Working with databases, concurrency control is the concept that ensures that database transactions are performed concurrently without violating data integrity.

There is a lot of theory and different approaches around this concept and how to accomplish it, but we will briefly refer to the way that PostgreSQL and MySQL (when using InnoDB) handle it, and a common problem that can arise in highly concurrent systems: deadlocks.

These engines implement concurrency control by using a method called MVCC (Multiversion Concurrency Control). In this method, when an item is being updated, the changes will not overwrite the original data, but instead a new version of the item (with the changes) will be created. Thus we will have several versions of the item …

Recently we were evaluating MySQL 8 Enterprise for a customer. During our installation (our MySQL Enterprise Edition installations are always RPM based) using RPM file (CentOS Linux release 7.4.1708 (Core))  we ended up in a very unusual error, “error: Failed dependencies:pkgconfig(openssl) is needed by mysql-commercial-devel-8.0.11-1.1.el7.x86_64” , This was happening more specifically during the installation of “mysql-commercial-devel-8.0.11-1.1.el7.x86_64.rpm” . So decided to write this post about the error and how we fixed it.

[root@localhost MySQL8-Enterprise-RPM]# rpm -ivh mysql-commercial-server-8.0.11-1.1.el7.x86_64.rpm mysql-commercial-client-8.0.11-1.1.el7.x86_64.rpm mysql-commercial-libs-8.0.11-1.1.el7.x86_64.rpm mysql-commercial-common-8.0.11-1.1.el7.x86_64.rpm mysql-commercial-devel-8.0.11-1.1.el7.x86_64.rpm 
warning: mysql-commercial-server-8.0.11-1.1.el7.x86_64.rpm: Header V3 DSA/SHA1 Signature, …

This post is about setting up MySQL InnoDB Cluster with 5 nodes on a sandbox deployment.  Here, we focus on implementation part, the core concepts will be explained in separate posts.

Prerequisites:

• MySQL Engine
• MySQL Shell
• MySQL Router

Deploying MySQL InnoDB Cluster involves the following steps:

• Deploying MySQL Engine (Sandbox Instance)
• Creating an InnoDB Cluster
• Adding nodes to InnoDB Cluster
• Configuring MySQL Router for High Availability.
• Testing High Availability.

Deploying MySQL Engine:

If the MySQL engines are already installed on all the nodes, you can skip this step and directly move into creating an InnoDB Cluster part.

I am deploying 5 Sandbox instances (which is in-built on MySQL Shell application) on a same …

MySQL has multiple timeout variables these slides helps to give an overview of the different  timeout variables and their purposes briefly.

Percona announces the release of Percona Server for MySQL 5.5.60-38.12 on May 18, 2018. Based on MySQL 5.5.60, including all the bug fixes in it, Percona Server for MySQL 5.5.60-38.12 is now the current stable release in the 5.5 series.

Percona Server for MySQL is open-source and free. Downloads are available here and from the Percona Software Repositories.

Bugs Fixed

• mysqldump utility with --innodb-optimize-keys option was incorrectly working with foreign …

MySQL has a long tradition in geographic replication. Distributing clusters to remote data centers reduces the effects of geographic latency by pushing data closer to the user. It also provides a capability for disaster recovery. Due to the significant cost of duplicating hardware in a separate site, not many companies were able to afford it in the past. Another cost is skilled staff who is able to design, implement and maintain a sophisticated multiple data centers environment.

With the Cloud and DevOps automation revolution, having distributed datacenter has never been more accessible to the masses. Cloud providers are increasing the range of services they offer for a better price.One can build cross-cloud, hybrid environments with data spread all over the world. One can make flexible and scalable DR plans to approach a broad range of disruption scenarios. In some cases, that can just be a backup stored offsite. In other cases, it can be a …

A really convenient feature in MySQL 8.0 is the ability to persist the values of global variables across server restarts, without writing them into an options file. This was developed primarily for the benefit of Cloud installations of MySQL, but is very handy for a DBA in on-premise installations too.

To use this feature you need to have the SYSTEM_VARIABLES_ADMIN and PERSIST_RO_VARIABLES_ADMIN privileges.

To demonstrate, we'll increase the value of the max_connections system variable from its default of 151 to 152 and then restart the MySQL server to check that MySQL remembers the new value.

mysql> SHOW GLOBAL VARIABLES LIKE 'max_connections'; +-----------------+-------+ | Variable_name | Value | +-----------------+-------+ | max_connections | 151 | +-----------------+-------+ 1 row in set (#.## sec)

Use SET PERSIST to persist the change that we're about to make:

mysql> SET PERSIST max_connections …

The MariaDB Foundation is pleased to announce the availability of MariaDB 10.2.15, the latest stable release in the MariaDB 10.2 series, and MariaDB Connector/J 2.2.4, the latest stable release in the MariaDB Connector/J 2.2 series. See the release notes and changelogs for details. Download MariaDB 10.2.15 Release Notes Changelog What is MariaDB 10.2? MariaDB APT […]

The post MariaDB 10.2.15 and MariaDB Connector/J 2.2.4 now available appeared first on MariaDB.org.

The MySQL Development team announced the General Availability of MySQL 8.0 on April 19th, 2018. Here we follow up with references to worklogs that were added in 8.0.11. Note the jump in version number from 8.0.4 (RC2) to 8.0.11 (GA) explained here.…

MariaDB Server 10.2.15 and Connector/J 2.2.4 now available dbart Fri, 05/18/2018 - 01:08

The MariaDB project is pleased to announce the immediate availability of MariaDB Server 10.2.15 and MariaDB Connector/J 2.2.4. See the release notes and changelogs for details and visit mariadb.com/downloads to download.

Download MariaDB Server 10.2.15

Release Notes Changelog What is MariaDB …