The London MySQL Meetup Group hosted a new evening of MySQL related talks on December 11, this time in Canonical’s offices in the Blue Fin Building. Conveniently, it was timed so that it coincided with the Debian/Ubuntu packaging sprint, which I also attended.

We started with pizza, beer and small talk. Since this was my first meetup in London, there were lots of new and interesting people to meet and talk to.

The topic of the evening was “MySQL distributions: in the cloud and on bare metal”, but before we got that far, James Page and Robie Basak presented the results so far of our ongoing …

In this post I will try to explain the new MySQL binlog_error_action server option. This new option is available from MySQL 5.6.22 and later.

Background:
——————–
As part of MySQL replication all data changes that happen on the master server are recorded into a binary log so that they can be sent to slave and replayed there. If an error occurs that prevents mysqld from writing to the binary log (disk full, readonly file system, etc.) then the logs are simply disabled and operations continue on the master. This error mainly occurs during rotation of the binary log or while opening a binary log file.

This problem creates a serious potential for data loss …

Background on Backup Locks

I was very excited to see Backup locks support in release notes for the latest Percona XtraDB Cluster 5.6.21 release. For those who are not aware, backup locks offer an alternative to FLUSH TABLES WITH READ LOCK (FTWRL) in Xtrabackup. While Xtrabackup can hot-copy Innodb, everything else in MySQL must be locked (usually briefly) to get a consistent snapshot that lines up with Innodb. This includes all other storage engines, but also things like table schemas (even on Innodb) and async replication binary logs. You can skip this lock, but it isn’t …

Hello,

We at Monitis want to thank you for being with us this past year and tell you what a pleasure it has been to help you reach your everyday business goals. Monitis is growing fast and we sincerely appreciate the trust you put in us to help you manage all your IT challenges.

During the past year we have worked diligently to expand and improve our suite of services to match your needs. We were especially excited to bring you new offerings such as;

 
– Powerful integrations with industry leading partners such as; WHMCS, Zapier, PagerDuty and VictorOps

– Enriching our Application monitoring and added; Log Monitor, Email Round Trip, MySQL and Node.js monitors

– Real …

If you are automating your infrastructure deployments with Chef, then read on. We are glad to announce the availability of a Chef cookbook for ClusterControl. This cookbook replaces previous cookbooks we released for ClusterControl and Galera Cluster. For those using Puppet, please have a look at our Puppet module for ClusterControl.

ClusterControl Cookbook on Chef Supermarket

The ClusterControl cookbook is available on Chef Supermarket, and getting the cookbook is as easy as:

$ knife cookbook site download clustercontrol

This cookbook supports the installation of ClusterControl on top of existing database clusters:

• Galera Cluster
  • MySQL Galera Cluster by Codership
  …

A few years ago Peter Zaitsev, in a post titled “To UUID or not to UUID,” wrote: “There is timestamp based part in UUID which has similar properties to auto_increment and which could be used to have values generated at same point in time physically local in BTREE index.”

For this post I’ve rearranged the timestamp part of UUID (Universal Unique Identifier) and did some benchmarks.

Many people store UUID as char (36) and use as row identity value (PRIMARY KEY) because it is unique across every table, every database and every server and allow easy merging of records from different databases. But here comes the problem, using it as PRIMARY KEY causes the problems described below.

Problems with UUID

• UUID has 36 characters which makes it bulky.
• InnoDB stores data in …

Debian/Ubuntu packaging sprint participants. From left: James Page, Norvald H. Ryeng, George Lorch, Akhil Mohan, Otto Kekäläinen, Robie Basak.

Last week, Canonical invited the MySQL packaging team in Debian to a packaging sprint in their London office, and most of us were able to participate. We’ve met online on IRC and UOSs before, but this was the first time we were all in the same room.

The results of our sprint will soon be available in a .deb near you. Since Debian Jessie is currently in feature freeze, most of it will hit Ubuntu first. The two main things we achieved on the MySQL side were to make MySQL 5.6 ready for Ubuntu Vivid (15.04) and to split MySQL, Percona and MariaDB configuration files. The configuration file split …

So this is just a simple example of how to set up a PARTITION and a SUBPARTITION in MySQL. The concept here is that you have data in a table with numerous values in a datetime field. You might have data that is spread across numerous years  (most likely you do). So one way to partition this data is to sort it by year but then also sort it by month within that yearly partition.

Below is an example that you can use for consideration.

Consider the test table. Your table with have many more fields of course.

CREATE TABLE `t1` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `date_time` datetime DEFAULT NOW(),
  PRIMARY KEY (`id`)
) ENGINE=InnoDB;


First I will populate the test table with random values for the  date_time field.

delimiter //
CREATE PROCEDURE populate_t1( IN rowsofdata INT )
…

HAProxy is frequently used as a software load balancer in the MySQL world. Peter Boros, in a past post, explained how to set it up with Percona XtraDB Cluster (PXC) so that it only sends queries to available nodes. The same approach can be used in a regular master-slaves setup to spread the read load across multiple slaves. However with MySQL replication, another factor comes into play: replication lag. In this case the approach mentioned for Percona XtraDB Cluster does not work that well as the check we presented only returns ‘up’ or ‘down’. We would like to be able to tune the weight of a replica inside HAProxy depending on its replication lag. This is what we will do in this post using HAProxy 1.5.

Agent …

TokuDB offers high throughput for write intensive applications, and the throughput scales with the number of concurrent clients.  However, when the binary log is turned on, TokuDB 7.5.2 throughput suffers.  The throughput scaling problem is caused by a poor interaction between the binary log group commit algorithm in MySQL 5.6 and the way TokuDB commits transactions.   TokuDB 7.5.4 for Percona Server 5.6 fixes this problem, and the result is roughly an order of magnitude increase in SysBench throughput for in memory workloads.

MySQL uses two phase commit protocol to synchronize the MySQL binary log with the recovery logs of the storage engines when a transaction commits.  Since fsync’s are used to ensure the durability of the data in the various logs, and fsync’s can be very slow, the fsync can easily become a bottleneck.  A …