I came across an interesting project that University of Michigan is doing called PowerNap

Basically the goal of the project is to put servers to sleep quickly when they are idle and wake them up quickly when they are called for again.

Here are some interesting quotes from the article:

"The Environmental Protection Agency expects the energy consumption of the nation's data centers to exceed 100 billion kWh by 2011, for an annual electricity cost of $7.4 billion. Those figures are about twice what they were in 2006, when data centers already drew more electricity than 5.8 million U.S. households."

"For the typical industrial data center, the average utilization is 20 to 30 percent. The computers are spending about four-fifths of their time doing nothing," Wenisch said. "And the way we build these computers today, they're still using 60 percent of peak power even when they're doing nothing."

It's a well recognized problem, I think. But I've yet to see an effective solution. I hope PowerNap will become one by itself. I think such technology can achieve its full potential by coordinating with not only operating systems but also applications such as Citrix infrastructure. For example, the applications can help making more intelligent decisions of where to route the traffic to increase the chance and duration that a server can be turned into a power saving mode. Today Citrix's products drive a large share of DataCenter work load, I think Citrix can play an important role in addressing this important issue.

I led an experimental project called PowerSmart not too long ago. The basic idea is to funnel the load to a smaller set of servers so that the rest of the servers can be powered off during off peak hours. But the project was suspended due to lack of resources. The good news however is that the development team has picked up the concept and is working on something better. I will blog more once I get clearance to do so.

What I am curious about is how the bad economy is going to affect the investment on "Green IT technologies". According to the articles, it sounds like saving energy in the data centers may still make sense as far as return on investment is concerned even in today's economy. What do you think?

Do you think companies will invest in Data Center Power Saving technology in today's environment?	Choose
yes
no

Of course, there are many variables in making investment decisions. I would appreciate it if you could elaborate in the comment section.

Here is another article I found titled "digital Diet - Computing industry gets serious about energy conservation" that offers additional data.

Ray (Ruiguo) Yang
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A group of volunteers from Citrix formed a Green team recently to promote "green" initiatives i.e. protect environment and reduce waste. 

One of the recent initiatives the team launched was called "Mug Day". Here is how it works:

Citrites present a mug to their floor captain, pledging to use it instead of disposable cups.They will be entered for a drawing.

As one of the floor captain, I was encouraged by the partication. Here is what one floor captain wrote afterwards:

"..On my floor, 29 engineers proudly showed me their coffee mugs for this raffle. Some of the mugs were brand new, purchased just for this raffle, possibly the only mugs these young guys own. .."

This experience shows that people do care and will respond if they are given an opportunity to do their part in some small but tangible way. I am proud to be working with such a group of people.

As a technology company, Citrix offers products that help people be green by enabling remote working, reducing physical machines etc. I created an experimental project called "Citrix PowerSmart" specifically for reducing power consumption. There is more to come. I will blog about them when I get clearance to do so

I want to share our success story with you and would like to hear yours. I hope we can learn from each other. Please comment if you have something to share.

Thanks

Ray Yang

My blogs

Now that a new year has begun, it is time to think about change. What did you do well in 2008, that you would repeat in 2009? What will you do differently?

Forecasting bad economic news for 2009 is old, and we all know it is going to be a tough year. I can think of several people I know personally that have already been affected. Among the predictions and forecasts from analysts is that IT spending will slow down. 2009 will be a tough year, and with spending on hold, if I was an IT infrastructure guy or a service provider, with all of the virtualization technology available, I would take more than a few minutes to rethink my strategy.

2009 Forecasts that cloud computing and virtualization will grow. It is not just a prediction that I believe in because I work for a virtualization company, I believe in it because I am an operations guy at heart and this virtualization stuff is real.

One of the things I am going to continue to do in 2009, is make use of XenServer and its tangentially related products. At Citrix, I spend a lot of time with my head buried in a lab working on several projects at a time. At any given time I may need to bring up Windows servers and clients, *nix Servers, install a partners product into a server, or install some enterprise application for testing. All of these I did in 2008 without spending any money on hardware. I had an existing Dell 2950 III that I use for XenServer. I can bring up, bring down any number of hosts at any time, for any purpose, without having to fill a rack with hardware that sucks the power grid dry, and depreciates in value the second I order it.

