The promise of DBaaS like RDS is to reduce operational overhead (among other things) and one of the stellar cases is upgrades (major and minor). The suggested procedure involves just a couple of steps. For example, using AWS Console, you can enable “Auto minor upgrade” or modify the DB instance and schedule the upgrade to run in the next maintenance window.

But, both these options are risky because the upgrade process will start during the maintenance window but it is NOT guaranteed that the upgrade will be completed within the specified duration. 

The Problem

RDS performs a few extra steps to ensure the data consistency and rollback, making the minor version upgrade a time-consuming process:

• It takes a backup (if automated backups are enabled) prior to starting the upgrade process.
• Performs slow shutdown after setting …

In this blog post series, we will discuss an overview of Vitess technology. Vitess is a database clustering solution for horizontal scaling of data sets currently suitable to 250Gb – 300Gb in sizes*. It’s a proven technology used by several web-scale companies including YouTube. PlanetScale is the company behind developing and supporting this open-sourced project. 

Introduction to Vitess 

Here’s high-level Vitess architecture visually explained. 

Ref: Sugu Sougoumarane presents an overview of Vitess at Highload in Moscow.

Basic Vitess Components

There are two main components of Vitess. One of them is vtgate which works as a query router where vttablet is a proxy to MySQL to serve the data. 

• …

While we’ve had MySQL Group Replication support in ProxySQL since version 1.3 (native as of v1.4), development has continued in subsequent versions. I’d like to describe a scenario of how latency can affect ProxySQL in a MySQL Group Replication environment, and outline a few new features that might help mitigate those issues. Before we dive into the specifics of the discussion, however, let’s take a quick overview of ProxySQL and Group Replication for those who may not be familiar.

MySQL Group Replication

Similar in functionality to Percona XtraDB Cluster or Galera, MySQL Group Replication is the only synchronous native HA solution for MySQL*. With built-in automatic distributed recovery, conflict detection, and group membership, MySQL GR provides a completely native HA solution for MySQL environments.

In a high concurrency world, where more and more users->connections->threads are used, contention is a given. But how do we identify the contention point easily?

Different approaches had been discussed previously, like the one using Perf and Flame graphs to track down the function taking way more time than expected. That method is great but how can we do it with what one normally has, like the MySQL Client? Enter: the SEMAPHORES section from the SHOW ENGINE INNODB STATUS command output.

SEMAPHORES

The SEMAPHORES section displays all the metrics related to InnoDB mechanics on waits. This section is your best friend if you have a high concurrency workload. In short, it contains 2 kinds of data: …

As the world’s most popular open-source database, MySQL has been around the block more than a few times. Traditionally installed in on-premise data centers, recent years have shown a major trend for MySQL in the cloud, and near the top of this list is Amazon RDS.

Amazon RDS allows you to deploy scalable MySQL servers within minutes in a cost-efficient manner with easily resizable hardware capacity. This frees you up to focus on application development and leaves many of the traditional database administration tasks such as backups, patching, and monitoring in the hands of AWS.

In this post I’d like to go over six important benefits of Amazon RDS, and why a move into RDS may be the right move for you.

Easy Deployment

Amazon RDS allows you to use either the AWS Management Console or a set of APIs to create, delete, and modify your database instances. You have full control of access and security …

The innodb_io_capacity and innodb_io_capacity_max are often misunderstood InnoDB parameters. As consultants, we see, at least every month, people setting this variable based on the top IO write specifications of their storage. Is this a correct choice? Is it an optimal value for performance? What about the SSD/Flash wear leveling?

Innodb_io_capacity 101

Let’s begin with what the manual has to say about innodb_io_capacity:

“The innodb_io_capacity variable defines the number of I/O operations per second (IOPS) available to InnoDB background tasks, such as flushing pages from the buffer pool and merging data from the change buffer.“

What does this mean exactly? …

If you do a quick web search about UUIDs and MySQL, you’ll get a fair number of results. Here are just a few examples:

• Storing UUID and Generated Columns
• Storing UUID Values in MySQL
• Illustrating Primary Key models in InnoDB and their impact on disk usage
• MySQL UUID Smackdown: UUID vs. INT for Primary Key
• GUID/UUID Performance Breakthrough
• …

Some say that the best password is the one you don’t have to remember. That’s possible with MySQL, thanks to the auth_socket plugin and its MariaDB version unix_socket.

Neither of these plugins is new, and some words have been written about the auth_socket on this blog before, for example: how to change passwords in MySQL 5.7 when using plugin: auth_socket. But while reviewing what’s new with MariaDB 10.4, I saw that the unix_socket now comes installed by default and is one of the authentication methods (one of them because in MariaDB 10.4 a single user can have more than one authentication plugin, …

Starting with the experimental release of Percona XtraDB Cluster 8.0, we have made changes to the SST process to make the process more robust and easier to use.

• mysqldump and rsync are no longer supported SST methods.

  Support for mysqldump was deprecated starting with PXC 5.7 and has now been completely removed.

  MySQL 8.0 introduced a new Redo Log format that limited the use of rsync while upgrading from PXC 5.7 to 8.0. In addition, the new Galera-4 also introduced changes that further limits the use of rsync.

  The only supported SST method is xtrabackup-v2.

• A separate Percona XtraBackup installation is no longer required.

  The required …

The problem

In PXC 5.6 and 5.7, when using xtrabackup-v2 as the SST method, the DBA must create a user with the appropriate privileges for use by Percona XtraBackup (PXB). The username and password of this backup user are specified in the wsrep_sst_auth variable.

This is a problem because this username and password was being stored in plaintext and required that the configuration file be secured.

The PXC 8.0 solution

(This feature is still under development and may change before PXC 8.0 GA)

Because the wsrep_sst_auth is only needed on the donor side to take a backup, PXC 8.0 uses an internal user (created specifically for use by PXC) with a randomly generated password. Since this user is only needed on the donor, the plaintext password is not needed on the joiner …