The latest from the MySQL community

Multi-writer replication has been a challenge in the MySQL ecosystem for years before truly dedicated solutions were introduced – first Galera (and so Percona XtradDB Cluster (PXC)) replication (around 2011), and then Group Replication (first GA in 2016).

Now, with both multi-writer technologies available, do we still need traditional asynchronous replication, set up in active-active topology? Apparently yes, there are still valid use cases. And you may need it not only when for some reason Galera/PXC or GR are not suitable, but also when you actually use them. Of course, the most typical case is to have a second cluster in a different …

It was interesting to note that the MySQL Connector/NET Developer Guide doesn’t have any instructions for connecting to the MySQL database from Microsoft Powershell. I thought it would be helpful to write a couple demonstrations scripts, especially when a quick search didn’t find a set of easy to follow samples.

The connection process to MySQL with Powershell is easiest with a non-query, so I created a db_connect table into which I could write a row of data:

CREATE TABLE db_connect
( db_connect_id  INT UNSIGNED PRIMARY KEY AUTO_INCREMENT
, version        VARCHAR(10)
, user           VARCHAR(24)
, db_name        VARCHAR(10));

The following insert.ps1 PowerShell script connects to the MySQL database, and inserts one row into the db_connect table:

# Connect to the libaray …

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.

…

Dear MySQL users,

MySQL Shell 8.0.24 is a maintenance release of MySQL Shell 8.0 Series (a
component of the MySQL Server). The MySQL Shell is provided under Oracle’s
dual-license.

MySQL Shell 8.0 is highly recommended for use with MySQL Server 8.0 and 5.7.
Please upgrade to MySQL Shell 8.0.24.

MySQL Shell is an interactive JavaScript, Python and SQL console interface,
supporting development and administration for the MySQL Server. It provides
APIs implemented in JavaScript and Python that enable you to work with MySQL
InnoDB Cluster and use MySQL as a document store.

The AdminAPI enables you to work with MySQL InnoDB Cluster and InnoDB
ReplicaSet, providing integrated solutions for high availability and
scalability using InnoDB based MySQL databases, without requiring advanced
MySQL expertise.  For more information …

MySQL Group Replication is a plugin that helps to implement highly available fault-tolerant replication topologies. In this blog, I am going to explain the complete steps involved in the below two topics.

• How to convert the group replication member to an asynchronous replica
• How to convert the asynchronous replica to a group replication member

Why Am I Converting From GR Back to Old Async?

Recently I had a requirement from one of our customers running 5 node GR clusters. Once a month they are doing the bulk read job for generating the business reports. When they are doing the job, it affects the overall cluster performance because of the flow control issues. The node which is executing the read job is overloaded and delays the certification and writes apply process. The read job queries can’t be split across the cluster.  So, they don’t want that …

At some points, many of our customers need to handle insertions of large data sets and run into slow insert statements. This article will try to give some guidance on how to speed up slow INSERT SQL queries.

The following recommendations may help optimize your data loading operations:

1. Remove existing indexes - Inserting data to a MySQL table will slow down once you add more and more indexes. Therefore, if you're loading data to a new table, it's best to load it to a table without any indexes, and only then create the indexes, once the data was loaded.

   When you're inserting records, the database needs to update the indexes on every insert, which is costly in terms of performance. It's much faster to insert all records without indexing them, and then create the indexes once for the entire table.

…

This blog provides high availability (HA) guidelines using group replication architecture and deployment recommendations in MySQL, based on our best practices.

Every architecture and deployment depends on the customer requirements and application demands for high availability and the estimated level of usage. For example, using high read or high write applications, or both, with a need for 99.999% availability.

Here, we give architecture and deployment recommendations along with a technical overview for a solution that provides a high level of high availability and assumes the usage of high read/write applications (20k or more queries per second).

Layout

Components

This architecture is composed of two main layers:

• Connection and distribution layer
• RDBMS …

This blog provides high availability (HA) guidelines using group replication architecture and deployment recommendations in MySQL, based on our best practices.

Every architecture and deployment depends on the customer requirements and application demands for high availability and the estimated level of usage. For example, using high read or high write applications, or both, with a need for 99.999% availability.

Here, we give architecture and deployment recommendations along with a technical overview for a solution that provides a high level of high availability and assumes the usage of high read/write applications (20k or more queries per second).

Layout

Components

This architecture is composed of two main layers:

• Connection and distribution layer
• RDBMS …

This blog provides high availability (HA) guidelines using group replication architecture and deployment recommendations in MySQL, based on our best practices.

Every architecture and deployment depends on the customer requirements and application demands for high availability and the estimated level of usage. For example, using high read or high write applications, or both, with a need for 99.999% availability.

Here, we give architecture and deployment recommendations along with a technical overview for a solution that provides a high level of high availability and assumes the usage of high read/write applications (20k or more queries per second).

Layout

Components

This architecture is composed of two main layers:

• Connection and distribution layer
• RDBMS …

Chasing bugs can be a tedious task, and multi-threaded software doesn’t make it any easier. Threads will be scheduled at different times, instructions will not have deterministic results, and in order for one to reproduce a particular issue, it might require the exact same threads, doing the exact same work, at the exact same time. As you can imagine, this is not straightforward.

Let’s say your database is crashing or even having a transient stall.  By the time you get to it, the crash has happened and you are stuck restoring service quickly and doing after-the-fact forensics.  Wouldn’t it be nice to replay the work from right before or during the crash and see exactly what was happening?

Record and Replay is a technique where we record the execution of a program allowing it to be replayed over and over producing the same result. Engineers at …