MySQL in Azure

January 19, 2021
Tags: ,
Ikaria Greece by Anastasia Papachristopoulou

Cloud computing is becoming more and more famous among the IT circles and it is growing super fast. Industries are charmed by its flexible character and the avoidance of having their own infrastructure.
An easy solution that offers automation on every field and they can scale up depending on the needs of each user and company.

There are many Cloud providers, such as Oracle Cloud Infrastructure, Microsoft Azure, Amazon Web Services, etc…
In this article, we are going to see how to set up a MySQL Database instance on Microsoft Azure Cloud.

At this point, it is important to clarify that we are going to set up MySQL as a Service (PaaS).

So, before starting with the actual Database creation, we need:

  • An Azure subscription, you may create a free Azure account that offers for the first month a $200 credit and for the first year the most wanted services.
  • Have an available resource group.
  • Have specifically access for MySQL.

Let’s sign in to Azure portal, and you should see a screen like the following:

Azure MySQL

We need to verify that we have the correct resources available for our subscription, in order to set up the MySQL DB:

  • From Azure Portal, go to Subscriptions
  • Then, on Development Services and choose Resource Provider
  • Scroll down and check if Microsoft.DBforMySQL is registered
Azure MySQL

If it is not registered, then click Register on the top left corner:

Azure MySQL

Once the registration is completed, we are ready for creating our DB.

Azure MySQL

To create the MySQL Database, we need to choose Azure Database for MySQL Servers:

Azure MySQL

By clicking the Add option on the top left, we are presented with two options, as it can be shown below:

Azure MySQL
  • Single Server is a fully managed database service with minimal requirements for customizations of the database. The single server platform is designed to handle most of the database management functions such as patching, backups, high availability, security with minimal user configuration and control. The architecture is optimized to provide 99.99% availability on single availability zone. Single servers are best suited for cloud native applications designed to handle automated patching without the need for granular control on the patching schedule and custom MySQL configuration settings. MySQL available version is 8.0.15
  • Flexible Server (Preview) is a fully managed database service designed to provide more granular control and flexibility over database management functions and configuration settings. In general, the service provides more flexibility and server configuration customizations compared to the single server deployment based on the user requirements. The flexible server architecture allows users to opt for high availability within a single availability zone and across multiple availability zones. Flexible servers also provide better cost optimization controls with the ability to start/stop your server and burstable SKUs, ideal for workloads that do not need full compute capacity continuously. MySQL version is 5.7 and 8.0.21 is on trial.

We choose Single Server for our start, and we are presented with the following screen:

Azure MySQL

Azure MySQL

We need to set accordingly:

Subscription: Make sure that you have choosen the corresponding subscription

Resource Group: Choose the proper resource group with the correct resources

Server name: This is actually the name of the MySQL Server

Data Source: You may create the new server from a Backup, here we choose none

Location: Choose the proper location that your resource group has access to

Version : Available versions 5.6,5.7 and 8.0

Compute+storage: Choose the best settings, we have Basic , General Purpose and Memory Optimized. The basic differences are among Basic & General Purpose/Memory Optimized.

Basic offers 2 cores and storage up to 1024GB.

General Purpose offers up to 64 cores and storage up to 16384GB.

Memory Optimized offers up to 32 cores and storage up to 16384GB.

All three available configurations offer Backup retention policy up to 35 days (default is 7 days).

General Purpose:

Azure MySQL

Azure MySQL

Azure MySQL
Azure MySQL

Azure MySQL

Admin username: Choose the proper name of the DB admin

Password and Confirm Password : Create a strong password for the DB admin

As soon as these settings are ready, we go to the Next:

Azure MySQL

Additional Settings:

We are able to select encryption:

Azure MySQL

And then moving on:

Azure MySQL

Tags : are name/value pairs that enable you to categorize and view consolidated billing by applying the same tag to multiple resources and resource groups. We won’t be organizing our resources with tags now so we are moving on to Review&Create to check the price and the options we have selected:

Azure MySQL

While our DB is being created, we see its progress:

Azure MySQL

Once ready, we are able to access the new resource that we created :

Azure MySQL

From this page, we may stop the server, reset the password , restore/delete and restart.

From the left side-bar, we may create alerts/metrics and to gather information.
The server logs are also available on this section, as well as the Replica option in case we need to set up a replica for our environment.

