In a previous blog post on Data Consistency for RDS for MySQL, we presented a workaround to manage run pt-table-checksum on RDS instances. However, if your instance is running a MySQL 8.0.X version, there’s a simpler way to check data consistency.

Starting with 8.0.1, MySQL introduced something called “Dynamic Privileges” which is a solution to grant more granulated privileges to the users, instead of the almighty SUPER privilege.

So what was the issue with pt-table-checksum and RDS again? Since there’s no SUPER privileges for any user, there was no way for the tool to change the binlog_format to STATEMENT… but not anymore.

The solution when using 8.0 is …

One of the questions you often will be faced with operating a Linux-based system is managing memory budget. If a program uses more memory than available you may get swapping to happen, oftentimes with a terrible performance impact, or have Out of Memory (OOM) Killer activated, killing process altogether.

Before adjusting memory usage, either by configuration, optimization, or just managing the load, it helps to know how much memory a given program really uses.

If your system runs essentially a single user program (there is always a bunch of system processes) it is easy.  For example, if I run a dedicated MySQL server on a system with 128GB of RAM I can use “used” as a good proxy of what is used and “available” as what can still be used.

root@rocky:/mnt/data2/mysql# free -h …

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Oracle Cloud Infrastructure (OCI) is the Oracle Cloud Platform where the tutorial leverages 3 services – namely the MySQL Database Service (MDS), Kubernetes Container (K8s) under Developer Services and Compute VM services.

This article is written to provide the steps to provision MDS, K8s and Compute VM services.   It also provides the steps to create a docker image from Image:java:latest as tar for local node image repository import (loading).  

2 Java Client sources are used with the tutorial.

• Helloworld.java – it is a simple hello world output java source
• HelloDB.java – it is multi-threaded java application with Runnable Thread to pump Data into MySQL Database Service.   It uses the Connect/J (MySQL JDBC Driver) to connect to MySQL MDS.

MySQL Shell is …

Please note that this is not recommended for any production purpose, don’t expose MySQL traffic to the Internet !

MySQL Database Service is now available, take a look at this nice introduction video:

It is usually a very bad idea to expose a database on a public IP (MySQL or any other database ). MDS doesn’t allow you to implement such bad security practice.

The best way to use your MySQL instance is to use a VPN as I explained in this article.

However, this can be restrictive for a simple test. In this post I will illustrate how you can setup a MDS instance and test it without having to setup any kind of VPN. Of course I recommend you to use such practice only for testing …

The MySQL DROP statement is one of many powerful DDL commands. Be it ALTER TABLE some_table DROP some_column or DROP some_table, this type of command can drastically change your data landscape because in executing MySQL DROP, you are completely removing objects from the database! If you are using the phpMyAdmin web interface, you can execute the MySQL DROP statement with just a few mouse clicks. Continue reading to see how…

Drops of water.

Self-Promotion:

If you enjoy the content written here, by all means, share this blog and your favorite post(s) with others who may benefit from or like it as well. Since coffee is my favorite drink, you can even buy me one if you would like!

Note: The …

MySQL for RDS and DBaaS, in general, are very controlled environments by the vendors, meaning that there are missing things like a SUPER grant for the root user (and any user in general). This has some implications on operations, one of them being the impossibility of running pt-table-checksum to verify data consistency between a primary and its replicas.

However, there’s a workaround that might overcome this situation and involves three things:

• The pt-table-checksum itself
• A way to collect executed queries
• And the last one, which can be controversial, is to remove the read-only from the replica and use a maintenance window to stop traffic to the database while pt-table-checksum runs.

The problem with RDS is that you cannot change binlog_format to STATEMENT, which is one of the requirements for pt-table-checksum to run.

The workaround consists of capturing the executed …

ProxySQL is proud to announce the release of the latest stable version of ProxySQL 2.0.14 on the 8th of September 2020

ProxySQL is a high performance, high availability, protocol aware proxy for MySQL, with a GPL license! It can be downloaded here or alternatively from the ProxySQL Repository, and freely usable and accessible according to the GNU GPL v3.0 license.

Release Overview Highlights

Before discussing the features and fixes in this release we’d like to mention that we are aware of the delays in new releases. Ideally we would like to release ProxySQL more rapidly however we have recently been focusing our development efforts on ProxySQL 2.1.

The next edition of ProxySQL brings improved performance as well as many new and exciting …

You may have noticed, I started to blog also on the official Oracle MySQL Blog.

When I will do so, I will also publish my articles on lefred.be after a short delay.

I really invite you to follow the official Oracle MySQL Blog where you will find information related to MySQL Community but also about our webinars.

Currently, we put the highlight on our great new MySQL Database Service on OCI. My first post, is precisely dedicated to it.

In this blog series, I’d like to introduce you gently to the topic on which I was working last 2 years, which is improving how InnoDB locks data (tables and rows) in order to provide illusion to clients that their queries are executed one after another, while in reality there is a lot of concurrency.…

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After spending four years working with ProxySQL in production, I’ve learned a few interesting lessons about interpreting and processing query rules. I hope to save you some time (and avoid wrong turns) with this summary of ProxySQL query rules.

ProxySQL query engine is very powerful and supports the building of complex rule sets. These can be used to route traffic to backend MySQL instances, rewrite queries, and for traffic mirroring, among other use cases.

When the rule set is short and simple, you can easily understand what the outcome for a certain query would be. However, for complex sets or combined scenarios, you need a deeper understanding of the engine logic.

Note 1: Rules are processed in rule_id order

It might seem like a trivial start, but during testing or implementation, …