In the previous post, we discussed how to verify that MySQL Replication is in good shape. We also looked at some of the typical problems. In this post, we will have a look at some more issues that you might see when dealing with MySQL replication.

Missing or Duplicated Entries

This is something which should not happen, yet it happens very often - a situation in which an SQL statement executed on the master succeeds but the same statement executed on one of slaves fails. Main reason is slave drift - something (usually errant transactions but also other issues or bugs in the replication) causes the slave to differ from its master. For example, a row which existed on the master does not exist on a …

In my previous blogs I told you to enable SSL/TLS and configure it to check the CA. So I followed my advice and did all that. Great!

So the --ssl-mode setting was used a few times as a solution. And it has a setting we didn't use yet: VERIFY_IDENTITY. In older MySQL versions you can use --ssl-verify-server-cert. Both turn on hostname verification.

The attack

Get any certificate which is trusted by the configured CA, this can for example be a certificate from a development machine. And use that with a man-in-the-middle proxy.

Then the client:

1. Checks if SSL is uses (--ssl-mode=REQUIRED)
2. Verify if the certificate is signed by a trusted CA (--ssl-mode=VERIFY_CA)

Both checks succeed. But the certificate might be for testhost01.example.com and the database server might be prod-websitedb-123.example.com. …

In this blog, I will provide answers to the Q & A for the Troubleshooting Issues with MySQL Character Sets webinar.

First, I want to thank everybody for attending the March 9 MySQL character sets troubleshooting webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: We’ve had some issues converting tables from

utf8

  to

utf8mb4

. Our issue was that the collation we wanted to use –

One of the challenges of language specific collations, is making sure they are accurate in the edge-cases of sometimes lesser-used language features. Since I am Norwegian, let me use the Danish collation (which is identical to Norwegian collation) as an example:

Most Scandinavian people know that in Danish (and Norwegian), we have three extra letters: ‘Æ’, ‘Ø’ and ‘Å’ and they follow after ‘Z’ in that order.…

Replication is one of the most common ways to achieve high availability for MySQL and MariaDB. It has become much more robust with the addition of GTIDs, and is thoroughly tested by thousands and thousands of users. MySQL Replication is not a ‘set and forget’ property though, it needs to be monitored for potential issues and maintained so it stays in good shape.  In this blog post, we’d like to share some tips and tricks on how to maintain, troubleshoot and fix issues with MySQL replication.

How to determine if MySQL replication is in a good shape?

This is hands down the most important skill that anyone taking care of a MySQL replication setup has to possess. Let’s take a look at where to look for information about the state of replication. There is a slight difference between MySQL and MariaDB and we will discuss this as well. …

TwinDB Backup supports encrypted backup copies since version 2.11.0. As usual the tool supports natively backup and restore operations, if backup copies are encrypted the tool takes care of decryption. Installing TwinDB Packages repository I will work with CentOS 7 system to show the example, but there are also packages for Ubuntu trusty and Debian […]

The post Howto Encrypt MySQL Backups on S3 appeared first on TwinDB.

In this blog, I’ll go over my thoughts on what we can expect in the world of SQL databases.

After reading Baron’s prediction on databases, here:

https://www.xaprb.com/blog/defining-moments-in-database-history/

I want to provide my own view on what’s coming up next for SQL databases. I think we live in interesting times, when we can see the beginning of the next-generation of RDBMSs.

There are defining characteristics of such databases:

1. Auto-scaling. The ability to add and use resources depending on the current load and database size. This is done transparently for users and DBAs.
2. Auto-healing. The automatic handling of node …

This video walks you through nine tips you should consider when deploying and managing a MySQL Replication environment and how utilizing ClusterControl can help make deploying, managing, monitoring, and scaling MySQL easy.

Though MySQL replication is one of the easier HA deployments to set up, it is also easy to break and time-consuming to troubleshoot.  ClusterControl’s point-and-click interface lets you securely automate deployment and scaling of MySQL replication setups to get production-ready environments up and running in a very short time. No need for guesswork, or time-consuming experimentation with different open source utilities.

ClusterControl and MySQL Replication

…

One of the most interesting features introduced in MySQL 8.0 is roles or the ability of defining a set of privileges as a named role and then granting that set to one or more users. The main benefits are more clarity of privileges and ease of administration. Using roles we can assign the same set of privileges to several users, and eventually modify or revoke all privileges at once.

Roles in a nutshell

Looking at the manual, we see that using roles is a matter of several steps.

(1) Create a role. The statement is similar to CREATE USER though the effects are slightly different (we will see it in more detail later on.)

mysql …

Percona announces the GA release of Percona Server for MySQL 5.7.17-12 on March 24, 2017. Download the latest version from the Percona web site or the Percona Software Repositories. You can also run Docker containers from the images in the Docker Hub repository.

Based on MySQL 5.7.17, including all the bug fixes in it, Percona Server for MySQL 5.7.17-12 is the current GA release in the Percona Server for MySQL 5.7 series. Percona’s …