Saturday, 8 December 2012

Application Sensors and Intelligent Power Management Part #2

IPMPlus provides built-in application sensor for most commonly used applications. However if you have custom applications  you can define your own application sensors. To define the application sensor policy  you need to identify the applications which are most often used (know their process/executable names) and then determine if it is an interactive or background application. 

Desktop interactive applications will require the monitor to be turned on when the application/user is active. For example Powerpoint user on a laptop - while doing a presentation the monitor should not be turned off even if the user is not active on the keyboard. The disk can be turned off (not to worry, when ever the system needs to read or write data it will automatically turn the disk on). If the user is away from the desktop and PowerPoint is not running - the monitor can be turned off.  Here is the example for PowerPoint.  Imagine the situation if you didn't  have application sensors, if you enable power savings on Windows with the default power policies, while you are doing a presentation the monitor turns off if you are away from the keyboard for a while and interrupts your presentation and irritates your audience.

 Applications sensor enable fine-grain power management. For each application the administrator can specify which components of a system can be selectively turned off or not and finally whether the entire system can be moved to standby/shutdown or not. Multiple applications can be selected and the  fine-grain power control can be specified for each of the applications. The policy can be enabled or disabled for each of the applications. The following example show the application sensor definition for running virtual machines using VmWare Player.

Now let us look at  another scenario of a server which is used most of the time in the day and at night it can be moved to a standby mode when the batch job is completed. In the application sensor policy define the name of the batch job and specify that the system cannot be in standby/hibernate/shutdown state when the batch job process is running. After the batch job completes the power policies will move the system to the low power state.

Multiple application sensors can be defined simultaneously, each application sensor policy can be associated with one or more power policies. However at a given time - which ever power policy is enforced will select the corresponding application sensor policy. In the following diagram you can see that the Power Scheme is referring to the default Application Senor Policy.  You can edit the existing Application Sensor Policies or Create New ones.

To summarize Application Sensors provide a mechanism to enable fine-grain power savings while allowing the respective applications to function and enable the user to work uninterrupted.

Sunday, 2 December 2012

What will you do with 1 TeraWattHour of Electric Energy?

DatacenterDynamics reports that in 2012 data centers across the globe have consumed 322 TeraWattHours of electric energy. [Even experts seem to be confused between units of Power and Energy. We'll stay puritan-istic in this regard and measure Electric Energy in Watt-Hours and Electric Power in Watts.]

If we assume that this is the energy in its aggregate form drawn from the grid, the sad news is only about 100 TWh would've really got used - the remaining having been wasted in various stages. [Refer Schneider's calculations in this regard on how energy is wasted in data centers.]

That being the point, I was just wondering how much is really 1 TeraWattHour of Electric Energy?

Firstly, what would it take to generate that much of electricity? Here are some options...

  • Nuclear generation: Run one of the two 1,000 MegaWatt units of Kudankulam Nuclear Plant at full capacity for 1,000 hours = 42 days on a 24x7 basis
  • Thermal generation: Burn 149x3 ~ 450 Kilotonnes of Coal [assuming 6.67 KWh/Kg of energy per Kg of coal and 30% as the thermodynamic efficiency of thermal power plants] 
  • Solar generation: Roughly 220 Sq.Km of Solar Panels [assuming 70 MilliWatts/Sq.Inch]

What can I do with it if I weren't running data centers? Well, to begin with, I can burn a tubelight or run a laptop at full power for 2.8 million years on a 24x7x365 basis. In other words, 5.6 Million houses can have at least 1 tubelight burning throughout the year for 12 hours a day - enough for 10 Million children to study if we assume each house has 2 children !

We invented the Internet and then Mobile telephony. Somewhere in between the bankers said - "High Availability and Zero Data Loss". Haven't we made the world a little too complicated in trying to make it a smarter planet? Now you know why few of us are spending sleepless nights over reducing power consumption of IT infrastructure. People today question us on return on investment when we offer IPMPlus at highly affordable prices - tomorrow there may be no choice :)