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 …

There are plenty of ways to run ProxySQL in Kubernetes (K8S). For example, we can deploy sidecar containers on the application pods, or run a dedicated ProxySQL service with its own pods.

We are going to discuss the latter approach, which is more likely to be used when dealing with a large number of application pods. Remember each ProxySQL instance runs a number of checks against the database backends. These checks monitor things like server-status and replication lag. Having too many proxies can cause significant overhead.

Creating a Cluster

For the purpose of this example, I am going to deploy a test cluster in GKE. We need to follow these steps:

1. Create a cluster

gcloud container clusters create ivan-cluster --preemptible --project my-project --zone us-central1-c --machine-type n2-standard-4 --num-nodes=3

2. Configure command-line access

gcloud …

As we’ve communicated in our blog post in May, the TokuDB Storage Engine has been marked as “deprecated” in Percona Server for MySQL 8.0. It will be removed in a future version (Percona Server for MySQL 8.0.28, expected to ship in Q1 2022).

With the release of Percona Server for MySQL 8.0.26, the storage engine will still be included in the binary builds and packages but will be disabled by default. If you are upgrading from a previous version, the TokuDB Storage Engine plugin will fail with an error message at server startup if it is installed.

You will still be able to re-enable it manually so that you can perform the necessary migration steps.

Re-enabling the TokuDB …

As part of my ongoing focus on MySQL 8 user and password management, I’ve covered how the new dual passwords feature can reduce the overall DBA workload and streamline the management process (see MySQL 8: Dual Passwords). This wasn’t the only change to user/password management in MySQL 8; one of the more security-focused changes was the implementation of temporary account locking, first introduced in MySQL 8.0.19. With this feature, database administrators can now configure user accounts so that too many consecutive login failures can temporarily lock the account.

The account locking feature only applies to the failure of a client to provide a correct password during the connection attempt. It does not apply to failure to connect for other reasons (network issues, unknown user account, etc.). In the case of dual passwords, either of the account …

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 …

As a Technical Account Manager at Percona, I get to work with many of our largest clients. While the industry verticals vary, one main core challenge generally remains the same – what do I do with all this data? Dealing with massive data sets in MySQL isn’t a new challenge, but the best approach still isn’t trivial. Each application is obviously different, but I wanted to discuss some of the main best practices around dealing with lakes of data.

Keep MySQL Instances Small

First and foremost, the architecture needs to be designed to keep each MySQL instance relatively small. A very common question I get from teams new to working with MySQL is: “So what is the largest instance size MySQL supports?”. My answer goes back to my time in consulting: “It depends”. Can my MySQL instance support a 20TB dataset? Maybe, but it depends on the workload pattern. Should I store 20TB of data in a single MySQL instance? In most cases, …

MySQL 8 comes with a lot of good features, and recently I explored its password management systems. I wanted to put together a series of blogs about it, and this is the first part. In this post, I am going to explain the following topics in detail.

• Password Reuse Policy
• Random Password Generation

Password Reuse Policy

MySQL has implemented restrictions on reusing passwords. Restriction can be established in two ways:

• Number of password changes
• Time elapsed

Number of Password Changes

From the MySQL documents:

If an account is restricted on the basis of number of password changes, a new password cannot be chosen from a specified number of the most recent passwords.

To test this, in my local environment I have created the user with “number of password changes = 2”.

mysql> create user …

Primary Key design is an important thing for InnoDB performance, and choosing a poor PK definition will have an impact on performance and also write propagation in databases. When this comes to Aurora, this impact is even worse than you may notice.

In short, we consider a poor definition of a Primary Key in InnoDB as “anything but quasi sequential values”, which may cause very random access to data and thus increase the IO dependency.

In this post, I’ll try to demonstrate the potential impact of the primary key design when running on Aurora, and how a bad design can lead to a 15x write latency penalty (or more).

The Analysis

Recently I worked on a case where a customer was having issues with scaling writes in Aurora MySQL. While this is a known limitation in Aurora considering how the distributed storage layer syncs out data among all nodes of the cluster, we observed additional latency occurring when more …

The new MyDumper 0.11.1 version, which includes many new features and bug fixes, is now available.  You can download the code from here.

For this release, there are three main changes: 1) we added config file functionality which allows users to set session-level variables (one of the most requested features!), 2) we developed a better and robust import mechanism, and 3) we fixed all the filename related issues.  Those changes and mostly the last one forced us to change the version number from 0.10.9 to 0.11.1 as a backup taken in 0.10.x will not work in 0.11.x and vice versa.

New Features:

• Adding order by part functionality #388
…

When doing migrations or failovers in MySQL, there is usually a need to do a topology change and repoint replica servers to obtain replication data from a different server.

For example, given servers {A, B, and C} and the following topology:

If you need to repoint C to be a replica of B, i.e:

You can follow the next steps:

Note: log_replica_updates should be enabled on the soon-to-be primary as it is a prerequisite for chain replication.

Note: It is assumed that both replicas only stream from Server A and there are no conflicting replication filters in place that might break replication later on.

If Using File/Position-Based Replication:

1) Stop B and C

STOP REPLICA;

2) If replicas are multi-threaded, correct MTS gaps and make them …