Azure MySQL

Same for the server settings:

Azure MySQL

One important note, before we connect officially to our Database.
We need to add the proper Firewall Rule to allow our Client to connect to the MySQL instance:

Azure MySQL

In order to connect to the Database via MySQL Workbench we need to use the Server name on the Hostname as well as the Username, like you may see on the following screenshot:

Azure MySQL

Finally, we are connected to the Database and we are able to execute any query we wish:

Azure MySQL

If you wish to delete the Database, Azure will give you a warning that the deletion is irreversible and you will need to provide MySQL Server’s name.

The same concept lies for the Flexible Server, but with a couple of differences:

Azure MySQL

Azure MySQL

Here, we need to specify the expected Workload type and based on that the most appropriate settings are being recommended and we also have Zone Redundancy available :

Azure MySQL

Backups offer the same retention policy as in Single Server:

Azure MySQL

To be able to connect, we need to set the Firewall Rules, either a specific Public address to access the Flexible MySQL Server or via a Virtual Network:

Azure MySQL

Azure MySQL

Flexible Servers offers synchronous replication when Zone Redundancy is enabled, however it does not offer read-only replicas and due to synchronous replication to another availability zone, primary database server can experience elevated write and commit latency.

We need to mention here that if a more updated version of MySQL is needed, then we will need to have a VM created.


Depending on your needs, Cloud computing can for sure serve them and most probably for a fair price. It offers a variety of services, so give it a try!

After all, it is no coincidence that our heads are up in the clouds.



MySQL SHELL – The new era

December 17, 2020
Kefallonia Lake Melissani by Anastasia Papachristopoulou

MySQL Shell is a modern tool that can be used by both developers and database administrators. It is a tool that can be used with any of the following:

  • SQL, Python, Javascript
  • MySQL Document Store (NoSQL, X DevAPI)
  • JSON Documents / SQL tables

In one of our previous articles – Setting up Replication with various methods for MySQL 8 – we reviewed how to create a replica with multiple tools.
Now, it is time to perform the same action but with MySQL Shell.

In general, MySQL Shell is used with MySQL InnoDB Cluster to deploy a MySQL Group Replication, with or without MySQL Router.
Here we will examine how to create an asynchronous replication.

First of all, we may download MySQL Shell via the following url:

We will be using MySQL Shell version 8.0.22, that is currently the latest and includes extra features.

Let’s start!

On the source database, we connect to mysqlsh:

We may use option \sql or \py to use SQL or Python respectively instead of the JavaScript mode (\js):

For creating the dump we will be using the util.dumpInstance().
Please note that the outputUrl (target directory to store the dump files) must be an empty folder, otherwise you will receive an error like :

util.dumpInstance: Cannot proceed with the dump, the specified directory ‘/’ already exists at the target location / and is not empty. (ArgumentError).

If the folder doesn’t exist mysqlsh is smart enough to create the folder for us:

Now, let’s take a minute to review the options we are using:

dryRun: This won’t dump anything, it will print information on what will be dumped.

ocimds: Enable checks for compatibility with MySQL Database Service (MDS).

threads: How many threads to be used for dumping data chunks from the server.

compatibility: Apply MySQL Database Service compatibility modifications when writing dump files. Supported values: “force_innodb”, “strip_definers”, “strip_restricted_grants”, “strip_tablespaces”.

force_innodb – The MySQL Database Service requires use of the InnoDB storage engine. This option will modify the ENGINE= clause of CREATE TABLE statements that use incompatible storage engines and replace them with InnoDB.

strip_definers – strips the “DEFINER=account” clause from views, routines, events and triggers. The MySQL Database Service requires special privileges to create these objects with a definer other than the user loading the schema. By stripping the DEFINER clause, these objects will be created with that default definer. Views and Routines will additionally have their SQL SECURITY clause changed from DEFINER to INVOKER. This ensures that the access permissions of the account querying or calling them are applied, instead of the user that created them. This should be sufficient for most users, but if your database security model requires that views and routines have more privileges than their invoker, you will need to manually modify the schema before loading it.

strip_restricted_grants – Certain privileges are restricted in the MySQL Database Service. Attempting to create users granting these privileges would fail, so this option allows dumped GRANT statements to be stripped of these privileges.

strip_tablespaces – Tablespaces have some restrictions in the MySQL Database Service. If you’d like to have tables created in their default tablespaces, this option will strip the TABLESPACE= option from CREATE TABLE statements.