Not only have I done a great job of saving money on capital expenditures in my lab, I have also saved a lot of energy and rack space. In addition, with faster time-to-deployment and more resources at hand, I have increased my productivity immensely.

I work with our internal Citrix IT and Training departments who both make use of Citrix Virtualization technology – this has proven to increase their productivity as well, while reducing cost.

Looking forward, I know I will be able to keep costs and spending down to almost nothing this year as I make continued use of Citrix Virtualization technology. As an operations guy at heart, nothing brings greater joy in slashing a budget and saving money going into 2009 while increasing productivity.

One of the most requested features from Service Providers and Enterprises is IP Address Management (IPAM). I can't tell you how many times I have listened to customers ask for a platform that manages IP Addresses effectively on a large scale, even to the point of managing disparate classes and subnets. What happens when two companies merge, do you munge spreadsheets or do you have this software yet? It's not only the software that is unique but that it runs as a XenServer VM in Para-Virtualized mode, meaning it is high-performance. Even better is these run in linux.

Nixu Software specializes in software designed for DNS, DHCP and IP address management. To run Nixu Products in a virtual machine environment, simply download the ISO installation media from their website and boot up a new virtual machine. The installation media auto-installs the entire server stack.

Unlike traditional computing appliances that require specific hardware to run on, Nixu Products provide a quick and cost-efficient way to migrate and consolidate core network services such as DNS and DHCP to virtualized computing environments. By streamlining tedious network and system management routines, Nixu Products offer exceptional availability and ROI.

Here are some of the Highlights of using NIXU DNS and DHCP in a XenServer VM:

• Centralized IP Address Management
  • Merge/Join IP Blocks
  • Split IP Blocks
  • Subnets in use – report
  • Subnets free – report
  • Addresses in use – report
  • Addresses free – report

• Runs in XenServer as a VM, optimized for Para-Virtualization
  • Supports pv-ops

• Supports IPv6
• Uses secure communication between secondary name servers, using keys
• Role based administration
  • Assign subnets to administrative domains

• Supports BIND syntax
  • For the BIND junkies

• Has a configuration checker
• Automated installation and maintenance reducing management overhead
• Centralized management of all nameservers
• Hardened design for security

WATCH this video tip:

Download the Nixu / XenServer Integration Guide.

Read about Nixu Software here.

Download Nixu Software here.

Read about Citrix XenServer 5.0 here.

Download Citrix XenServer 5.0 here.

Tap into the power of AppExpert!

Sean Whetstone, Head of IT Services at Reed Managed Services in the UK, is a big fan of going green. By using a combination of Citrix XenApp, NetScaler and XenDesktop, Reed Managed Services was able to reduce operating expenses by over 20%, centralize and secure data from over 300 offices, and reduce their carbon footprint by 2500 tons. According to the post on Sean's blog, Reed Managed Services was able to cut utility usage by 5,500,000 kilowatt hours to save over 100,000 pounds as a result of this project.

Sean recently posted a video interview he did at a Citrix event in London on his blog.

You can view Sean's presentation on this topic here.

I've been encouraged lately by a noticeable rise in interest in Green IT. For some time I have been talking and blogging about the need to reduce the somewhat significant ecological footprint of IT operations, and I can tell you that even little over a year ago the reaction was mostly one of indifference. At some presentations, I could almost hear the whispers of "go back to Berkeley hippy", even though I have never been there and my hair is quite short .Fellow Green advocates  reported similar results, so it wasn't just my presenting skills. Lately though, the questions I get at presentations show not only more interest, but more engagement and a wider understanding of the issue. Mostly this engagement comes from people in Government IT roles, where there are departmental Green directives with real targets  on  a wide range of operational activities, including  IT.

Increasingly it is also businesses that are starting to understand that there can be financial benefits to reducing the amount of electricity being used to power IT, a fairly major factor in ITs environmental impact (the other main factors are hardware making its way into landfills and the hazardous materials used in manufacturing hardware). With average commercial electricity prices rising 12% since 2005 (a figure I worked out from checking out the US Dept of Energy site), coupled with the fact that  we have been throwing more and more servers (each increasingly power hungry due to their increased performance) into our data centers, the cost of powering these data centers must surely becoming more noticeable.

