After upgrading some of our slaves to latest 5.7, I have found  what looks like a serious regression introduced in MySQL 5.7.
A couple weeks ago I noticed that the error log file of one of our clusters, where I had implemented my in place transparent compression of binary logs,  was literally flooded by the following error:

[ERROR] Binlog has bad magic number;  It's not a binary log file that can be used by this version of MySQL

In the above setup this is  an harmless error, and it should only happen at server startup, where mysqld opens and reads all available binary log files.  The error is due to the fact that since files are now compressed, mysqld doesn't recognize them as valid - not an issue, as only older files are compressed, and only after …

We have brought further enhancement to MySQL Group Replication 5.7 release by backporting some most requested features to MySQL 5.7.20 release:

• Member weight for automatic primary election on failover
• Disallow writes after leaving the group

And to MySQL 5.7.19 release:

• Transaction savepoint support

Member weight for automatic primary election on failover

The Member weight for automatic primary election on failover feature will allow user to influence primary member election using a integer member weight value.…

A few days ago I faced an issue in my Ruby on Rails application. The issue was caused by some duplicate rows in a very large the MySQL table (more than 1,5 million rows). The obvious solution of course is to remove duplicate rows from the table and add a unique constraint on some columns to make sure no duplicate rows will ever appear again.

The question is how to remove duplicate rows? The table schema is like this:

describe table1;

| id           | int(11)       
| category     | varchar(255)  
| image_set_id | int(11)       
| position     | decimal(16,6) 

In my case, it was duplicate on the combination (category, image_set_id). I want to make sure that combined value will always be unique.

Searching on Google and I quickly found the solution. The query is something like this:

DELETE n1 FROM names n1, names n2 WHERE n1.id > n2.id AND n1.name = n2.name

This topic is about, simple approach to run multiple sql statements for testing XtraBackup behaviour – if it is going to kill them due to blocked FTWRL(FLUSH TABLES WITH READ LOCK).

According to the DOC -> Backup Locks

Percona Server has implemented this feature to be a lightweight alternative to FLUSH TABLES WITH READ LOCK for both physical and logical backups. Three new statements are now available: LOCK TABLES FOR BACKUP, LOCK BINLOG FOR BACKUP and UNLOCK BINLOG.

So by default, if you are using PS it is going to use LOCK TABLES FOR BACKUP prior copying non-InnoDB tables.

Well, how to force to use FTWRL instead of Backup Locks?
Congratulations – we have --no-backup-locks option, if you specify it, the FTWRL will be used.

Okay, again reading the DOC …

Idea to create channel in the telegram came me from my friend. I have a lot of  useful electronic materials about programming, and he offered me to share them in telegram channel. To create channel is very easy. But share materials manually is very boring and wasting time. That’s why I’ve decided to automate it using mysql and python. First of all I’ve created table in the mysql to store my books there. And then i’ve created my first bot in telegram. Documentation of telegram bots: https://core.telegram.org/bots

Also you can find API documentation of telegram bots here: https://core.telegram.org/bots/api

And than was created channel. You can learn how to create channel from here:  …

We are pleased to announce that MySQL Enterprise Monitor 3.4.5 is now available for download on the My Oracle Support (MOS) web site. This is a maintenance release that includes a few new features and fixes a number of bugs. You can find more information on the contents of this release in the change log.

You will find binaries for the new release on My Oracle Support. Choose the "Patches & Updates" tab, and then choose the "Product or Family (Advanced Search)" side tab in the "Patch Search" portlet.

Important: MySQL Enterprise Monitor (MEM) 4.0 offers many significant improvements over MEM 3.4 and we highly recommend that you consider upgrading. More information on MEM 4.0 is available here:

• …

Percona announces the release of Percona Server for MySQL 5.6.38-83.0 on December 8, 2017. Download the latest version from the Percona web site or the Percona Software Repositories. You can also run Docker containers from the images in the Docker Hub repository.

Based on MySQL 5.6.38, and including all the bug fixes …

Dear MySQL users,

MySQL Connector/Net 6.10.5 is the second GA release and the first to
introduce .NET Core 2.0 and Entity Framework Core 2.0 support.

To download MySQL Connector/Net 6.10.5 GA, see the “Generally Available
(GA) Releases” tab at http://dev.mysql.com/downloads/connector/net/

Changes in MySQL Connector/Net 6.10.5 (2017-12-08, General
Availability)

   Functionality Added or Changed

     * Support for .NET Core 2.0 and .NET Standard 2.0 has been
       added (.NET Core 1.1 support continues). With .NET Core 2.0, most
       of the common ADO.NET classes are available for use, such as:

          + System.Data.DataTable, System.Data.DataColumn, and
            System.Data.DataRow

          + System.Data.DataSet

          + System.Data.Common.DataAdapter

     * Support for Entity Framework Core …

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

I highly recommend submitting to the CFP for Percona Live Santa Clara 2018 even though it only closes December 22 2017. By the 3rd week of December, i.e. before the CfP closes, it is very likely that we will announce some of the schedule. So get in early! Keep in mind the broad topics, there are some ideas here.

Also: we are looking for sponsors for Percona Live – you can email me for more information.

Releases

• MongoDB 3.6 …

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 …