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Displaying posts with tag: Insight for DBAs (reset)
MySQL Connection Security With Connection Control Plugins

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 …

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Backup and Restore with MyDumper on Docker

At the end of 2021, I pushed the first Docker image to 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 
     -v ${backups}:/backups  
     sh -c "rm -rf /backups/data; 
          mydumper -h 
               -o /backups/data 
               -B test 
               -v 3 
               -r 1000 
               -L /backups/mydumper.log"

You will find the …

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Proof of Concept: Horizontal Write Scaling for MySQL With Kubernetes Operator

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 …

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How To Use pt-secure-collect for Capturing Data in a Secure Way From the OS and Database System

Sometimes crucial data sharing is avoided because of compliance rules, organizational policies, or numerous security concerns. The common use cases involve sharing pt-mysql-summary, pt-stalk, and other OS-related details to assist Support Engineers or any other third-party team troubleshoot database-related issues.

In this context, pt-secure-collect is a very important utility from Percona, which helps capture the required information securely and also provides aid in masking the existing information.

Pt-secure-collect helps in collecting, sanitizing, and encrypting data from various sources. By default, this utility collects the output with the help of pt-stalk, pt-summary, and pt-mysql-summary.

Let’s see how this tool …

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Save Money in AWS RDS: Don’t Trust the Defaults

Default settings can help you get started quickly – but they can also cost you performance and a higher cloud bill at the end of the month. Want to save money on your AWS RDS bill? I’ll show you some MySQL settings to tune to get better performance, and cost savings, with AWS RDS.

Recently I was engaged in a MySQL Performance Audit for a customer to help troubleshoot performance issues that led to downtime during periods of high traffic on their AWS RDS MySQL instances. During heavy loads, they would see messages about their InnoDB settings in the error logs:

[Note] InnoDB: page_cleaner: 1000ms intended loop took 4460ms. The settings might not be optimal. (flushed=140, during the time.)

This message is normally a side effect of a storage subsystem that is not capable of keeping up with the number of writes (e.g., IOPs) required by MySQL. This …

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Fixing Errant GTID With Orchestrator: The Easy Way Out

In this article, we will discuss errant Transaction /GTID and how we can solve them with the Orchestrator tool.

Orchestrator is a MySQL high availability and replication management tool that runs as a service and provides command line access, HTTP API, and Web interface. I will not go into the details of the Orchestrator but will explore one of the features that can help us solve the errant GTID in a replication topology.

What are errant transactions?

Simply stated, they are transactions executed directly on a replica. Thus they only exist on a specific replica. This could result from a mistake (the application wrote to a replica instead of writing to the source) or by design (you need additional tables for reports).

What problem can errant transactions cause?

The major problem it causes during a planned change in a MySQL replication topology is that the transaction is not present in the binlog and hence …

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Upgrading to MySQL 8: Tools That Can Help

As we approach end of life for MySQL 5.7 later this year, many businesses are currently working towards upgrading to MySQL 8. Such major version upgrades are rarely simple, but thankfully there are tools that can help smooth the process and ensure a successful upgrade.

It should be noted that while the technical aspects of the upgrade process are beyond the scope of this blog post, it is crucial to create a testing environment to verify the upgrade before proceeding to upgrade your production servers, particularly with MySQL 8. 

As there is no procedure for downgrading from MySQL 8 other than restoring a backup, testing and validation are more critical than previous major version …

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MySQL 8.0.33 – A Quick Peek

MySQL released version 8.0.33 on April 18th, featuring some attention-catching features.  This blog post is a quick review of the release notes looking for the exciting items, and comments in italics are solely my own.

User-defined collations are now deprecated and will be removed in a future version.  This is probably not a show-stopper for most and probably a scary situation for those dependent on them as there may not be an alternative.  Hopefully, UTF8MB4 is good enough.

The Performance Shema now has a Server Telemetry Traces service. This interface provides plugins and components a way to retrieve notifications related to SQL statements’ lifetime. We are directed to the Server telemetry traces service section in the MySQL Source Code documentation

The SSL library has been updated to OpenSSL version …

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Don’t Auto pt-online-schema-change for Tables With Foreign Keys

During the early stages of my career, I was captivated by the theories and concepts surrounding foreign keys and how they empowered us to maintain data integrity. However, in practical application, I have found them to be quite challenging to manage. I am sure you’re a champion DBA, but I keep my distance from foreign keys.

With that short story as a background, this post aims to address the dilemma that arises when utilizing the pt-online-schema-change tool on tables that contain foreign keys.

We already know what one of the most used Percona tools pt-online-schema-change is and how pt-online-schema-change handles foreign keys.

When utilizing the pt-online-schema-change tool to alter a table, such as …

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Take This Unique Quiz About Duplicate Indexes In MySQL | pt-duplicate-key-checker

Indexes are crucial for optimizing query execution times in databases, but having an excessive number of indexes, or redundant ones, can negatively impact performance. While pt-duplicate-key-checker is the go-to tool for identifying duplicate or redundant indexes in MySQL, it may not catch all duplicates.

In this blog post, we’ll put ourselves to the test and see if we can identify duplicate and redundant indexes in MySQL. Toward the end, we will identify what the pt-duplicate-key-checker doesn’t.

The unique quiz

Consider the following MySQL table definition. Let’s put our brains to work and note any of the duplicate or redundant indexes (play fair, don’t cheat):

CREATE TABLE `table_with_lot_of_trouble` (
`id` int NOT NULL,
`col1` varchar(1) DEFAULT NULL,
`col2` varchar(2) DEFAULT NULL,
`col3` varchar(3) …
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