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MySQL Master Replication Crash Safety part #4: benchmarks (under the hood)

This post is a sister post to MySQL Master Replication Crash Safety Part #4: benchmarks of high and low durability.  There are no introduction or conclusion to this post, only landing sections: reading this post without its context is not recommended. You should start with the main post and come back here for more details.

Environment

My benchmark environment is composed of three vms in

Understand Database Performance Trends – SQL Diagnostic Manager for MySQL (formerly Monyog)

Next in our Benefits of SQL Diagnostic Manager for MySQL (formerly Monyog) blog series, we discuss monitoring and understanding performance trends using visual analytics and the display dashboard of SQL Diagnostic Manager for MySQL. If you missed it, you can read last week’s blog on identifying and analyzing problematic SQL queries.

View and Understand Trends By Analyzing Historical Data

Configure the time duration for storing the data collected by SQL Diagnostic Manager for MySQL. It stores the data in a high-performance database (that is, the embedded relational database management system SQLite). By analyzing historical data, quickly obtain answers to questions like:

  • How many times and when did database servers go down during the last six months? Which …
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Summary of trailing spaces handling in MySQL, with version 8.0 upgrade considerations

Fairly recently, we’ve upgraded to MySQL 8; it’s been a relatively smooth transition, however, some minor differences needed to be handled. One of them is the behavior of trailing spaces.

Trailing spaces are a (not in a good way) surprising, but also widely covered argument. This article gives a short overview, and relates it to how this affects people upgrading to MySQL 8.0.

Contents:

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MySQL Workbench and OpenStreetMap Data Visualization

I have a presentation next month on MySQL and GIS.  MySQL 8.0 has benefited greatly from the three dimensional libraries from Boost.Geometry. There are many facets to the Geographic Data world that it is damn near impossible not to lurch down one rabbit hole into another in an unending spiral of acronyms, standards, projections, and functions.  But thankfully I have MySQL Workbench to aid me.

Texas
I wanted some test data to use for some GIS exercises and was very happy to find many useful sets curated by the OpenStreetMaps folks. Shapefiles are used to hold the various data points of an item of interest.  I had assumed that the data would have some sort of longitude/latitude pairs but was wondering what I would need to do to work with that data and what ever came bundled with it.  I download the Texas data and then …

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The Best Way to Host MySQL on Azure Cloud

Are you looking to get started with the world’s most popular open-source database, and wondering how you should setup your MySQL hosting? So many default to Amazon RDS, when MySQL performs exceptionally well on Azure Cloud. While Microsoft Azure does offer a managed solution, Azure Database, the solution has some major limitations you should know about before migrating your MySQL deployments. In this post, we outline the best way to host MySQL on Azure, including managed solutions, instance types, high availability replication, backup, and disk types to use to optimize your cloud database performance.

MySQL DBaaS vs. Self-Managed MySQL

The first thing to consider when weighing between self-management and a MySQL Database-as-a-Service …

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Preview of the upcoming new features in MySQL 8.0.17

Note: I am no longer working for Oracle/MySQL. This post is based on public information.

The MySQL 8.0.17 release is around the corner. Let's take a look at the new features in the upcoming release.

InnoDB redo log archive

InnoDB added new parameter “--innodb-redo-log-archive-dirs” in 8.0.17, according to the doc page. The implementation of both page archive and redo log archive has been in the code for a while, under arch directory. This feature can be used by backup and database clone.


Multi-Valued Indexes

As of MySQL 8.0.17, InnoDB supports multi-valued indexes. A multi-valued index is a secondary index defined on a column that stores an array of values. A “normal” index has one index record for each data record (1:1). A multi-valued index …

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MySQL Replication with ProxySQL on WHM/cPanel Servers - Part 1

WHM and cPanel is no doubt the most popular hosting control panel for Linux based environments. It supports a number of database backends - MySQL, MariaDB and PostgreSQL as the application datastore. WHM only supports standalone database setups and you can either have it deployed locally (default configuration) or remotely, by integrating with an external database server. The latter would be better if you want to have better load distribution, as WHM/cPanel handles a number of processes and applications like HTTP(S), FTP, DNS, MySQL and such.

In this blog post, we are going to show you how to integrate an external MySQL replication setup into WHM seamlessly, to improve the database availability and offload the WHM/cPanel hosting server. Hosting providers who run MySQL locally on the WHM server would know how demanding MySQL is in terms of resource utilization (depending on the number of accounts it hosts and the server specs).

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Fixing MySQL 1045 Error: Access Denied

During our work in support, we see this again and again: “I try to connect to MySQL and am getting a 1045 error”, and most times it comes accompanied with “…but I am sure my user and password are OK”.  So we decided it was worth showing other reasons this error may occur.

MySQL 1045 error Access Denied triggers in the following cases: 1) Connecting to wrong host:

[engineer@percona]# mysql -u root -psekret
mysql: [Warning] Using a password on the command line interface can be insecure. 
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

If not specifying the host to connect (with -h flag), MySQL client will try to connect to the localhost instance while you may be trying to connect to another host/port instance.

Fix: Double check if you are trying to connect to localhost, or be sure to specify host and port if it’s not localhost:

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SQL Except Clause Example | Except Statement In SQL

SQL Except Clause Example | Except Statement In SQL is today’s topic. The SQL EXCEPT operator is used to combine two select statements, which in turn returns the row that is present in the first select statement and not in the second select statement. This Clause acts like a subtract operation that we perform in sets and Venn diagrams.

SQL Except Clause Example

In SQL, EXCEPT returns those tuples that are returned by the first SELECT operation, and not returned by the second SELECT operation.

#Pictorial Representation

 

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Galera Cluster at Percona Live Austin, DataOps.Barcelona and where next

It is July now, and summer is upon us. The team at Codership are busy making Galera Cluster 4 for MySQL, and we are just hot of the heels of celebrating the launch of Galera Cluster 4 with MariaDB Server 10.4

At the end of May, Galera Cluster had a booth and several talks at Percona Live Austin. This was the first time the event happened there, and we thoroughly enjoyed it. The key takeaway from that event would be Seppo Jaakola’s talk titled: Galera Cluster New Features. It covered the then upcoming MariaDB Server 10.4 release with Galera Cluster 4, went in-depth into how streaming replication works …

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