However, when I mention rising power costs to an audience, I like to ask for a show of hands on how many of them, being IT professionals, actually see their power bill let alone are held accountable. Usually the response is about 10% who do. This may go partly to explain the still low adoption of Green IT plans in businesses as the pain points are not being felt by CIOs, and maybe even the CFO/CBCs ("Chief Bean Counters") who get the corporate power bill have not yet put 2 and 2 together.

So, this leads me to my the question I'd like to throw out there - with most of the economic outlooks forecasting a downturn over the next year or so, will the resultant close look at costs be an opportunity to promote Green IT strategies that are goaled on measured on reducing operating and capital costs?

If you are looking for an opportunity to get approval for a Green IT project at work, this may be your chance. Even if you aren't that motivated by the need to reduce ITs carbon footprint, wouldn't you rather have your companies reduce costs by using virtualization to reduce the power bill and hardware costs than having to do something else such as layoffs?

Either way, your Green IT proposal needs to be sold to the CFO as well as the CIO. As such, your plan will need to include real and measurable financial targets  on the amount of electricity cost savings as well as the usual ROI.

I'm planning on creating a calculator that can demonstrate the ROI of Green server consolidation and thin client projects. If you have any ideas or know of similar calculators, please let me know.

Also, if you are in a Government department and want to raise awareness of Green IT with your CIO, we are holding a Virtual Roundtable on Green It in Government on August 12.   A panel of experts from Federal, State and Local Government agencies, as well as Simon Crosby from Citrix will be there to discuss ROI models, existing mandates and what the future may hold. This will be a low time investment opportunity for your CIO to learn more about Green IT. If you are a CIO yourself, I'm glad to see you are choosing to use some of your valuable time to read my blog and please register for the Roundtable  .

You can register for the Virtual CIO Roundtable here.  

In my previous blog entry, I described the Green benefits of telecommuting and my plan to "road test" telecommuting technologies and experience. For my first test, I have chosen voice communications.

My reasons for choosing this over something more obvious such as remote application access, is that most telecommuting scenarios that I have seen or experienced were based on the telecommuter being able to use a mobile phone for making and receiving calls business calls. This is not always the case, and not in my current temporary scenario where I am overseas from my Silicon Valley office. And if my mobile phone did work here, it would be extremely expensive to use for the number and length of calls I normally make. Generally, I also find this reliance on mobile phone a hassle due to the cost when compared to business or even home landlines, and the knowledge that people who want to call me need to know a. that I am not currently in the office and, b. what my cell phone number is.

Here's something else, I strongly believe that talking is still the most efficient and effective form of communication between two people and sometimes more. I have seen way too much misunderstanding, delays, unnecessary stress or conflict through even best written email, as the written word often lacks the nuances you get in verbal communications. While talking on the phone is still less effective than true face to face talking, it still is a big advancement on email or even IM. I'm sorry, but emoticons just don't match body language ?.

So, as I start this particular evaluation, I have three criteria that I want to test:

1. As many of us work in a highly mobile manner, with the "office" now including when working from home, business travel and other mobile scenarios, how do we maintain a consistent way to be contacted by voice as well as email?

2. We all have a single work email address that is constant wherever we are, but what about our phone number? Why is it that we have to guess whether the best phone number to use is the desk or cell phone?

3. How often do you have to be the manual link between two electronic systems when you have to enter a phone number from an email or customer record into a phone keypad? How often do you type the wrong number because of this? I know I have.

4. How expensive is it to use mobile, home or hotel phones to maintain a consistent amount of voice communication? I believe that the frequency of calls to staff, management, colleagues and customers should not diminish just because you are not in the office.

Now the last 2 of these criteria I can test by using one of Citrix's own products, EasyCall. By installing EasyCall, I can make calls from my PC either by entering the number, or using the click to call feature to dial directly from, say, an email footer. Rather than being a VoIP solution, EasyCall connects a call by first calling my own phone (could be my home line or mobile) before establishing the connection to the number I have dialed. It also has a pretty cool corporate directory function, allowing me to search for colleagues by their name in a similar manner to the deskphone I have in the office.

