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Displaying posts with tag: Insight for Developers (reset)
MySQL 8.0.28 Quick Peek

Oracle released MySQL 8.0.28 on January 18th with little fanfare, as part of their four times a year release cycle.  So what is included in the new release? Over the past few years, there have been some cool new features included in these ‘dot’ releases that some in the community say would have been better off being labeled as a major release. But what is in .28? Below are the more interesting changes in the database server and the shell, as there was not a whole lot changed in the other products such as router or MEM… I put my asides in italics and my views probably do not reflect the views of anyone else.

And remember, 8.0.29 is due in April.

The TL;DR

The TL;DR synopsis is that a lot of excellent work went into MySQL Server & shell 8.0.28 but the pressing question is do you really need to install it right away?  On the scale from ‘you probably should wait to upgrade’ to ‘update ASAP’ it …

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Using Percona Server for MySQL 8.0 and Percona XtraBackup 8.0 with HashiCorp Vault Enterprise KMIP Secrets Engine

KMIP (Key Management Interoperability Protocol) is an open standard developed by OASIS (Organization for Advancement of Structured Information Standards) for the encryption of stored data and cryptographic key management.

Percona Server for MySQL 8.0.27 and Percona XtraBackup 8.0.27 now include a KMIP keyring plugin to enable the exchange of cryptographic keys between a key management server and the database for encryption purposes. The procedure to use them with HashiCorp Vault Enterprise is described below.

Install Hashicorp Vault Enterprise

We will first install Hashicorp Vault Enterprise on Ubuntu Linux “Bionic” and then enable …

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Economical Comparison of AWS CPUs for MySQL (ARM vs Intel vs AMD)

It is always hard to select a CPU for your own purpose. You could waste hours reviewing different benchmarks, reviews, and bloggers, and in the end, we would limit all our requirements to performance and price. For performance measuring we already have some specific metrics (e.g. in MHz to some specific tool), however, for economic comparison, it is quite hard.  Mostly we are limited by our budget. Again, for our personal purposes, we are limited only with the cash in our pockets. It is easy to compare only two or three CPUs; it is required just to compare their price and performance and then create a simple bar plot and then check the results. However, what do you do if you have at least three types of CPU, a different number of CPUs cores on board, and seven different scenarios?  It was a challenge to do it for performance, and for economic efficiency, it has become a nightmare. For a one-time purchase, it should be easier than for the …

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In Application and Database Design, Small Things Can Have a Big Impact

With modern application design, systems are becoming more diverse, varied and have more components than ever before. Developers are often forced to become master chefs adding the ingredients from dozens of different technologies and blending them together to create something tasty and amazing. But with so many different ingredients, it is often difficult to understand how the individual ingredients interact with each other. The more diverse the application, the more likely it is that some seemingly insignificant combination of technology may cause cascading effects.

Many people I talk to have hundreds if not thousands of different libraries, APIs, components, and services making up the systems they support. In this type of environment, it is very difficult to know what small thing could add up to something much bigger. Look at some of the more recent …

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Q & A on Webinar “MySQL Performance for DevOps”

First I want to thank everyone who attended my November 16, 2021 webinar “MySQL Performance for DevOps“. Recording and slides are available on the webinar page.

Here are answers to the questions from participants which I was not able to provide during the webinar.

Q: Hi! We have troubles with DELETE queries. We have to remove some data periodically (like, hourly, daily) and we have short-term server stalls during these DELETEs. Server is running on modern NVMe’s so we wonder why do we have this situation. Those DELETE’s are not so large, like 10 000 – 15 000 records, but tables on which DELETE’s are performed update frequently.

A: I would test if a similar

DELETE

  statement is slow when you run it on …

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What if … MySQL’s Repeatable Reads Cause You to Lose Money?

Well, let me say if that happens it’s because there is a logic mistake in your application. But you need to know and understand what happens in MySQL to be able to avoid the problem. 

In short, the WHY of this article is to inform you about possible pitfalls and how to prevent them from causing you damage.

Let us start by having a short introduction to what Repeatable reads are about. Given I am extremely lazy, I am going to use (a lot) existing documentation from the MySQL documentation.

Transaction isolation is one of the foundations of database processing. Isolation is the I in the acronym ACID; the isolation level is the setting that fine-tunes the balance between performance and reliability, consistency, and reproducibility of results when multiple transactions are making changes and performing …

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MySQL 8: Random Password Generator

As part of my ongoing focus on MySQL 8 user and password management, I’ve covered how using the new dual passwords feature can reduce the overall DBA workload and streamline the management process. I’ve also covered how the new password failure tracking features can enable the locking of an account with too many failed password attempts (see MySQL 8: Account Locking).

There are other new and useful features that have been added to the user management capabilities in MySQL 8 however, and an often overlooked change was the implementation of a random password generator. First introduced in MySQL 8.0.18, with this feature, CREATE USER, ALTER USER, and SET PASSWORD statements have the capability of generating random passwords for user accounts as an alternative to …

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Horizontal Scaling in MySQL – Sharding Followup

In a previous post, A Horizontal Scalability Mindset for MySQL, I discussed the concerns around growing individual MySQL instances too large and some basic strategies:

  • Optimizing/minimizing size with proper data types
  • Removing unused/duplicate indexes
  • Keeping your Primary Keys small
  • Pruning data

Finally, if those methods have been exhausted, I touched on horizontal sharding as the approach to keep individual instances at a reasonable size. When discussing my thoughts across our internal teams, there was lots of feedback that we needed to dive into the sharding topic in more detail. This post aims to give more theory and considerations around sharding along with a lightweight ProxySQL sample implementation.

What is Sharding?

Sharding is a word that is frequently used but …

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Resolving the MySQL Active-Active Replication Dilemma

Multi-writer replication has been a challenge in the MySQL ecosystem for years before truly dedicated solutions were introduced – first Galera (and so Percona XtradDB Cluster (PXC)) replication (around 2011), and then Group Replication (first GA in 2016).

Now, with both multi-writer technologies available, do we still need traditional asynchronous replication, set up in active-active topology? Apparently yes, there are still valid use cases. And you may need it not only when for some reason Galera/PXC or GR are not suitable, but also when you actually use them. Of course, the most typical case is to have a second cluster in a different …

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Yearly Reminder: DDLs That Fail to Propagate May Cause Percona XtraDB Cluster Inconsistencies

Apologies for the silly title, but the issue is a real one, even though it is not a new thing. Schema upgrades are not an ordinary operation in Galera. For the subject at hand, the bottom line is: under the default Total Order Isolation (TOI) method, “the cluster replicates the schema change query as a statement before its execution.” What this means in practice is that a DDL issued in one node is replicated to other nodes in the cluster before it is even executed in the source node, let alone completed successfully.

As a result of this, it may fail in one node and be successful in another, and this without raising loud alerts or stopping nodes to protect against data inconsistency. This is not a bug in itself but rather a compromise of design. With new changes in MySQL and the …

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