As we are using a database that contains other storage engines apart from InnoDB engine, we will be using option force_innodb, along with strip_restricted_grants and strip_definers, as we have routines with DEFINER.

So, here we go:

As this moves along, we may open a new connection to our target host, enabling the local_infile parameter so the dump can be imported and at the same time we disable innodb_redo_log as well.
Disabling redo logging speeds up data loading by avoiding redo log writes and doublewrite buffering:

Before proceeding, let’s discuss once again the options we are using:

/data_imp: is where the files will be located.

threads: The number of parallel threads to use to upload chunks of data to the target MySQL instance.

updateGtidSet: Apply the gtid_executed GTID set from the source MySQL instance, as recorded in the dump metadata, to the gtid_purged GTID set on the target MySQL instance.

skipBinlog: Skips binary logging on the target MySQL instance for the sessions used by the utility during the course of the import, by issuing a SET sql_log_bin=0 statement.

waitDumpTimeout: Setting this option activates concurrent loading by specifying a timeout (in seconds) for which the utility waits for further data after all uploaded data chunks in the dump location have been processed.

updateGtidSet is available from 8.0.22 version.
If you are using 8.0.21, then you will need to manually set the GTID by locating the gtidExecuted field in the @.json dump file in the dump metadata:

So, basically we have taken a dump from the source host and at the same time, restore it to the target host.
Once it is completed, and as MySQL Shell is really fast we won’t have to wait for that long, we log in to the target host and execute the following command:

And our replica is all set.

Apart from the util.dumpInstance(), we also have the options to use util.dumpSchemas() and util.dumpTables(), that was introduced in MySQL Shell 8.0.22, and offers the option for dumping specific schemas, tables or views.

It is also important to mention that the above-mentioned utilities are fully compatible with Oracle Cloud Infrastructure.


MySQL Shell is a really useful tool that offers a variety of functionalities.
It is super fast and saves us a lot of time when dealing with broken replication or with data transfer.

Try it, you will love it 🙂



Setting up Replication with various methods for MySQL 8

December 10, 2020
Irish Castle and mountains by Olivier DASINI

In the world of the Databases, one of the most important value that we are all trying to achieve is High Availability. Not to loose our valuable data or in case one server fails to always have another to step in and take control.

So, it is critical to have along with our primary database, other identical instances, the replicas.

On this blog post, we will see the most famous ways to set up our replication.

MySQL offers a variety of options to achieve replication set up. Here we are going to review how to create a replica based on GTID replication by using one of the following methods:

  • mysqldump
  • rsync
  • MySQL Enterprise Backup (MEB)
  • Clone plugin

MySQL Shell, using the utilities, is another method. Please see this article.

Before we initiate any process we need to make sure that on our my.cnf, primary & replica, have set the following parameters:

1st Replication Method – mysqldump

So, starting with mysqldump option we need to make sure that we have enabled gtid-purged:

Once this is finished, if we do :

We will receive the corresponding gtid that is needed for setting up our replica. The backup.sql file should be moved to the replica, a simple scp should do.

Moving along to the replica, we perform the following command:

After this import is completed, we simple need to execute the following:

If both the above commands are executed with no issue, perform a show slave status\G to verify that both Slave_IO_Running and Slave_SQL_Running are set to yes.

2nd Replication Method – rsync

When using the rsync option, the database on the replica must not be running. And on the primary db we will need to have a lock on the tables. As soon as the tables are locked we may proceed with rsyncing the data.


Once the copy is completed, we will need to remove the auto.cnf (as this will give the same UUID and we will not be able to set up our replica) and we will also remove mysql.sock.

The next steps will be to start our database and set it up as a replica:

And of course do not forget to reverse the lock command on the primary:

3rd Replication Method – MEB

MEB, MySQL Enterprise Backup, is a commercially licensed backup utility for MySQL databases. One of the fastest and easiest way to set up your replication while primary db is up and running.

Please note that the db on the replica should not be running and the corresponding paths should be empty, as this may cause confusion. For example, imagine having forgotten a binlog file and binlog_index to trying to read from erroneous binlogs. This will lead to having the replication broken.

So, for mysqlback & restore we can perform:

In one command we are sending our data to the replica as well.

