If you are thinking of using ProxySQL in our Percona XtraDB Cluster environment, I’ll explain how to use ProxySQL 2 for failover tasks.

How to Test

ProxySQL uses the “weight” column to define who is the WRITER node. For this example, I’ll use the following list of hostnames and IPs for references:

+-----------+----------------+
| node_name | ip             |
+-----------+----------------+
| pxc1      | 192.168.88.134 |
| pxc2      | 192.168.88.125 |
| pxc3      | 192.168.88.132 |
+-----------+----------------+

My current WRITER node is the “pxc1” node, but how can I see who is the current WRITER? It’s easy, just run the following query:

proxysql> select hostgroup_id, comment, hostname, status, weight from runtime_mysql_servers;

This is the output: …

The management of database performance is an area that businesses when administrators often find themselves contributing more time to than they expected.

Monitoring and reacting to the production database performance issues is one of the most critical tasks within a database administrator job. It is an ongoing process that requires constant care. Application and underlying databases usually evolve with time; grow in size, number of users, workload, schema changes that come with code changes.

Long-running queries are seldom inevitable in a MySQL database. In some circumstances, a long-running query may be a harmful event. If you care about your database, optimizing query performance, and detecting long-running queries must be performed …

The importance of having periodic backups is a given in Database life. There are different flavors: binary ones (Percona XtraBackup), binlog backups, disk snapshots (lvm, ebs, etc) and the classic ones: logical backups, the ones that you can take with tools like mysqldump, mydumper, or mysqlpump. Each of them with a specific purpose, MTTRs, retention policies, etc.

Another given is the fact that taking backups can be a very slow task as soon as your datadir grows: more data stored, more data to read and backup. But also, another fact is that not only does data grow but also the amount of MySQL instances available in your environment increases (usually). So, why not take advantage of more MySQL instances to take logical backups in an attempt to make this operation faster?

Distributed Backups (or Using all the Slaves Available)

…

Given: a table with JSON arrays

CREATE TABLE t (id int auto_increment primary key, d json);
INSERT INTO t VALUES (1, '["apple", "apple", "orange"]');
INSERT INTO t VALUES (2, '["apple", "banana", "orange", "orange", "orange"]');

The desired output is each row with a count of the unique objects:

+------+----------------------------------------+
| id   | fruitCount                             |
+------+----------------------------------------+
|    1 | {"apple": 2, "orange": 1}              |
|    2 | {"apple": 1, "banana": 1, "orange": 3} |
+------+----------------------------------------+

JSON_TABLE() can transform the array into rows.

SELECT id, fruit
FROM t,
JSON_TABLE(d,
    "$[*]" COLUMNS (
        fruit VARCHAR(100) PATH "$"
    )
) AS dt;

+----+--------+
| id | fruit  |
+----+--------+
|  1 | apple  |
|  1 | apple  |
|  1 | orange |
|  2 | apple  |
|  2 | banana |
|  2 | orange |
|  2 | orange |
|  2 | …

We are happy to announce that on Monday, Jan 13, 2020 there will be a meetup in Dubai on the "MySQL 8 - State of the Dolphin" topic. Please find details below:

• Name: MySQL User Group U.A.E meetup
• Topic: MySQL 8 - State of the Dolphin
• Date: Monday, January 13, 2020
• Time: 7pm - 10pm
• Place: Dubai Internet City
• Agenda:
  • Kenny Gryp from the MySQL Product Management Group talk about MySQL Database Architectures (MySQL InnoDB cluster)
  • Frederic (LeFred) Descamps from the MySQL Community team will talk about MySQL Shell (including NoSQL)
  • Mario Beck, Manager of MySQL Enterprise PreSales team & Chetan …

Recently, I was puzzled by MySQL replication !  Some weird, but completely documented, behavior of replication had me scratching my head for hours.  I am sharing this war story so you can avoid losing time like me (and also maybe avoid corrupting your data when restoring a backup).  The exact justification will come in a follow-up post, so you can also scratch your head trying

MySQL obviously got many things right, otherwise, it would not be the World’s Most Popular Open Source Database (according to DB-Engines). Sometimes, however, I run into some decisions or behaviors which are just plain bad designs. Many such designs have a lot of historical reasoning behind them and maybe they are still here because not enough resources are allocated to cleaning up technical debt.

I’m passionate about observability, especially when it comes to understanding system performance. One of the most important pieces of data to understand MySQL Performance is understanding its latches contention (mutexes, rwlocks, etc).

The “best” way to understand latches in MySQL is Performance Schema. Unfortunately latching profiling is disabled by default in Performance Schema because it causes quite a significant overhead; significant enough you likely will not be …

Percona Monitoring and Management (PMM) has been on the road for a while now, and it brings exciting new features and improvements. For those who are not familiar with the tool, PMM allows deep insight into the performance of applications and databases. The most crucial highlight: it is 100% open-source. Also, the source code is present on GitHub.

Back to new features and improvements. One of them, that customers were requesting, was the support for LDAP. This feature finally arrived with PMM version 2 thanks to the new version of Grafana, and I intend to demonstrate in …

Throughout this tutorial for beginners you'll learn to use Laravel 6 - the latest version of one of the most popular PHP frameworks - to create a CRUD web application with a MySQL database and Bootstrap 4 styles from scratch and step by step starting with the installation of Composer (PHP package manager) to implementing and serving your application.

Note: Laravel 6 is recently released and this tutorial is upgraded to the latest version.

What is Bootstrap 4?

Bootstrap 4 is the latest version of Twitter Bootstrap which is a CSS framework that allows web developers to professionally style their web interfaces without being experts in CSS.

Bootstrap 4 is based on Flexbox and allows you to build responsive layouts with easy classes and utilities.

What is CRUD?

CRUD stands for Create, Read, Update and Delete which are operations needed in most data-driven apps that access and work with data from a …

Debezium has packed with monitoring metrics as well. We just need to consume and expose it to the Prometheus. A lot of use of useful metrics are available in Debezium. But unfortunately, we didn’t find any Grafana dashboards to visualizing the Debezium metrics. So we built a dashboard and share it with the Debezium community. Still, a few things need to improve, but almost all the metrics are covered in one single dashboard.

Debezium MySQL monitoring metrics:

Debezium MySQL connector has three types of metrics.

1. Schema History — Track the schema level changes.
2. Snapshot — Track the progress about the snapshot.
3. Binlog — Real-time reading binlog events.

Setup Monitoring for MySQL connector:

We need to install JMX exporter for monitoring the debezium MySQL connector. We have already blogged about this with detailed steps.

…