The latest from the MySQL community

Galera Cluster’s automatic node provisioning simplifies the complexity of scaling out a database cluster with guaranteed data consistency. SST and IST improve the usability of initial data synchronization without the need to manually backup the database and copy it to the new node. Combine this with Galera's ability to tolerate different network setups (e.g, WAN replication), we can now migrate the database between different isolated networks with zero service disruption.

In this blog post, we are going to look into how to migrate our MySQL Galera Cluster without downtime. We will move the database from Amazon Web Service (AWS) EC2 to Google Cloud Platform (GCP) Compute Engine, with the help of a relay node. Note that we had a similar blog post in the past, but this one uses a different approach.

The …

Percona announces the release of Percona Monitoring and Management 1.5.3. This release contains fixes for bugs found after the release of Percona Monitoring and Management 1.5.2, as well as some important fixes and improvements not related to the previous release.

Improvements

• PMM-1874: The read timeout of the proxy server (/prometheus) has been increased from the default of 60 seconds to avoid nxginx gateway timeout error when loading data-rich dashboards.
• PMM-1863: We improved our handling of temporary Grafana credentials

Bug fixes

• …

We had a really great session yesterday during the webinar on Amazon Redshift replication, but sadly ran out of time for questions. So as promised, let’s try and answer the questions asked now!

Are you going to support SAP IQ as a target ?

This is the first request we’ve ever received, and so therefore there are no firm plans for supporting it. As a target, SAP IQ supports a JDBC interface, and therefore is not hugely complicated to achieve compared to more complex, customer appliers.

Can you replicate from SAP ASE ?

No, and no current plans.

What about latin1 character ? Is it supported ?

Yes, although the default mode is for us to use UTF-8 for all extract and apply jobs. You can certainly change the character set, although leaving UTF-8 should also work.

Is it a problem not to have primary keys on Redshift ? …

In this blog post, we’ll look at how sequence numbers work in Percona XtraDB Cluster.

Introduction

Percona XtraDB Cluster uses multiple sequence numbers (seqno), each having a special role to play. Let’s try to understand the significance of each sequence number.

global_seqno

An active Percona XtraDB Cluster cluster has multiple write-sets (transactions) generated from one or more nodes. These transactions then get replicated to other nodes of the cluster. Each write-set/transaction should have a unique identity across the cluster. global_seqno helps serve this identity. Given write-set will have the same global_seqno on …

I’ve recently been trying to improve the performance of the Vertica replicator, particularly in the form of the of the new single schema replication. We’ve done a lot in the new Tungsten Replicator 5.3.0 release to improve (and ultimately support) the new single schema model.

As part of that, I’ve also been personally looking to Kodiak MemCloud as a deployment platform. The people at Kodiak have been really helpful (disclaimer: I’ve worked with some of them in the past). MemCloud is a high-performance cloud platform that is based on hardware with high speed (and volume) RAM, SSD and fast Ethernet connections. This means that even without any adjustment and tuning you’ve got a fast platform to work on.

However, if you are willing to put in some extra time, you can tune things further. Once you have a super quick …

I’ve recently been trying to improve the performance of the Vertica replicator, particularly in the form of the of the new single schema replication. We’ve done a lot in the new Tungsten Replicator 5.3.0 release to improve (and ultimately support) the new single schema model.

As part of that, I’ve also been personally looking to Kodiak MemCloud as a deployment platform. The people at Kodiak have been really helpful (disclaimer: I’ve worked with some of them in the past). MemCloud is a high-performance cloud platform that is based on hardware with high speed (and volume) RAM, SSD and fast Ethernet connections. This means that even without any adjustment and tuning you’ve got a fast platform to work on.

However, if you are willing to put in some extra time, you can tune things further. Once you have a super quick …

Working in an operations environment means that you get a lot of questions.  There’s the inevitable troubleshooting tasks that go along with being a DBA.  This is designed to be a quick reference post, much like my more in depth post in 2016 about timeouts. These typical error messages can create confusion and unneeded activities to diagnose.  To aid my own process of elimination and those of others, here are three error messages every DBA should know by heart.

SQLSTATE[HY000] [2002] Connection timed out

Plain and simple: this error means the client cannot connect to the server.

• The calling program is trying to connect to the wrong database server (one that it cannot reach).
• The database server is completely down (you’d get another error if the server and client actually made a connection). …

This post is a hands-on look at ZFS with MySQL.

In my previous post, I highlighted the similarities between MySQL and ZFS. Before going any further, I’d like you to be able to play and experiment with ZFS. This post shows you how to configure ZFS with MySQL in a minimalistic way on either Ubuntu 16.04 or Centos 7.

Installation

In order to be able to use ZFS, you need some available storage space. For storage – since the goal here is just to have a hands-on experience – we’ll use a simple file as a storage device. Although simplistic, I have now been using a similar setup on my laptop for nearly three years (just can’t get rid of it, it is too useful). For simplicity, I suggest you use a small Centos7 or Ubuntu 16.04 VM with one core, 8GB of disk and 1GB of RAM.

First, you need to install …

Percona announces the release of Percona Monitoring and Management 1.5.2. This release contains fixes to bugs found after Percona Monitoring and Management 1.5.1 was released.

Bug fixes

• PMM-1790: QAN displayed query metrics even for a host that was not configured for mysql:queries or mongodb:queries. We have fixed the behaviour to display an appropriate warning message when there are no query metrics for the selected host.
• PMM-1826: If PMM Server 1.5.0 is deployed via Docker, the Update button would not upgrade the instance to a later release.
• …

Migrating a MySQL database usually requires only few simple steps, but can take quite some time, depending on the amount of data you would like to migrate.

The following steps will guide through how to export the MySQL database from the old server, secure it, copy it to the new server, import it successfully and make sure the data is there.

Exporting MySQL database to a dump file

Oracle provides a utility named mysqldump which allows to easily export the database structure and data to an SQL dump file. Use the following command:

mysqldump -u root -p --opt [database name] > [database name].sql

Few notes:

• We’re using the –single-transaction flag to avoid a database lock while exporting the data. It will allow you to continue updating data in your …