Real-time web/mobile application is becoming popular day by day. Services like Firebase and Pusher provides API’s and Services to develop effective real-time notification system for your mobile and web apps. We are not going to use these Services in this post; instead, we will develop an application that pops up a notification on a particular […]

Starting a long time ago, we wanted to reproduce workload in a non-production environment, and there were different attempts to achieve that goal (Query Playback is just one of them). But there is another point of view, where you need to write your own workload to do so.

Both Have Pros and Cons

Reproduce Workload:

Pros:

• Simple to implement
• Ready to go

Cons:

• Need to rebuild the environment each time

Custom Scripts:

Pros:

• Possible to have a more realistic workload
• You can reuse the environment
• You can use Sysbench that allows you to change …

Due to CVE-2020-29488, Percona XtraBackup is modifying how xbstream handles absolute paths to prevent malicious file injections. Like the tar archiving utility, the new behavior removes the leading ‘/’ character and references to the parent directory.

Fixes are available in Percona XtraBackup versions:

>= 2.4.22

>= 8.0.23-16.0

For example, ../../../d1/../d2/h.txt will be saved in the stream with the relative path ./d2/h.txt.

The updated function provides a warning when creating a stream with a file with an absolute path:

$ xbstream -c /tmp/data

xbstream: Removing leading '/' from member names

The function also will not extract …

This post will guide you to set up and automate the MySQL logical backups using mysqldump on Ubuntu Linux. We will set-up MySQL backup using mysqldump and automate it with…

The post MySQL Backup setup, automation using Holland, mysqldump on Ubuntu first appeared on Change Is Inevitable.

Whats new in NDB Cluster 7.5 version (Contd.)

In cluster 7.5 the READ_BACKUP and FULLY_REPLICATED table features were added. These features are both designed to improve read performance and scalability, and can be set on a per-table basis. These features are fully implemented inside MySQL Cluster, and tables using these features support all of the normal MySQL Cluster features - secondary unique and ordered indexes, foreign keys, disk resident columns, replication etc. The read performance improvements do not require any special effort to take advantage of – MySQL Cluster automatically chooses the most efficient way to execute reads, whether issued over NdbApi, or via SQL, executed in MySQLD or pushed down for parallel execution in the data nodes.

READ_BACKUP:

Prior to 7.5, all Committed Read operations were routed to a primary replica of the table or index fragment to be read. The …

 There are a couple of questions about the blog post on automatic thread configuration in RonDB. Rather than providing an extensive answer in the comment section I thought it was better to answer the questions in a separate blog. In addition I performed a set of microbenchmarks to verify my expectations.

The first question was the following:

ScyllaDB also does something similar with execution stages for better instruction cache. Is this similar to what you're implementing for instruction cache on separating the threads?

The second question is:

I don't really get the functional separation of threads. To execute a query, your data will now go through a pipeline of …

The idea of ACID transactions are a basic feature of SQL’s individual Data Manipulation Language (DML) commands, like the INSERT, UPDATE, and DELETE statements. Transactions across two or more tables are a natural extension of ACID compliance features provided by DML commands. However, they require a structured programming approach, like a store procedure or like API implemented in an imperative language.

Surprisingly, transaction management wasn’t covered well in Alan Beaulieu’s Learning SQL because he only provided pseudo code logic. While I thought troubleshoot some broken MySQL SQL/PSM logic would be a good learning experience for students, it wasn’t. So, I wrote this sample code to show how to achieve an all or nothing transaction across four tables.

The code for this example on transaction management lets you perform the important tasks necessary to effect transaction …

Up until now we have seen MDS (MySQL Database Service) and MySQL in Azure.
As the Cloud technology keeps moving fast, I thought it would be a good idea to see how to set up a MySQL in Amazon , as a service, that is RDS.

The post MySQL in Amazon (RDS) first appeared on dasini.net - Diary of a MySQL experts.

A question has cropped up recently: how does one install Galera Cluster 4 with MySQL 8 on Ubuntu 20.04 LTS (Focal Fossa)? This quick guide will get you started.

Install 3 Galera Cluster nodes with the base OS being Ubuntu 20.04. Remember to run apt update and apt upgrade.

Once this is done, edit: /etc/apt/sources.list.d/galera.list and add the following lines:

deb https://releases.galeracluster.com/galera-4/ubuntu focal main
deb https://releases.galeracluster.com/mysql-wsrep-8.0/ubuntu focal main

Once that is done, don’t forget to also pin the preference to the Galera Cluster repository. To do this, edit: /etc/apt/preferences.d/galera.pref and have it read:

# Prefer the Codership repository
Package: *
Pin: origin releases.galeracluster.com
Pin-Priority: 1001

Once you are done, run apt update yet again. Now you are ready to install Galera Cluster 4 with MySQL 8, just by …

Recently one of our customers ran into an issue, wherein a bad actor(code) from the application had made the wrong update to 16 M records of a critical table in the database, causing the entire production process to go down. The application Team was able to find the bad actor and block it, our Remote DBA was involved in the Data Recovery/Rollback.

Here I would like to discuss possible recovery methods for the above said scenario

Delayed Slave:

A simple and effective way to recover is by using a delayed slave, RDS started supporting this feature from version 5.6.40 and 5.7.22 i.e., you can induce a SQL thread delay-interval for applying the writes to a slave, detailed implementation is covered in our blog here. It’s …