If you were to stand at a road, and the cars are whipping by, and all you can do is take a snapshot of the way the road looked five minutes ago. How would you know when to cross the road? 9 out of 10 organizations still make decisions this way every day using out-of-date information. The organizations that are most competitive are going to be the ones that can make sense of what they learn as fast as they learn it. That's what I'm working on. I'm an IBMer. Let's build a smarter planet.

• Playlist: Why Information Matters
• A Smarter Planet Relies on Data Analysis

The first major screen of db2top that we will examine is the Database screen. This screen gives you the big picture view of your database. You can use this screen to see how busy your database is in terms of the number of applications connected to it and issuing work, the amounts of memory being consumed for various purposes, such as sorts or the caching of reads and writes, the efficiency of I/O, and the impacts of contention, such as high lock wait times and lock escalations.

The database screen differs from the majority of screens in db2top in that it only ever has one object to show – the database itself. It takes advantage of this by showing every column at once and not requiring you to scroll to see more. The top half of the screen consists of a set of four gauges when the screen is between 80 and 140 columns wide:

Gauge Name	Gauge Type	Definition
MaxActSess	Normal	The current number of connections with executing work in proportion to the highest number of connections simultaneously executing work. (local_cons_in_exec + rem_cons_in_exec) / coord_agents_top
SortMemory	Normal	The total sort memory (both shared and private) in proportion to the sort memory threshold configured for the database manager. (sort_heap_allocated + sort_shrheap_allocated) / sheapthres
LogUsed	Normal	The proportion of total log space that is consumed by uncommitted transactions. total_log_used / (total_log_available + total_log_used)
FCM BufLow	Normal	(buff_free - buff_free_bottom) / buff_free_bottom

A fifth gauge, AssAgents, is added between MaxActSess and SortMemory when the screen is wider than 140 columns:

Gauge Name	Gauge Type	Definition
AssAgents	Normal	The proportion of registered database agents that are not idle. 1 - (idle_agents / agents_registered)

Section of db2top database screen showing five gauges

The second change that happens when the screen width is 141 columns or wider is that, if you have taken a backup of the database, you will see three rows of backup information to the right of the gauges, as shown below:

db2top Database screen at 141 columns wide

The three new rows are as follows:

• Last backup date
• Last backup time
• Log retain

The bottom half of the screen consists of four rows of seven columns each. Each column has a title with a corresponding value beneath it. In the next post, we will examine each of the four rows of data.

I once got in trouble with a woman I was dating because I bought her an “appliance” for Christmas.  It was a combination VCR/DVD player (this was a while ago) and she liked movies.  Go figure.  I’ve also gotten in trouble with my wife for *not* buying an appliance - in this case a new, energy efficient clothes dryer; she pays the electric bills.  So you would think that I would steer clear of appliances.  You would be wrong.

Database “appliances” are integrated packages of software including operating system, database software (e.g. DB2), and other useful features.  Sometimes these appliances are pre-configured and optimized on hardware servers as well.  Some prominent examples are IBM’s Smart Analytics System (ISAS) and Oracle’s Exadata.  ISAS is the follow-on to IBM’s Balanced Configuration Unit (BCU) which clearly needed a new, better name.  ISAS combines InfoSphere Warehouse with IBM server hardware and a back-end storage system that provide a complete out-of-the-box solution.  The systems are “balanced” in terms of configured machine resources (i.e. CPU, memory, SAN) based on projected data volumes so you don’t have to spend weeks trying to figure all of that out.  That job has been done for you.  You can begin achieving ROI shortly after powering on the unit.

Appliances don’t always include hardware, however.  Some flavors of ISAS are VMWare images that can be deployed on existing hardware.  This benefits organizations which have established hardware standards in their enterprises and don’t want to deviate.

Want to get started with an appliance (and not get in trouble with your “significant other”)?  Check out this link on Channel DB2.  Anil Mahadev has put together Dubuntu, an all-in-one VMWare image DB2 appliance built on the open source Linux operating system Ubuntu.  It’s all *free*.  This is not a trial.  Using open source application development tools and DB2 Express-C, Anil has put together quite a cool package.

You can download Dubuntu at http://www.idug.org/anil-dubuntu/dubuntu-appliance.html from the IDUG website.  This is perfect for small - even one-person - development shops that can’t invest in expensive up-front software licensing.  If you are a DB2 for z/OS specialist and want to expand your skills to the distributed platforms, here’s a terrific tool.

