Recently we had a report from a user who had seen a stunning 90% performance regression after upgrading his server to a Linux kernel with KPTI (kernel page-table isolation – a remedy for the Meltdown vulnerability). A big deal of those 90% was caused by running in an old version of VMware which doesn’t pass […]

The post MyISAM and KPTI – Performance Implications From The Meltdown Fix appeared first on MariaDB.org.

Please join Percona’s Principal Support Engineer, Sveta Smirnova, as she presents “Basic Internal Troubleshooting Tools for MySQL Server” on Thursday, February 15, 2018, at 10:00 am PST (UTC-8) / 1:00 pm EST (UTC-5).

Register Now

MySQL Server has many built-in troubleshooting tools. They are always available and can provide many insights on what is happening internally. Many graphical tools, such as Percona Monitoring and Management …

I was involved in one of the development support for MySQL. Here is an interesting case

The application needs a Sequence generator as it was not present inbuilt with MySQL ( MariaDB will have it in 10.3 ) they have made sequence generator function with ‘select for update‘ statement. But it tends to cause more locking at high concurrency with their XtraDB Cluster deployment.

To get rid of this , the sequence generation were made as direct Update queries and sequence is fetched using Select @next.

UPDATE EO_PK_TABLE SET PK = (@next := PK …

Percona Monitoring and Management (PMM) is a free and open-source platform for managing and monitoring MySQL and MongoDB performance. You can run PMM in your own environment for maximum security and reliability. It provides thorough time-based analysis for MySQL and MongoDB servers to ensure that your data works as efficiently as possible.

Starting with version 1.4.0 and improved in 1.7.0, PMM supports external monitoring services. This means you can plug in Prometheus exporters for technologies not directly provided by Percona. For example, you can start monitoring the metrics of your  …

The world is brimming with the ideas of self-driving cars and all sorts of
other concepts where computers are supposed to take care of
decision making.

This makes a bit worried, for one because I simply like to drive and
would not want a computer to interfere with my driving. I am already
quite irritated by many automatic things in cars that don't really work
when winter is upon in Sweden :)

Anyways this post is not about that, this post is more about the general
problem of designing adaptive algorithms.

I've been designing NDB software for more than 20 years. During the
course of these years I have learned a bit about what is optimal
when executing NDB. Most of the software I write today is about
putting this knowledge into the NDB software itself.

This is a trend in databases today to automate configuration handling
…

As promised, the following are links to slides from my talks during MySQL Day and FOSDEM @Brussels in Feb.2018 :

• MySQL Day : 8.0-dev Scalability & Benchmarks
• FOSDEM #18 : 8.0 InnoDB Re-Design

NOTE : for those who did not follow, CATS is not the only change in InnoDB ;-))

Rgds,
-Dimitri

You may already know that MySQL 8.0 is coming with a nice requested feature : ROLES

A role is a named collection of privileges. When you watch some slidedeck about MySQL 8.0 and ROLES, some times you can see a graph illustrating the ROLES and their eventual hierarchy. From the documentation, it seems those graphs are made using the ROLES_GRAPHML() function.

I tried it… and my first try is not really what I was expecting…

Input file

To create the input file I used the following command:

mysql> SELECT ROLES_GRAPHML() into outfile '/var/lib/mysql-files/test_roles.graphml';
Query OK, 1 row affected (0.19 sec)

Then I used yEd to …

Codership is pleased to announce the release of Galera Replication library 3.23, implementing wsrep API version 25.

This release incorporates all changes up to MySQL 5.7.21, MySQL 5.6.39 and MySQL 5.5.59, including several fixes to vulnerabilities reported by Oracle in here.

New features and notable fixes in Galera replication since last binary release
by Codership (3.22):

• Write set serialization has been changed to use proper memory alignment in order to avoid crashes on platforms which do not allow unaligned memory access (http://www2.galeracluster.com/e/38852/codership-galera-issues-445/88b8yp/875788176)

Notable bug fixes in MySQL 5.7.21: …

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

Percona Live Santa Clara 2018 update: tutorials have been announced. The committee rated over 300+ talks, and easily 70% of the schedule should go live next week as well. In practice, then, you should see about 50 talks announced next week. There’s been great competition: we only have 70 slots in total, so about 1 in 5 talks get picked — talk about a competitive ratio.

FOSDEM

FOSDEM was truly awesome last week. From a Percona standpoint, we had a lot of excellent booth traffic (being outside of the PostgreSQL room on Saturday, and not too far out from the MySQL room on Sunday). We gave away bottle openers — …

One of the more common struggles I’ve had to assist with in regard to Amazon RDS is enabling binary logging on read replicas, or forming multi-tier replication in instances using version 5.6 or later after seeing that multi-tier replication is not supported in version 5.5 (for a reason that will become clear by the end of this post.)

First off, let’s have a look at the topology that I have in place in my AWS account. As you’ll see below I have a master, blog1, and a read replica that I created via the AWS console called blog2. You’ll also notice that, despite being supported, if I select instance actions while having blog2 highlighted the option to create a read replica is grayed out.

Further, if we use the MySQL CLI to connect to blog2 and check the global variables for log_bin and binlog_format, you’ll see that binary logging is off and binlog_format is set to statement. This is strange considering that the parameter …