Now before you think I am just using this blog just to promote EasyCall, there are still the other 2 telecommuting phone criteria that it seems I cannot use EasyCall to evaluate. This means that I still have not re-routed inbound calls so that people calling me, especially from outside Citrix, need not to know that I am in the office or out. In previous telecommuting scenarios I have had to set up, I achieved this by using softphone products such as Avaya IP Agent. In my personal life, I am a heavy user of Skype, so will also be looking at it and other VoIP solutions for inbound calls as well as possibly outbound. The only issue I can foresee with this is that my current connection to the internet has nowhere near the performance I have become used to in California, which may mean the call quality is not to flash. I'll keep you posted on what I try for inbound calls and how it works (or not).

Now back to EasyCall. To use it, I need to install an agent as well as have a EasyCall Gateway installed between the LAN and PBX. Fortunately, the good folks at Citrix IT Services have installed the gateway, allowing me to worry only about the agent. Installing the EasyCall agent is pretty straight forward, the only things I really need to know is where to find the installation files and the host name of my EasyCall Gateway. To see what the installation process was like, check it out at http://www.utipu.com/app/tip/id/2955.

As with all my blogs on Telecommuting, I am eager to hear from you your own views on this topic, or any criteria or scenarios you think I have missed for my evaluations. Just post a comment to this entry.

Most of what is written on Green IT concentrates on how the IT Department can reduce the carbon footprint of its operations, primarily through reducing Data Center power consumption. While this is important as IT operations makes up 2-3% of global power consumption, our efforts to reduce our environmental impact should not end with the data-center. As well as including the end-point into Green IT planning (something I covered in a previous entry), IT can have a role in enabling Green business practices such as the paper-less office, Remote Collaboration (thus reducing the need for business travel) and Telecommuting.

Its this last practice, Telecommuting, which I want to discuss in more detail. For one thing, its something that we can do as individuals (work and management permitting, of course) as well as on a cross-company, cross-industry and even national basis. It fits in with the "think globally, act locally" mantra, with the emphasis on "local".

The Telecommuting trend has for some time been more tied to employee satisfaction, work-life balance and increasingly recruitment strategies (such as "homesourcing"). However, the rapid increase in the price of oil has made the cost of commuting to work a much larger percentage of household budgets, and therefore more noticeable to the average Joe or Jane. While many of us may wish that people would find other motivations to reduce their carbon footprint other than the hip-pocket nerve, rising costs will probably have the most realistic chance of effecting widespread change.

Increasing the number of employees that telecommute rather than drive to the office can cause a significant reduction in the fuel consumption, and therefore carbon emissions, of those individual employees. While this may seem obvious, you can read a detailed study conducted by the University of California....back in 1988! As well, more recent EPA studies have shown that even a 10% reduction of cars during peak hours can reduce the fuel consumption of those vehicles still traveling to the office, as the improved traffic flow results in less time burning fuel in gridlock. To get an idea of how this works, think about how much better your own commute is during school vacation periods.

While this shows there there would be significant benefits to the environment if a greater proportion of the workforce spent at least some time of the working week telecommuting, how practical is this generally, and in specific job roles? If your job does not involve "face time" with customers, telecommuting is probably a more practical option for you than those involved in regular customer interaction. That being said,  there are a number of organizations allowing call-center agents to work from home, such as Cox Communications.

While I have regularly telecommuted over the last decade or so, as well as introduced telecommuting programs for employees doing Tech Support and Customer Care, I have decided to use a period where I need to work remotely to try to measure (at least to qualify if not to quantify) the effectiveness of the technologies used to enable telecommuting. Over the next few weeks, I will blog on my experience based on the following criteria:

• Voice: How can I remain in verbal contact with staff, colleagues and customers? How do they get in contact with me without having to know whether I am in the office or not?
• Applications: How does my app performance vary when not in the office? What impact does occasional offline access make to this?
• Security: What would happen if my laptop or home PC was stolen or otherwise compromised? How do I set up my physical facilities to minimize security risks?
• Collaboration: How important are those "water-cooler" discussions and other face-to-face formal and informal interactions? If they are important, how do you replicate this when remote?

