Those who’ve been around the MySQL world are probably aware of the much-discussed topics of GPL licensing, dual licensing, and in particular, licensing of the client libraries (also called connectors or drivers) and the FOSS exception to that licensing. This is newly relevant with the announcement of a permissively-licensed MySQL-compatible client library for MariaDB.
I was just bitten by failing to catch a MySQL warning. It’s the old familiar tune: I inserted 100 characters into a VARCHAR(50) and it didn’t throw an error*. Of course, then subsequent SELECT statements didn’t find the value I inserted.
Even if you are using a GUI tool to connect to your MySQL servers, one day or another, you will have to deal with the command line. So it is nice to know a few tips that can really make your work easier.
Note: The commands below are only available for Unix/Linux.
Most of the graphical tools paginate results, which is very handy. But this is not the way the command line client works: it just outputs all results. It can be annoying but it is easily solved by using the pager command:
A couple of months ago I bent the ear of a friend whose opinion I really respect. She’s a totally sharp engineer who actively writes code for a living as well as managing large teams. She’s held top-level technical roles at some large and extremely respectable companies. In short, her perspective and experience is very valuable.
If you are using SElinux, you should know that it’s advised to disable it to avoid issue with PXC. Generally the communication between your nodes doesn’t work properly and a node having SElinux enabled won’t be able to join the cluster.
So when a node doesn’t join the cluster where it should, my first reflex is to have a look at audit.log. But recently I faced another problem: the node joined the cluster but SST failed (whatever which method was used, discarding skip).
We are doing a migration from Amazon RDS to EC2 with a customer. This, unfortunately, involves some downtime – if you are an RDS user, you probably know you can’t replicate an RDS instance to an external server (or even EC2). While this is annoying, this post isn’t going to be a rant on how RDS can make you feel locked in. Instead, I wanted to give you a quick tip.
So here’s the thing – you can’t stop replication on RDS read replica: