes in MySQL …

Learn how to seamlessly add a new node to MySQL Group Replication from a backup. Scale your cluster, save time, and efficiently manage data updates and recoveries.

1. Hot Physical backup approach
2. Clone plugin approach
3. Logical backup approach

We highly recommend checking out our previous blog post on …

This blog post was originally published in November 2017 and was updated in June 2023.

In this blog, we’ll provide a comparison between MariaDB vs. MySQL (including Percona Server for MySQL).

Introduction: MariaDB vs. MySQL

The goal of this blog post is to evaluate, at a higher level, MariaDB vs. MySQL vs. Percona Server for MySQL side-by-side to better inform the decision making process. It is largely an unofficial response to published comments from the MariaDB Corporation.

It is worth noting that Percona Server for MySQL is a drop-in compatible branch of MySQL, where Percona contributes as much as possible upstream. MariaDB Server, on the other hand, is a fork of MySQL 5.5. They cherry-picked MySQL features and don’t …

Learn how the parallel index rebuild feature in MySQL 8.0.31 improves performance by optimizing index and column additions. Explore the multithreaded insert phase, sort index build process, and system configurations for enhanced efficiency.

1. Understanding Sorted Index Build
   1. When does InnoDB use a sort index build approach?
2. Phases of Sort …

Discover how to troubleshoot a MySQL replica IO thread stuck in a connecting state. Learn about the replication architecture, security group rules for AWS EC2 instances, and how to address common issues like network restrictions and bind address configuration.

MySQL is a powerful database management and a widely used cloud database service. One of its key features is the ability to create replicas of a master database to improve its availability and scalability. However, at times the IO thread in a MySQL replica may get stuck in a connecting state, which can cause replication issues and affect the overall data consistency …

Table of contents:

1. Introduction
2. Common reasons for switching the primary node
3. Primary Promotion and its importance
4. Methods for switching the primary node
5. …