Upgrading to MySQL version 8.0 is a hot topic since version 5.7 is approaching the official end of life very soon. MySQL 5.7 EOL is set for the end of October 2023.

If you feel unprepared for the upgrade, consider post-EOL support from Percona. But it would be the worst if you proceeded with the upgrade in haste.

• Long database service downtime
• Some queries become slow
• Applications stop working due to incompatibilities
• Data loss

This is what can happen if MySQL’s major upgrade to 8.0 turns out not as you hoped for. Yes, it can be that serious, so do consider the major upgrade as an important project, not just a routine maintenance task! From my experience as a Support Engineer, I think the most frequent problem is query …

This post was originally published in July 2018 and was updated in July 2023.

Now that Database-as-a-service (DBaaS) is in high demand, there are multiple questions regarding AWS services that cannot always be answered easily: When should I use Aurora and when should I use RDS MySQL?  What are the differences between Aurora and RDS? How do I choose which one to use?

In this blog, we will answer all of these important questions and provide a general overview comparing the two database services, Aurora vs RDS.

Understanding DBaaS

DBaaS cloud services allow users to use databases without configuring physical hardware and infrastructure or installing software. But …

Recently, I was working on a very unfortunate case that revolved around diverging clusters, data loss, missing important log errors, and forcing commands on Percona XtraDB Cluster (PXC). Even though PXC tries its best to explain what happens in the error log, I can vouch that it can be missed or overlooked when you do not know what to expect.

This blog post is a warning tale, an invitation to try yourself and break stuff (not in production, right?).

TLDR:
Do you know right away what happened when seeing this log?

2023-06-22T08:23:29.003334Z 0 [ERROR] [MY-000000] [Galera] gcs/src/gcs_group.cpp:group_post_state_exchange():433: Reversing history: 171 -> 44, this member has applied 127 more events than the primary component.Data loss is possible. Must abort.

Demonstration

Using the …

MySQL Shell is an advanced client and code editor for MySQL. In addition to the provided SQL functionality, similar to MySQL, MySQL Shell provides scripting capabilities for JavaScript and Python and includes APIs for working with MySQL. The X DevAPI enables you to work with both relational and document data, and MySQL Shell 8.0 is highly recommended for use with MySQL Server 8.0 and 5.7.

MySQL Shell includes utilities for working with MySQL. To access the utilities from within MySQL Shell, use the util global object, which is available in JavaScript and Python modes, but not SQL mode. These are the utilities to take a backup; let’s see some basic commands.

• util.dumpTables – Dump one or more tables from single database
• util.dumpSchemas – Dump one or more databases
• util.dumpInstance – Dump full instance
• util.loadDump – Restore dump

1. Single table …

In Percona Managed Services, one key aspect of managing the databases is configuring backups. Percona XtraBackup is one of the best tools for performing physical database backups.

It is a good practice to compress the backups to save costs on storage and to encrypt the backups so those can’t be used if the files are compromised as long as you keep your encryption keys safe!

Percona XtraBackup supports both compression and encryption of the backups. When the data is too big (tens of TB and more), the backups can take several hours or even days to complete. In order to speed up the backup process along with the compression and encryption, we can use multiple threads. We can specify the number of threads to be used for each operation (copy, compression, …

Often while managing and creating new users, we use all the default options and tend not to use extra features provided by MySQL. These extra options could prevent a user from using all the resources and degrading the performance of MySQL. In this blog, we will discuss a few such features that will put resource restrictions on users.

max_user_connections

Sometimes, due to unprecedented growth or huge transactions, a single user makes too many connections, and the MySQL server gets starved of free connections. This blocks the DBA from logging into MySQL to fix it. To fix it in MySQL 5.7 and below, we have to do a restart. For MySQL 8, it can be done without a restart, but we have to configure the admin interface beforehand. You can read more about it here in Dealing With “Too Many Connections” Error in MySQL 8.

This blog post was originally published in November 2017 and was updated in June 2023.

In this blog, we’ll provide a comparison between MariaDB vs. MySQL (including Percona Server for MySQL).

Introduction: MariaDB vs. MySQL

The goal of this blog post is to evaluate, at a higher level, MariaDB vs. MySQL vs. Percona Server for MySQL side-by-side to better inform the decision making process. It is largely an unofficial response to published comments from the MariaDB Corporation.

It is worth noting that Percona Server for MySQL is a drop-in compatible branch of MySQL, where Percona contributes as much as possible upstream. MariaDB Server, on the other hand, is a fork of MySQL 5.5. They cherry-picked MySQL features and don’t …

As a database administrator, have you ever been in a situation when your database confronted a brute force attack? A brute force attack can be launched against a user account in MySQL. MySQL replies with success or error based on supplied credentials, and the time required for the verification is almost the same in either case. Hence, an attacker can launch a brute force attack against a MySQL user account at a rapid rate and can try many different passwords.

According to cryptography, a brute-force attack consists of an attacker trying many passwords or passphrases with the hope of eventually guessing correctly. The attacker systematically checks all possible passwords and passphrases until the correct one is found.

It’s not just brute force attacks going on; the IT industry has recently seen a steady increase in distributed denial of service (DDoS) attacks. Have you also been targeted in such a type of connection flow on port …

At the end of 2021, I pushed the first Docker image to hub.docker.com. This was the first official image and since then, we have been improving our testing and packaging procedures based on Docker, CircleCI, and GitHub Actions. However, when I’m coding,  I’m not testing in Docker. But a couple of weeks ago, when I was reviewing an issue, I realized some interesting Docker use cases that I want to share.

Common use case

First, we are going to review how to take a simple backup with MyDumper to warm you up:

docker run --name mydumper 
     --rm 
     -v ${backups}:/backups  
     mydumper/mydumper:v0.14.4-7 
     sh -c "rm -rf /backups/data; 
          mydumper -h 172.17.0.5 
               -o /backups/data 
               -B test 
               -v 3 
               -r 1000 
               -L /backups/mydumper.log"

You will find the backup …

Historically MySQL is great in horizontal READ scale. The scaling, in that case, is offered by the different number of Replica nodes, no matter if using standard asynchronous replication or synchronous replication.

However, those solutions do not offer the same level of scaling for writes operation.

Why? Because the solutions still rely on writing in one single node that works as Primary. Also, in the case of multi-Primary, the writes will be distributed by transaction. In both cases, when using virtually-synchronous replication, the process will require certification from each node and local (by node) write; as such, the number of writes is NOT distributed across multiple nodes but duplicated.

The main reason behind this is that MySQL is a relational database system (RDBMS), and any data that is going to be written in it must respect the RDBMS …