On November 15th at 1PM Eastern / 10 AM Pacific, I will be giving a webinar entitled “The Hazards of Multi-writing in a Dual-Master Setup“.  In my experience many people do not understand the difficulty of managing writes to RDBMS datastores in a high availability environment, especially where asynchronous replication is used (which is almost everywhere).

This talk gives an overview and concrete examples of how writing across dual-masters can and will break your assumptions about ACID compliance, how you can work around it, and some alternative solutions that are on the market today that attempt to address this problem.  This will be a great session for DBAs just getting into this problem space, are moving from hot-cold …

It certainly has been a tough week on the East Coast. In the Boston area, where I am located, we got grazed by Sandy – power outages, trees down, schools closed, and Halloween delayed. This though, pales in comparison to what our NY office had to endure. One of our co-founders for example is one of the first few to get his power back at his home on Long Island just yesterday. He considers himself lucky – one of the several pine trees that came down on his property was just a few degrees off from destroying his house (it ended up taking down the gutter instead). Needless to say, it’s going to be a long recovery for NY and NJ. If you are looking to help, see here.

Of course, NYC is known for its resiliency. The first post-Sandy event at Manhattan’s Javitis Conference Center,  …

This week we continue part 3 of the Operations Report Card and how it relates to database administration. This week we talk about the section on "Operational Practices", and it covers how operations are run. In Ear Candy we present different tools for finding a machine's external IP address, and in At the Movies we present a video about MySQL Security from when Sheeri was touring Latin America in July.

Feedback
Webyog's blog noted that the OurSQL blog/podcast was among the Top MySQL Blogs You Should Be …

Please help me welcome a new member of the MySQL Community Team. Lenka Kasparova is based in Prague and joined Oracle with Sun acquisition in 2009-2010. She was the Project Manager for R&D on FP7 grant project AEGIS where she was responsible for the financial/administrative aspects as well as day to day project management activities. At Sun Lenka was part of the NetBeans acquisition and went through several positions from administrative, HR, and Project Management area… “Both Sun and Oracle gave me a great opportunity to learn a lot of things which I am happy to use in my new position.”

So please look for Lenka at next MySQL Community Team event near you!

Here is your chance to learn how this powerful relational database management system can make your life easier and more fun! The MySQL for Beginners class covers all the basics and will get you on your way, with a solid foundation. This instructor led, hands-on class covers the fundamentals of SQL and relational databases, using MySQL[tm] as a teaching tool.

You can take the MySQL for Beginners, 4 day instructor-led, class in any of the following three ways:

• Training-On-Demand: See what Ben Krug, MySQL Support Engineer has to say about his experience taking the MySQL for Beginners TOD. With this streaming video delivery, you get started on taking the MySQL for Beginners course within 24 hrs of purchase, and follow the course at your own pace.
• Live-Virtual-Class: Take …

Along with lots of new features in performance schema, a new summary table, event_statement_summary_by_digest, has been added to MySQL 5.6. This tables gives a consolidated view of different statements executed/executing on MySQL server.

WHAT IS DIGEST?
Digest is a hash calculated on normalized form of statement text which removes general property of a statement but keeps specific property. For ex. for two statements X and Y,

Removing general property means
normalized (X) == normalized (Y)
Preserving specific property after normalization means:
normalized (X) != normalized (Y)

On these normalized statement, a hash is calculated which is called DIGEST. So digest is a unique representation of statements having same structure.


Example :
SELECT 1 FROM t1; 
SELECT 2 FROM t1; 
Above two statements have same general structure …

This post is the following part #2 of the previous one - in fact Vadim's comments bring me in some doubts about the possible radical difference in implementation of AIO vs normal I/O in Linux and filesystems. As well I've never used Sysbench for I/O testing until now, and was curious to see it in action. From the previous tests the main suspect point was about random writes (Wrnd) performance on a single data file, so I'm focusing only on this case within the following tests. On XFS performance issues started since 16 concurrent IO write processes, so I'm limiting the test cases only to 1, 2, 4, 8 and 16 concurrent write threads (Sysbench is multi-threaded), and for AIO writes seems 2 or 4 write threads may be more than enough as each thread by default is managing 128 AIO write requests..

Few words about Sysbench …

I write a fair number of scripts on this site and have posted a lot of code over the years. Generally if I am not pasting the code to be viewed on the webpage then I link to a file that a user can download; which leads to a lot of mish-mash code that doesn’t have a home. I’ve always kept the code files in a private SVN repo over the years but have recently moved them all to BitBucket Git repositories. So here they are: lots of code samples and useful bits of programming to save time.

Generic Shell Scripts: https://bitbucket.org/themattreid/generic-bash-scripts/src
Generic Python Scripts: https://bitbucket.org/themattreid/generic-python-scripts/src
Generic MySQL Stored Procs: …

One of most easiest and preferred way of MySQL installation is binary installation. While performing mysql binary install using the below command, run into following errors.

[root@localhost mysql]# scripts/mysql_install_db --user=mysql
Installing MySQL system tables...
./bin/mysqld: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

Installation of system tables failed!  Examine the logs in
./data for more information.

To fix the problem, you have to install library (Kernel Asynchronous I/O (AIO) Support for Linux)

[root@localhost mysql]# yum install libaio                  [On CentOS]

After this mysql get installed successfully.

[root@localhost mysql]# scripts/mysql_install_db --user=mysql
Installing MySQL system tables...
OK
Filling help tables...
OK

To …

As many folks know, I do a bit of traveling, both going to conferences, and speaking at them (MySQL and others). So I have compiled a list of tips and tricks, from the basics like “do not forget to eat breakfast” to putting your business cards inside your bag. I have a list with pictures that I will add to as I think of more. I hope you enjoy this tumblr-style list of conference tips!