I have experienced challenges with each of these criterion in my own experiences as well as those relayed to me be customers.
While most of the technologies I will be using come from Citrix (partly because we like to eat our own dog food but mainly because we have been a long-time enabler remote work practices such as telecommuting), I will be also looking at other products and technologies to fill any gaps or compare.

I mentioned earlier that I want to use this as an opportunity to discuss telecommuting. As such, I would really appreciate your comments and suggestions on what I should be testing (technologies, criteria and scenarios), what your own experiences have been, and whether you think an increased proportion of your work time as telecommuting would have a benefit to you, your employer, customers/partners and the environment. Please contribute to this discussion by posting comments to this entry. In a later entry I will add a forum address if there is sufficient interest in this topic.

Citrix PowerSmart Utility is created to help XenApp users conserve energy. To learn more about this project, please visit the project site.

To try out the utility however requires access to physical servers with certain capabilities, such as HP ILO2 support for example. I understand not everyone has easy access to these machines. To make it easier for people to understand the utility, I created a short demo video. The video shows how to configure this utility and see it in action.

If you have trouble viewing the embedded version above or see the notes below. Please click here to view the standard version.

Click here to see all of my videos.

I'd love to hear your feedbacks.  

I was fortunate enough to recently meet Christian Knermann from the Fraunhofer Umsicht Institute in Germany. Christian and some of his colleagues conducted a study on the positive environmental impact of replacing PCs with thin clients, using XenApp to deliver their desktops and applications. Having very precise  calculations combined with a detailed explanation of how these calculations were made is significant.

I've been promoting the concept of Green IT within and outside of Citrix for some time now,  motivated by the desire to do something for this world we live in at work as well as in my personal life. While I haven't converted to solar power yet, I have replaced all my commuting and most of my personal traveling from car to bike. I know this isn't something everyone can do (and I can't lug my family of 5 behind me on a bike), I believe we all can do something to reduce the environmental impact of IT operations.

I won't get into the argument of the causes or even the existence of global warming, but it is obvious to anyone that the more electricity we use to power Data Centers and end-points, the more pollution is released into the air. As well, the frequency in which we replace our hardware (and I have been a culprit here) in turn increases the amount of landfill, including some hazardous materials, into the environment.

In my efforts to raise Green IT awareness, I have seen a lot of calculations of the benefits of one technology over another. Sometimes its difficult to verify or even understand the math involved - which has been noticed and noted by others. Particularly when these calculations are on the power consumed or saved, and the costs involved. In many of the cases, I can see the logic behind them and therefore give the results some credence, but I would not have the same level of confidence if I had to relay these figures to an audience, especially one comprised of geeks who tend to, like me, question figures that are stated.

And that is where the Fraunhofer study becomes useful. Their study takes into consideration criteria such as the entire life-cycle of hardware from manufacturing to disposal, the different profiles of user from light to power users and even the effect of powering off at night. Impact was measured not only in power consumption, but also emissions, hazardous waste and even water consumed. The report is very detailed and includes a lot of graphs and tables to support their findings.

I recommend that anyone interested in implementing Green IT take a look at the report which can be found here. While the primary focus of the report is on replacing PCs with Thin Clients, it also covers in summary additional approaches such using 64 bit processors as well as virtualization.

If you speak german, you can also see and hear Christian talk about his work at the Synergy Underground site(http://community.citrix.com/underground/). The badly mangled german questions are from me .

The HP team who helped with testing the Citrix PowerSmart Utility just released a new white paper explaining how the utility adds value to HP Integrated Lights-Out(iLO) 2 technology. The white paper also includes some interesting data about power and cooling cost. You can find the white paper at HP web site here.

A colleague pointed me to an article that talks about how much power data centers are consuming. The number is staggering.

"The electricity used by servers in the U.S. -- including servers, cooling, and auxiliary equipment -- was approximately 45 billion kWh, resulting in total utility bills amounting to $2.7 billion in 2005"

"The study goes to project that, based on current trends, worldwide server consumption from 2005 to 2010 would require an additional capacity equal to more than 10 additional 1000 MW power plants."

