MySQL environments are notorious for being understaffed – MySQL is everywhere, and an organization is lucky if they have one full-time DBA, as opposed to a developer or sysadmin/SRE responsible for it.

That being said, MySQL is a complex program and it’s useful to have a record of configuration changes made. Not just for compliance and auditing, but sometimes – even if you’re the only person who works on the system – you want to know “when was that variable changed?” In the past, I’ve relied on the timestamp on the file when I was the lone DBA, but that is a terrible idea.

I am going to talk about configuration changes in this post, mostly because change control for configuration (usually /etc/my.cnf) is sorely lacking in many organizations. Having a record of data changes falls under backups and binary logging, and having a record of schema changes is something many organizations integrate with their ORM, so …

Thanks to everyone who participated in our recent webinar on how to load balance MySQL and MariaDB with ClusterControl and ProxySQL!

This joint webinar with ProxySQL creator René Cannaò generated a lot of interest … and a lot of questions!

We covered topics such as ProxySQL concepts (with hostgroups, query rules, connection multiplexing and configuration management), went through a live demo of a ProxySQL setup in ClusterControl (try it free) and discussed upcoming ClusterControl features for ProxySQL.

These topics triggered a lot of related questions, to which you can find our answers below.

If you missed the webinar, would like …

In this blog post, we’ll look at the performance of SST data transfer using encryption.

In my previous post, we reviewed SST data transfer in an unsecured environment. Now let’s take a closer look at a setup with encrypted network connections between the donor and joiner nodes.

The base setup is the same as the previous time:

• Database server: Percona XtraDB Cluster 5.7 on donor node
• Database: sysbench database – 100 tables 4M rows each (total ~122GB)
• Network: donor/joiner hosts are connected with dedicated 10Gbit LAN
• Hardware: donor/joiner hosts – boxes with 28 Cores+HT/RAM 256GB/Samsung SSD 850/Ubuntu 16.04

The setup details for the encryption aspects in our testing:

• Cryptography libraries: openssl-1.0.2, …

One of the interesting features introduced in MySQL 5.7 is that innodb_buffer_pool_size is a dynamic variable (since 5.7.5, to be more specific). Yet, past experience tells us that just because a variable is dynamic, it does not make it is safe to change it on the fly.

To find out how safe this new feature is, I measured throughput on a synthetic workload (sysbench 1.0 running the oltp script) as I made changes to this variable. In this post, I will show the results that came through.

The Environment

For my tests, I used a Google Cloud Compute instance of type n1-standard-4 (that is 4 vCPUs and 15 GB of memory) with 25 GB of persistent …

This post is just following up my previous blog post which describes how to setup 3-nodes MariaDB Galera Cluster with MySQL-Sandbox on single server.

Today, I’ll try to explain how we can setup MariaDB MaxScale over the Galera Cluster. Before I move ahead, I would like to explain about MaxScale little bit.

MariaDB MaxScale is a database proxy that enables horizontal database scaling while maintaining a fast response to client applications. You can implement MaxScale on either MySQL Replication or Galera cluster. With MySQL Replication, you can either use Read/Write Splitting or Connection routing and same with Galera Cluster. You can get more information here about this product.

…

In this blog, we’ll look at evaluating the performance of an SST data transfer without encryption.

A State Snapshot Transfer (SST) operation is an important part of Percona XtraDB Cluster. It’s used to provision the joining node with all the necessary data. There are three methods of SST operation available: mysqldump, rsync, xtrabackup. The most advanced one – xtrabackup – is the default method for SST in Percona XtraDB Cluster.

We decided to evaluate the current state of xtrabackup, focusing on the process of transferring data between the donor and joiner nodes tp find out if there is any room for improvements or optimizations.

Taking into account that the security of the network connections used for Percona XtraDB Cluster deployment is one of the most important factors that affects SST performance, we will evaluate SST operations in two setups: without network encryption, and in …

Please join Percona’s Principal Technical Services Engineer Sveta Smirnova, and Senior Software Engineer George Lorch, MariaDB’s Query Optimizer Developer Sergei Petrunia and Facebook’s Database Engineer Yoshinori Matsunobu as they present MyRocks Troubleshooting on March 30, 2017 at 11:00 am PDT / 2:00 pm EDT (UTC-7).

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MyRocks is an alternative storage engine designed for flash storage. It provides great write workload performance and space efficiency. Like any other powerful engine, it has its own specific configuration scenarios that require special troubleshooting solutions.

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 –