When connecting to a local MySQL instance, you have two commonly used methods: use TCP/IP protocol to connect to local address –  “localhost” or 127.0.0.1  – or use Unix Domain Socket.

If you have a choice (if your application supports both methods), use Unix Domain Socket as this is both more secure and more efficient.

How much more efficient, though?  I have not looked at this topic in years, so let’s see how a modern MySQL version does on relatively modern hardware and modern Linux.

Benchmarking  TCP/IP Connection vs Unix Domain Socket for MySQL

I’m testing Percona Server for MySQL 8.0.19 running on Ubuntu 18.04 on a Dual Socket 28 Core/56 Threads Server.  (Though I have validated results on 4 …

The backup and restore of a complete database is an extensive exercise. But what if you need to restore just one table which has been mistakenly modified by an incorrect query? Help is at hand with Percona XtraBackup.

For our purpose, we will take a test database having tables created by the sysbench tool. The 8.0 versions of Percona XtraBackup and Percona Server for MySQL have been used in this test.

Restore Single Table

Here we will take the backup of the sbtest2 table and restore it. The initial checksum of the table is given below:

8.0.19>CHECKSUM TABLE sbtest2;
+--------------+-----------+
| Table        | Checksum | …

Percona Server for MySQL 8.0.19 includes the experimental simple LDAP authentication plugin, which allows for direct authentication using an LDAP server. Similarly to the data masking plugin added in 8.0.18, this plugin was also added as a community contribution from Francisco Miguel Biete.

Authenticating with LDAP

In earlier versions, Percona Server for MySQL supported the built-in authentication mechanism of MySQL and also included a port of the PAM plugin from MySQL enterprise.

As LDAP servers can be configured as backends for PAM, this already provided a way to authenticate SQL users using LDAP, by adding PAM as an intermediate layer — requiring setting up both the auth_pam plugin and configuring PAM to use LDAP for authenticating mysqld users.

With this …

We recently released an experimental version of percona-dbaas command-line tool with the goal of significantly simplifying the deployment of database instances in Kubernetes.

We have Kubernetes Operators for Percona XtraDB Cluster and Percona Server for MongoDB, which provide great flexibility, but they also come with the complexity of managing configuration and deployment files, so we wanted to make it even simpler to deploy database instances. We found it hard enough to get a MySQL instance up and running in Kubernetes, and then a whole different process to get MongoDB up, and we thought it should be a unified set of commands. This is how the percona-dbaas CLI tool was born. You can get more information on installation of the percona-dbaas-cli tool and in this …

While there is no magic bullet for MySQL 5.7 database tuning, there are a few areas that can be focused on upfront that can dramatically improve the performance of your MySQL installation. While much information has been published on this topic over the years, I wanted to break down some of the more critical settings that anyone can implement – with no guesswork required.

Depending on the version of MySQL you are running, some of the default values used in this post may differ from your install, but the premise is still largely the same. We will focus on MySQL 5.7 for the purposes of this article.

Initial MySQL performance tuning can be broken down to the following categories:

• Tuning for your hardware
• Tuning for best performance/best practices
• Tuning for your workload

MySQL 5.7 Database Tuning Tuning For Your Hardware

Depending on the hardware …

In my Webinar on Using Percona Monitoring and Management (PMM) for MySQL Troubleshooting, I showed how to use direct queries to ClickHouse for advanced query analysis tasks. In the followup Webinar Q&A, I promised to describe it in more detail and share some queries, so here it goes.

PMM uses ClickHouse to store query performance data which gives us great performance and a very high compression ratio. ClickHouse stores data in column-store format so it handles denormalized data very well. As a result, all query performance data is stored in one simple “metrics” table:

More and more people are nowadays thinking of cloud migration. The question of “Which cloud provider performs better for my MySQL workload?” is really common but cannot always be easily answered. However, there are ways to come up with an answer. This question also applies when thinking of moving to any provider, not necessarily a cloud one or DBaaS.

The Problem

The most reliable conclusion can be found if you have a testing environment that is fully identical and can produce the same amount of traffic compared to your production version. In this case, the comparison should be straightforward as what you have to do is point your testing environment against the under-evaluation (cloud) providers, and evaluate the differences in performance. But this is not always easy, as many organizations do not have such environments or it’s not always possible to replay all traffic.

The Idea

In this …

Disclaimer: The following blog post does not try to provide a solution for split-brain situations, and the example provided is for demonstrative purposes only. Inconsistencies resulting from a split-brain scenario might possibly be more complex than the one shown, so do not use the following example as a complete guide.

What is Split-Brain?

A split-brain scenario is the result of two data sets (which were originally synced) losing the ability to sync while potentially continuing to receive DMLs over the same rows and ids on both sides. This could have consequences such as data corruption or inconsistencies where each side has data that does not exist on the other side.

For example before split-brain:

After split-brain:

Node1:

Node2:

It can be seen that after the split-brain scenario there are many differences between the nodes:

• Customer row id=2 was deleted …

Percona is happy to announce the experimental release of Percona XtraDB Cluster 8.0. This is a major step for tuning Percona XtraDB Cluster to be more cloud- and user-friendly. This is the second experimental release that combines the updated and feature-rich Galera 4, with substantial improvements made by our development team.

Improvements and New Features in Percona XtraDB Cluster

Galera 4, included in Percona XtraDB Cluster 8.0, has many new features. Here is a list of the most essential improvements:

• Streaming replication to support large transactions
• The synchronization functions allow action coordination (wsrep_last_seen_gtid, wsrep_last_written_gtid, wsrep_sync_wait_upto_gtid)
• More granular and improved error logging. wsrep_debug is …

As a MySQL DBA, the databases powering your applications need to handle changing traffic workloads while remaining responsive and stable so you can deliver an excellent user experience. Optimizing MySQL performance and troubleshooting MySQL problems cost-efficiently are some of the most critical and challenging tasks for MySQL DBAs. In this presentation, we will look at specific, common MySQL problems and demonstrate how Percona Monitoring and Management (PMM), built on free and open-source software, enables you to solve these challenges.

Please join Percona CEO Peter Zaitsev on Wednesday, March 18, 2020, at 1:30 pm EDT for his webinar “Optimize and Troubleshoot MySQL Using Percona Monitoring and Management”.

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