The InnoDB storage engine has done wonders for MySQL users that needed higher concurrency than MyISAM could provide for demanding web applications. And the automatic crash recovery is a real bonus too.

But InnoDB's performance (in terms of concurrency, not really raw speed) comes at a cost: disk space. The technique for achieving this, multiversion concurrency control, can chew up a lot of space. In fact, that Wikipedia article says:

The obvious drawback to this system is the cost of storing multiple versions of objects in the database. On the other hand reads are never blocked, which can be important for workloads mostly involving reading values from the database.

Indeed.

Imagine a set of database tables will tens of …

A system is not a system unless it can be monitored and controlled...I recall something like that from a university course in Control Theory.

However, in a couple of blogs from now on I am going to give some ideas on how to monitor and control MySQL Cluster. To control, we need to have process management software that automatically restarts processes.

To do monitoring we need to have a tool to collect information... and here is a new monitoring tool, called CMON (instructions further down). CMON aggregates information from MySQL Cluster that earlier was only accessible from the cluster log or the management client, such as:

• cluster state
• node state
• backup statistics
• statistics
• cluster events (cluster log basically)

.. and let's you access the …

Server monitoring is a big part of running a solid web site.  As an admin, you must know what is going on your server.  One of the tools most Linux/Unix admins are used to is called “top”.  “top” by itself is a very powerful tool.  Here is a quick guide on how to read output from top:  introduction to load averages under top.  It just makes sense that somebody went and created httptop to monitor http traffic.

Install perl modules:

install Term::ReadKey
install File::Tail
install Time::HiRes

Now copy paste the script below and save it in a location and set +x attribute on it so you can execute it.  On my …

Why generalizations about open source product usability don't apply to vendor-sponsored open source projects READ MORE

Why generalizations about open source product usability don't apply to vendor-sponsored open source projects READ MORE

MySQL allows user specific options to be placed in a user options file under your home directory. This is handy if you use automated scripts or want to avoid typing in your MySQL user’s password everytime you login in. To do this, create the ~/.my.cnf with the options below:

[client]
user=mysqlusername
password=mysqlpassword

Then make sure no one else on the system can read this file. It’s essential for security as it contains your password in clear text!

$ chmod 600 ~/.my.cnf
$ ls -l ~/.my.cnf
-rw------- 1 alice alice 36 Aug 12 17:49 /home/alice/.my.cnf

Now you can just type mysql to login. Note that this will work for other MySQL clients like mysqldump. And you can always override the .my.cnf settings in the command line. For example:

$ mysql -ubob -pbobspassword

You can add other parameters to this file. For a full reference check out:
…

Introduction

The purpose of this document is to explain the power-efficeincy analysis proess, power-efficiency issues and solutions in MySQL database server as an example to help identify the right tools and procedures that support the development of energy-efficient application.

Analysis Process

1. Install and start test application(MySQL) on idle system, create workload to simulate the scenario that multiple concurrent clients connecting to the MySQL server without executing any queries.

2. Run PowerTop on Solaris to see how much time the CPUs are spending running in lower power states, and how much time the CPU are spending running in C0 state(meaning CPU is actually executing instructions.)

3. Use DTrace to profile application understand the source of the wakeups causing …

Introduction

The purpose of this document is to explain the power-efficeincy analysis proess, power-efficiency issues and solutions in MySQL database server as an example to help identify the right tools and procedures that support the development of energy-efficient application.

Analysis Process

1. Install and start test application(MySQL) on idle system, create workload to simulate the scenario that multiple concurrent clients connecting to the MySQL server without executing any queries.

2. Run PowerTop on Solaris to see how much time the CPUs are spending running in lower power states, and how much time the CPU are spending running in C0 state(meaning CPU is actually executing instructions.)

3. Use DTrace to profile application understand the source of the wakeups causing …

I was in San Francisco at the tail-end of last week and was fortunate to have some time to meet up with Josh Berkus, a member of the PostgreSQL core team and, until recently, a Sun employee.

Our conversation covered a lot of ground, including his reasons for leaving Sun (he didn’t go into detail but suffice to say he’s working a business idea), the future of the database market (more choice, more horizontal scaling, more use of specialist databases), the future of PostgreSQL (as a development platform), the level or authorization afforded to the Drizzle project, and the future of Sun.

I won’t go into the latter now, but the …

Hi,

I needed to install AMP on my OpenSolaris laptop to do some PHP development, and I thought some people would be interested to know how to do this.

Here we go.

AMP is available from the OpenSolaris Web Stack project, which also includes other open source components such as Perl, Ruby, Memcached, Lighthttpd, etc.

The nice thing with OpenSolaris is that - assuming my laptop is connected to the Internet - I can use the Package Manager to automatically download and install AMP on my laptop. I access the Package Manager through the menu System/Administration.

Once the Package Manager is launched, I make sure that the Repository is set to opensolaris.org and  I do a search on amp:

The amp and amp-dev packages are now listed in the selection …