Once, this is completed we go into the /tmp folder in the primary node and inside the meta folder, we take note of the command inside the backup_gtid_purged.sql file. This is needed for setting up our replica:

Our replica is up and running with no trouble.

4th Replication Method – clone plugin

Last but not least we have the clone method. Clone is initiated at 8.0.17 version and it is a really useful tool.

First thing we need to do is to install the clone plugin on both the primary and wannabe replica as well as the user with the proper grants:

Verify that plugin is indeed active:

And we will also set up our donor on the replica:

Now we need to log in to the replica with the clone_user we created on the above-mentioned steps and execute the following command:

Once this is completed, we log out from clone_user and log in with root and set up our replica:

Please note that the master_user that is being used to set up our replica in all the methods needs to have access on our replica and have the replication_slave privilege.


To sum up, MySQL offers a variety of ways to set up tour replication, what you will choose depends on your needs for speed, performance and down time.



Create a Cloud Backup with MySQL Enterprise Backup

December 10, 2020
Tags: ,
Cloud from above by Olivier DASINI

MySQL Enterprise Edition customers have access to MySQL Enterprise Backup.

MySQL Enterprise Backup provides enterprise-grade backup and recovery for MySQL. It delivers hot, online, non-blocking backups on multiple platforms including Linux, Windows, Mac & Solaris.

Cloud backup is a strategy increasingly used in organizations. Send copies of your data to the cloud, can help you to prevent a devastating IT crisis and ensure business continuity.

Currently, MySQL Enterprise Backup supports the following types of cloud storage services:

In this blog post I will use the OCI object storage, for obvious reasons 🙂 and also because it’s probably the best feature/price ratio choice.

Create a pre-authenticated request for a bucket

First we must create an OCI Pre-Authenticated Request (PAR) for a bucket.

Pre-authenticated requests provide a way to let users access a bucket or an object without having their own credentials, as long as the request creator has permissions to access those objects.

You can create, delete, or list pre-authenticated requests using the Console, using the CLI, or by using an SDK to access the API.
Click here to see how to create a PAR.

If you use the console, you’ll have something like:

OCI Pre-Authenticated Requests by Olivier DASINI

My Oracle Cloud Infrastructure Pre-Authenticated Request name is : MEB-par-bucket-20201203-1612

OCI Pre-Authenticated Requests by Olivier DASINI

An URL is generated. It is very important to save it!
We’ll use it with MySQL Enterprise Backup.

I can also see my list of PARs in the console:

OCI Pre-Authenticated Requests by Olivier DASINI

Create a Cloud Backup on Oracle Cloud Infrastructure Object Storage

I’m using MySQL Enterprise Backup 8.0.22.
The extra options to backup your data into OCI Object Storage are:

cloud-service : Cloud service for data backup or restoration.
Currently, there are 3 types of cloud storage services supported by mysqlbackup, represented by the following values for the option:

  • OCI: Oracle Cloud Infrastructure Object Storage
  • openstack: OpenStack Swift or compatible object storage services
  • S3: Amazon Simple Storage Service (S3) or compatible storage service.

cloud-object : The storage object for the backup image.
Note that names of objects within the same bucket have to be unique.

cloud-par-url : The Pre-Authenticated Request (PAR) URL for OCI Object Storage.
For a backup to OCI Object Storage, it is the PAR URL for the storage bucket; for restore and other operations on an object stored on OCI, it is the PAR URL for the object.

Click here to find the complete list of cloud storage options (OCI, Amazon S3 & OpenStack Swift options).

In this article the values of these options are:

  • cloud-service=OCI
  • cloud-par-url=<…snip…>_bucket-20200908-1001/o/
  • cloud-object=myBck_20201203-1600.mbi

I assume your already know what to do before the first backup.

Let’s create the backup then:

Don’t forget the value “” (dash) for backup-image parameter:

The backup is now completed and stored on the Oracle Cloud Infrastructure object storage bucket.

OCI Pre-Authenticated Requests by Olivier DASINI

Restore a Backup from Oracle Cloud Infrastructure

Again, a Pre-Authenticated Request (PAR) URL for OCI Object Storage will be used.
This time we will use a PAR on an object with Read PAR privileges created before the restoration.

