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Displaying posts with tag: Percona XtraDB Cluster (reset)
Percona XtraDB Cluster on Amazon EC2 and Two Interesting Changes in PXC 8.0

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 …

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How to Build Percona XtraDB Cluster From Sources

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 …

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Managing MySQL Configurations with the PXC Kubernetes Operator V1.10.0 Part 1: Introduction

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 …

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Preventing Stale Reads on Percona XtraDB Cluster by Enforcing Causality Checks on a Per-Query Basis

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 …

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A Look Into Percona XtraDB Cluster Non-Blocking Operation for Online Schema Upgrade

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 …

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PXC Scheduler Handler: The Missing Piece for Galera/Percona XtraDB Cluster Puzzle

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 …

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How To Recover Percona XtraDB Cluster 5.7 Node Without SST

The Problem

State Snapshot Transfer can be a very long and expensive process, depending on the size of your Percona XtraDB Cluster (PXC)/Galera cluster, as well as network and disk bandwidth. There are situations where it is needed though, like after long enough node separation, where the gcache on other members was too small to keep all the needed transactions.

Let’s see how we can avoid SST, yet recover fast and without even the need for doing a full backup from another node.

Below, I will present a simple scenario, where one of the cluster nodes was having a broken network for long enough that it will make …

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Skipping Percona Server for MySQL Version 8.0.24 and Releasing 8.0.25 Next

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 …

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Yearly Reminder: DDLs That Fail to Propagate May Cause Percona XtraDB Cluster Inconsistencies

Apologies for the silly title, but the issue is a real one, even though it is not a new thing. Schema upgrades are not an ordinary operation in Galera. For the subject at hand, the bottom line is: under the default Total Order Isolation (TOI) method, “the cluster replicates the schema change query as a statement before its execution.” What this means in practice is that a DDL issued in one node is replicated to other nodes in the cluster before it is even executed in the source node, let alone completed successfully.

As a result of this, it may fail in one node and be successful in another, and this without raising loud alerts or stopping nodes to protect against data inconsistency. This is not a bug in itself but rather a compromise of design. With new changes in MySQL and the …

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Point-In-Time Recovery in Kubernetes Operator for Percona XtraDB Cluster – Architecture Decisions

Point-In-Time Recovery (PITR) for MySQL databases is an important feature that is essential and covers common use cases, like a recovery to the latest possible transaction or roll-back the database to a specific date before some bad query was executed. Percona Kubernetes Operator for Percona XtraDB Cluster (PXC) added support for PITR in version 1.7, and in this blog post we are going to look into the technical details and decisions we made to implement this feature.

Architecture Decisions Store Binary Logs on Object Storage

MySQL uses …

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