We’ve been having a problem with MySQL replication at VividCortex. Replicas periodically tend to fall behind and we couldn’t really figure out how to speed things up. It wasn’t about resources. The replicas have plenty of CPU and I/O available. We’re also using multithreaded replication (a.k.a. MTR) but most of the replication threads were idle.

One thing that we decided to try out was the new LOGICAL_CLOCK parallelization policy introduced in MySQL 5.7.2. Here’s what the MySQL reference manual says about slave-parallel-type:

When using a multi-threaded slave (slave_parallel_workers is greater than 0), this option specifies the policy used to decide which transactions are allowed to execute in …

Today’s blog post is related again to MySQL Group Replication.

By default MySQL Group Replication runs in Single-Primary mode. And it’s the best option and the option you should use.

But sometimes it might happen that in very specific cases you would like to run you MGR Cluster in Multi-Primary mode: writing simultaneously on all the nodes member of the Group.

It’s of course feasible but you need to make some extra verification as not all workload are compatible with this behavior of the cluster.

Requirements

The requirements are the same as those for using MGR in Single-Primary mode:

• InnoDB Storage Engine
• Primary Keys
• IPv4 Network
• Binary Log Active
• Slave Updates Logged
• Binary …

This blog provides a query language type overview.

The idea for this blog originated from some customers asking me questions. When working in a particular field, you often a dedicated vocabulary that makes sense to your peers. It often includes phrases and abbreviations because it’s efficient. It’s no different in the database world. Much of this language might make sense to DBA’s, but it might sound like “voodoo” to people not used to it. The overview below covers the basic types of query languages inside SQL. I hope it clarifies what they mean, how they’re used and how you should interpret them.

DDL (Data Definition Language)

A database schema is a visualization of information. It contains the data structure separated by tables structures, views and anything that contains structure …

Welcome to another post in the series of Percona Live featured tutorial speakers blogs! In these blogs, we’ll highlight some of the tutorial speakers that will be at this year’s Percona Live conference. We’ll also discuss how these tutorials 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 tutorial, we’ll meet Øystein Grøvlen, Senior Principal Software Engineer at Oracle. His tutorial is on How to Analyze and Tune MySQL Queries for Better Performance. SQL query …

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:

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 …

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 …

Related resources  How to Perform Efficient Backup for MySQL and MariaDB  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

MySQL offers multiple storage engines to store its data, with InnoDB and MyISAM …

Related resources  How to Perform Efficient Backup for MySQL and MariaDB  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

MySQL offers multiple storage engines to store its data, with InnoDB and MyISAM …