To set correct system variable values is the essential step to get the correct server behavior against the workload.  

In MySQL we have many System variables that can be changed at runtime, most of them can be set at session or at global scope. 

To change the value of a system variable at global level in the past user need to have SUPER privileges. Once the system variable value is modified as global, the server will change his behavior for the session, and obviously as global scope. For instance, one of the most commonly adjusted variables is probably max_connections. If you have max_connection=100 in your my.cnf or as default value, and during the day as DBA you notice that the number of them is not enough, it is easy just to add new connections on the fly, the command:

SET GLOBAL MAX_CONNECTIONS=500;

Will do the work. But here is the issue. We had changed a GLOBAL value, that apply to the whole …

MySQL Memory Calculator

Check out the “MySQL Memory Calculator” added to my blog page, which will be helpful to calculate MySQL memory usage during tuning of MySQL memory parameters. https://www.abhinavbit.com/p/mysql-memory-calculator.html

Photo by Kelly Sikkema on  …

Through Amazon Web Services (AWS), you can create virtual servers (i.e., instances). You can install database and Galera software on them. In this article, we’ll create three nodes, the minimum recommended for a healthy cluster, and configure them to use Galera Cluster.

Incidentally, there is a more detailed version of this article in the Tutorial section of our Library.

Assumptions & Preparation

We’re assuming you have an AWS account and know the basics of the EC2 (Elastic Compute Cloud) platform.

To access the nodes, you’ll need an encryption key. Create a new one specifically for Galera, using a tool such as ssh-keygen. Add that key to AWS, under Key Pairs.

Creating AWS Instances

To …

Overview The Skinny

Part of the power of Tungsten Clustering for MySQL / MariaDB is its intelligent MySQL Proxy, known as the Tungsten Connector. The Tungsten Connector has built-in read-write splitting capabilities, and it is also possible to configure different algorithms which select the appropriate slave (i.e. Round-Robin or Lowest-Latency).

The Question Recently, a customer asked us:

How do we best share the load between read-only slaves? Currently, there appears to be an imbalance, with most of the read-only queries reaching just one slave. What may we do to improve this situation?

This customer noticed that a couple of long …

Without a doubt, the MySQL database is the most popular database that already exists. There are countless tricks, options, and functions available for MySQL developers. The developers often are surrounded by many technical and detailed contents which can easily distract them from MySQL's big picture. The problem is that they lack a checklist of all the essential techniques to master. I have developed and normalized many advance MySQL databases (along with IT consulting), which motivated me to write this article. What follows are 15 essential tricks or things that any serious MySQL developer should know.

When somebody wants to migrate from a single MySQL instance to a full HA solution using MySQL InnoDB Cluster, the best solution to reduce the downtime is to use asynchronous replication and switch database only once at a certain point in time when everything is ready. This is almost what I explained already in this post.

The most difficult part was related to the provisioning of the existing data to the new cluster members. A backup (physical or logical) was required. It should have been restored on every nodes and we had to be sure to not mess up with the GTIDs.

This is not more the case since MySQL 8.0.17 ! Now we can use the CLONE plugin to start the cluster provisioning too.

The current situation

…

Percona is glad to announce the release of Percona XtraBackup 8.0.7 on August 7, 2019. You can download it from our download site and apt and yum repositories.

Percona XtraBackup enables MySQL backups without blocking user queries, making it ideal for companies with large data sets and mission-critical applications that cannot tolerate long periods of downtime. Offered free as an open source solution, it …

This tutorial explains how you can grant privileges on a database in MySQL. It will introduce you all the steps beginning from connecting to MySQL and then accessing the MySQL commands to set the desired level of privileges. So, if you wish to grant or update the privileges in MySQL, first you should connect to […]

The post Grant Privileges on a Database in MySQL appeared first on TechBeamers.

This tutorial explains how you can grant privileges on a database in MySQL. It will introduce you all the steps beginning from connecting to MySQL and then accessing the MySQL commands to set the desired level of privileges. So, if you wish to grant or update the privileges in MySQL, first you should connect to […]

The post Grant Privileges on a Database in MySQL appeared first on TechBeamers.

This tutorial explains how to use the MySQL FROM_UNIXTIME() function with the help of examples. By using it, you can convert or display a UNIX_TIMESTAMP value to a timestamp. The output format is either YYYY-MM-DD-HH-MM-SS or YYYYMMDDHHMMSS, which depends on the calling context of the function. It means that FROM_UNIXTIME() would return a string for […]

The post MySQL FROM_UNIXTIME() Function appeared first on TechBeamers.