What is great with MySQL Shell Plugins, it’s that it provides you an infinite amount of possibilities. While I was writing the part I and part II of the check plugin, I realized I could extend it event more.

The new methods I added to the plugin are especially useful when you are considering to use MySQL InnoDB Cluster in Multi-Primary mode, but not only

Let’s have a look at these new methods:

These 4 new methods are targeting large queries or large transactions. It’s also possible to get the eventual hot spots.

Let’s see the first two that are more basic in action:

The first method …

In the first part of this article related to the check plugin, we discovered information retrieved from the binary logs. This part, is about what Performance_Schema and SYS can provide us about the queries hitting the MySQL database.

Currently, 3 methods are available:

• getSlowerQuery()
• getQueryTempDisk()
• getFullTableScanQuery()

The method’s name should be self explaining.

This is an overview of the parameters for each methods:

ext.check.getSlowQuery()ext.check.getQueryTempDisk()ext.check.getFullTableScanQuery()

Some methods allow a select parameter if only SELECT statements should be returned.

When only one query is returned (default), it’s also possible to …

This blog was initially referring to the audit plugin, but I renamed it as check plugin to be more compatible with all the current and future methods included in it.

As you may know, it’s now possible to create your own plugins for MySQL Shell. See the following posts:

• https://lefred.be/content/overview-on-mysql-shell-8-0-17-extensions-plugins-and-how-to-write-yours/
• https://lefred.be/content/mysql-router-8-0-17s-rest-api-mysql-shell-extensions/
• …

To illustrate how easy it’s to see who’s trying to access data they have not been granted for, we will first create a schema with two tables:

mysql> create database mydata;
mysql> use mydata
mysql> create table table1 (id int auto_increment primary key, 
              name varchar(20), something varchar(20));
mysql> create table table2 (id int auto_increment primary key, 
              name varchar(20), something varchar(20));

Now, let’s create a user :

mysql> create user myuser identified by 'mypassword';

And as it’s always good to talk about SQL ROLES, let’s define 3 roles for our user:

• myrole1: user has access to both tables in their entirety, reads and writes
• myrole2: user has access only to `table2`, reads and writes
• myrole3: user has only access to the column `name`of `table1` and …

MySQL 8.0 is now part of RedHat Enterprise 8 and other distros based on it like CentOS and Oracle Linux.. This is a very good thing !

However if for any reason you want to use the latest version of MySQL from the Community Repository, you may encounter some frustration if you are not familiar with the new way the package manager works.

Let’s start by verifying our system:

LSB Version:    :core-4.1-amd64:core-4.1-noarch
Distributor ID:    OracleServer
Description:    Oracle Linux Server release 8.0
Release:    8.0
Codename:    n/a

We can see that we are on Oracle Linux 8.0. So now let’s try to install MySQL Server:

[root@localhost ~]# dnf install mysql-server
Last metadata expiration check: 0:08:15 ago on Sat 02 Nov 2019 09:54:07 AM UTC.
Dependencies resolved.
============================================================================================
  Package                 Arch   Version …

This article is an update of a previous post explaining how to setup a second cluster on a second data center to be used as disaster recovery (or to run some off site queries, like long reports, etc..).

This new article covers also the CLONE plugin. Before you ask, CLONE plugin and Replication Channel Based Filters are only available in MySQL 8.0 ! It’s time to upgrade, MySQL 8 is Great !

Also, for DR only, a single MySQL instance acting as asynchronous replica is enough. But if for any reason you want to also have a HA cluster in the second data …

Yesterday, Bhuvanesh published an article about how to verify the difference between allocated diskspace for a tablespace and the the data in it.

I commented with an old post explaining how to get some similar info only using SQL in case you don’t have filesystem access.

And finally, my friend Bill Karwin, commented how this info is not always accurate. Which, of course, I agree with.

This is why, I checked …

MySQL InnoDB Cluster is the most easy and integrated High Availability solution for MySQL.

The solution is composed of:

• MySQL Server
• MySQL Group Replication Plugin
• MySQL Clone Plugin
• MySQL Router
• MySQL Shell

All those components are developed and tested together to provide the easiest and best experience to the MySQL users.

As the MySQL Router is a TCP Level 4 router (like HA Proxy), some users requiring a more “intelligent” proxy having other extra features like caching, read/write splitting in relation with the user or SQL, firewall, … may be interested in using ProxySQL… and this is a good choice !

ProxySQL / MySQL Router in OSI Model

However, even is ProxySQL supports MysQL Group Replication, for …

Mid September, MySQL Community, MySQL Customers and MySQL Engineers will be in San Francisco to share their experience and present the new features of your favorite database !

The event will be held in Moscone South (just Mirko Ortensi‘s Hands-on Lab will be delivered in Moscone West).

During the week, the MySQL Community Team will host the traditional MySQL Reception. We got so great feedback from last year that we decided to renew the experience in the same awesome location, the Samovar Tea Lounge at Yerba Buena Gardens. Don’t forget that you need to register for this reception but no OOW pass is required. Please register here !

Back to the conference, you can find the full schedule for the session in the …

Answering this question is not easy. Like always, the best response is “it depends” !

But let’s try to give you all the necessary info the provide the most accurate answer. Also, may be fixing one single query is not enough and looking for that specific statement will lead in finding multiple problematic statements.

The most consuming one

The first candidate to be fixed is the query that consumes most of the execution time (latency). To identify it, we will use the sys schema and join it with events_statements_summary_by_digest from performance_schemato retrieve a real example of the query (see this post for more details).

Let’s take a look at what sys schema has to offer us related to our mission:

> show tables like …