With apologies to Cole Porter: “Do do that Dubuntu that you do so well.”

As a thank you for following my blog, I’d like to introduce you to what I think is a great opportunity for the right students. My team is looking for two bright students for a 16 month, full-time internship opportunity with IBM.

Aside from being a bright and ambitious student, you should currently be working towards a Computer Science degree at any recognized University in the world (and have completed at least 2 years of your degree). You read that right, this opportunity is not limited to Canadian students. We are looking for the most talented students in the world, so as long as you’re ready to relocate to Toronto for 16 months, and are able to start the internship program in May 2010, we have the means to get you here. The location for this internship will be the Toronto Software Lab, in Markham, Ontario.

In particular, we are looking for students who are highly skilled in the area of web technologies and who are enthusiastic about cloud computing. This is NOT your run-of-the-mill, boring student job. You’ll be working with cutting edge technology on high visibility, fast paced projects that involve web technologies, cloud computing, Xp/Agile methodologies, and other related fields. You’ll be granted ample freedom to express yourself and your programming creativity. Should you be accepted for this well paid (in my opinion) internship program, you will report directly to my manager (a cool, down to earth guy) and I’ll be your mentor.

If you fit the criteria described above, please get in touch (cangiano at ca dot ibm dot com) and tell me a bit about yourself. You don’t need to attach your résumé at this stage, but if you drop me a line, I’ll be able to provide you with info on how to apply through the official IBM channels. We’ll take it from there.

Please note that I do NOT receive any form of compensation for referring you. I’m just hoping to provide a tiny subset of my readership with what could be a really great opportunity.

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Before we can examine the various interactive screens of data that make up db2top, we need to become familiar with one of the ways these data are presented – gauges.

Gauges in db2top are graphical representations of proportions. Gauges appear on many of db2top’s screens, often grouped together.

A gauge shows what percentage of a certain measurement has some attribute. For example, in the picture below, the MaxActSess gauge from the Sessions screen shows the percentage of total sessions that are actively executing work. It shows this with a bar made of ‘-’ characters. The same is done for all of the gauges in the group, including the AssAgents and FCM BufLow gauges.

db2top Database screen gauges

There is another type of gauge that shows what percentage of a certain measurement has some attribute for more than one attribute. For example, in the Sessions screen, there is a gauge labeled “Sys/Usr Cpu%” that represents a measure of system CPU time with a repeating sequence of the character ’s’ and a measure of user CPU time with a repeating sequence of the character ‘u’:

db2top Sessions screen gauges

There are two ways the width of such character sequences can be calculated:

Normal

The width of the character sequence is a percentage of some total. e.g. the “ActSessions” gauge in the Sessions screen – represents the percentage of sessions that are active.

Avg Seconds

The width of the character sequence is the portion of some measurement that has a certain attribute measured during the last interval divided by the average of that same measurement taken since the last snapshot reset or database activation. e.g. “Sys/Usr Cpu%” gauge in the Sessions screen – the size of the sequence of ‘u’ characters is the amount of user CPU time measured in the last interval divided by the average amount of user CPU time + system CPU time measured since the last snapshot reset or database activation. The size of the sequence of ’s’ characters is the amount of system CPU time measured in the last interval divided by the average amount of user CPU time + system CPU time measured since the last snapshot reset or database activation.

Gauges generally occupy the upper part of the screen. This section of the screen can be hidden by pressing the ‘g’ key. Any other data displayed in the same section is hidden as well, even if it is not in the form of a gauge. It can be shown again by pressing ‘g’ again.

The countdown to the first day of Spring is below 20!  Spring can’t come soon enough for me, as here in Baltimore we’ve had over 80 inches of snow - our average is 18.  In preparation for Spring I am coordinating events with the local IBM teams to introduce customers to two great technologies we hope everyone will consider implementing in 2010:  InfoSphere Change Data Capture (CDC) and Optim Data Growth Solutions. 

Both events are planned for Baltimore’s beautiful Camden Yards, home of the Baltimore Orioles.  The tentative date for the CDC event is Thursday, May 6th, with a PoT scheduled two weeks later on May 20th.  I am working on getting the Optim dates on the calendar.  If you will be in the Baltimore/Washington area please try to join us - both topics should be of value to organizations looking for ways to better control their data.  CDC’s niche is in quickly moving data to where it’s most effective, while Optim Data Growth Solutions can help any organization with a packrat in the IT Department.  You know who you are.

Hope to see you there!