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Displaying posts with tag: Databases (reset)
PreFOSDEM talk: Upgrading from MySQL 5.7 to MySQL 8.0

In this post I’ll expand on the subject of my MySQL pre-FOSDEM talk: what dbadmins need to know and do, when upgrading from MySQL 5.7 to 8.0.

I’ve already published two posts on two specific issues; in this article, I’ll give the complete picture.

As usual, I’ll use this post to introduce tooling concepts that may be useful in generic system administration.

The presentation code is hosted on a GitHub repository (including the …

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MySQL Cloning: more thoughts

I posted a few days ago some initial thoughts on the the MySQL native cloning functionality. Overall this looks good and I need to spend time to test further. I’m here in San Francisco ahead of Oracle Open World which starts today. As is usual with trips like this jet lag wakes you up rather … Continue reading MySQL Cloning: more thoughts

The post MySQL Cloning: more thoughts first appeared on Simon J Mudd's Blog.

MySQL 8.0.17+: Cloning is now much easier

If you use replication with MySQL, if you need a backup, if you need a spare copy of a system for testing and for many other reasons you need a way to make a copy of your MySQL system. In the past you could make a copy in various ways: using a cold file system … Continue reading MySQL 8.0.17+: Cloning is now much easier

The post MySQL 8.0.17+: Cloning is now much easier first appeared on Simon J Mudd's Blog.

Summary of trailing spaces handling in MySQL, with version 8.0 upgrade considerations

Fairly recently, we’ve upgraded to MySQL 8; it’s been a relatively smooth transition, however, some minor differences needed to be handled. One of them is the behavior of trailing spaces.

Trailing spaces are a (not in a good way) surprising, but also widely covered argument. This article gives a short overview, and relates it to how this affects people upgrading to MySQL 8.0.

Contents:

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Communications link failure MySQL JDBC with TLS

Ran into an interesting situation trying to configure a MySQL JDBC driver to connect over TLS (though the driver may call it SSL, TLS is the name for more recent versions of the protocol).

The error I was getting was pretty generic:

Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

With the relevant parts of the stacktrace, also being non helpful:

at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
        at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
        at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835)
        at com.mysql.cj.jdbc.ConnectionImpl.(ConnectionImpl.java:455)
        at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
        at …
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An in depth DBA’s guide to migrating a MySQL database from the `utf8` to the `utf8mb4` charset

We’re in the process of upgrading our MySQL databases from v5.7 to v8.0; since one of the differences in v8.0 is that the default encoding changed from utf8 to utf8mb4, and we had the conversion in plan anyway, we anticipated it and performed it as preliminary step for the upgrade.

This post describes in depth the overall experience, including tooling and pitfalls, and related subjects.

Contents:

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Giving back to the Community -- ChickTech Austin

I am doing something this weekend that is way out of my comfort zone and I want to encourage you to do something similar.  On Saturday I will be teaching a pop up workshop for Chick Tech Austin titled An Introduction to Databases with MySQL.  

Why is this out of my comfort zone?  I regularly speak to computer professional on databases and programming and have done so for years.  But this Saturday the class is made up of young women between the ages of fourteen and eighteen.For us oldsters, the class is made up of people half the age of MySQL, Python, and Java.  Their parents are probably younger than Structured Query Language! But these young folks are going to be inheriting our code bases based on technologies used today and integrated with future innovations. 

Another point of reference is that the …

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Dropping a database column in production without waiting time and/or schema-aware code, on a MySQL/Rails setup

We recently had to drop a column in production, from a relatively large (order of 10⁷ records) table.

On modern MySQL setups, dropping a column doesn’t lock the table (it does, actually, but for a relatively short time), however, we wanted to improve a very typical Rails migration scenario in a few ways:

  1. offloading the column dropping time from the deploy;
  2. ensuring that in the time between the column is dropped and the app servers restarted, the app doesn’t raise errors due to the expectation that the column is present;
  3. not overloading the database with I/O.

I’ll give the Gh-ost tool a brief introduction, and show how to fulfill the above requirements in a simple way, by using this tool and an ActiveRecord flag.

This workflow can be applied to almost any table alteration scenario.

Contents:

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Reminder: Madrid MySQL User Group Meetup presenting dbdeployer on Thursday in Madrid

This is a quick reminder that on Thursday (tomorrow) there there is a Madrid MySQL Users Group Meeting where Giuseppe Maxia will be presenting dbdeployer to us. More information can be found here. Do not forget to sign up if you are interested. We look forward to seeing you there.

The post Reminder: Madrid MySQL User Group Meetup presenting dbdeployer on Thursday in Madrid first appeared on Simon J Mudd's Blog.

Reminder: MySQL User Group NL and Madrid MySQL User Group Meetups presenting Scaling MySQL this week (Monday/Thursday)

This is a quick reminder that this week there are 2 MySQL User Group Meetings (Amsterdam and Madrid) where we will be talking about Scaling MySQL. Guest speaker will be Morgan Tocker from PingCap who will talk about TiDB. More information: MySQL User Group NL  meetup taking place on Monday (presenting: Morgan, Daniël and Simon) … Continue reading Reminder: MySQL User Group NL and Madrid MySQL User Group Meetups presenting Scaling MySQL this week (Monday/Thursday)

The post Reminder: MySQL User Group NL and Madrid MySQL User Group Meetups presenting Scaling MySQL this week (Monday/Thursday)

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