The MySQL team are busily working on improving ways to use MySQL in scalable highly available systems. As most of you are already aware, the MySQL Group Replication project is progressing at full speed. Indeed, we just got preview release 0.5 out, while Fabric 1.5.6 was just released and work is ongoing for the Fabric 1.6 release.…

This Log Buffer Edition dives deep into the ocean of blogosphere and surfaces with some cool blog posts from Oracle, SQL Server and MySQL.

Oracle:

• Lets Talk DB Perth
• The Fundamental Challenge of Computer System Performance
• Index Advanced Compression: Multi-Column Index
• Middleware Diagnostics Advisor (MDA) Setup
• Most people are now aware that in 12c, a …

Intro

The purpose of this project was to measure the potential overhead of VividCortex Agent, which is used by VividCortex.com database monitoring system. This benchmark is part of a consulting engagement with VividCortex and paid by the customer.

The assumption is that VividCortex agent uses CPU processing time, and we should see an impact on user queries when the workload is CPU-intensive (how much is to be measured). The impact on IO-bound should be small or insignificant.

Workload Description
For this, we use LinkBenchX benchmark in a combination of different options.

Workloads

There are 3 different workloads we want to look into:

• CPU bound. …

In two earlier posts, I gave some examples on how to use Perl to send tweets stored in a MySQL database to Twitter, and then how to automatically reply to your retweets with a “thanks”. In this post, I will show you how to automatically download your direct messages from Twitter, store the messages in a MySQL database, and then delete them.

I don’t like the way Twitter makes me read my direct messages. Granted, the majority of them are not real messages. The message is usually thanking me for following the sender, and then there is a personal website link or a link to a product they are selling. But if I want to delete a direct message, I have to …

Recently Aphyr (Kyle Kingsbury) published https://aphyr.com/posts/327-call-me-maybe-mariadb-galera-cluster

The article is technically valid, I am not going to dispute a conclusion Aphyr made, but it is also quite technically involved, so users who just jump to conclusion may get the wrong impression and we’re left with more questions than ever.

So, let me state what is the real conclusion of this article:
“Galera cluster does not support SNAPSHOT ISOLATION LEVEL, in contract to what was stated in the documentation”.
Following that conclusion is using Galera cluster may result in “corrupted” data.

I do not quite like the usage of the word “corrupted” here. For me, the more correct word be to use is “inconsistent”.

So with this clarification, the …

Recently we encountered an issue with aurora, where our cpu started spiking every X minutes. (X < 30)

we had like 20-30 connections, out of which majority were inserts and a few selects.

every time the spike occurred our inserts would start waiting and waiting….

here is innotop output

we checked our code. nothing major had changed.

The mysql error log had this mysterious message which i could not trace in the mysql/percona/maria source.

“Innodb: Retracted crabbing in btr_cur_search_to_nth_level 33001 times since restart”

if you get to know the meaning of this – please do let me know – would love to understand this.

…

Thanks to all who attended my webinar Introduction to MySQL SYS Schema. This blog is for me to address the extra questions I didn’t have time to answer on the stream.

Can i have the performance_schema enabled in 5.6 and then install the sys schema? Or they are one and the same?

You need to have enabled the performance_schema in order to use it through the sys schema. They are different entities. In general, performance_schema collects and stores the data, and sys schema reads and presents the data.

The installation of sys schema on primary database will be replicated to the slaves?

By default, no. If you wish that the Sys Schema replicates to the slaves, you can modify the before_setup.sql ( …

Over the years, MySQL has used three different mechanisms for securing passwords both for storage and for transmission across networks. This blog post aims to provide a brief history of the various mechanisms and highlight reasons to migrate accounts to use the sha256_password mechanism introduced in MySQL Server 5.6.…

Percona is glad to announce the release of Percona Server 5.6.26-74.0 on September 15, 2015. Download the latest version from the Percona web site or from the Percona Software Repositories.

Based on MySQL 5.6.26, including all the bug fixes in it, Percona Server 5.6.26-74.0 is the current GA release in the Percona Server 5.6 series. Percona Server is open-source and free – …

Hi all, keeping our steady release cycle, it is time again to do another preview release of MySQL Group Replication, the plugin that brings multi-master update everywhere to MySQL, like we described in Hello World post.

We are very proud to do the fourth preview release of MySQL Group Replication, version 0.5.0 based on MySQL Server 5.7.8, which introduces new exciting features, please enjoy the highlights!…