In a previous article, Ovais demonstrated how a DDL can render a table blocked from new queries. In another article, Valerii introduced performance_schema.metadata_locks, which is available in MySQL 5.7 and exposes metadata lock details. Given this information, here’s a quick way to troubleshoot metadata locks by creating a stored procedure that can:

• Find out which thread(s) have the metadata lock
• Determine which thread has been waiting for it the longest
• Find other threads waiting for the metadata lock

Setting up …

This year, the MySQL & Friends Devroom will be held on Saturday 4th February 2017.

After having received a lot of submission (the highest amount ever!), with MySQL Community Team, we decided to organize and extra MySQL day that will take place at ICAB Incubator, 4 Rue des Pères Blancs in Brussels (same location as the MySQL Community Dinner). More to come on this day in a future blog post.

So back to the MySQL & Friends Devroom, the Committee high rated the following talks:

In this blog post, we’ll find out how to use Percona XtraBackup on a MySQL instance with a large number of tables.

As of Percona Xtrabackup 2.4.5, you are required to have enough open files to open every single InnoDB tablespace in the instance you’re trying to back up. So if you’re running innodb_file_per_table=1, and have a large number of tables, you’re very likely to see Percona XtraBackup fail with the following error message:

InnoDB: Operating system error number 24 in a file operation.
InnoDB: Error number 24 means 'Too many open files'
InnoDB: Some operating system error numbers are described at http://dev.mysql.com/doc/refman/5.7/en/operating-system-error-codes.html
InnoDB: File ./sbtest/sbtest132841.ibd: 'open' returned OS error 124. Cannot continue operation
InnoDB: Cannot …

Recently I was testing data migration from MSSQL to MySQL using MySQL Workbench. My aim was to include data with all datatype available in MSSQL for migration. In this following blog post will see data migration prerequisites, migration steps and few common errors.

• About MySQL Workbench
• Prerequisite
• DATA SOURCE ODBC Configuration
• Required privileges on MS-SQL DB
• DB Servers Data Types …

Please join Percona’s Consultant David Ducos on Thursday, December 29, 2016 at 10 am PST/ 1:00 pm EST (UTC-8) as he presents JSON in MySQL 5.7.

Since it was implemented in MySQL 5.7, we can use JSON as a data type. In this webinar, we will review some of the useful functions that have been added to work with JSON.

We will examine and analyze how JSON works internally, and take into account some of the costs related to employing this new technology. 

At the end of the webinar, you will know the answers to the following questions: 

• What is JSON?
• Why don’t we keep using VARCHAR?
• How does it work? 
• What are the costs?
• What limitations should we take …

This blog discusses how to prepare your database for the new leap second coming in the new year.

At the end of this year, on December 31, 2016, a new leap second gets added. Many of us remember the huge problems this caused back in 2012. Some of our customers asked how they should prepare for this year’s event to avoid any unexpected problems.

It’s a little late, but I thought discussing the issue might still be useful.

The first thing is to make sure your systems avoid the issue with abnormally high CPU usage. This was an problem in 2012 due to a Linux kernel bug. After the leap second was added, CPU utilization sky-rocketed on many systems, taking down …

Related resources  The choice of MySQL storage engine and its impact on backup procedures  Customizing your database backups with ClusterControl  Become a ClusterControl DBA - Safeguarding your data  Webinar: Become a MySQL DBA - Backups  Become a MySQL DBA blog series - Backup and Restore

All backup methods have their pros and cons. They …

Related resources  The choice of MySQL storage engine and its impact on backup procedures  Customizing your database backups with ClusterControl  Become a ClusterControl DBA - Safeguarding your data  Webinar: Become a MySQL DBA - Backups  Become a MySQL DBA blog series - Backup and Restore

All backup methods have their pros and cons. They …

Today in our series of articles related to MySQL Group Replication’s limitations, let’s have a quick look at Savepoints.

The manual is clear about this: Transaction savepoints are not supported.

The first thing to check then is if the application that will use our MySQL Group Replication Cluster is currently using savepoints.

We have two ways to find this, the first is using STATUS variables:

mysql> show global status like '%save%';
+----------------------------+-------+
| Variable_name              | Value |
+----------------------------+-------+
| Com_release_savepoint      | 2     |
| Com_rollback_to_savepoint  | 0     |
| Com_savepoint              | 4     |
| Handler_savepoint          | 0     |
| Handler_savepoint_rollback | 0     |
+----------------------------+-------+

…

This is a bug-fix release.  Please refer details below.

Changes as compared to SQLyog MySQL GUI 12.3.2 include:

Bug Fixes:

* Fixed an issue where Import External Data -jobs failed to authenticate SMTP.
* The sja.log would record syntax errors on recent servers if  Scheduled Backup was running with ‘Flush Master’ option. The generated backup file was OK. ‘Flush Master’ was deprecated in MySQL 5.6 and replaced with ‘Reset Master’. We now use ‘Reset Master’ with such servers.
* In email settings of Import External Data wizard it was possible to leave the subject empty.
* When re-ordering columns, an ON UPDATE -clause could be lost in specific cases.
* Fixed cases where index-level comments were not saved and …