MySQL Cluster Manager 1.4.2 is now available for download from My Oracle Support.

In this blog post we will highlight some of the details of the MCM 1.4.2 release.

Progress reporting
First, some eye candy. With MCM 1.4.2 we added simple progress reporting.…

MySQL Connector/Node.js is a new Node.js driver for use with the X DevAPI. This release, v1.0.6 M5, is the fourth development release of the MySQL Connector/Node.js 1.0 series.

The X DevAPI enables application developers to write code that combines the strengths of the relational and document models using a modern, NoSQL-like syntax that does not assume previous experience writing traditional SQL.

MySQL Connector/Node.js can be downloaded through npm (see https://www.npmjs.com/package/@mysql/xdevapi for details) or from https://dev.mysql.com/downloads/connector/nodejs/.

To learn more about how to write applications using the X DevAPI, see  …

Please join Percona’s Principal Technical Services Engineer, Sveta Smirnova as she presents “Troubleshooting Issues with MySQL Character Sets ” on March 9, 2017, at 11:00 am PST / 2:00 pm EST (UTC-8).

Register Now

Many MySQL novices find MySQL character sets support puzzling. But after you understand how it is designed, you will find it much more powerful than many other competing database solutions.

MySQL allows to specify a character set for every object, and change it online. For years this has helped to create fast applications that can work …

In this blog post, we’ll look at how “operator error” can cause serious problems (like the one we saw last week with AWS), and how to avoid them in MySQL using

--i-am-a-dummy

.

Recently, AWS had some serious downtime in their East region, which they explained as the consequence of a bad deployment. It seems like most of the Internet was affected in one way or another. Some on Twitter dubbed it “S3 Dependency Awareness Day.”

Since the outage, many companies (especially Amazon!) are reviewing their production access and deployment procedures. It would be a lie if I claimed I’ve never made a mistake in production. In fact, I would be afraid of working with someone who claims to have never made a mistake in a production environment.

Making a mistake or two is how you learn to have a full sense …

Recently, I had to go through crash recovery of a large MariaDB 10.1.21 instance.  After starting MariaDB, I started tailing the error logs expecting to wait many minutes while InnoDB was scanning ibd files.  I was surprised (and actually delighted) with this:

[...] [...]:34:36 [...] [Note] InnoDB: Reading tablespace information from the .ibd files... [...]:34:53 [...] [Note] InnoDB: Processed

MySQL Enterprise Backup Team is pleased to announce major improvements in incremental backup performance starting with release 4.1.

Introduction

The current incremental backup algorithm scans all the tables to gather changed pages even if very few tables are modified since the previous backup and thus results in a 'full-scan' incremental backup. This may result in increment backups requiring the same amount of time as full backup because it scans all the tables. The new algorithm aims to eliminate this extra time.

The new algorithm scans only those tables that have been modified since the previous backup. This algorithm relies on modification time, which is similar to an earlier improvement made for full backup. That full backup algorithm is known as optimistic full backup, hence new improvement is named …

Running out of disk space is something which, of course, should never happen as we all setup monitoring and alerting and only run well behaved applications. But when it does happen we want things to fail gracefully.

So what happens when mysqld runs out of disk space?
The answer is: It depends

1. It might start to wait until disk space becomes available.
2. It might crash intentionally after a 'long semaphore wait'
3. It might return an error to the client (e.g. 'table full')
4. It might skip writing to the binlog (see binlog_error_action )

What actually happens might depend on the filesystem and OS.

Fixing the disk space issue can be done by adding more space or cleaning up some space. The later can often be …

MySQL Group Replication has been released since MySQL 5.7.17.
A quick start guide can be on the following URL
http://mysqlhighavailability.com/mysql-group-replication-a-quick-start-guide/

If there is a network partition between a group of Servers, it may introduce arbitration to find out and determine the next action for the Group of the Servers.
For documentation about Network Partitioning with Group Replication, please refer to the following URL::
https://dev.mysql.com/doc/refman/5.7/en/group-replication-network-partitioning.html

This blog is written to introduce my 'demo' version of arbitrator / watchdog.   From here onwards, I refer this arbitrator as gr_watchdog.
Another public arbitrator from Matt Lord can also be found on :
https://github.com/mattlord/myarbitratord
As an example, an application connecting to a group of servers with 5 MySQL instances …

The MariaDB subquery cache feature added in MariaDB 5.3 is not widely known. Let’s see what it is and how it works.

What is a subquery cache?

The MariaDB subquery cache optimizes the execution of correlated subqueries. Correlated subqueries refer to a value from the parent query. For example:

SELECT id FROM product WHERE price NOT IN (SELECT MAX(price) FROM product GROUP BY category);

MariaDB only uses this optimization if the parent query is a SELECT, not an UPDATE or a DELETE. The subquery results get cached only for the duration of the parent query.

MariaDB added the subquery cache in v5.3. It is controlled by …

This is a rant. It’s a strong one mainly because of what I’ve been dealing with over the past few days. But it’s still just a rant, so I’m going to exaggerate 😛. I’ve been with my employer for several years, and a lot of the stuff I’m writing about isn’t really new. I think most of it has been like this for years. I didn’t really pay attention to this stuff in the past because I didn’t have to. I didn’t want to either1, but now our team is handling ops and I have to care 😐.

Doing it wrong with MySQL

We use async, bidirectional replication. It’s a nightmare.

Using async replication means you don’t care about replicas, basically by definition. If the master isn’t waiting for replicas, then they can fall arbitrarily behind, crash, fail, whatever and the master will happily keep going. You can use hacks like delaying binlog commits on the master to improve parallelization on the …