Virtual servers for MySQL are popular but are they the answer? Should we be containing our instances instead. An Updated Performance Comparison of
Virtual Machines and Linux Containers is an interesting study of using containers over VMs by four brilliant folk from IBM Research in Austin. There are several benefits to containers that are detailed in the study.

So what is wrong with VMs? IBM has been using them since the 1970s. Well, VMs have a static number of virtual CPUs (vCPU) and a fixed amount of RAM that bound performance. And each vCPU can only use up to one real CPUs of clock cycles. Since each VM is a Linux process, resource management like the scheduler come into play.

Containers? They are built on the kernel namespaces. A container acts like its own little Linux box but …

Jeremy Cole recently blogged about the feature SET GLOBAL sql_log_bin. In his blog post, Jeremy suggested that there is no strong use-case for this feature, and that it is too easy to run accidentally (i.e. SET GLOBAL instead of SET [SESSION]). The result of this incorrect usage is that slaves will drift out of sync from masters.

We discussed Jeremy's request in the MySQL team, and we agree that the syntax should produce an error in MySQL 5.7. However, we have not yet determined which steps should be taken for MySQL 5.5 and MySQL 5.6. The two proposals we would like to float are:

1. The statement SET GLOBAL sql_log_bin=N produces a warning.
2. The statement SET GLOBAL sql_log_bin=N produces an error.

Option #1 does not …

MaxScale 1.0 from SkySQL is now in Beta and there are some cool features in it, I guess some adventurous people has already put it into production. There are still some rough edges and stuff to be fixed, but it is clearly close to GA. One thing missing though are something to manage starting and stopping MaxScale in a somewhat controlled way, which is what this blog is all about.

I have developed two simple scripts that should help you manage MaxScale in a reasonable way, but before we go into the actual scripts, there are a few things I need to tell you. To begin with, if you haven't yet downloaded MaxScale 1.0 beta, you can get it from MariaDB.com, just go to Resources->MaxScale and to get to the downloads you first need to register (which is free). Here are downloads to rpms and source, but if you are currently looking for a …

A few moments ago I pushed the buttons and PHP 5.3.29 came out. As this is the final release for 5.3 it is a good time to look back. PHP 5.3's history starts somewhere in 2005. We knew what a pressure point of PHP was - a language made for solving The Web Problem needs a good Unicode story. So some developers went deep into that complex area and created a prototype version of PHP with Unicode support from deep within the engine. As this was a big and pressing issue and the need was obvious and the solution looked promising it was quickly areed on making that the base for a future PHP 6. And then time passed, initial enthusiasm passed and the sheer amount of work became obvious. Two years in we noticed that the ongoing PHP 6 work blocked other work - new features couldn't be added to 5.2, the current version at that time, and adding them to (at that time) CVS's HEAD.

Thank you to the MySQL Community, on behalf of the MySQL team @ Oracle. Your bug reports, testcases and patches have helped create a better MySQL 5.6.20.

In particular:

• Thank you to Jeremy Cole for reporting a case where InnoDB's redo log could become corrupt with externally stored blobs. Jeremy also provided a testcase to demonstrate the problem. Bug #69477.
• Thank you to Ronald Bradford for identifying that MySQL would continue to operate even though the binary log could not be written. Our team picked up Ronald's blog post, and filed a bug in response. Bug #51014.
• Thank you to Daniël van Eeden, Andrew Garner, Detlef Ulherr and Bjoern Boschman …

Restarting production database servers with gigabytes of memory is difficult. It can lead to cold caches and other operational complexities.

The InnoDB team is looking to make improvements so that restarting MySQL is required as little as possible. Please help them out by answering which configuration settings you are most eager to see made dynamic.

Thanks!

Thu, 2014-08-14 10:49mriddoch

Here we take a look at how one of the example filters supplied with the MaxScale 1.0 beta can answer that simplest of profiling questions - "Which of my database queries run within the MySQL server for the longest time?".

Why A MaxScale Filter?

MaxScale filters, although they can be thought of as simply a way to modify the SQL requests that pass through MaxScale, are also a good place to insert logging or monitoring. They have the advantage that that receive not just the SQL statements that are sent to the server, but they may also receive the returned results. This means that MaxScale can not just log the query information, but it can also record timestamps related to when it observes different parts of the request or response. As a way to demonstrate this a very simple example filter was constructed for the 1.0 Beta release of MaxScale - the top filter.

What Does Topfilter Do? …

Here we take a look at how one of the example filters supplied with the MaxScale 1.0 beta can answer that simplest of profiling questions - "Which of my database queries run within the MySQL server for the longest time?".Why A MaxScale Filter?MaxScale filters, although they can be thought of as simply a way to modify the SQL requests that pass through MaxScale, are also a good place to insert logging or monitoring. They have the advantage that that receive not just the SQL statements that are sent to the server, but they may also receive the returned results. This means that MaxScale can not just log the query information, but it can also record timestamps related to when it observes different parts of the request or response. As a way to demonstrate this a very simple example filter was constructed for the 1.0 Beta release of MaxScale - the top filter.What Does Topfilter Do? …

So I ran across a situation today dealing with having to update a field but the user was unable to do so because of the related foreign key constraints.

This blog post with be a simple example showing a foreign key and how to update them if you have to do so.

First let us create a simple table and populate it with random data.

CREATE TABLE `table_w_code` (
`SOMECode` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`NameofCode` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
PRIMARY KEY (`SOMECode`)
) ENGINE=InnoDB ;


Now we will need another table that has a foreign key tied to our previous table.

[anothermysqldba]> CREATE TABLE `table_with_fk` (
`SOMEID` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`SOMECode` varchar(50) COLLATE utf8_unicode_ci NOT NULL,
`Somemorefields` varchar(150) COLLATE utf8_unicode_ci …

We recently researched furniture for our office transition and, in doing so, encountered a surprising number of seating options. Long gone are the days where every office chair is uniform; they have evolved to fit the needs of almost any seating preference. Here are the five we found most relevant to our search:

Office Chairs

These are the most common because they are practical and affordable. They adjust, swivel and roll, making them a versatile option for the workplace. If you want to upgrade, you can get ergonomic or mesh chairs - or ergonomic mesh chairs. Ergonomic chairs boast superior back support and maximum comfort, and mesh chairs provide relief to the generally over-heated through their porous material.

Guest Chairs

As the name implies, these chairs are meant for visitors. They do not have adjustable features, as the guest will not be sitting for a prolonged period. …