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MySQL Encryption: Talking About Keyrings

It has been possible to enable Transparent Data Encryption (TDE) in Percona Server for MySQL/MySQL for a while now, but have you ever wondered how it works under the hood and what kind of implications TDE can have on your server instance? In this blog posts series, we are going to have a look at how TDE works internally. First, we talk about keyrings, as they are required for any encryption to work. Then we explore in detail how encryption in Percona Server for MySQL/MySQL works and what the extra encryption features are that Percona Server for MySQL provides.

MySQL Keyrings

Keyrings are plugins that allow a server to fetch/create/delete keys in a local file (keyring_file) or on a remote server (for example, HashiCorp Vault). All keys are cached locally inside the keyring’s cache to speed up fetching keys. They can be separated into …

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Tips for Designing Grafana Dashboards

As Grafana powers our star product – Percona Monitoring and Management (PMM) – we have developed a lot of experience creating Grafana Dashboards over the last few years.   In this article, I will share some of the considerations for designing Grafana Dashboards. As usual, when it comes to questions of design they are quite subjective, and I do not expect you to chose to apply all of them to your dashboards, but I hope they will help you to think through your dashboard design better.

Design Practical Dashboards

Grafana features many panel types, and even more are available as plugins. It may be very attractive to use many of them in your dashboards using many different visualization options. Do not!  Stick to a few data visualization patterns and only add additional visualizations when they provide …

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Profiling Software Using perf and Flame Graphs

In this blog post, we will see how to use perf (a.k.a.: perf_events) together with Flame Graphs. They are used to generate a graphical representation of what functions are being called within our software of choice. Percona Server for MySQL is used here, but it can be extended to any software you can take a resolved stack trace from.

Before moving forward, a word of caution. As with any profiling tool, DON’T run this in production systems unless you know what you are doing.

Installing Packages Needed

For simplicity, I’ll use commands for CentOS 7, but things should be the same for Debian-based distros (apt-get install linux-tools-$(uname -r) instead of the yum command is the only difference in the steps).

To install perf, simply issue:

SHELL> sudo yum install -y perf …
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Understanding Hash Joins in MySQL 8

In MySQL 8.0.18 there is a new feature called Hash Joins, and I wanted to see how it works and in which situations it can help us. Here you can find a nice detailed explanation about how it works under the hood.

The high-level basics are the following: if there is a join, it will create an in-memory hash table based on one of the tables and will read the other table row by row, calculate a hash, and do a lookup on the in-memory hash table.

Great, but does this give us any performance benefits?

First of all, this only works on fields that are not indexed, so that is an immediate table scan and we usually do not recommend doing joins without indexes because it is slow. Here is …

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Column Histograms on Percona Server and MySQL 8.0

From time to time you may have experienced that MySQL was not able to find the best execution plan for a query. You felt the query should have been faster. You felt that something didn’t work, but you didn’t realize exactly what.

Maybe some of you did tests and discovered there was a better execution plan that MySQL wasn’t able to find (forcing the order of the tables with STRAIGHT_JOIN for example).

In this article, we’ll see a new interesting feature available on MySQL 8.0 as well as Percona Server for MySQL 8.0: the histogram-based statistics.

Today, we’ll see what a histogram is, how you can create and manage it, and how MySQL’s optimizer can use it.

Just for completeness, histogram statistics have been available on MariaDB since version 10.0.2, with a slightly different …

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ProxySQL 2.0.7 and proxysql-admin Tool Now Available

ProxySQL 2.0.7, released by ProxySQL, is now available for download in the Percona Repository along with Percona’s proxysql-admin tool.

ProxySQL is a high-performance proxy, currently for MySQL and database servers in the MySQL ecosystem (like Percona Server for MySQL and MariaDB). It acts as an intermediary for client requests seeking resources from the database. René Cannaò created ProxySQL for DBAs as a means of solving complex replication topology issues.

This release includes ProxySQL 2.0.7 which introduces many new features and enhancements and also …

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How to Start a 3-Node Percona XtraDB Cluster with the Binary Tarball Package

This blog post will help you configure a 3-node Percona XtraDB Cluster using a binary tarball on your local machine. Configuration files are auto-generated with mostly default configurations except for port/IP address details. The tool has the handy script to create configuration files and start multiple Percona XtraDB Cluster nodes on the fly, helping you to start PXC quickly without spending time on startup configuration as well as avoid using any virtual environments.  The script is available in the percona-qa github project. Currently, this script supports PXC binary tarball distributions only.

You can download the appropriate tarball package from the Percona-XtraDB-Cluster-8.0 downloads page. Once you have the packages available on your local machine, unpack the …

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Percona XtraDB Cluster 8.0 (experimental release) : SST Improvements

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 …

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Percona XtraDB Cluster 8.0 New Feature: wsrep_sst_auth Removal

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 …

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Experimental Binary of Percona XtraDB Cluster 8.0

Percona is happy to announce the first experimental binary of Percona XtraDB Cluster 8.0 on October 1, 2019. This is a major step for tuning Percona XtraDB Cluster to be more cloud- and user-friendly. This release combines the updated and feature-rich Galera 4, with substantial improvements made by our development team.

Improvements and New Features

Galera 4, included in Percona XtraDB Cluster 8.0, has many new features. Here is a list of the most essential improvements:

  • Streaming replication supports large transactions
  • The synchronization functions allow action coordination (wsrep_last_seen_gtid, wsrep_last_written_gtid, wsrep_sync_wait_upto_gtid)
  • More granular and improved error logging. wsrep_debug is now a multi-valued variable to assist in controlling the logging, and logging messages have been significantly improved.
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