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RE: [EnergyPlus_Support] Running E+ on the "cloud"
Or to rewrite the E+ core and all component models, using OpenMP ;-)
This is not impossible. I bet there are tools that help you identify parallelizable code blocks. But, how many people out there thinking a single run of E+ is too long, if they are not trying to repeatedly run the same model? My guess at the moment is, a GUI that can adapt a parallel workflow to a 'slow' engine is more practical than to speed up the engine...
Yi
Dr Yi Zhang
IESD, De Montfort University, United Kingdom
________________________________
From: EnergyPlus_Support@xxxxxxxxxxxxxxx on behalf of Marcus
Sent: Fri 23/12/2011 10:11
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: Re: [EnergyPlus_Support] Running E+ on the "cloud"
Lot's of great discussion points about one of my favorite topics, here are my two cents,
Dr. Li; I have to take a contrary opinion here and bet that internet capacity in the aggregate will fall in price and both bandwidth, processing, and storage will become more accessible in the near and long term future. But even if we are headed to a change in the market, I am still willing to pay good money for a cloud based simulation service, if it means, such as in Jim's case, that we can reduce from 16 hours (2 hours per run over ~8 ASHRAE 90.1 runs) for multi-use LEED certified facility, to something around a lunch or coffee break. I believe this is possible with the hardware sitting 95% idle in most consultancy offices, or with fee based cloud computing like EC2.
One challenge is how to parallelize the problem. We can already parallelize the discrete simulation runs. I've heard this called "embarrassingly parallel". This is done by the "multiple simulation" tab in EnergyPlus, and also done independently many times over for building simulation and other engineering domains. This would break up Jim's 16 hour problem down to 2 hours if you had 8 cores. And this works great for global search meta heuristics like evolutionary algorithms if your runs are small and population size can be large. But to get below 2 the two hours barrier requires significantly more effort. I see three strategies;
1. Underlying simulation kernel can run naturally in parallel (domain decomposition?)
- This would be true parallelization, where the solution of the underlying equations and algorithms is distributable, i.e. Matlab parallel for loop.
- Or individual EnergyPlus simulation modules are running in parallel?
- Is this really possible for a building simulation?
2a. Break up individual run, functional decomposition
- Jim has proposed breaking the building apart into sub-geometry/systems.
- I see this as fine for some cases, but generally speaking it has two challenges; one is simply knowing how to break it apart (time cost of expert user intervention), and two is that a building is inherently tightly coupled leading to high bandwidth between sub problems or loss of accuracy (paraphrasing Building Sim. Augenbroe 2001)
2b. Break up individual run, temporal decomposition
- For an annual simulation, break up into i.e. 12 months over 12 processors, and stitch them back together at the end, as in (Garg 2011) that Yi Zhang kindly pointed out.
3. Other problem decomposition approaches?
Sounds like a project for 2012!
Cheers and happy holidays,
Marcus
--
Marcus Jones, M.Sc., LEED®AP BD+C
http://www.optimalenergetics.com/
Freelance energy consultant
Vienna, Austria
On Thu, Dec 22, 2011 at 11:03 PM, YuanLu Li <yli006@xxxxxxxxxxx> wrote:
Running EPlus in the "Cloud" with distributed computing is definitely possible, if you are going to pay for the usage of the cloud service. EPlus is already in a private Cloud by running the on line simulation program.
I do not think any "Cloud" server or provider would let you run your own program with multiple users free of charge, or with the current Internet connection charge and without additional network access control.
We are running on the left over cream of the Y2K bubble. Very soon the Internet capacity will not be free any more. VOIP, Face book, U-tube, etc. will not be free any more.
I paid C$8.00 for 1GB of excess usage last month. It was because I had to accept free Microsoft up-date for Windows7, SP1, SP2 and all the .net, Office, Visual Studio, etc. When a large project is run in the Cloud, the connection cost would go up. The CD that is sold at a shop is just for the registration and the base software. It is not up-to-date.
I cannot imagine that the Cloud providers would allow users to tap the Cloud CPU power for distributed computing without paying a fee. If it is on "when availaable" basis, then it may take un-known time to complete a job.
I am already getting "loading" "sorry the service is not available" warnings on Hotmail on regular intervals. Please pay $29.99 annual fee, if you would prefer faster service and no commercials to cover the displayed message. There is large overhead control loaded with every Hotmail message.
This is the reason why I was commenting that the public free Cloud computing may not be that wonderful for real production computing. Organisation whould build their own Cloud for their users by re-organizing and improving their current private LAN.
Apps for Banking, looking up Chinese food, socializing, are not really "must have" services in the Cloud. When the cloud is not there, you can always pick up a phone. This is also the reason I do not want to give up by land line phone connection for the "home phone". When the unitility service is down, or the internet is down, the home phone is also not available.
There are now public Cloud, private Cloud, etc. I think, the availability of Cloud computing and what is a Cloud are still very cloudy.
==========================
"developing an energy optimization design tool by combining optimization algorithms with energyplus."
