Are you planning an upgrade for your Percona XtraDB Cluster (PXC)? Upgrading to PXC 8.0 can be a smooth process, but sometimes challenges arise that require careful troubleshooting. In this…

The post How to fix Percona XtraDB Cluster 8.0 Upgrade issues first appeared on Change Is Inevitable.

Recently, I was working on a very unfortunate case that revolved around diverging clusters, data loss, missing important log errors, and forcing commands on Percona XtraDB Cluster (PXC). Even though PXC tries its best to explain what happens in the error log, I can vouch that it can be missed or overlooked when you do not know what to expect.

This blog post is a warning tale, an invitation to try yourself and break stuff (not in production, right?).

TLDR:
Do you know right away what happened when seeing this log?

2023-06-22T08:23:29.003334Z 0 [ERROR] [MY-000000] [Galera] gcs/src/gcs_group.cpp:group_post_state_exchange():433: Reversing history: 171 -> 44, this member has applied 127 more events than the primary component.Data loss is possible. Must abort.

Demonstration

Using the …

Course Dates

Public course: EMEA timezone 26th of September. USA timezone 27th of September.

Company dedicated training or consulting session, request for dates for your company via email to: sales@galeracluster.com

Course Duration

1 day.  The breakdown is 3 hours, with a half hour lunch break, and another 3 hours per day. There will be bio-breaks. The total contact time with the trainer is 6 hours over a span of 1 day.

Requirements

• You need to be able to use Zoom the platform we will be using
• You will need to have access to an SSH client. Being in a Microsoft Windows environment is OK, but you need to have SSH to access the remote servers that we provide you access to.
• Some basic understanding of Linux (e.g. package management) as well as MySQL
…

In this blog post, I will try to cover a few dump and data-loading utilities offered by MySQL Shell.

What is MySQL Shell?

It is a robust client and code editor for MySQL. In addition to having APIs for dealing with MySQL, MySQL Shell offers scripting capabilities for JavaScript and Python. It provides an AdminAPI to manage MySQL servers and create InnoDB Cluster and ReplicaSet deployments. It supports an X DevAPI to work on both SQL and NoSQL interfaces via the X Protocol. Finally, it provides utilities to make working with MySQL in Python and Javascript mode easier.

Now, let’s jump into some practical stuff and see what these tools offer us.

Dump Utility

In the dump utility, there are three tools: util.dumpInstance(), util.dumpSchemas(), and util.dumpTables () so let’s discuss them one by one. 

1.  “util.dumpInstance()” – This was introduced in MySQL Shell 8.0.21 and …

This article outlines the basic configurations for setting up and deploying Percona XtraDB Cluster 8.0 (PXC) on Amazon EC2, as well as what is new in the setup compared to Percona XtraDB Cluster 5.7.

What is Percona XtraDB Cluster an ideal fit for?

Percona XtraDB Cluster is a cost-effective, high-performance clustering solution for mission-critical data. It combines all the improvements, and functionality found in MySQL 8 with Percona Server for MySQL‘s Enterprise features and Percona’s upgraded Galera library.

A Percona XtraDB Cluster environment is an ideal fit for applications requiring 5-9s uptime with high read …

Percona XtraDB Cluster (PXC) is a database clustering solution for MySQL. It ensures high availability, prevents downtime and data loss, and provides linear scalability for a growing environment.

Lately, the number of questions about how to build Percona software has increased. More and more people try to add their own patches, add some modifications, and build software by themselves. But this raises the question of how to do this in the same way as Percona does, as sometimes the compiler flag can make a drastic impact on the final binary. This is a really essential question and let’s look at how we build Percona XtraDB Cluster here at Percona.

At the first glance, the building process is not something difficult. Everyone knows that magic make install all command and suppose that as a result everything will be …

Introduction/FAQ

Question: I need to run a production-grade open source MySQL DB.

Answer: Percona to the rescue! Percona XtraDB Cluster (PXC) is an open source enterprise MySQL solution that helps you to ensure data availability for your applications while improving security and simplifying the development of new applications in the most demanding public, private, and hybrid cloud environments

Question: I forgot to mention that I need to run it on Kubernetes.

Answer: Percona to the rescue again! Percona Distribution for MySQL Operator based on Percona XtraDB Cluster contains everything you need to quickly and consistently deploy and scale Percona XtraDB …

When we run a SELECT in a replica server and it returns a different result to the one we would have obtained had we queried the source server instead, due to changes in the dataset that have not yet been replicated or synchronized to the replica, we get what is known as a stale read. My colleague Marcelo has blogged about Stale Reads and How to Fix Them before.

The need to avoid stale reads is a constraint that leads people into migrating to Percona XtraDB Cluster (PXC) / Galera Cluster or, more recently, Group Replication. I am focusing on PXC and Galera in this short blog post, which, similar to Group Replication, implements not exactly a synchronous replication model but what is commonly referred to as a …

Percona XtraDB Cluster 8.0.25 (PXC) has introduced a new option to perform online schema modifications: NBO (Non-Blocking Operation).

When using PXC, the cluster relies on the wsrep_OSU_method parameter to define the Online Schema Upgrade (OSU) method the node uses to replicate DDL statements. 

Until now, we normally have three options:

• Use Total Isolation Order (TOI, the default)
• Use Rolling Schema Upgrade (RSU)
• Use Percona’s online schema change tool (TOI + PTOSC)

Each method has some positive and negative aspects. TOI will lock the whole …

Working on a real case scenario in a five node Percona XtraDB Cluster (PXC), we were forced to use wsrep_sync_wait = 1, because the app does reads-after-write and we send reads to all the nodes. We had the idea to leave some nodes in DESYNC mode to reduce the flow control messages during peak load and expected to have a steadier write throughput keeping the read consistency.

We decided to test Perconas’s new PXC Scheduler Handler which is an application that manages integration between ProxySQL and Galera/PXC (the scope is to maintain the ProxySQL mysql_server table, if a negative scenario occurs, like: failures, service degradation, and maintenance). However, we realized that when a node is in DESYNC mode, it is kicked out of the read hostgroup. That is …