This blog post will cover the basic setup of the InnoDB ClusterSet environment, which provides disaster tolerance for InnoDB Cluster deployments by associating a primary InnoDB Cluster with one or more replicas in alternate locations/different data centers. InnoDB ClusterSet automatically manages replication from the primary cluster to the replica clusters via a specific ClusterSet Async replication channel. If the primary cluster becomes inaccessible due to a loss of network connectivity or a data center issue, you can make a replica cluster active in its place.

Now, let’s see in detail how exactly we can configure the topology.

We have used the sandbox environment available via MySQLShell utility for this setup.

Environment

Cluster1:
         127.0.0.1:3308
         127.0.0.1:3309
         127.0.0.1:3310

Cluster2:
         127.0.0.1:3311
         127.0.0.1:3312
         127.0.0.1:3313

Router: …

This blog was originally published in February 2017 and was updated in September 2023.

In this blog post, I provide an in-depth introduction to MySQL Replication, answering what it is, how it works, its benefits and challenges, as well as reviewing some of the MySQL replication concepts that are part of the MySQL environment (and Percona Server for MySQL specifically). I will finish by also clarifying some of the common misconceptions people have about replication and how Percona can help.

Since I’ve been working on the Solution Engineering team, I’ve noticed that – although information is plentiful – replication is often misunderstood or incompletely understood.

What is MySQL Replication?

MySQL replication is …

On the Internet, you can get a lot of advice from almost anywhere when you’re looking for information on how to do your DBA job.

My blog is one of these sources of advice, and depending on the source, we generally trust the advice more or less.

But sometimes advice doesn’t take the whole picture into account, and even if it comes from a recognized authority, it can lead to more or less serious problems.

Let’s consider the following situation:

We have an InnoDB ReplicaSet with 1 replication source (primary) and 2 replicas:

 JS > rs.status()
{
    "replicaSet": {
        "name": "myReplicaSet", 
        "primary": "127.0.0.1:3310", 
        "status": "AVAILABLE", 
        "statusText": "All instances available.", 
        "topology": {
            "127.0.0.1:3310": {
                "address": "127.0.0.1:3310", 
                "instanceRole": "PRIMARY", 
                "mode": "R/W", …

To continue our journey to Moodle on Oracle Cloud Infrastructure using Ampere compute instances and MySQL HeatWave Database Service [1] [2], in this article we will see how to scale our architecture using multiple Moodle instances, High Availability for the Database and Read Scale-Out.

This is the architecture we will deploy:

The same principles can be applied to other projects, not just Moodle.

Multiple Compute Instances & MySQL HeatWave High Availability

The first step is to use again the Stack to deploy the initial resources. We must insure that we use a MySQL Shape that has at least 4 OCPUs …

In the previous post, we saw how to quickly deploy Moodle to Oracle Cloud Infrastructure on Ampere compute instances and using MySQL HeatWave.

In this post, we will explore some other features and the benefits of running on OCI and MySQL HeatWave to extend our architecture dedicated to Moodle in the Cloud.

Read Replicas

Moodle natively offers the possibility of distributing the load between reads and writes. When using MySQL HeatWave Database Service, adding read replicas is also a very easy task. Let’s see how we can benefit from it.

To be able to use MySQL HeatWave Read Replicas, the MySQL shape must have at least 4 OCPUs.

Let’s modify the moodle stack and deploy it again but this time we choose a bigger shape for MySQL:

When everything is ready, …

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 …

I am finalizing my Percona Live talk MySQL and Vitess (and Kubernetes) at HubSpot.  In this talk, I mentioned that I like that Percona is providing better MySQL with Percona Server.  This comes with a little inconvenience though: with improvements, sometimes comes regression.  This post is about such regression and a workaround I implemented some time ago (I should have shared it

Explore the powerful features of Aurora Serverless V2 for MySQL in this informative blog series. Learn about read-only scaling, parameter support, and cost performance. Compare costs between Provisioned Aurora and Aurora Serverless V2. Discover key takeaways for optimizing your MySQL deployment on the cloud. Read now!

1. Read-only Scaling
   1. Failover replicas
   2. …

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. …