After I updated a Fedora 30 instance, I could no longer connect to the MySQL database. An attempt to connect raised the following error:

Error: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

My guess was correct, the mysqld.service got removed during the update (a synonym for upgrade). So, I ran the following command as a sudoer user:

sudo systemctl enable mysqld.service

It creates the following symbolic link:

Created symlink /etc/systemd/system/multi-user.target.wants/mysqld.service → /usr/lib/systemd/system/mysqld.service.

That would start the MySQL Daemon (mysqld) on the next restart of the OS. However, I didn’t want to restart to have access to the service. I simply started it with the following command:

sudo systemctl start mysqld.service

Then, I could connect to the MySQL database. As always, …

MinervaDB Webinar – MySQL Backup Strategies and Tools 

Most often Database Systems outages happen due to user error and it is also the biggest reason for data loss / damage or corruption. In these type of failures, It is application modifying or destroying the data on its own or through a user choice. Hardware failure also contributes to database infrastructure crashes and corruption. To address these sort of data reliability issues, you must recover and restore to the point in time before the corruption occurred. Disaster Recover tools returns the data to its original state at the cost of any other changes that were being made to the data since the point the corruption took place. MinervaDB founder and Principal, hosted a webinar (Thursday, June 18, 2020 – 06:00 PM to 07:00 PM PDT) on MySQL backup strategies and tools addressing the topics below:

• Proactive MySQL DR – From strategy to execution
…

MySQL Backup and Disaster Recovery Webinar (Thursday, June 18, 2020 – 06:00 PM to 07:00 PM PDT)

There can be several reasons for a MySQL database outage: hardware failure, power outage, human error, natural disaster etc. We may not be able prevent all the disaster from happening but investing on a robust disaster recovery plan is very important for building fault-tolerant database infrastructure operations on MySQL.  Every MySQL DBA is accountable for developing a disaster recovery plan addressing data sensitivity, data loss tolerance and data security. Join Shiv Iyer, Founder and Principal of MinervaDB to lean about the best practices for building highly reliable MySQL DR strategy and operations on Thursday, June 18, 2020 – 06:00 PM to 07:00 PM PDT. Building DR for a high traffic MySQL database infrastructure means deep understanding of multiple backup strategies and choosing optimal ones which are best suited for performance …

MySQL Backup Strategies – What you should know before considering MySQL DR solutions ? 

MySQL powers all the major internet properties, Which include Google, Facebook, Twitter, LinkedIn, Uber etc. So how do we plan for MySQL disaster recovery and what are the most common MySQL DR tools used today for building highly reliable database infrastructure operations ? There can be several reasons for a MySQL database outage: hardware failure, power outage, human error, natural disaster etc. We may not be able prevent all the disaster from happening but investing on a robust disaster recovery plan is very important for building fault-tolerant database infrastructure operations on MySQL.  Every MySQL DBA is accountable for developing a disaster recovery plan addressing data sensitivity, data loss tolerance and data security. Functionally you have several database backup strategies available with MySQL:

• Full backup – Full …

Data SRE – Building Database Systems Infrastructure Operations for Performance and Reliability

Recently ( on Friday, 5 June 2020 – 06:00 PM PDT to 06:45 PM PDT  ) our Founder and Principal ( Shiv Iyer ) did a webinar on building Database Systems Infrastructure Operations for Performance and Reliability. In this webinar, he discussed about capacity planning / sizing, observability & resilience, performance audit / health-check / diagnostics / forensics, performance optimization & tuning and building highly available / fault-tolerant / self-healing systems architecture. You can download the PDF of the webinar here . Thanks for joining the webinar and making it a success, Looking forward to seeing you all in the next webinar.

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MinervaDB Webinar – Building MySQL Database Infrastructure for Performance and Reliability

Recently I did a webinar on ” Building MySQL Database Infrastructure for Performance and Reliability ” , It was big success and thought will share the slides of webinar in this blog. I get lot of emails daily from Database Architects, DBAs, Database Engineers, Technical Managers and Developers worldwide on best practices and checklist to build MySQL for performance, scalability, high availability and database SRE, The objective of this webinar is to share with them a cockpit view of MySQL infrastructure operations from MinervaDB perspective. Database Systems are growing faster than ever, The modern datanomy businesses like Facebook, Uber, Airbnb, LinkedIn etc. are powered by Database Systems, This makes Database Infrastructure operationally complex and we can’t technically scale such systems with eyeballs. Building MySQL …

My students want to transfer their course setup MySQL files from the Linux VM that I provide to Microsoft Windows 10. This post explains how because I found a couple small errors in the Google’d posts they would most likely see.

The first step is required because when I didn’t assign a name or domain to the the Fedora VM, which allows it to run as localhost on any student machine. In tandem, I didn’t assign a static IP address but opted for dynamic IP assignment. That means, the first step to securely copy the files requires you to find the assigned IP address. You can do that with the following Linux command:

ifconfig -a | grep 'inet[[:blank:]]' | head -1 | cut -c 14-30

It would return something like:

192.168.147.198

After you have discovered the IP address, you need to download PuTTy from their web site because includes the pscp (PuTTy …

It’s the in-between term time and we’re all stuck at home. I decided to update the image for my Fedora 30 virtual machine. I had a work around to the update issue that I had encountered last October in Bug #96969 but it was not required with the current version. However, after updating from MySQL 8.0.17 to MySQL 8.0.19, I found that my Java connection example failed.

The $CLASSPATH value was correct:

/usr/share/java/mysql-connector-java.jar:.

The first error that I got was the my reference to MySQL JDBC driver was incorrect. The error message is quite clear:

Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.
Cannot connect to database server:
The server time zone …

As a part of Mydbops Consulting we have a below problem statement from one of our client.

“We have a high powered server for reporting which in turn powers our internal dashboard for viewing the logistics status.Even with a high end hardware, we had a heavy CPU usage and which in turn triggers spikes in replication lag and slowness. Below is the hardware configuration.“

OS : Debian 9 (Stretch)

CPU : 40

RAM : 220G (Usable)

Disk : 3T SSD with 80K sustained IOPS.

MySQL : 5.6.43-84.3-log Percona Server (GPL)

Datasize : 2.2TB

Below is the graph on CPU utilisation from Grafana.

Since the work load is purely reporting(OLAP) we could observe a similar type of queries with different ranges. Below is the Execution plan of the query. It is a join query over 6 tables.

Explain Plan:

 …

In my previous blog, I have explained how the MySQL clone plugin works internally. In this blog, I am going to do a comparison of  Backup and Recovery speed of MySQL clone plugin with other available mysql open source backup tools.

Below tools are used for speed comparison of Backup and Recovery,

1. Clone-Plugin
2. Xtrabackup
3. mysqldump
4. mydumper with myloader
5. mysqlpump

Test …