I’m happy to be back in London in May 2016, to talk at two events:

1. The London MySQL Meetup Group – Monday May 9 – 6.30 PM – 9.00 PM – options for High Availability in the ecosystem that one would consider today. This is a cut down from my Percona Live tutorial, which had about 88 registered attendees and about that amount showed up and asked questions even through the break and after. I had a lot of fun, and I expect I will have similar fun in London talking about this area that has changed a lot in recent times.
2. Data for the Enterprise – MariaDB Roadshow in London – Wednesday, May 11, 2016 from 9:30 AM to 2:00 …

Who are the top individual authors of influential recent posts to planet MySQL?  The planet MySQL page includes a list of the top 20 authors as well as a list of the top 10 vendor blogs.  However, since posts to the vendor blogs make up at least 1/4 of all of the posts, and the authors of vendor blog posts are not included in the top author list, I decided to compute my own top author list.  I include the hidden authors from the vendor blogs when computing my top author list.

The first problem is to identify the hidden authors for posts from each vendor blog.  This requires that the author information be extracted from the individual posts, and this requires a specialized parser for each vendor blog to extract the author name from the document.
The second problem is to rank the authors using some criteria such as the number of posts in a given recent time range.   I could run a page rank algorithm if I …

Since documentation is not very clear to me on the topic of InnoDB flushing in combination with Linux IO (specifically the write system call), I decided to put together this article in hopes of shedding some light on the matter.

How Linux does I/O

By default, the write() system call returns after all data has been copied from the user space file descriptor into the kernel space buffers. There is no guarantee that data has actually reached the physical storage.

The fsync() call is our friend here. This will block and return only after the data and metadata (e.g. file size, last update time) is completely transferred to the actual physical storage.

There is also fdatasync() which only guarantees the data …

Recently the mysql community got an awesome monitoring solution for mysql

with Prometheus & Grafana. The graphs are simply beautiful and really lively.

I started off with this nice post on the mysql performance blog  by Roman Vynar and got the solution up and running very easily.

You can actually monitor Amazon RDS instance with the same steps mentioned in the above post but with a few changes:

The monitoring framework consists of 4 components:

1. Prometheus server on port 9090
2. Grafana server on port 3000
3. MySQL …

What is MetaData Lock?

MySQL uses metadata locking to manage concurrent access to database objects, and to ensure data consistency when performing modifications to the schema: DDL operations. Metadata locking applies not just to tables, but also to schemas and stored programs (procedures, functions, triggers, and scheduled events).

In this post I am going to cover metadata locks on tables and triggers, that are usually seen by DBAs during regular operations/maintenance.

Kindly refer to these 4 different connections to MySQL Instance:

The screenshot shows that the uncommitted transaction may cause metadata lock to ALTER operations. The ALTER will not proceed until the transaction is committed or rolled-back. What is worse, after the ALTER is issued, any queries to that table (even simple SELECT queries) will be blocked. If the ALTER operation is an …

In this blog post, we’ll discuss how to use multi-threaded LRU flushing to prevent bottlenecks in MySQL.

In the previous post, we saw that InnoDB 5.7 performs a lot of single-page LRU flushes, which in turn are serialized by the shared doublewrite buffer. Based on our 5.6 experience we have decided to attack the single-page flush issue first.

Let’s start with describing a single-page flush. If the working set of a database instance is bigger than the available buffer pool, existing data pages will have to be evicted or flushed (and then evicted) to make room for queries reading in new pages. InnoDB tries to anticipate this by maintaining a list of free pages per buffer pool instance; these are the pages that can be immediately used for placing the newly-read data pages. The target length of the free page list is governed by the …

Using Docker for development is a great way of ensuring that what you develop will be the same that you deploy in production. This is true for almost everything. If you develop on Linux, the above statement holds. If you develop on a different operating system (OSX or Windows) there are several restrictions.

I showed one of those issues in a recent article (MySQL and Docker on a Mac: networking oddity.) When you want to export a port from a service running in the container, the exported port is not available in your mac, but in the virtual machine that runs Docker services. This happens with any application that listens to a port.

The second limitation I found affects only MySQL, and it is related to using volumes. The proper way of achieving data persistence with …

In an industry as fast-growing and interconnected as database technology’s, it’s exciting to track how innovations in one platform can ignite beneficial, rippling effects on other, surrounding systems. At VividCortex we frequently find ourselves faced with opportunities to improve our monitoring solutions based on how database technologies (such as MySQL, Redis, PostgreSQL, etc) develop and integrate new upgrades.

When those platforms that we monitor -- already powerful, tried and true -- equip themselves with new features, we work to discover how VividCortex can leverage those features and make our own technology even better. In the case of MySQL 5.7.8’s recent introduction of Generated Virtual Columns, we found the opportunity to use a new feature to make our queries simpler and more elegant, with results …

This blog post discusses what is going on in the MySQL high availability market, and what Percona’s plans are for helping customers with high availability solutions.

One thing I like to tell people is that you shouldn’t view Percona as a “software” company, but as a “solution” company. Our goal has always been to provide the best solution that meets each customer’s situation, rather than push our own software, regardless of whether it is the best fit or not. As a result, we have customers running all kinds of MySQL “flavors”: MySQL, MariaDB, Percona Server, Amazon RDS and Google Cloud SQL. We’re happy to help customers be successful with the technology of their choice, and advise them on alternatives when we see a better fit.

One area where I …

The MariaDB project is pleased to announce the immediate availability of MariaDB Galera Cluster 10.0.25. See the release notes and changelog for details on this release. Download MariaDB Galera Cluster 10.0.25 Release Notes Changelog What is MariaDB Galera Cluster? MariaDB APT and YUM Repository Configuration Generator Thanks, and enjoy MariaDB!

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