This is great in principle. However, for real grobal energy saving design in buildings or other equipment, it is not a mathematical computational problem. It is an engineering and cultural problem.
Dr. Li
________________________________
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: santiagogvelez@xxxxxxxxx
Date: Thu, 22 Dec 2011 16:59:33 -0300
Subject: Re: [EnergyPlus_Support] Running E+ on the "cloud"
Daniel, I'm definitely interested in hearing about your experience with EC2. I'm currently doing my thesis on developing an energy optimization design tool by combining optimization algorithms with energyplus. Given the number of simulation required I'm guessing cloud computing would be the only way to make it practical for commercial use. Im still on reaserch stage though, so not sure how plausible this is.
Best,
Santiago.
2011/12/22 Daniel Bergey <daniel@xxxxxxxxxxxxxxxxxxx>
Yesterday I created an EC2 account, installed Energy+, and ran a couple
of the packaged examples on a cloud machine. It took about an hour all
told to get started, mostly reading docs. I'd be happy to help if you
go this route.
This seems good for small numbers of sims. For big search problems,
next steps might be:
* package a disk image that has suitable software installed
* set up a work item queue, so that each computer automatically pulls
the next sim from the queue
* put postprocessing on the cloud machine to reduce bandwidth costs
Anyone interested?
Daniel
On Thu, 22 Dec 2011 09:17:28 -0500, "Jim Dirkes" <jim@xxxxxxxxxxxxxxxxxxxxxxxxxxx <mailto:jim%40buildingperformanceteam.com> > wrote:
> Dear Marcus,
>
> Keeping in mind that this is somewhat hypothetical at the moment.
>
> It's my understanding that E+ spends the most time figuring out the energy
> balance of all the mass in the building. Additional time, although of a
> smaller magnitude, is spent on HVAC energy balances and report variables.
> That said, I am imagining:
>
> . A multi-use facility (i.e., many different occupancy types and
> HVAC systems)
>
> . In a roughly 300,000 m2 (3,200,000 ft2) facility
>
> . Which wants to attain LEED certification
>
>
>
> I anticipate no difficulty creating HVAC systems since my past experience
> covers most or all of the systems, but the sheer size suggests that there
> will be a LOT of run time, even on a fast PC. My strategy will be to
> prepare small portions of the building and its HVAC individually, test them
> and make sure unmet load hours are acceptable. After the smaller portions
> are complete, I'll join them together for a complete building simulation and
> the various rotations.
>
> In this scenario, I should be able to keep several building portions
> underway simultaneously if I am using multiple PCs or the cloud equivalent.
> Up until this point I have been focusing on making the energy modeling
> process more effective, accurate and fast. Because I don't run full year
> simulations until the end of the process, I've been tolerating long run
> times. Now I want to take (or at least evaluate) the next step in making
> the whole process go faster.
>
> I just finished a small multi-use facility (~10,000 m2) which required 2
> hours for a complete run on a PC with reasonable speed (i5 CPU, 6GB RAM and
> solid state hard drive) - too long!
>
> At this point I think that not too many of the people who participate on
> this forum are worried about this, but I know some of you have addressed the
> issue and appreciate the feedback I've received.
>
>
>
> The Building Performance Team
> James V. Dirkes II, P.E., BEMP , LEED AP
> 1631 Acacia Drive NW
> Grand Rapids, MI 49504
> 616 450 8653
>
>
>
> From: EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com>
> [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com> ] On Behalf Of Marcus
> Sent: Thursday, December 22, 2011 4:15 AM
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx <mailto:EnergyPlus_Support%40yahoogroups.com>
> Subject: RE: [EnergyPlus_Support] Running E+ on the "cloud"
>
>
>
>
>
> Dear Jim,
>
> What type of application are you interested in when you say "large project"?
>
>
> If you are describing a single large ASHRAE 90.1 model that may take over 15
> minutes to run, I often simply use the "group of input files" tab to execute
> my approx. 8 models (i.e. 4 baseline and 4 proposed with different
> oversizing in the HVAC) using my 4 processor cores simultaneously, so it
> takes 30 minutes instead of 2 hours. And if you do this often, it might make
> sense to buy a new dedicated multicore core machine that you can use to
> execute jobs, and access the files over a network. I would recommend this
> approach just because it requires no extra software or setup.
>
> If however you are doing global optimization or parametric studies with
> HUNDREDS of executions, then you will likely need the approach that Dr.
> Crawley or Dr. Li have mentioned, and invest into grid/cluster/cloud
> computing. Fortunately, this is a problem that has been solved many times
> over in the IT world and there are many approaches and platforms available,
> the problem really is choosing one.
>
> (Aside: This is all a topic near and dear to my PhD and professional
> objectives, so if anyone wants to submit a paper or research project let me
> know!)
>
> Cheers,
>
> Marcus
> --
> Marcus Jones, M.Sc., LEEDRAP BD+C
> http://www.optimalenergetics.com/
> Freelance energy consultant
> Vienna, Austria
>
>
>
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