Galera is the best solution for High Availability, It is being used by many peoples world wide . Galera is doing synchronous replication ( really it is Certification based replication ) to keep update the data on group nodes . In this blog I have explained about “How the Galera replication works?” . For the better understanding, I have made an architecture diagram to describe the replication flow . I have also provided the explanation for the key words which has used in the architecture diagram .

Architecture flow Diagram :

What is writeset ?

Writeset contains all changes made to the database by the transaction and append_key of the changed rows .

What is append_key ?

Append_key registers the key of the changed data by the transaction. The key for rows can be represented in three parts as DATABASE NAME, TABLE NAME, PRIMARY KEY . …

Overview The Skinny

In this blog post we explore various options for tuning MySQL traffic routing in the Tungsten Connector for better control of the distribution.

A Tungsten Cluster relies upon the Tungsten Connector to route client requests to the master node or optionally to the slaves. The Connector makes decisions about where to route requests based on a number of factors.

This blog post will focus on the Load Balancer algorithms available via configuration that allow you to adjust the routing behavior of the Connector, along with ways to debug the Connector Load Balancer’s routing decisions.

The Question Recently, a customer asked us:

How do I know which load balancer algorithm is in use by the Connector? And how do we enable debug logging for the Connector load balancer?

In the last blog post of this series, we discussed in detail how Master Key encryption works. In this post, based on what we already know about Master Key encryption, we look into how Master Key rotation works.

The idea behind Master Key rotation is that we want to generate a new Master Key and use this new Master Key to re-encrypt the tablespace key (stored in tablespace’s header).

Let’s remind ourselves what a Master Key encryption header looks like (it is located in tablespace’s header):

From the previous blog post, we know that when a server starts it goes through all encrypted tablespaces’ encryption headers. During that, it remembers the highest KEY ID it read from all the encrypted tablespaces. For instance, if we have three tables with KEY_ID = 3 and one table with KEY ID = 4, it means that …

This talk covers some of the challenges we sought to address by creating a Kubernetes Operator for Percona XtraDB Cluster, as well as a look into the current state of the Operator, a brief demonstration of its capabilities, and a preview of the roadmap for the remainder of the year. Find out how you can deploy a 3-node PXC cluster in under five minutes and handle providing self-service databases on the cloud in a cloud-vendor agnostic way. You’ll have the opportunity to ask the Product Manager questions and provide feedback on what challenges you’d like us to solve in the Kubernetes landscape.

Please join Percona Product Manager Tyler Duzan on Wednesday, February 26, 2020, at 1 pm EST for his webinar “Building a Kubernetes Operator for Percona XtraDB Cluster”.

…

We are well aware that ProxySQL is one of the powerful SQL aware proxy for MySQL. The ProxySQL configuration is flexible and the maximum part of configurations can be done with the ProxySQL client itself.

The latest ProxySQL release ( 2.0.9 ) has few impressive features like “SQL injection engine, Firewall whitelist, Config file generate” . In this blog I am going to explain, how to generate the ProxySQL config file using the proxySQL client .

Why configuration file ?

• Backup solution
• Helpful for Ansible deployments in multipul environments

There are two important commands involved in the ProxySQL config file generation.

• Print the config file text in ProxySQL client itself ( like query output )
• Export the configurations in separate file

Print the config file text in ProxySQL client ( like …

In a MySQL master-slave high availability (HA) setup, it is important to continuously monitor the health of the master and slave servers so you can detect potential issues and take corrective actions. In this blog post, we explain some basic health checks you can do on your MySQL master and slave nodes to ensure your setup is healthy. The monitoring program or script must alert the high availability framework in case any of the health checks fails, enabling the high availability framework to take corrective actions in order to ensure service availability.

MySQL Master Server Health Checks

We recommended that your MySQL master monitoring program or scripts runs at frequent intervals. Assuming that the monitoring script is running on the same server as your …

In this post, I am going to show you how to run Orchestrator on FreeBSD. The instructions have been tested in FreeBSD 11.3 but the general steps should apply to other versions as well.

At the time of this writing, Orchestrator doesn’t provide FreeBSD binaries, so we will need to compile it.

Preparing the Environment

The first step is to install the prerequisites. Let’s start by installing git:

[vagrant@freebsd ~]$ sudo pkg update
Updating FreeBSD repository catalogue...
Fetching meta.txz: 100% 944 B 0.9kB/s 00:01
Fetching packagesite.txz: 100% 6 MiB 492.3kB/s 00:13
Processing entries: 100%
FreeBSD repository update completed. 31526 packages processed.
All repositories are up to date.

[vagrant@freebsd ~]$ sudo pkg install git
Updating FreeBSD repository catalogue...
FreeBSD repository is up to date.
All repositories are up to date.
New …

Presentation of some of the new features of MySQL 8.0.19 released on January 13, 2020.

The post MySQL 8.0.19 New Features Summary first appeared on dasini.net - Diary of a MySQL expert.

TL;DR — If you are hosting your database server in GCE, then you have to be very cautious with capacity planning. The number of CPU cores has an impact on IOPS you get. Even if your workload is not CPU intensive, you might want to provision enough depending on the kind of IOPS you are going to need. For more details, read through one of the problems we faced and the RCA.

Problem statement:

We had a master-slave setup for one of the MySQL database servers. The MySQL server’s performance was good, we didn’t notice any performance related issues initially. But we recently noticed replication lag on the slave. and we figured out that the slave thread was very slow.

Server’s Capacity:

Both our master-slave servers are of the same size.

• 4 Core CPU
• 16GB Memory
• 2 databases are hosted
• 20GB is the database size.
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This is the second part of a two-articles series. In the first part, we introduced the Common Table Expression (CTE), a new feature available on MySQL 8.0 as well as Percona Server for MySQL 8.0. In this article, we’ll present the Recursive Common Table Expression. SQL is generally poor at recursive structures, but it is now possible on MySQL to write recursive queries. Before MySQL 8.0, recursion was possible only by creating stored routines.

What is a Recursive Common Table Expression?

A recursive CTE is one having a subquery that refers to its own name. It is particularly useful in the following cases:

• To generate series
• Hierarchical or tree-structured data traversal