When Tungsten Replicator extracts data, the information that has been extracted is written down into the Tungsten History Log, or THL. These files are in a specific format and they are used to store all of the extracted information in a format that can easily be used to recreate and generate data in a target.

Each transaction from the source is written into the THL as an event, so within a single THL file there will be one or more events stored. For each event, we record information about the overall transaction, as well as then information about the transaction itself. That event can contain one or more statements, or rows, or both. Because we don’t want to get an ever increasing single file, the replicator will also divide up the THL into multiple files to tmake the data easier to manage.

We’ll get down into the details soon, until then, let’s start by looking at the basics of the THL, files and sequence numbers and how to …

… or what I should keep in mind in case of disaster

To retrieve and maintain in SQL format the definition of all tables in a database, is a best practice that we all should adopt. To have that under version control is also another best practice to keep in mind.

While doing that may seem redundant, it can become a life saver in several situations. From the need to review what has historically changed in a table, to knowing who changed what and why… to when you need to recover your data and have your beloved MySQL instance not start…

But let’s be honest, only a few do the right thing, and even fewer keep that information up to date. Given that’s the case, what can we do when we have the need to discover/recover the table structure?

From the beginning, MySQL has used some external files to describe its internal structure.

For instance, if I have a schema named windmills and a table …

In this blog, I will provide a step by step procedure to migrate from on-premise MySQL to Amazon RDS/Aurora using Percona-xtrabackup

Both RDS and Aurora is a DBAAS provided by Amazon. To know more on DBAAS you can view our presentation here.

When you are having a database in size of few GB, it would be very convenient to take a logical backup using a logical backup tool such as Mysqldump or Mydumper and restore it Amazon RDS/Aurora easily. But this is not the case when you are having a data size of a few hundred GB or TB, Where the logical backup and restore is very painful and time-consuming. To overcome this we can use …

Have you been experiencing slow MySQL startup times in GTID mode? We recently ran into this issue on one of our MySQL hosting deployments and set out to solve the problem. In this blog, we break down the issue that could be slowing down your MySQL restart times, how to debug for your deployment, and what you can do to decrease your start time and improve your understanding of GTID-based replication.

How We Found The Problem

We were investigating slow MySQL startup times on a low-end, disk-based MySQL 5.7.21 deployment which had GTID mode enabled. The system was part of a master-slave pair and was under a moderate write load. When restarting during a scheduled maintenance, we …

Working on a test case with sysbench, I encountered this:

mysql> select * from sbtest1 where id = round(rand()*10000, 0);
+------+--------+-------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------+
| id   | k      | c                                                                                                                       | pad                                                         |
+------+--------+-------------------------------------------------------------------------------------------------------------------------+-------------------------------------------------------------+
|  179 | 499871 | 09833083632-34593445843-98203182724-77632394229-31240034691-22855093589-98577647071-95962909368-34814236148-76937610370 | 62233363025-41327474153-95482195752-11204169522-13131828192 |
| 1606 | 502031 | …

Percona announces the release of Percona Server for MySQL 5.7.24-26 on December 4, 2018 (downloads are available here and from the Percona Software Repositories). This release merges changes of MySQL 5.7.24, including all the bug fixes in it. Percona Server for MySQL 5.7.24-26 is now the current GA release in the 5.7 series. All of Percona’s software is open-source and free.

This release includes fixes to the following upstream CVEs (Common Vulnerabilities and Exposures): CVE-2016-9843, CVE-2018-3155, …

For the third year in a row, we will take advantage of the mass presence of our MySQL Engineers during FOSDEM to organize the pre-FOSDEM MySQL Day.

The program of this 3rd edition is already on track, thank you to all the speakers who already confirmed their participation.

Announcing the opening of the Percona Live 2019 Open Source Database Conference call for papers. It will be open from now until January 20, 2019. The Percona Live Open Source Database Conference 2019 takes place May 28-30 in Austin, Texas.

Our theme this year is CONNECT. ACCELERATE. INNOVATE.

As a speaker at Percona Live, you’ll have the opportunity to CONNECT with your peers—open source database experts and enthusiasts who share your commitment to improving knowledge and exchanging ideas. ACCELERATE your projects and career by presenting at the premier open source database event, a great way to build your personal and company brands. And …

Percona announces the release of Percona Server 5.6.42-84.2 on November 29, 2018 (Downloads are available here and from the Percona Software Repositories).

Based on MySQL 5.6.42, including all the bug fixes in it, Percona Server 5.6.42-84.2 is the current GA release in the Percona Server 5.6 series. All of Percona‘s software is open-source and free.

Improvements

• …

In this three-part blog series, we will explain the details and functionality of a High Availability (HA) framework for MySQL hosting using MySQL semisynchronous replication and the Corosync plus Pacemaker stack. In Part I, we’ll walk you through the basics of High Availability, the components of an HA framework, and then introduce you to the HA framework for MySQL.

What is High Availability?

The availability of a computer system is the percentage of time its services are up during a period of time. It’s generally expressed as a series of 9′s. For example, the table below shows availability and the corresponding downtime measured over one year.