Using the console, after selecting my Bucket, I create a pre-authenticated request for an object:

OCI Pre-Authenticated Requests by Olivier DASINI

The PAR target is Object
My object name is myBck_20201203-1600.mbi
An read only access type is sufficient : Access Type: Permit reads on the object

Et voilà!
My PAR is created

OCI Pre-Authenticated Requests by Olivier DASINI

An URL is generated. It is very important to save it!
We’ll use it with MySQL Enterprise Backup.

Now we have all that is needed to restore with MySQL Enterprise Backup.

I assuming you already now how to restore a MySQL instance with MEB.

Thus in our context, to restore a single-file backup from an OCI Object Storage to a MySQL Server, we will use:

The restore is now completed.

As a side note, if you want to see the 4 warnings, take a look at the MEB logfile, located in the –backup-dir, meb-tmp in this article:

Nothing really serious in this context.
If you need more information, please click here.

The rest of the story is classic, restart your MySQL instance and you good to go 🙂

One more thing to know and to keep in mind, is that a cloud backup always uses one write thread.
In clear backup & restore duration could be much longer than for a local operation.

However, it is a good practice, when possible, to keep a local copy of the backup file.

It is usually easier and much faster to recover from a local location.

MySQL Enterprise Edition

MySQL Enterprise Edition includes the most comprehensive set of advanced features, management tools and technical support to achieve the highest levels of MySQL scalability, security, reliability, and uptime.

It reduces the risk, cost, and complexity in developing, deploying, and managing business-critical MySQL applications.

MySQL Enterprise Edition server Trial Download (Note – Select Product Pack: MySQL Database).

MySQL Enterprise Edition


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Thanks for using MySQL!


MySQL 8.0.22 New Features Summary

November 10, 2020
Sakila mozaik by Olivier DASINI

Presentation of some of the new features of MySQL 8.0.22 released on October 19th, 2020.



Download this presentation and others on my SlideShare account.


That might interest you

Follow me on twitter

Watch my videos on my YouTube channel and subscribe.

My Slideshare account.

Thanks for using MySQL!


Automatic connection failover for Asynchronous Replication

November 5, 2020
Plage par Olivier DASINI


Since MySQL 8.0.22 there is a mechanism in asynchronous replication that makes the receiver automatically try to re-establish an asynchronous replication connection to another sender, in case the current connection gets interrupted due to the failure of the current sender.

Asynchronous automatic connection failover automates the process of re-establishment of an asynchronous replication connection to another sender of sender list.
That means if a the source of a replica crashed, this replica will be able to automatically connect to another source.
One of the biggest interest is to improve Disaster Recovery (DR) architecture.

With this feature, a typical architecture is to have a 3 nodes asynchronous replication cluster.
2 primary nodes in active/passive mode (if you need active/active architecture use MySQL InnoDB Cluster) and the third one is connected to one of the primary, either for DR or for some specialized task like analytics for example.
So in case of unavailability of its primary – if the replication I/O thread stops due to the source stopping or due to a network failure – this replica will automatically connect to the other primary.

Another architecture is to use this asynchronous automatic connection failover feature with MySQL InnoDB Cluster.

Hey guess what? this is the topic of this tutorial and by the way, we will use some of the fanciest MySQL 8.0 features 🙂


4 MySQL 8.0.22 instances :

– mysql_node1 :
– mysql_node2 :
– mysql_node3 :
These 3 are members of a MySQL Group Replication cluster.
I created a MySQL InnoDB Cluster (resources here and here).
I will not use MySQL Router in this tutorial.

– mysql_node4 :
It’s my replica.
It will be asynchronously connected to the Group Replication.

Because a picture is worth a thousand words, below is the architecture I want to achieve :

Asynchronous Replica of a MySQL Group Replication by Olivier DASINI

Graphs in this article are from MySQL Enterprise Monitor.

Current status

I’m using MySQL 8.0.22 :

I have a 3 nodes Group Replication cluster up and running :

Setup the replication user

Like you know, there are some preparation steps to be able to use MySQL Asynchronous Replication. If you’re not familiar with replication using GTID, please read this.

On the Group Replication primary – currently mysql_node1 – I setting up the asynchronous replication user:

Setup the clone user

The clone plugin is one of my favorite feature!

It permits cloning data locally or from a remote MySQL server instance.
Cloned data is a physical snapshot of data stored in InnoDB that includes schemas, tables, tablespaces, and data dictionary metadata.
The cloned data comprises a fully functional data directory, which permits using the clone plugin for MySQL server provisioning.

