In my talk at Percona Live 2021, “Creating Chaos in Databases”, I discussed how creating a controlled interruption in available resources (I used primary pod and network interruptions) allows us to test the stability of a database, and in our case, Percona XtraDB Cluster.

I also mentioned in the talk that my testing led to diagnosing a few unpleasant bugs, namely:

• PXC-3437: Node fails to join in the endless loop
• PXC-3580: Aggressive network outages on one node makes the whole cluster unusable
• …

The practice of running databases in containers continues to grow in popularity.  As a Technical Account Manager at Percona, I get asked regularly about our Percona Distribution for MySQL Operator.  Additionally, I’m asked what I’m seeing in the industry in terms of adoption.  In most cases, the questions stem around new deployments.  Our DBaaS tool (currently in Technical Preview) makes launching a new cluster in a Kubernetes deployment trivial.  

Once the operator completes and verifies the setup, the UI displays the endpoint and credentials and you are on your way.  Voila!  You now have a cluster, behind a load balancer, that you can access from within your k8s cluster or …

In the previous release of our Percona Distribution for MySQL Operator, we implemented one interesting feature, which can be seen as “self-healing”: https://jira.percona.com/browse/K8SPXC-564.

I do not think it got enough attention, so I want to write more about this.

As it is well known, a 3-node cluster can survive a crash of one node (or pod, in Kubernetes terminology), and this case is very well handled by itself. However, if there is a problem with 2 nodes at the same time, this scenario is problematic for Percona XtraDB Cluster. Let’s see why this is a problem.

First, let’s review if the first node goes offline:

In this case, the cluster can continue work, because Node 1 and Node 2 figure out …

The combination of the information obtained from the “pt-summaries” discussed in the previous posts of this series (Part 1: The Percona Support Way, Part 2: Knowing the Server, Part 3: What MySQL?) helps us come up with the first impression of a MySQL server. However, apart from the quick glance we get at two samples of a selective group of MySQL status variables, they provide what I call a “static” view of the server, akin to looking at a still picture of an engine. We get the chance to spot some major discrepancies in the MySQL configuration in view of the available resources in the …

In the previous post of this series, we looked at the hardware specifications and operating system settings of the host server through the lenses of a pt-summary report. Now that we know the foundation on which the database is running, we can turn our focus to MySQL itself. The second of our triad of tools from the Percona Toolkit will help us with that:

pt-mysql-summary conveniently summarizes the status and configuration of a MySQL database server so that you can learn about it at a glance. 

The goal for this part is to find what MySQL distribution and version is being used if the server …

After Oracle released MySQL version 8.0.24 on April 20, 2021, our engineering team got started right away with merging our enhancements to prepare the corresponding 8.0.24 version of Percona Server for MySQL.

However, Oracle released MySQL version 8.0.25 shortly afterward on May 11, 2021, to fix a critical bug that we also observed during our initial testing and reported back to them.

Therefore, we have decided to skip releasing Percona Server for MySQL 8.0.24 both as a standalone product and a distribution as well as the …

Back in December 2018, when we announced the general availability of Percona Server for MySQL 8.0, we also announced that the TokuDB Storage Engine has been marked as “deprecated” in this release, recommending to use the MyRocks Storage Engine as an alternative. We believe that MyRocks provides similar benefits for the majority of workloads and is better optimized for modern hardware.

Since then, we have continued maintaining the storage engine in the 8.0 release, e.g. by incorporating bug fixes. However, the ongoing amount of …

Percona Server for MySQL 8.0.23-14 was released last week and I wanted to take a minute to call out some of the interesting new features that we have introduced in this release. These are included in addition to the features and improvements in MySQL 8.0.23 that were introduced by the Oracle MySQL team (and to which Percona also contributed).

Hashicorp Vault Plugin Support for KV Secrets Engine – Version 2 (PS-5364)

As of Percona Server for MySQL 8.0.23-14, the Hashicorp Vault plugin can be configured to specifically use either V1 or V2 Secrets Engine API or it can be configured to probe and auto-detect the best version to use.

…

This blog post will show how to compile the Percona XtraBackup (PXB) tool for ARM. For this, we are going to use an AWS EC2 ARM instance with Ubuntu 20.04(Focal Fossa).

The motivation for this was born in my interest in the new generation of ARM processors and if this is a viable option for the future. Ideally, I do not recommend installing all the necessary packages to compile Xtrabackup in a production environment for security reasons. Still, you can have a “compiling” server for this purpose and then move the binaries around.

Machine Configuration

For this blog post, I picked a c6g.2xlarge instance. The machine has the following hardware configuration:

Multi-writer replication has been a challenge in the MySQL ecosystem for years before truly dedicated solutions were introduced – first Galera (and so Percona XtradDB Cluster (PXC)) replication (around 2011), and then Group Replication (first GA in 2016).

Now, with both multi-writer technologies available, do we still need traditional asynchronous replication, set up in active-active topology? Apparently yes, there are still valid use cases. And you may need it not only when for some reason Galera/PXC or GR are not suitable, but also when you actually use them. Of course, the most typical case is to have a second cluster in a different …