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Displaying posts with tag: MySQL (reset)
MySQL 8.0.22: SHOW PROCESSLIST Version 2 – Now Available From PERFORMANCE_SCHEMA

The “SHOW PROCESSLIST” command is very famous and very useful for MySQL DBAs. It will help you to understand the ongoing thread activities and their current states. By default, the “show processlist” output details will be collected from the thread manager, and it needs the global mutex. From MySQL 8.0.22, we have an alternative way to get the process details from the PERFORMANCE_SCHEMA. It doesn’t need the global mutex. 🙂

Note: We also have the non-blocking SYS schema views “processlist” and “x$processlist”, which provide more complete information than the SHOW PROCESSLIST statement and the INFORMATION_SCHEMA.PROCESSLIST and PERFORMANCE_SCHEMA.PROCESSLIST. But, we can’t integrate this with the “SHOW PROCESSLIST” command.

In this blog, I am going to explain the complete details about the new processlist implementation using PERFORMANCE_SCHEMA.

“SHOW PROCESSLIST” Using Thread …

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MySQL NDB Cluster Backup & Restore In An Easy Way

In this post, we will see, how easily user can take NDB Cluster backup and then restore it. NDB cluster supports online backups, which are taken while transactions are modifying the data being backed up. In NDB Cluster, each backup captures all of the table content stored in the cluster.


User can take backup in the following states:


  • When the cluster is live and fully operational
  • When the cluster is live, but in a degraded state:
    • Some data nodes are down
    • Some data nodes are restarting
  • During read and write transactions

Users can restore backups in the following cluster environments:

  • Restore to the same physical cluster
  • Restore into a different physical cluster
  • Restore into a different configuration cluster i.e. backup …
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MySQL Backup and Recovery Best Practices

In this blog, we will review all the backup and restore strategies for MySQL, the cornerstones of any application. There are a few options, depending on your topology, MySQL versions, etc. And based on that, there are some questions we need to ask ourselves to make sure we make the right choices.

How many backups we need to keep safe, or what’s the best retention policy for us?

This means the number of backups to safeguard, whether local or remote (external fileserver, cloud). The retention policy can be daily, weekly, or monthly, depending on the free space available.

What is the Recovery Time Objective?

The Recovery Time Objective (RTO) refers to the amount of time that may pass during a disruption before it exceeds the maximum allowable threshold specified in the Business Continuity Plan.

The key question related to RTO is, “How quickly must the data on this system be restored?”

What is …

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FOSDEM 2021 MySQL Devroom Schedule

The FOSDEM 2021 MySQL Devroom Schedule is now online.

Thank you again to all who submitted a talk and thank you the to Committee for having build such agenda.

It seems that once again, MySQL Operations and Architecture are very popular.

As you probably know already, this event will be totally online this year.

I would like to thanks the people who were able to jump after some cancellations… virtual events are not the most popular for speakers.

The MySQL Devroom will take place Sunday February 7th form 10AM to 6PM CEST.

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Webinar January 26: Using Percona Monitoring and Management to Identify and Troubleshoot Problematic MySQL Queries

Join us as Michael Coburn, Percona Product Manager, discusses two methods to identify and troubleshoot problematic MySQL queries using the RED Method and Percona Monitoring and Management (PMM) Query Analytics. He will also highlight specific Dashboards in PMM that visualize the rate, errors, and duration of MySQL events that may be impacting the stability and performance of your database instance.

Please join Michael Coburn, Product Manager, Percona, on Tuesday, January 26th, 2021 at 2:30 pm for his webinar “Using Percona Monitoring and Management to Identify and Troubleshoot Problematic MySQL Queries”.

Register for Webinar

If you can’t attend, sign up anyway

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MySQL macOS Docker

While you can download MySQL as a DMG package, a number of users would prefer to install it as a Docker instance. You won’t find the macOS downloads on the same web site as other downloads. You can use the following macOS download site.

After installing Docker on your macOS, you can pull a copy of the current MySQL Server with the following command:

docker pull mysql/mysql-server

You should create a mysql directory inside your ~/Documents directory with this command:

mkdir ~/Documents/mysql

Then, you should use the cd command to change into the ~/Documents/mysql directory and run this command:

pwd

It should return the following directory: …

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MySQL Group Replication – How to Elect the New Primary Node

In this blog, I am going to explain the different ways of electing the PRIMARY node in MySQL group replication. Before MySQL 8.0.2, primary election was based on the member’s UUID, with the lowest UUID elected as the new primary in the event of a failover.

From MySQL 8.0.2: We can select the node to be promoted as a PRIMARY using the server weight ( group_replication_member_weight ). This can be achieved during the failure of the current primary node.

From MySQL 8.0.12: We can promote any node as a PRIMARY using the function “group_replication_set_as_primary”. This can be set anytime without any failures of nodes.

Scenario:

 I have installed the 3 node group replication cluster. I am using Percona Server for MySQL 8.0.22.

mysql> select …
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Full Read Consistency Within Percona Kubernetes Operator for Percona XtraDB Cluster

The aim of Percona Kubernetes Operator for Percona XtraDB Cluster is to be a special type of controller introduced to simplify complex deployments. The Operator extends the Kubernetes API with custom resources. The Operator solution is using Percona XtraDB Cluster (PXC) behind the hood to provide a highly available, resilient, and scalable MySQL service in the Kubernetes space. 

This solution comes with all the advantages/disadvantages provided by Kubernetes, plus some advantages of its own like the capacity to scale reads on the nodes that are not Primary.

Of course, there are some limitations like the way PXC handles DDLs, which may impact the service, but there is always a cost to pay to get something, expecting to have it all for free is unreasonable.     

In this context, we need to …

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Percona Kubernetes Operator for Percona XtraDB Cluster: HAProxy or ProxySQL?

Percona Kubernetes Operator for Percona XtraDB Cluster comes with two different proxies, HAProxy and ProxySQL. While the initial version was based on ProxySQL, in time, Percona opted to set HAProxy as the default Proxy for the operator, without removing ProxySQL. 

While one of the main points was to guarantee users to have a 1:1 compatibility with vanilla MySQL in the way the operator allows connections, there are also other factors that are involved in the decision to have two proxies. In this article, I will scratch the surface of this why.

Operator Assumptions

When working with the Percona Operator, there are few things to keep in mind:

  • Each deployment has to be seen as a single MySQL service as if a single MySQL instance
  • The technology used to provide the service may change in time …
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MySQL sakila Database

While I thought my instructions were clear, it appears there should have been more in my examples for using the MySQL MSI. A key thing that happened is that students opted not to install:

Samples and Examples 8.0.22

Unfortunately, they may not have read the Preface of Alan Beaulieu’s Learning SQL, 3rd Edition where he explains how to manually download the files from the MySQL web site. Here are those, very clear, instructions (pg. XV) with my additions in italics for the MySQL Shell:

First, you will need to launch the mysql command-line client or the mysqlsh command-line shell, and provide a password, and then perform the following steps:

  1. Go to https://dev.mysql.com/doc/index-other.html and download the files for the …
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