Apologies for the silly title, but the issue is a real one, even though it is not a new thing. Schema upgrades are not an ordinary operation in Galera. For the subject at hand, the bottom line is: under the default Total Order Isolation (TOI) method, “the cluster replicates the schema change query as a statement before its execution.” What this means in practice is that a DDL issued in one node is replicated to other nodes in the cluster before it is even executed in the source node, let alone completed successfully.

As a result of this, it may fail in one node and be successful in another, and this without raising loud alerts or stopping nodes to protect against data inconsistency. This is not a bug in itself but rather a compromise of design. With new changes in MySQL and the …

Recently I posted an article on how to deal with arrays when trying to use MySQL Shell Dump Utility in command line.

Of course, this proposed solution was a workaround for MySQL Shell <= 8.0.23. The new version of MySQL Shell 8.0.24 supports now arrays \o/ !

So if we take the same example of the previous post, we can now use the following syntax:

$ mysqlsh root@localhost -- util dump-instance /tmp/dump \
    --excludeSchemas=["mysql_innodb_cluster_metadata","fred_test"] \
    --threads=8 --showProgress

Please mind that lack of <space> between the elements of the array. If you use …

The new role of recovery (RPO and RTO) in a continuous, highly available MySQL environment?

After downloading and installing MySQL 8.0.24 yesterday, I opened a command shell. In the command shell, I could access the MySQL Shell (mysqlsh.exe) but not the MySQL Client (mysql.exe). Typing in the following:

C:\WINDOWS\system32>mysql

It returned:

'mysql' is not recognized as an internal or external command,
operable program or batch file.

The MySQL Client (mysql.exe) was installed because MySQL Workbench relies on it. However, the MySQL Microsoft Software Installer (MSI) does not put the mysql.exe file’s directory in the common Windows %PATH% environment variable. You can find the required %PATH% directory variable by opening the File Manager and searching for the mysql.exe file.

You should return several directories and programs but the directory you want is:

C:\Program …

Sometimes things go wrong, and it surely would be nice if you at least knew afterwards what happened. Where I work, we are running a shell script older than time itself, once a minute. The script writes files to /var/log/mysql_pl, into a directory named after the current weekday and named after the current hour and minute.

So when a box crashes on Thursday at 22:09, as long as I can login to it, I still can try to look at /var/log/mysql_pl/Thu/22_0? and try to reconstruct what happened before the crash. Often the buildup to catastrophe is clearly visible.

A version in Python

Our shell script is not really portable or viable outside the work environment, so I rewrite a similar thing in Python. It has no dependencies outside of a base install of a modern Python, except for mysqlclient …

In this post, we will see how to access database and its objects in MySQL NDB Cluster from Connector/python program. I assume that the reader has some basic understanding of python language and MySQL NDB Cluster.
Let’s create a MySQL NDB Cluster with the following environment:

• MySQL NDB Cluster version (Latest GA version)
• 1 Management node
• 4 Data nodes
• 1 Mysqld server
• Configuration slots for up to 4 additional API nodes
• Connector/Python version (Latest GA version)

Note: Python software must be installed on the same host where we are planning to install MySQL Connector/Python.

MySQL NDB Cluster Architecture:
Let’s look at the MySQL NDB Cluster architecture.

…

You have curly quotes in your query…

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MySQL databases keep getting larger and larger. And the larger the databases get, the harder it is to backup and restore them.  MyDumper has changed the way that we perform logical backups to enable you to restore tables or objects from large databases. Over the years it has evolved into a tool that we use at Percona to back up petabytes of data every day. It has several features, but the most important one, from my point of view, is how it speeds up the entire process of export and import.

Until the beginning of this year, the latest release was from 2018; yes, more than two years without any release. However, we started 2021 with release v0.10.1 in January, with all the merges up to that point and we committed ourselves to release every two months… and we delivered! …

The MySQL team is proud to announce the general availability of version 8.0.24 of the MySQL Shell.

In addition to a considerable number of bugs fixed, the following changes were introduced.

Improved Command Line Integration

Integrating the shell functionality in DevOps operations is a key feature and this release has introduced a big improvement on this area being the most remarkable improvements the following:

• No longer need to execute APIs using the –execute (-e) command line argument: all of the data required for any API available in CLI can be defined through command line arguments (including lists).

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Atomics (or GCC intrinsics) were first introduced in InnoDB (5.0) by a patch  from Mark Callaghan’s team at Google for mutexes and rw-locks. InnoDB code then was written in C.  When the code was ported to C++ ,  part of the 5.6 release, there was no C++ standard for atomics.…

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