And at the end the author suggested "Don't forget to turn off the lights when you leave the office at the end of the day." Although it is a big challenge to solve the overall power consumption issue, there are relatively simple steps we can take that have potentially big payoff. It's the same simple idea this Citrix PowerSmart Project is based on.

Here is the link to the article.

We released the Citrix PowerSmart Utility for Presentation Server just before the holiday. Now that people are coming back to work mode, I hope more people will have the opportunity to try out this utility.  We want to make it easier for users to exchange ideas and ask questions. Please use the MFCOM user forum to post PowerSmart related questions.

Shawn Bass wrote a good blog about the new PowerSmart Utility

In his blog, he explained his take on our choice of of using WinRm and server vendors's out of band management products. It's a good read.

One thing I need to clarify is that it is fairly simple to configure this version of PowerSmart to power on HP servers if you follow the user guide. We'd like to hear your experience and improve the tool and its documentation.

Shawn was right that if you just want to give the tool a quick try without reading much, the out of the box default configuration will allow you to try it without much restriction. It will even work in a virtualized environment.  Please see the minimum requirement section of the download page. The trade-off however is that this default configuration won't power on servers. A good default power on mechanism is hard to find because user environments are likely to be very different.  The included HP script won't work with IBM servers for example. We thought this default is a safer option and it can lead the users to think about the best way to power on servers. Plus this default makes it easier for users to have an alternative mechanism to power on servers. For example, users can use windows scheduler to schedule a script to power on servers. Yes, the HP scripts we provided can be easily modified to do so.

We thought about using Wake On LAN as default. But we soon realized that it has many limitations too. Please see the FAQ page for more details. However If you know WOL well or you can get some experts such as Shawn to help, it may very well work for you.  I heard a large company had successfully used WOL to save millions of dollars by powering off idle desktops. In the data center, I expect administrators may have more control over the servers and thus WOL may have a higher chance to be useful.

Please share your experience with others so that we can benefit from each other.

The wait is over. I am happy to announce that Citrix PowerSmart Utility is available for download now at this newly designed Developer Network site. Please visit this page for more information and to download the utility. Be sure to check out the related page section for the FAQ page page and new idea page page.

The new site makes it so much easier to post new projects. I love it. Please try it out. I hope you like it too. I've even left the FAQ page open so that you can edit directly yourself.

A great platform is of no use if no one is using it. We'd love to hear from you and we hope the new platform makes it easier.

I've also posted the same information at my blog post at official citrix blog site. Going forward, I guess I will post more CDN specific information here and general information at Citrix blog site and cross reference. It's the power of the web...

Many thanks to everyone who have contributed to this project!

Merry Christmas and  Happy New Year!

Ray Yang

I am happy to announce that Citrix PowerSmart Utility is available for download at the new Citrix Developer Network web site now. Please visit this page for more information and to download the utility. Be sure to check out the related page section for the FAQ page and new idea page.

Many thanks to everyone who have contributed to this project!

We'd love to hear from you. The new Wiki based Citrix Developer Network is cool. Please check it out.  I've even left the FAQ page open so that you can edit directly yourself. 

Merry Christmas and  Happy New Year!

Ray Yang 

Update: 

The utility has been released to CDN. Here is the link

----

Hi my name is Ray Yang. I am a senior technical business development manager at Citrix. The new official Citrix blog site displays my name as Ruiguo Yang. But most people at Citrix refer me simply as Ray Yang. That was the name I used for the old community blog.

I haven't posted anything new recently because I've been busy working on an exciting new project called "Citrix Power Smart".

So what's "Citrix Power Smart"?

Nowadays, server power consumption and associated cooling cost have been a hot issue. Many people in Citrix and Citrix customers are asking what Citrix can do to help addressing this issue.

During a discussion with some members of the CTO Office team, a small group of us conceived the idea of powering off idle presentation server during off peak hours.  Here is our thought process.

