Shinguz's blog

FromDual has the pleasure to announce the release of the new version 2.1.0 of its popular Database Performance Monitor for MariaDB and Galera Cluster fpmmm.

Translated by deepl.com

Introduction

Two points in advance:

1. A deadlock is a state in which two different transactions are no longer able to continue working because each transaction holds a lock that the other transaction would need. Because both transactions are now waiting for the other transaction to release their locks, neither transaction will release their respective locks. And that would last forever. To avoid this, the MariaDB instance intervenes and kills the transaction that has done less work. The application then receives a deadlock error message of this type:

Scenario: MariaDB Community Server is release every 3 months. The exact date is not known but it is typically about 2 to 3 weeks after the MySQL/Oracle CPU.

FromDual has the pleasure to announce the release of the new version 1.2.1 of its popular FromDual Ops Center focmm, a Graphical User Interface (GUI) for MariaDB, MySQL and compatible databases.

FromDual has the pleasure to announce the release of the new version 1.2.0 of its popular FromDual Ops Center focmm, a Graphical User Interface (GUI) for MariaDB, MySQL and compatible databases.

Table of Contents

• Systemd Notizen
• InnoDB NUMA interleave with MariaDB
• Checking Galera Cluster SST timeout with Systemd
• Kill MariaDB Galera node under Systemd
• MariaDB Memory locking (--memlock) with Systemd
• Who is restarting my mariadbd?
• Location of Systemd unit files

Systemd Notizen

Systemd paged per default nach less. Das ist ungewohnt und doof, weil es gegen allgemeines Linux-Verhalten verstösst. Abhilfe schafft:

A while ago I read a paper about Optimizer Benchmarks: How Good Are Query Optimizers, Really? by Viktor Leis from Fakultät für Informatik of the Technische Universität München.

Before you consider migrating your data from MySQL to another database you have to know which objects have to be migrated.

If you do not feel at home on the command line, you may prefer to use a graphical user interface (GUI). These also have advantages, for example when displaying data or structures, or they can simplify and therefore speed up work processes.

Sometimes SQL developers ask me if there is a difference between putting the Filter in the WHERE Clause and putting the Filter in the ON Clause and if yes, what the difference is. To explain it the best I have stolen a little example (Source at the end):

Currently we are in the testing phase of the next release of our Ops Center (focmm). This testing is quite complex because it includes testing the interaction of various different components like a MariaDB Galera Cluster, a Galera Load Balancer, a virtual IP, etc.

The newest release of the Performance Monitor for MariaDB and MySQL v2.0.0 (fpmmm) allows you to monitor your MariaDB and MySQL databases via SNMP (Simple Network Management Protocol).

FromDual has the pleasure to announce the release of the new version 2.0.0 of its popular Database Performance Monitor for MariaDB and Galera Cluster fpmmm.

For this how-to we were working with a MariaDB 10.6.5 database server and the newest MariaDB MaxScale 6.3.0 (aka 2.6) load balancer/proxy.

Because the original MariaDB documentation is a little bit sparse about this topic here are some notes about how to do a streaming MariaDB backup:

FromDual has the pleasure to announce the release of the new version 2.2.5 of its popular Backup and Recovery Manager for MariaDB and MySQL (brman).

Are containers so popular because application developers do not know how to write multi-threaded applications well? With containers you can circumvent this problem a bit. You ramp up man single threaded applications in containers and thus get a multi-threaded behaviour.
Databases ARE already multi-threaded. So no need to containerize them.

As already mentioned earlier, we roughly have a hand full of customers which are playing with the though of sharding solutions. They typically have many different customers (clients, tenants) and the number of customers becomes so huge (thousands to millions) that one machine cannot cope with the load any more.

In the last months we got more and more requests for supporting MariaDB/MySQL/Galera Cluster in (mostly Docker) containers.