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The latest from the MySQL community

Ideas, releases, practical guides, and perspectives from the people building with MySQL.

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Displaying posts with tag: Databases (reset)
A database for everyone (comments on Sybase acquisition)

One thing I haven't seen anybody commenting on is the fact that with SAP acquiring Sybase, it will be the last major independent database company to be merged into a larger SW company. (To say this, you can qualify MySQL AB as a major database company, but disqualify, say, EnterpriseDB or InterBase, which imho is entirely reasonable.)

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Initial thoughts on space compression using the innodb_plugin

While setting up MySQL Enterprise Monitor 2.2 (Merlin) on a system which had been running version 2.1 I thought I’d try and see what difference the change from using normal innodb tables to using the compressed table format available in the innodb plugin.

I’ve been using a separate db backend for merlin because for me it’s easier to manage and also the database backend has been put on a dedicated server. I’ve also been trying the innodb_plugin on another busier server as I had performance problems with the normal 5.1.42 built-in innodb engine which the plugin managed to solve.

So given that I was using a separate db server I upgraded it to 5.1.47, configured the server to use the plugin (1.0.8) rather than to use the built-in innodb engine and then decided to …

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MySQL Monitoring – What’s really needed

The implementation of MySQL Monitoring is critical for any organization that uses a database and wants to avoid the inevitable disaster. There are 3 important components that all serve a key purpose to “MySQL Monitoring” in general:

  • Monitoring – Historical and graphical information
  • Alerting – Tell me when something is wrong
  • Dashboard – The State of NOW

Monitoring

There is no one option for Monitoring that is significantly better then another. A short list of what’s on offer can be found at http://monitoring-mysql.com/monitoring-products. What’s important is you have monitoring in place so historically you can review situations and compare across your servers and enabling the better identification of physical or database bottlenecks. My recommendations for products are …

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Finalized speakers list for Kaleidoscope conference

We have secured approval for our final two speakers and now have a full schedule for the 4 day MySQL track at ODTUG Kaleidoscope conference. The conference is in Washington DC from Monday June 28th to Thursday July 1st. Welcome to Josh Sled and Craig Sylvester that will be joining our existing list of speakers.

This conference will include 19 sessions of dedicated MySQL content from Monday thru Thursday by well qualified MySQL community members, as well a forums discussion and reception on Monday night. You don’t need to be an Oracle developer to get the benefit of this conference. We will offering a discount code for MySQL attendees in the upcoming days.

If you are in the DC area, the Monday night forum (known as the sundown sessions) as well as the reception are FREE for the MySQL community. This was a great jesture of the Oracle …

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Why is my database slow?

Not part of my Don’t Assume series, but when a client states “Why is my database slow”", you need to determine if indeed the database is slow.

Some simple tools come to the rescue here, one is Firebug. If a web page takes 5 seconds to load, but the .htm file takes 400ms, and the 100+ assets being downloaded from one base url, then is the database actually slow? Tuning the database will only improve the 400ms portion of 5,000ms download.

There some very simple tips here. MySQL is my domain expertise and I will not profess to improving the entire stack however perception is everything to a user and you can often do a lot. Some simple points include:

  • Know about blocking assets in your <head> element, e.g. .js files.
  • Streamline .js, .css and images to what’s needed. .e.g. download a 100k image only to resize to a thumbnail via style …
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More on understanding sort_buffer_size

There have been a few posts by Sheeri and Baron today on the MySQL sort_buffer_size variable. I wanted to add some more information about this buffer, what is impacted when it is changed, and what to do about it?

The first thing you need to know is the sort_buffer_size is a per session buffer. That is this memory is assigned per connection/thread. I’ve seen clients that set this assuming it’s a global buffer Don’t Assume – Per Session Buffers.

Second, internally in the OS usage independently of MySQL, there is a threshold > 256K. From Monty Taylor “if buffer is set to over 256K, it uses mmap() instead of malloc() for memory allocation. Actually – this is a libc malloc thing and is tunable, but …

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The Drizzle Census

One thing I have often wondered is just how many MySQL instances exist in the world and what MySQL versions and architectures are in use. We hear of 50,000 windows downloads per day but this is misleading because MySQL is basically bundled with Linux by default or installed from various repositories. Linux servers powers many websites.

In Drizzle we have a proposed plan, the Drizzle Census. From the productive Drizzle Developers Day recently at the 2010 MySQL conference we sat down and created a blueprint, and subsequent high level spec of what we considered this optional plugin should do. We didn’t get as far as I would have liked in a code …

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DbCharmer – Rails Can Scale!

Back in November 2009 I was working on a project to port Scribd.com code base to Rails 2.2 and noticed that some old plugins we were using in 2.1 were abandoned by their authors. Some of them were just removed from the code base, but one needed a replacement – that was an old plugin called acts_as_readonlyable that helped us to distribute our queries among a cluster of MySQL slaves. There were some alternatives but we didn’t like them for one or another reasons so we’ve decided to go with creating our own ActiveRecord plugin, that would help us scale our databases out. That’s the story behind the first release of DbCharmer.

Today, six months after the first release of …

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Event based programming vs threading by Rob von Behren, Jeremy Condit and Eric Brewer

Saw this interesting paper about highly concurrent programming methods and figured the word should be spread! It’s not new material but it’s a good read. See the full article here: http://www.usenix.org/events/hotos03/tech/full_papers/vonbehren/vonbehren_html/

“Highly concurrent applications such as Internet servers and transaction processing databases present a number of challenges to application designers. First, handling large numbers of concurrent tasks requires the use of scalable data structures. Second, these systems typically operate near maximum capacity, which creates resource contention and high sensitivity to scheduling decisions; overload must be handled with care to avoid thrashing. Finally, race conditions and subtle corner cases are common, which makes debugging and code maintenance difficult.

…

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My acceptance with Oracle as ACE Director

I hinted last week of my acceptance with Oracle before the formal announcement this week at the MySQL Users Conference, not for a job but as Oracle ACE Director. In today’s State of the MySQL Community keynote by Kaj Arnö I was one of the first three MySQL nominees that are now part of this program.

What exactly is an ACE Director? Using the description from the Oracle website.

Oracle ACEs and Oracle ACE Directors are known for their strong credentials as Oracle community enthusiasts and advocates, with candidates nominated by anyone in the Oracle …

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