It’s a very convenient way to copy data from the source (the Group Replication) to the replica (mysql_node4).

Thanks to InnoDB Cluster the Clone plugin is already installed on the 3 members.
So on the primary member – currently mysql_node1 – I’ll create a dedicated clone user with the donor privileges for using and monitoring the clone plugin:

Note that I could have used the cluster administrator dedicated user instead of create a specialized clone user.

On mysql_node4, the future replica, I’ll create the same user but with the recipient privileges.
But before I’ll install the clone plugin and set the clone donor list:

Clone a MySQL instance

Now we have everything all set to create the replica from a member of the group.

On the future replica – mysql_node4 – we can now run the clone instance command:

If you want to monitor the cloning progress run the following query:

When the cloning is over, the MySQL instance must be restarted (that will normally happen automatically).
After the restart, you can verify that the clone completed successfully with the queries below:


Add the replica

First I will setup the configuration information for a replication source server to the source list for a replication channel.
To do that we use the function: asynchronous_connection_failover_add_source
Information needed are the replication channel name, the source server address, port and network namespace, and also the weight.

More information are available here.

For this tutorial I chose the following values:

  • Channel name: autof
  • Source server addresses: mysql_node1, mysql_node2, mysql_node3
  • Source server port: 3306
  • Source server network namespace: ” (empty)
  • Weight: respectively: 50, 90, 90

The replica’s source lists for each replication channel for the asynchronous connection failover mechanism can be viewed in the Performance Schema table replication_asynchronous_connection_failover.

To set the parameters that the replica server uses for connect to the source, we use the well known CHANGE MASTER TO statement.
You already know most of its clauses, so let’s only focus on some of them:

  • SOURCE_CONNECTION_AUTO_FAILOVER : activates the asynchronous connection failover mechanism.
  • MASTER_RETRY_COUNT & MASTER_CONNECT_RETRY : define the failover time. The default setting is… 60 days, probably not what you want :). So, you (most likely) should reduced the settings. e.g. 1 minute is respectively 20 and 3. (20 x 3 = 60)
  • FOR CHANNEL : enables you to name which replication channel the statement applies to. The CHANGE MASTER TO statement applies to this specific replication channel.

Now let’s configure the replication:

Please note that my failover time in this tutorial is 15 seconds (3 x 5). Obviously the relevant setting depends on your needs. A longer duration will probably makes more sense in real life.

Then start the replication, on channel autof using START REPLICA:

 Status information of the replication can be seen with SHOW REPLICA:

Automatic connection failover

We have now configured our replication, with an InnoDB Cluster/Group Replication as a source and a standalone MySQL server as a replica.
Let’s see how the automatic connection failover works.

Restart the replica

I want to see the behavior after a restart of the replication.

State before the stop:

Stop the replication:

MySQL Enterprise Monitor

After a while, start the replication:

Replica picks up where it left off… as you would have expected.

Short unavailability of the source

I want to see the behavior after a short unavailability of the source. I mean a duration lower than the failover threshold – connection_retry_interval x connection_retry_count – 15 seconds (5×3) in this example.

State before the stop of the source, mysql_node2:

… Stop mysql_node2 for 10 seconds …

MySQL Enterprise Monitor

State after the start of the source mysql_node2:

MySQL Enterprise Monitor

Well… nothing changed!
The unavailability of the source was not long enough to trigger the failover.
That is awesome to prevent non necessary failover.

Long unavailability of the source

I want to see the behavior after a longer unavailability of the source. I mean a duration greater than the failover threshold – connection_retry_interval x connection_retry_count – 15 seconds (5×3) in this example.

State before the stop of the source, mysql_node2:

… Stop mysql_node2 for 20 seconds …

MySQL Enterprise Monitor

As expected, the asynchronous automatic connection failover took place. \o/
The new source is now mysql_node3, because it has a bigger weight than mysql_node1 (90 vs 50) and because it was available 🙂


Please be aware that in 8.0.22 this feature lacks of some of the needed functionality to replace MySQL Router as means to replicate from an InnoDB Cluster/Group Replication cluster.

Things such as:

  • does not automatically learn about new members or members that are removed
  • does not follow the primary role, it stays connected to whatever host it was connected to
  • does not follow the majority network partition
  • does not care if a host is not part of the group any longer, as long as it can connect, it will

These limitations will be lifted in future versions.

