In this blog, I will provide answers to the Q & A for the MySQL Replication Troubleshooting webinar.

First, I want to thank everybody for attending the August 25 webinar. The recording and slides for the webinar are available here. Below is the list of your questions that I wasn’t able to answer during the webinar, with responses:

Q: Hi Sveta. One question: how is it possible to get N previous events using the SHOW BINLOG EVENTS command? For example, the position is 999 and I want to analyze the previous five events. Is it possible?

A: Not, there is no such option. You cannot get the previous five events using

SHOW BINLOG EVENTS

. …

.NET Core and MySQL Connector NET

It is exciting times!  Recently Microsoft released .NET Core 1.0, a cross platform implementation of the .NET Framework.  .NET Core works on Windows, Mac OS, and Linux and is fully open source!

We wanted to enable users of Connector/Net to be able to use .NET Core so we have been working hard for the past few months to make our provider fully .NET Core compatible.  Because .NET Core does not yet fully replace the traditional .NET Framework, we will continue to ensure our provider is compatible with both frameworks.

Along with these exciting changes, we are also including in our most recent release support for Entity Framwork 7.0  and Entity Framework Core 1.0.

In this article I will explain how to install and setup .NET Core and how to make a simple sample that connects and retrieve data in screen.

Setup

Further information about …

After having played with MySQL Group Replication and HAProxy, it’s time to show you how easy it’s to setup MySQL HA with ProxySQL.

ProxySQL is a high performance open source proxy for MySQL. It has many features that invite you to discover on proxysql.com and on github.

If you remember, I wrote in my last post that it is recommended to use Group Replication with only one WRITER group member. As it is the preferred architecture, I will show you how to achieve this using ProxySQL. With ProxySQL, you don’t need to have two different interfaces to split reads and writes.

In fact, when you use ProxySQL, you have a much larger amount of options to route your queries. In production, the smart DBA, will identify …

This article demonstrates how MySQL sharding with ProxySQL works.

Recently a colleague of mine asked me to provide a simple example on how ProxySQL performs sharding.

In response, I’m writing this short tutorial in the hope it will illustrate ProxySQL’s sharding functionalities, and help people out there better understand how to use it.

ProxySQL is a very powerful platform that allows us to manipulate and manage our connections and queries in a simple but effective way. This article shows you how.

Before starting let’s clarify some basic concepts.

• ProxySQL organizes its internal set of servers in Host Groups (HG), and each HG can be associated with users and Query Rules (QR)
• Each QR can be final (apply = 1) or = let ProxySQL continue to parse other QRs
• A QR can be a rewrite action, be a simple match, have a specific target HG, or be generic
• QRs are defined …

Today we had a very interesting phenomena at a customer. He complained that MySQL always get some errors of the following type:

[ERROR] mysqld: Sort aborted: Error writing file '/tmp/MYGbBrpA' (Errcode: 28 - No space left on device)

After a first investigation we found that df -h /tmp shows from time to time a full disk but we could not see any file with ls -la /tmp/MY*.

After some more investigation we found even the query from the Slow Query Log which was producing the same problem. It looked similar to this query:

SELECT * FROM test ORDER BY field5, field4, field3, field2, field1;

Now we were capable to simulate the problem at will with the following table:

CREATE TABLE `test` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `data` varchar(64) DEFAULT NULL,
  `ts` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE …

The MySQL development team recently made a new labs release of the Group Replication plugin for MySQL Server. This is a preview of a new plugin that adds virtually synchronous replication with support for multi-master or active/active update-anywhere replication groups to the already strong lineup of native replication options in MySQL. Docker is a great […]

This article shows the essential parts of the configuration for a quick console application using the .NET Core command-line (CLI) tool. The application will show how to create an EF Core model and some basic operations that can easily be done in Windows, Linux or OSx.

1. Requirements

Install the sdk, framework and tools:

Windows:
Install
– .NET Core SDK for Windows direct link here
– Visual Studio 2015 Update 3* here’s the publication page with more information about the update.
– .NET Core 1.0 tooling for Visual Studio direct link here

Linux:
An …

MySQL Group Replication is just one component of the upcoming MySQL HA Solution as Matt Lord explained it in his GR quick start guide. So while mysql-router is back to school to become smarter and learn how to take the right decision we can already use existing 3rd party solutions. To be honest, if people are already using a load balancer/proxy with MySQL asynchronous, semi-sync or other virtual synchronous solution and want to evaluate and migrate to MySQL’s native Group Replication, they might not migrate load balancer at the same time as they move to GR. Step-by-step migration, one component at the time is always recommended in complex architecture.

So in this post, I want to cover HAProxy and a dedicated health check  related to what might be the more common architecture. Matt already explained in his start guide how to use …

Recently a colleague of mine ask me to provide a simple example on how ProxySQL can perform sharding.
ProxySQL is a very powerful platform that allow us to manipulate and manage our connections and query in a simple but effective way.
In this article I will show you how.

{autotoc enabled=yes}

Before starting is better to clarify some basic concepts.

ProxySQL organize its internal set of servers in Host Groups (HG), each HG can be associate to users and to Query Rules (QR).

Each QR can be final (apply = 1) or can let ProxySQL continue to parse other QR.

A QR can be a rewrite action, or can be a simple match, it can have a specific target HG, or be generic, finally QR are defined using regex.

You can see QR as a sequence of filters and transformation that you can arrange as you like.

These simple basic rules give us enormous flexibility, …

Recently a colleague of mine ask me to provide a simple example on how ProxySQL can perform sharding.
ProxySQL is a very powerful platform that allow us to manipulate and manage our connections and query in a simple but effective way.
In this article I will show you how.

{autotoc enabled=yes}

Before starting is better to clarify some basic concepts.

ProxySQL organize its internal set of servers in Host Groups (HG), each HG can be associate to users and to Query Rules (QR).

Each QR can be final (apply = 1) or can let ProxySQL continue to parse other QR.

A QR can be a rewrite action, or can be a simple match, it can have a specific target HG, or be generic, finally QR are defined using regex.

You can see QR as a sequence of filters and transformation that you can arrange as you like.

These simple basic rules give us enormous flexibility, …