Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.

Hello again after the hiatus last week. I’m en route to Portland for OSCON, and am very excited as it is the conference’s 20th anniversary! I hope to see some of you at my talk on July 19.

On July 18, join me for a webinar: MariaDB 10.3 vs. MySQL 8.0 at 9:00 AM PDT (UTC-7) / 12:00 PM EDT (UTC-4). I’m also feverishly working on an update to MySQL vs. MariaDB: Reality Check, now that both MySQL 8.0 and MariaDB Server 10.3 are generally available.

Rather important: …

What if I want the cluster to be less sensitive to network, especially WAN latency?

Continuent Clustering supports having clusters at multiple sites with active-active replication meshing them together.

This is extraordinarily powerful, yet at times high network latency can make it harder for messaging between the sites to arrive in a timely manner.

This is evidenced by seeing the following in the Manager log files named tmsvc.log:

2018/07/08 16:51:05 | db3 |  INFO [Rule_0604$u58$_DETECT_UNREACHABLE_REMOTE_SERVICE1555959201] - CONSEQUENCE: [Sun Jul 08 16:51:04 UTC 2018] CLUSTER global/omega(state=UNREACHABLE)
...
2018/07/08 16:51:42 | db3 |  INFO [Rule_2025$u58$_REPORT_COMPONENT_STATE_TRANSITIONS1542395297] - CLUSTER 'omega@global' STATE TRANSITION UNREACHABLE => ONLINE

The delta is 37 seconds in the above example between state=UNREACHABLE and UNREACHABLE => ONLINE

The default …

Recently, Dimitri published the results of measuring MySQL 8.0 on Intel Optane storage device. In this blog post, I wanted to look at this in more detail and explore the performance of MySQL 8, MySQL 5.7 and Percona Server for MySQL using a similar set up. The Intel Optane is a very capable device, so I was puzzled that Dimitri chose MySQL options that are either not safe or not recommended for production workloads.

Since we have an Intel Optane in our labs, I wanted to run a similar benchmark, but using settings that we would recommend our customers to use, namely:

• use innodb_checksum
• use innodb_doublewrite
• use binary logs with sync_binlog=1
• enable (by default) Performance …

Before you attempt to perform any schema changes on your production databases, you should make sure that you have a rock solid rollback plan; and that your change procedure has been successfully tested and validated in a separate environment. At the same time, it’s your responsibility to make sure that the change causes none or the least possible impact acceptable to the business. It’s definitely not an easy task.

In this article, we will take a look at how to perform database changes on MySQL and MariaDB in a controlled way. We will talk about some good habits in your day-to-day DBA work. We’ll focus on pre-requirements and tasks during the actual operations and problems that you may face when you deal with database schema changes. We will also talk about open source tools that may help you in the process.

Test and rollback scenarios

Backup

There are many ways to lose your data. Schema upgrade failure is …

Oracle has done a great technical work with MySQL. Specifically a nice job has been done around security. There is one useful feature that exists in Oracle MySQL and that currently does not exist in MariaDB. Oracle MySQL offers the possibility from within the server to generate asymetric key pairs. It is then possible use ...continue reading "Porting this Oracle MySQL feature to MariaDB would be great ;-)"

MySQL stored procedures, functions and triggers are tempting constructs for application developers. However, as I discovered, there can be an impact on database performance when using MySQL stored routines. Not being entirely sure of what I was seeing during a customer visit, I set out to create some simple tests to measure the impact of triggers on database performance. The outcome might surprise you.

Why stored routines are not optimal performance wise: short version

Recently, I worked with a customer to profile the performance of triggers and stored routines. What I’ve learned about stored routines: “dead” code (the code in a branch which will never run) can still significantly slow down the response time of a function/procedure/trigger. We will need to be careful to clean up what we do not need.

Profiling MySQL stored functions

Let’s compare these four simple stored functions (in MySQL 5.7): …

In the old days, when we wanted to strengthen our skills the only option was to buy a good book. Nowadays one can find a lot of resources on the Internet, however quality is often poor. Fortunately there are still some great people who are brave enough to write new books that will help a new generation of women and men to build modern applications with MySQL the world's most popular open source database. Let me introduce you 3 MySQL books : Introducing the MySQL 8 Document Store / MySQL and JSON: A Practical Programming Guide / Pro MySQL NDB Cluster

Missed our Continuent Clustering 6.0 webinar and technical deep dive? Don’t sweat it. Watch these recordings of our presentations and find out what’s new and latest for multisite, multimaster clustering, what’s changed, improvements that we’ve made under the hood, and how this will improve the quality and support for your multimaster MySQL/Percona/MariaDB deployments.

In our technical deep dive, we take a detailed look at the new deployment model, how the different components work together, and how you can now manage and support your new multimaster environment using Continuent Clustering 6.0. We cover the new integration of the replication, how that affects your deployment, and how that alters …

MySQL semisynchronous replication provides improved data integrity because when a commit returns successfully, it’s known that the data exists in at least two places – the master and its slave. In this blog post, we review some of the MySQL hosting configurations that influence the data integrity and performance aspects of semisynchronous replication. We’ll be using InnoDB storage engine and GTID-based replication in a 3-node replica set (master and 2 slaves), which will ensure there is redundancy in the slaves. This means that if there are issues with one slave, we can fall back on the other.

Configurations Applicable to Both Master and Slave Nodes

…

Ever since AMD released their EPYC CPU for servers I wanted to test it, but I did not have the opportunity until recently, when Packet.net started offering bare metal servers for a reasonable price. So I started a couple of instances to test Percona Server for MySQL under this CPU. In this benchmark, I discovered some interesting discrepancies in performance between  AMD and Intel CPUs when running under systemd .

The set up

To test CPU performance, I used a read-only in-memory sysbench OLTP benchmark, as it burns CPU cycles and no IO is performed by Percona Server.

For this benchmark I used Packet.net c2.medium.x86 instances powered by AMD EPYC …