This is a very nice feature starting with MySQL 8.0.22, useful for both MySQL Replication and MySQL Group Replication architectures.

And you know what? There is more to come 😉

Stay tuned!


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Plan your MySQL upgrade

October 21, 2020
Jardin Balata Martinique by Olivier DASINI

I’ve made a short video that will give you tips and tricks to successfully upgrade to MySQL 8

These information are from my presentation : Upgrade from MySQL 5.7 to MySQL 8.0

Thanks for using MySQL!

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MySQL 8.0.21 New Features Summary

August 27, 2020
Sakila mozaik by Olivier DASINI

Presentation of some of the new features of MySQL 8.0.21 released on July 13th, 2020.


  • Runtime disabling Innodb Redo Log
  • JSON_VALUE fonction
  • CREATE TABLE… SELECT is atomic
  • Per-user Comments & Attributes
  • MySQL Document Store Enhancements
  • MySQL Shell Enhancements
  • MySQL Router Enhancements
  • MySQL InnoDB Cluster Enhancements
  • MySQL Group Replication Enhancements
  • Thanks to the Contributors


Download this presentation and others on my SlideShare account.

Watch my videos on my YouTube channel.

That might interest you

Follow me on twitter

Watch my videos on my YouTube channel and subscribe.

My Slideshare account.

Thanks for using MySQL!


MySQL 8.0.20 New Features Summary

May 26, 2020
Sakila mozaik by Olivier DASINI

Presentation of some of the new features of MySQL 8.0.20 released on April 27th, 2020.


  • Hash Joins
  • New InnoDB Doublewrite Buffer
  • Index-Level Optimizer Hints
  • SHOW_ROUTINE Privilege
  • MySQL Shell Enhancements
  • MySQL Router Enhancements
  • MySQL InnoDB Cluster Enhancements
  • MySQL Replication Enhancements
  • MySQL NDB Cluster Enhancements
  • MySQL Enterprise New Features
  • Thanks to the Contributors


Download this presentation and others on my SlideShare account.


Watch this video and others on my YouTube channel.

That might interest you

Follow me on twitter

Watch my videos on my YouTube channel and subscribe.

My Slideshare account.

Thanks for using MySQL!


MySQL Security – Dual Password Support

May 19, 2020

When thinking about security within a MySQL installation, you can consider a wide range of possible procedures / best practices and how they affect the security of your MySQL server and related applications.

MySQL provides many tools / features / plugins or components in order to protect your data including some advanced features like Transparent Data Encryption (TDE)Audit, Data Masking & De-Identification, Firewall, Random Password Generation, Password Expiration Policy, Password Reuse Policy, Password Verification-Required Policy, Failed-Login Tracking and Temporary Account Locking, Connection-Control Plugins, Password Validation Component, etc…

MySQL Security


Dual-password capability makes it possible to seamlessly perform credential changes without downtime.

MySQL implements dual-password capability with syntax that saves and discards secondary passwords :

  • The RETAIN CURRENT PASSWORD clause for the ALTER USER and SET PASSWORD statements saves an account current password as its secondary password when you assign a new primary password.
  • The DISCARD OLD PASSWORD clause for ALTER USER discards an account secondary password, leaving only the primary password.

The purpose is to avoid downtime while changing passwords in a replicated environment.

Clients can use the old password while a new password is being established in a group of servers and retire the old password only when the new password has been established across the whole group.

The workflow is :

  1. On each server that is not a replication slave, establish the new password
  2. Wait for the password change to replicate throughout the system to all slave servers
  3. Modify each application that uses the myApp account so that it connects to the servers using a password of ‘NEW_password’ rather than ‘OLD_password’
  4. On each server that is not a replication slave, discard the secondary password

Let’s take a quick look using MySQL 8.0

Create a user account myApp@localhost with password pwd1 :

Now we can connect with the name and the password :

As indicated in the output, it is a very bad practice to put the password on the command line interface.

Now the DBA (super user) use ALTER USER statement with the RETAIN CURRENT PASSWORD clause to perform credential changes using the dual password mechanism by adding as primary password pwd2.
Thus pwd1 is now the secondary password :

We can use the user name and the new password (pwd2) to connect :

But the old password (pwd1) is still valid :

Now it is the time to discard the secondary password (pwd1) :

As you can see, only the new password (pwd2) is valid.

To Go Further

Reference Manual

MySQL Security Serie (1st edition)

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