The latest from the MySQL community

As a follow up to the previous blog from Aug 15, we are happy to announce a list of events and conferences where you can find MySQL Community and/or MySQL Team at. Please see the updated list below, with past events at the end of the report below: Past Events:

MySQL offers a wide array of options to configure replication, but with all of those options, how can you be sure you are doing it right?

Replication is the first step to providing a higher level of availability to your MySQL database. A well configured replication architecture can be the difference between your data being highly available, or your MySQL setup becoming a management nightmare. At PlanetScale, we support hundreds of thousands of database clusters, all using replication to provide high availability, so we have a little bit of experience in this arena!

In this article, we’re going to explore some of the best practices when it comes to replication, both locally and across longer distances.

Use an active/passive configuration

When replicating with …

We don't say that quite often, but here is an update to end all updates, one of the biggest bulks of new features and enhancements that dbForge Studio for MySQL has ever seen.

The post Meet the Grand New dbForge Studio MySQL 10.0 with Integrated Source Control! appeared first on Devart Blog.

A common strategy of modern development, especially in serverless applications, is to offload user management to third-party authentication services, commonly referred to as Identity Providers (IdP). While this shifts the focus and responsibility of managing your users’ data to another organization, implementing this strategy brings several tradeoffs:

1. You don’t have direct access to user data within your own systems.
2. You can’t perform secondary actions when a user changes their data in some way.
3. Any API calls where the user’s info is used would require you to call the IdP, making the responses take longer.

In this article, you’ll learn how to address each of these issues using webhooks, a pattern where the IdP can send an HTTP call to your API to inform you of any changes made on their end. To do this, you’ll be using a combination of Clerk, Netlify, and PlanetScale.

For …

In this blog post, we’ll review how to run Linux profilers such as perf and produce flame graphs on Kubernetes environments.

Flame graphs are a graphical representation of function calls. It shows which code paths are more busy on the CPU in given samples. They can be generated with any OS profiler that contains stack traces such as perf, eBPF, and SystemTap.

An example of a flame graph can be found below:

Each box is a function in the stack, and wider boxes mean more time the system was busy on CPU on these functions.

Kubernetes limitations

In Linux, by default, performance system events can’t be collected by unprivileged users. In regular environments, this can be easily worked around by running the profiler with a sudo privilege.

On the other hand, in Kubernetes environments, pods are the smallest deployable unit that consists of one or more containers. Exploits are generally targeted to …

As the usage of your app grows, performance can steadily decline.

There’s nothing necessarily surprising by that statement, but what is surprising is the number of bottlenecks that can surface and the options available to you to fix them. One such bottleneck can be directly related to the time it takes to read from and write to your database. After all, behind the complexities of a relational database, you’re still working with storage systems that have inherent IO latency.

This is where a well-architected caching system can help.

A good caching system can reduce the load on your database and increase the general performance of your application. A faster application results in happier users and potentially more revenue, which is always a good thing! However, caching systems have their own setup complexities, along with a number of gotchas that might creep up unexpectedly.

In this article, we’ll explore …

This blog post discusses roles in MySQL 8.0, which are named collections of privileges. Like user accounts, roles can have privileges granted and revoked as required.

Typically, we have multiple users with the same set of privileges. Previously, the only way to grant and revoke privileges to multiple users was to change the privileges of each user individually, which was time-consuming. To make it easier, MySQL provided a new object called role. A role is a named collection of privileges.

Here are the primary SQL commands that we will be discussing in relation to managing MySQL roles:

CREATE ROLE and DROP ROLE create and remove roles.
GRANT and REVOKE assign privileges to revoke privileges from user accounts and roles.
SHOW GRANTS displays privilege and role assignments for user accounts and roles.
SET DEFAULT ROLE specifies which account roles are active by default.
SET ROLE changes the active roles within the current session.
The …

Performing an operation is always challenging when dealing with K8s.

When on-prem or DBaaS like RDS or Cloud SQL, it is relatively straightforward to apply a change. You can perform a DIRECT ALTER, use a tool such as pt-osc, or even, for certain cases where async replication is in use, perform changes on replicas and failover.

In this blog post, I’ll provide some thoughts on how schema changes can be performed when running MySQL on Kubernetes

I won’t focus on DIRECT ALTERs as it is pretty straightforward to apply them. You can just connect to the MySQL service POD and perform the ALTER.

But how can we apply changes in more complex scenarios where we may want to benefit from pt-osc, gain better control over the operation, or take advantage of the K8s features?

One convenient way that I’ve found …

Transparent Huge Pages (THP) is a memory management feature in Linux operating systems that aims to enhance system performance. While THP can be beneficial for many applications, enabling it on a database server could have unintended consequences. In this post, we will explore THP, its impact on database servers, and how to disable it for optimal performance and stability.

What are Transparent Huge Pages?

In order to understand THP, we should first start with a brief description of Linux HugePages. The concept of HugePages in Linux has existed for many years, first introduced in 2007. By default, the majority of widely used Linux distributions employ a virtual memory page size of 4KB. However, the inclusion of the HugePages feature allows the Linux kernel to efficiently handle substantial memory pages alongside the standard 4KB size.

In order for an application to utilize HugePages, however, it must explicitly include an …

As a DBA, one of the very frequent tasks is to stop/start MySQL service for batching or some other activities. Before stopping MySQL, we may need to check if there are any active connections; if there are, we may need to kill all those. Generally, we use pt-kill to kill the application connections or prepare kill statements using the select queries.

Example commands:

pt-kill --host=192.168.11.11 --user=percona -p --sentinel /tmp/pt-kill.sentinel2 --pid /tmp/pt-kill.pid  --victims all --match-command 'Query' --ignore-user 'pmm|rdsadmin|system_user|percona' --busy-time 10 --verbose --print --kill 

select concat('kill ',id,';') from information_schema.processlist where user='app_user';

MySQL has a variable called offline_mode to set the server into maintenance mode. When you set this, it immediately disconnects all the client connections that don’t …