Author: Robert Agar

A constant in the computing world is that it is always evolving and offering new challenges and opportunities. Software solutions come and go with some becoming staples in the business community while others barely cause a ripple as they disappear into the ether. Take MySQL as an example. From its humble beginnings in 1994, the platform has grown to become the most popular SQL database in 2019. If you are a database professional, chances are very good that you work with MySQL regularly.

The popularity of the database platform has not gone unnoticed by the unscrupulous entities that engage in cybersecurity attacks with nefarious intentions. Whether acting …

One of the great things about working at Percona is the constant innovation that occurs as a result of a deep level of technical expertise. A more recent conversation about the Information Schema table: innodb_cached_indexes led to the desire to produce this information in an easy to digest and useful format. Enter PMM.

Our goal with creating this dashboard was to help bring further insight into how your MySQL database cache is being used. Why is this important? Data is accessed significantly faster when it is cached, so indexes that are cached will allow for an increase in query performance. Until now there has not been an easy way to see which indexes are cached and which are not. We want to take the …

Author: Robert Agar

The role of a corporate database administrator has evolved tremendously since the introduction of relational databases in the late 1970s. A DBA from the early 1980s would be totally unprepared for the complexities that face database professionals in 2019. It’s a completely different world and the skillset required has radically changed.

The heightened focus on the value of a company’s accumulated data has made DBAs more important to the business goals of an organization than ever before. Keeping this valuable resource safe and accessible is one of the modern DBA’s primary responsibilities. Many diverse methods are required to fulfill these duties, and a DBA must be comfortable using them all to address problems encountered in day-to-day activities.

Common Issues Faced by DBAs

The laundry list of issues that DBAs must deal with regularly is a long one. …

Overview The Skinny

Tungsten Clustering provides high availability, disaster recovery, and a host of other benefits for MySQL / MariaDB / Percona Server databases. In this blog post we will explore some of the shell aliases I use every day to administer various Tungsten Clusters.

Shell Aliases: A Quick Review Quick and Easy

A shell alias is simply a way to create a shortcut for frequently-used command sequences.

For example, I like to shorten the command clear to cls, i.e.

shell> alias cls=clear
shell> cls

If you create an alias on the fly it will be lost when the shell exits.

To save aliases so they are available to all shell sessions, update your shell’s profile or rc script.

For example, add the below line to the bottom of …

Are you looking to get started with the world’s most popular open-source database, and wondering how you should setup your MySQL hosting? So many default to Amazon RDS, when MySQL performs exceptionally well on Azure Cloud. While Microsoft Azure does offer a managed solution, Azure Database, the solution has some major limitations you should know about before migrating your MySQL deployments. In this post, we outline the best way to host MySQL on Azure, including managed solutions, instance types, high availability replication, backup, and disk types to use to optimize your cloud database performance.

MySQL DBaaS vs. Self-Managed MySQL

The first thing to consider when weighing between self-management and a MySQL Database-as-a-Service …

Author: Robert Agar

The working life of a DBA is often centered on optimizing their systems to provide users with the best performance. There are many aspects of a MySQL implementation that can be tuned to increase its functionality. These improvements will result in a more efficient system and enhanced user experience.

One of the problems facing the DBA responsible for instituting performance tuning is to identify the particular areas to address that will impact the system in a positive manner. Approaching this task in a haphazard fashion is not advisable. Randomly modifying parameters is just as likely to cause further issues than to lead to performance gains. Luckily, there is a solution to this dilemma.

Conducting focused monitoring can be instrumental in enabling the DBA to pinpoint the source of performance degradation. Armed with this knowledge, informed decisions can be made regarding how …

The Question Recently, a customer asked us:

What is the meaning of this error message found in trepsvc.log?

2019/05/14 01:48:04.973 | mysql02.prod.example.com | [east - binlog-to-q-0] INFO pipeline.SingleThreadStageTask Performing rollback of possible partial transaction: seqno=(unavailable)

Simple Overview The Skinny

This message is an indication that we are dropping any uncommitted or incomplete data read from the MySQL binary logs due to a pending error.

The Answer Safety First

This error is often seen before another error and is an indication that we are rolling back anything uncommitted, for safety. On a master this is normally very little and would likely be internal transactions in the trep_commit_seqno table, for example.

As you may know with the replicator we always extract complete transactions, and so this particular message is …

Overview The Skinny

In this blog post we will discuss how the managed cross-site replication streams work in a Composite Multi-Master Tungsten Cluster for MySQL, MariaDB and Percona Server.

Agenda What’s Here?

• Briefly explore how managed cross-site replication works in a Tungsten Composite Multi-Master Cluster
• Describe the reasons why the default design was chosen
• Explain the pros and cons of changing the configuration
• Examine how to change the configuration of the managed cross-site replicators

Cross-Site Replication A Very Brief Summary

In a standard Composite Multi-Master (CMM) deployment, the managed cross-site replicators pull Transaction History Logs (THL) from every remote cluster’s current master node. …

The Question Recently, a customer asked us:

Why would Tungsten Replicator be slow to apply to MySQL?

The Answer Performance Tuning 101

When you run trepctl status and see:
appliedLatency : 7332.394
like this on a slave, it is almost always due to the inability for the target database to keep up with the applier.

This means that we often need to look first to the database layer for the solution.

Here are some of the things to think about when dealing with this issue:

Architecture and Environment
√ Are you on bare metal?
√ Using the cloud?
√ Dev or Prod?
√ Network speed and latency?
√ Distance the data needs to travel?
√ Network round trip times? Is the …

The Question Recently, a customer asked us:

If we move to using the INI configuration method instead of staging, would password-less SSH still be required?

The Answer The answer is both “Yes” and “No”

No, for installation and updates/upgrades specifically. Since INI-based configurations force the tpm command to act upon the local host only for installs and updates/upgrades, password-less SSH is not required.

Yes, because there are certain commands that do rely upon password-less SSH to function. These are:

• tungsten_provision_slave
• prov-sl.sh
• multi_trepctl
• tpm diag (pre-6.0.5)
• tpm diag --hosts (>= 6.0.5)
• Any tpm-based backup and restore operations that involve a remote node

Summary The Wrap-Up

In …