In this blog post, we’ll discuss trackable flow control in Percona XtraDB Cluster.

Introduction

Percona XtraDB Cluster has a self-regulating mechanism called Flow Control. This mechanism helps to avoid a situation wherein the weakest/slowest member of the cluster falls significantly behind other members of the cluster.

When a member of a cluster is slow at applying write-sets (while simultaneously continuing to receive write-sets from the cluster group channel), then the incoming/receive queue grows in size. If this queue crosses a set threshold (gcs.fc_limit), the node emits a FLOW_CONTROL message asking other members to slow down or halt processing.

While …

Welcome to another post in the series of Percona Live featured session blogs! In these blogs, we’ll highlight some of the session speakers that will be at this year’s Percona Live conference. We’ll also discuss how these sessions can help you improve your database environment. Make sure to read to the end to get a special Percona Live 2017 registration bonus!

In this Percona Live featured session, we’ll meet Casper Kejlberg-Rasmussen, Software Developer at Uber. His session is Placing Databases @ Uber. Uber has many thousands of MySQL databases running inside of Docker containers on thousands …

This is just a note to myself. I don’t do this often enough to remember the command, but whenever I’m searching for this, it takes half a minute to find it in MySQL manual, so hopefully this gets indexed better (in my memory as well as in Google).

Here’s the simple command to create a login path:

mysql_config_editor set --login-path=mysql1  --host=localhost \
   --port=3306 --socket=/path/to/socket --user=root --password

Obviously you can remove just about anything and only leave the essentials.

Once that’s done, accessing different MySQL instances is as simple as mysql --login-path=mysql1, which is especially useful if you’re accessing different servers from one machine, or if you’re running several MySQL instances on the same machine.

More information on login paths …

Our journey in adopting MySQL and MariaDB in containerized environments continues, with ClusterControl coming into the picture to facilitate deployment and management. We already have our ClusterControl image hosted in Docker Hub, where it can deploy different replication/cluster topologies on multiple containers. With the introduction of Docker Swarm, a native orchestration tools embedded inside Docker Engine, scaling and provisioning containers has become much easier. It also has high availability covered by running services on multiple Docker hosts.

In this blog post, we’ll be experimenting with automatic provisioning of Galera Cluster on Docker Swarm with ClusterControl. ClusterControl would usually deploy database clusters on bare-metal, virtual machines and cloud instances. ClusterControl relies on SSH (through libssh) as core communication module …

In this blog post, we’ll look at the actions and efforts Percona experts took to scale Percona XtraDB Cluster.

Introduction

When we first started analyzing Percona XtraDB Cluster performance, it was pretty bad. We would see contention even with 16 threads. Performance was even worse with sync binlog=1, although the same pattern was observed even with the binary log disabled. The effect was not only limited to OLTP workloads, as even other workloads (like update-key/non-key) were also affected in a wider sense than OLTP.

That’s when we started analyzing the contention issues and found multiple problems. We will discuss all these problems and the solutions we adapted. But …

Percona announces the release of Percona XtraDB Cluster 5.6.35-26.20-3 on April 13, 2017. Binaries are available from the downloads section or our software repositories.

Percona XtraDB Cluster 5.6.35-26.20-3 is now the current release, based on the following:

• Percona Server 5.6.35-81.0
• Galera Replication library 3.20
• wsrep API version 26

All Percona software is open-source and free.

…

Last week I published a blog post in the MySQL Server Blog where I showed how the execution time of a query was reduced by 50% by using a Common Table Expression (CTE) instead of a view.

In the coming weeks, there will be several opportunities to attend a presentation on CTE and another SQL feature that will arrive in MySQL 8.0, Window Functions.  This presentation is part of the Oracle MySQL Innovation Day that will be held both in the Bay Area (April 28) and in the Boston Area (May 2).

I will also give the presentation at the …

In our latest release of Percona XtraDB Cluster, we’ve introduced major performance improvements to the MySQLwrite-set replication layer. In this post, we want to show what these improvements look like.

For the test, we used the sysbench OLTP_RW, UPDATE_KEY and UPDATE_NOKEY workloads with 100 tables, 4mln rows each, which gives about 100GB of datasize. In all the tests we use a three-node setup, connected via a 10GB network, with the sysbench load directed to the one primary node.

In the first chart, we show improvements comparing to the previous version (5.7.16):

The main improvements come from concurrent workloads, under multiple threads.

The …

Percona announces the release of Percona XtraDB Cluster 5.7.17-29.20 on April 19, 2017. Binaries are available from the downloads section or our software repositories.

NOTE: You can also run Docker containers from the images in the Docker Hub repository.

Percona XtraDB Cluster 5.7.17-29.20 is now the current release, based on the following:

• …

Dear MySQL users,

MySQL Connector/Python 2.1.6 GA is a fourth GA version of 2.1 release
series of the pure Python database driver for MySQL. It can be used for
production environments.

MySQL Connector/Python version 2.1.6 GA is compatible with MySQL Server
versions 5.5 and greater. Python 2.6 and greater as well as Python 3.3
and greater are supported. Python 2.4, 2.5 and 3.1, 3.2 are not
supported.

MySQL Connector/Python 2.1.6 is available for download from:

http://dev.mysql.com/downloads/connector/python/#downloads

The ChangeLog file included in the distribution contains a brief summary
of changes in MySQL Connector/Python 2.1.6. For a more complete list of
changes, see below or online at:

http://dev.mysql.com/doc/relnotes/connector-python/en/

Enjoy!

Changes in MySQL Connector/Python 2.1.6 (2017-04-18, General
…