July 10, 2014 By Severalnines

ClusterControl uses the Apache HTTP Server to serve its web interface, but it is also possible to use nginx. nginx + PHP fastcgi is well-known for its capabilities to run on a small memory footprint compared to standard Apache + PHP DSO.

In this post, we will show you how to run ClusterControl on nginx web server by swapping out the default Apache web server installed during the initial deployment. This blog post does not mean that we officially support nginx, it just an alternative way that a portion of our users have been interested in. For instance, Phil Bayfield wrote a blog on the same topic a while back.

Apache Configuration

Before we jump into nginx configurations, let’s look at how the …

Introduction

Human mistakes are inevitable. Wrong “DROP DATABASE” or “DROP TABLE” may destroy critical data on the MySQL server. Backups would help however they’re not always available. This situation is frightening but not hopeless. In many cases it is possible to recover almost all the data that was in the database or table.
Let’s look how we can do it. The recovery plan depends on whether InnoDB kept all data in a single ibdata1 or each table had its own tablespace . In this post we will consider the case innodb_file_per_table=OFF. This option assumes that all tables are stored in a common file, usually located at /var/lib/mysql/ibdata1.

Wrong action – table deletion

For our scenario we will use test database sakila that is shipped together with the tool.
Suppose we drop my mistake table actor:

mysql> SELECT * FROM actor LIMIT 10; …

We are using Percona Server + TokuDB engine extensively in Percona Cloud Tools and getting real usage operational experience with this engine. So I want to share some findings we came across, in hope it may help someone in their work with TokuDB.

So, one problem I faced is that SELECT * FROM INFORMATION_SCHEMA.TABLES is quite slow when I have thousands tables in TokuDB. How slow? For example…

select * from information_schema.tables limit 1000;
...
1000 rows in set (18 min 31.93 sec)

This is very similar to what InnoDB faced a couple years back. InnoDB solved it by adding variable …

A while back, I made some changes to the plugin interface for pt-online-schema-change which allows custom replication checks to be written. As I was adding this functionality, I also added the --plugin option to pt-table-checksum. This was released in Percona Toolkit 2.2.8.

With these additions, I spent some time writing a plugin that allows Percona Toolkit tools to use Tungsten Replicator to check for slave lag, you can find the code at https://github.com/grypyrg/percona-toolkit-plugin-tungsten-replicator

…

Hello all,

I hope you're doing well. After the successful event last year it's a no brainer to arrange another community dinner when we're all together again in London this November. We had a fantastic turn-out for the meal last year, seating over 100 MySQLers in a venue whom were expecting only 60. So this year join the MySQL community again for a bite to eat and a beverage or two and discuss life, love and data.

The When
Monday, November 3rd 2014

The Where 
Masala Zone, Covent Garden

The Why
We have a vibrant community surrounding the MySQL ecosystem. Whether you want to talk about the meaning of life with Colin Charles or find out how Facebook take their logical backups even quiz Shlomi Noach about where thinks up his latest and greatest MySQL tools; why not do it with a curry and a …

I have found myself using UNION in MySQL more and more lately. In this example, I am using it to speed up queries that are using IN clauses. MySQL handles the IN clause like a big OR operation. Recently, I created what looks like a very crazy query using UNION, that in fact helped our MySQL servers perform much better.

With any technology you use, you have to ask yourself, "What is this tech good at doing?" For me, MySQL has always been excelent at running lots of small queries that use primary, unique, or well defined covering indexes. I guess most databases are good at that. Perhaps that is the bare minimum for any database. MySQL seems to excel at doing this however. We had a query that looked like this:

select category_id, count(*) from some_table

where

    article_id in (1,2,3,4,5,6,7,8,9) and

    category_id in (11,22,33,44,55,66,77,88,99) and

    some_date_time > now() - interval 30 day
 …

This comes from an issue that I worked on recently, wherein a customer reported that their application was working fine under stock MySQL 5.6 but producing erroneous results when they tried running it on Amazon RDS 5.6. They had a table which, on the working server, contained two TIMESTAMP columns, one which defaulted to CURRENT_TIMESTAMP and the other which defaulted to ’0000-00-00 00:00:00′, like so:

CREATE TABLE mysql56 (
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  ts1 TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  ts2 TIMESTAMP NOT NULL DEFAULT '0000-00-00 00:00:00',
);

However, under Amazon RDS, the same table looked like this:

CREATE TABLE rds56 ( 
  id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
  ts1 TIMESTAMP NULL DEFAULT NULL,
  ts2 TIMESTAMP NULL DEFAULT NULL, 
);

They mentioned that their schema contains TIMESTAMP column definitions without any modifiers for nullability or …

A few weeks ago we announced the availability of the MySQL Central @ OpenWorld content catalog.

We're now pleased to announce additional keynotes delivered by MySQL power users. They will follow the "State of The Dolphin" keynote address by Oracle's Chief Corporate Architect Edward Screven and VP of MySQL Engineering Tomas Ulin, and include:

High Speed Event Logging at Booking.com
Nicolai Plum, Senior Systems Architect, will provide an overview of Booking.com's MySQL-based event logging application, recording data from all customer interactions in order to develop the best customer …

While there are many graphing tools out there and we’ve used Munin for a while now.

The MySQL plugin for Munin had fallen out of date and the show engine innodb status output changed in 5.5 making some bits of the plugin simply not work any more. Also the show global status has some extra variables so there was a need to create new graphs.

All of these are now in the 2.1.8+ development releases of Munin.

Here are samples of the new/updated graphs.

Tables

Table …

It was a year ago, on a nice Sunday night of the English Summer (apologies for the oxymoron), that Mark Riddoch came to see me and together we headed to the Vansittart Arms, our local family pub round the corner. A pint of London Pride on one side and a Honey Dew on the other were the perfect add-on to Mark’s MacBook Pro, on which Mark was showing me the 0.1 version of MaxScale. It was the result of the joint efforts of Mark’s team, Massimiliano and Vilho, who had worked hard to bring to life the first version of something that I believe will be a natural addition to clusters of MySQL/Percona/MariaDB servers in the near future.

A year ago, Mark showed me a …