In my previous post about InnoDB Stalls on Empty Free List, I used a test environment that might look a little artificial : a table larger than the InnoDB Buffer Pool but fitting in the Linux Page Cache.  This configuration allows serving very quickly what MySQL thinks are IOs because these are hit in the filesystem cache.  In this post, I explain why this environment is not

If, in Percona Server, you are observing tail latencies on queries that should be fast, this might be a side effect of Percona's improved InnoDB Empty Free List Algorithm.  When using this algorithm (the default in 5.6 and 5.7 and optional configuration in 8.0), a query needing a free page while none are available waits until the LRU Manager Thread refills the free list.  Because this

There is an interesting feature in MySQL 5.7+: the global variable super_read_only.  MySQL 5.6 and before only had the read_only global variable which is not preventing a user with SUPER privilege to write to the database.  With super_read_only, those users cannot write anymore.  But this feature comes with a surprise.

TL&DR: changing super_read_only to ON also sets read_only to ON and setting

We’re happy to announce that our white paper ‘Tungsten Clustering – Benefits & Configurations’ for MySQL, MariaDB and Percona Server is available to read on our website.

Tungsten Clustering is a one-of-a-kind software solution that provides clustering, disaster recovery and high availability for MySQL, MariaDB & Percona Server databases.

It allows enterprises running business-critical database applications to cost-effectively achieve continuous operations on a global scale with:

• Commercial-grade high availability (HA)
• Geographically redundant disaster recovery (DR)
• Global operations with geographically distributed multi-master

…

Database Administration is a tough, often ungrateful job. Especially if you run a 24/7 business-critical MySQL or MariaDB deployment.

MySQL has proven to be a remarkably solid database which supports billions of dollars in revenue. On some level this very solidity creates a false sense of security. There are many things that can wrong at any given time, whether that is a change to your app, a bug in the database, hardware failure or just simply running out of disk space.

Percona recently conducted a poll: “What keeps you up at night?”

Not surprisingly, “Downtime/HA” is very high on the list.

While there are many challenging issues and tasks that a DBA must deal …

This is the first in a series of blog articles in which I will discuss the changing landscape of open source and money. Or, more specifically, open source databases and money. And even more specifically MySQL and its all variants (AWS Aurora, MariaDB, Percona Server, RDS/MySQL) and money. But before going too deep into what is changing, let’s review all the traditional business models in and around the MySQL marketplace.

In general, these are the following types of companies in the MySQL commercial ecosystem, sorted by total annual revenue and addressable market size:

• Developers who do not aim to monetize the open source code, just provide value to others and hope to get development and other contributions in return. This is the purest form of open source. For example, all …

Overview The Skinny

When it comes to zero downtime, proxies are the first line components of a cluster.

In order to achieve High Availability (HA) for MySQL, MariaDB and Percona Server, a commonly deployed setup consists of configuring load balancers (hardware or software) on top of those proxies.

A Strong Architecture How is Maintenance Made Possible?

With this proxy + load balancer architecture, server maintenance is made possible on any of the proxy hosts, as follows:

• the proxy is stopped
• the load balancer detects the dead proxy and removes it from the pool
• new connection requests go to live proxies

The Problem What Happens to Existing Sessions?

But wait… even though new connections are re-routed correctly, what happens …

This will be a short rant: why is relay_log_space_limit still not dynamic ?

This is obviously a rhetorical question.  I see no reason why this MySQL System Variable is not (yet) dynamic.  Obviously, changing the value of this variable could need replication to be stopped (like for slave_parallel_type, slave_parallel_workers and slave_preserve_commit_order), but at least it would not need a MySQL

This blog will show how to install the Percona XtraDB Cluster on three CentOS 7.3 servers, using the packages from Percona repositories. This is a step-by-step installation and configuration blog, We recommend Percona XtraDB Cluster for maximum availability / reliability and scale-out READ/WRITE optimally. We are an private-label independent and vendor neutral consulting, support, managed services and education solutions provider for MySQL, MariaDB, Percona Server and ClickHouse with core expertise in performance, scalability, high availability and database reliability engineering. All our blog posts are purely focussed on education and research across open source database systems infrastructure operations. To engage us for building and managing web-scale database infrastructure operations, Please contact us on contact@minervadb.com

This cluster will be assembled of three servers/nodes:

This blog will show how to install the Percona XtraDB Cluster on three CentOS 7.3 servers, using the packages from Percona repositories. This is a step-by-step installation and configuration blog, We recommend Percona XtraDB Cluster for maximum availability / reliability and scale-out READ/WRITE optimally. We are an private-label independent and vendor neutral consulting, support, managed services and education solutions provider for MySQL, MariaDB, Percona Server and ClickHouse with core expertise in performance, scalability, high availability and database reliability engineering. All our blog posts are purely focussed on education and research across open source database systems infrastructure operations. To engage us for building and managing web-scale database infrastructure operations, Please contact us on contact@minervadb.com  

This cluster will be assembled of three …