Just imagine you have 10 presentation servers.  During the business hours they are fully utilized. However at nights or on weekends hardly anyone connects to them. These servers however still consume power needlessly during such "off business hours".  Simply powering off such servers during "off business hours" can save you up to 30-50% of your presentation server farm power consumption based on our rough estimate.  It sounds easy. But why haven't we found many people doing so? Many of them do want to save money and are environmentally conscious. We think one of the reasons is that it has to be made easy and reliably before such practice is widely adopted. Can you imagine the following scene?

A presentation server administrator stays late every night.

Wait for the last person to log off.

Shut down each idle server.

Get up early to power on all servers before everyone else comes to work.

It's a bit tough to do, isn't it?

Well, such repetitive work is best left for computers. And they can be programmed to do it reliably!

In fact, we realized that the existing presentation server and the underling server platforms have the necessary ingredients already. The existing Presentation Server SDK provides the ability to see what user sessions are running on a given presentation server. There are existing standards such as IPMI and infrastructure such as Windows Remote Management available to power on/off servers reliably. What's missing is a small piece of software to tie them together.

But wait a minute. What if some poor fellow do have to check emails or get some work done during the "off business hours"? You can leave some Presentation Servers running to serve them. However without additional work, the default Presentation Server load balancer will typically distribute the load evenly across all the servers preventing many servers to be shut down. To give you an example, say you have 10 servers in your farm. Each server is capable of supporting 50 concurrent user sessions.  Based on historical data, you expect at most 30 concurrent user sessions will be needed during "off business hours". So I only need to keep one server running after business hour then. But wait. You have set up your presentation servers to balance user load evenly across your servers. These 30 user sessions will be spread across all 10 servers during "off business hours" preventing you from shutting them down. After all you don't want to lose your job because you disconnect your CEO's session when he is checking an important email at home.

So how can we improve our simple algorithm? Well, it turns out that Presentation Server has a "scheduling rule" for all the currently supported versions. You can define the time periods when certain servers are available. Perfect, we thought. If we add a simple scheduling rule, to make sure the servers we want to shut down aren't going to accept new connections in "off business hours", chances are much greater that these servers will have zero active sessions as people log off.

"Sounds great and simple. We have App Delivery Expo coming up next month. It's going to be a great talking point. Can you have it done, like tomorrow?" Marketing guys asked.

"Well, we like it but it is likely going to take XXX man weeks to go through the release cycle. And we are fully booked" answered development team.

Finally, the technical folks in the business development group volunteered to deliver the first version via Citrix Developer Network with forum support. Because of my developer background, I volunteered to lead the project. We volunteered because we love doing something good for the environment, sooner than later. And we believe once we showed the leadership and initiative, the community (users and partners) will help us get there even if the initial functionality is limited. And it is easier to convince the product team to include such features in the future releases once we have positive feedbacks from users. Personally it is gratifying to be able to contribute to something I believe in while getting paid 

Thus "Citrix Power Smart for Presentation Server" project is born.

At this year's "App Delivery Expo" (AKA IForum), we announced "Power Smart" initiative. Here is the link to the press release. If this project is successful, we may bring more exciting projects under this model. For example, a Power Smart Utility for Xen. Since then we've got many interests from partners and customers. I may be able to share some more information on that subject later.

We know Presentation Server very well. But we are not the experts in controlling the physical servers such as powering on/off servers. Luckily we found some like-minded folks at one of our great partners HP to help us. HP's development team is busy too. But they gratefully provided advices and test equipments to allow us deliver a solution that will work with HP servers. And they happily agreed to do joint marketing with us. It's been a pleasure working with the HP team involved with this project so far.

I've been itching to share more information with Citrix community about this project. But I felt I had to get the utility working and release it on schedule first.  I am still running some last minutes testing and getting feedbacks from selected beta users.  It now looks promising that we will have the utility delivered to the community as a New Year gift from Citrix.

I will share more details with you as we make progress.

In the mean time, I'd love to hear from you, good or bad. If you prefer, you can also send an email to me at Ray.Yang@citrix.com. I can't promise to respond to every email. But I will try. For this reason, I would encourage you to comment on my blog or soon to be setup user forum to exchange your ideas with the broader community. Let's do something good, together!

I hope you find this blog interesting. And if you do, please help us spread the message.

Thanks!