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Displaying posts with tag: Group Replication (reset)
MySQL 8.3: Purging data from your InnoDB Cluster

Maintaining a production dataset at a manageable size can present a considerable challenge during the administration of a MySQL InnoDB Cluster.

Old Days

Back in the day when we only had one main copy of our data (the source), and one read copy (the replica) that we used to look at current and old data from our main system, we used a special trick to remove data without affecting the replica. The trick was to turn off writes to the binary log for our removal commands in the main system. External tools like pt-archiver were also able to use that trick. To stop bypass writing into the binary log, we used the command: SET SQL_LOG_BIN=0.

This mean that on the main production server (replication source), we were purging the data without writing the delete operation into the binary logs:

Current Days

These …

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How to Use Group Replication with Haproxy

When working with group replication, MySQL router would be the obvious choice for the connection layer. It is tightly coupled with the rest of the technologies since it is part of the InnoDB cluster stack.The problem is that except for simple workloads, MySQL router’s performance is still not on par with other proxies like Haproxy […]

MySQL 8 and Replication Observability

Many of us, old MySQL DBAs used Seconds_Behind_Source from SHOW REPLICA STATUS to find out the status and correct execution of (asynchronous) replication.

Please pay attention of the new terminology. I’m sure we’ve all used the old terminology.

However, MySQL replication has evolved a lot and the replication team has worked to include a lot of useful information about all the replication flavors available with MySQL.

For example, we’ve added parallel replication, group replication, … all that information is missing from the the good old SHOW REPLICA STATUS result.

There much better ways to monitoring and observing the replication process(es) using Performance_Schema.

Currently in Performance_Schema, there are 15 tables relating to replication instrumentation:

+------------------------------------------------------+
| …
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Moodle on OCI with MySQL HeatWave: Extended Architectures – part 2

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

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Moodle on OCI with MySQL HeatWave: Extended Architectures – part 1

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, …

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Adding a New Node to MySQL Group Replication from a Backup: A Step-by-Step Guide

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 …

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VTGR: Vitess with Group Replication

Update June 12, 2023: This component has been deprecated in v17 and will be removed in v18! We recommend that you instead use VTOrc with the semi_sync durability policy. Introduction # MySQL group replication is a new replication mechanism that was released in 2016. Group replication involves establishing a group of nodes that are coordinated automatically via Group Communication System (GCS) protocols, an implementation of Paxos. For a transaction to commit, a majority of the group has to agree on the order of a given transaction in the global sequence of transactions.

ClusterSet, Router Integration & Operational Details uncovered, part2 of a Series

In the first part of this short series, we went through the build of a full Clusterset architecture, which included 2 full clusters (3 members each) and an additional cluster with one member, which can serve different purposes. With the MySQL ClusterSet, there are new capabilities with the router instances. These features enable valuable options for users of… Read More »

Crashing MySQL with Malicious Intent and a lot of Determination

A year ago, I blogged about An Unprivileged User can crash your MySQL Server.  At the time, I explained how to protect yourself against this problem.  A few weeks ago, I revisited this vulnerability in a follow-up post in which I explained the fix, claimed that the MySQL 5.7 default configuration for Group Replication is still problematic, and explained a tuning to avoid the

Online DDL With Group Replication in MySQL 8.0.27

In April 2021, I wrote an article about Online DDL and Group Replication. At that time we were dealing with MySQL 8.0.23 and also opened a bug report which did not have the right answer to the case presented. 

Anyhow, in that article I have shown how an online DDL was de facto locking the whole cluster for a very long time even when using the consistency level set to EVENTUAL.

This article is to give justice to the work done by the MySQL/Oracle engineers to correct that annoying inconvenience. 

Before going ahead, let us remember how an Online DDL was propagated in a group replication cluster, and identify the differences with what happens now, all with the consistency level set to EVENTUAL ( …

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