1 Gig-VDF

[lingo]

Hey there,

I'm using Vensim for a round-based strategy game. The players have around 15 minutes to make their decisions, then the round ends and Vensim executes one timestep. The decisions by the players are made on a web-interface, these decisions are saved in a SQL-database, Vensim uses data from that database. I hope you were able to understand what I am trying to say.

The problem is that sometimes an unknown error occurs that makes the VDF-file that belongs to the actual run explode- more than 1 Gigabyte. As a result, of course, the simulation is aborted. I don't have any clue why that happens, that's why I want to ask wether an error like that ever occured before.

I'm not able to replicate the error as it doesn't occur frequently and the VDF-Files are too big to simply upload them. I opened the VDF with UltraEdit because it's to big for Editor or Notepad to be opened. As you may guess, the undless rows of 0s didn't really give me a clue.

Does anyone have an idea?

[tomfid]

Right, the vdf is binary, so you won't see much in there with an editor. They're numerically dense, so piles of 0s are a bad sign though.

It sounds like you're running this with ordinary Vensim, rather than the .dll? What version & platform? Are you importing the SQL data via text or ODBC?

[Administrator]

Check the value of FINAL TIME as well.

For a normal simulation, the results VDF file will be compressed. For games, they are not and so can get really large if FINAL TIME is set to a silly number (the file is created large enough to store all vals at all time steps).

Hope this makes sense.

Tony.

[tomfid]

If you can post the model, it's often helpful.

[lingo]

Jep, I don't use the dll, the version is DSS, 6.00 beta on a Win7SP1-system (further information required?).

I use ODBC to import data.

The FINALTIME is 12.

That's the model, do you need the vdi-and vdo-file, too?

Hope it's not a stupid, embarrasing mistake of myself.^^

[Administrator]

I cannot see anything in the model that causes concern.

What size is one of the error runs when you zip it? If small, can you upload it?

[tomfid]

It would be interesting to see your vdi and vdo too - especially the first.

[lingo]

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT GuestPay

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT GuestCost

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT RepairCosts

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT GuestRoomSatisfaction

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT GuestWorkLoad

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT GuestsActive

:DATA
:VARID ID
:TIME T
:Value Sector
:SELECT StaffSectors

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT InvestmentCosts

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT BreweryConstantWaterPrice

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT BreweryCosts

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT BreweryAmmountProduced

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT BreweryQuality

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT MarketingCosts

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT MarketingLocalEffects

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT MarketingSupraRegionalEffects

:DATA
:VARID ID
:TIME T
:VALUE Value
:SELECT MarketingSustainabilityEffects


:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT BeergardenSeasonalEffect

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT BeergardenConsumption

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT Weather

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT RestaurantConsumption

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT RestaurantSeasonalEffect

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT RepairCosts

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT StaffWages

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT GuesthouseRunningCosts

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT InvestmentIncome

:DATA
:VARID ID
:VALUE Value
:TIME T
:SELECT BreweryIncome


:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupMarketing

:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupGuests

:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupStaff

:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupQualitys

:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupFinances

:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupBrewery

:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupMarketing

:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupBeergarden

:VARLOOKUP
:VARID ID
:VARNAME Variable
:SUB Subs
:SELECT VarLookupRestaurant

[lingo]

That's one of the error runs.

[Administrator]

It seems that final time has been corrupted somehow.

I'll try and set up an experiment here to see if I can reproduce the error. Are you able to email me (vensim@vensim.com) the SQL dump for the table that is read via ODBC?

[Administrator]

Thanks for the SQL. I did try replying via email to say thanks, but got an "undelivered" message.

Tony.

[Administrator]

I've got the model running now.

Is there any particular changes to the database that cause the large VDF?

And can you email me the output.vdo file, it may be that it has not finished writing to the database and that is causing the problem.

Tony.

[lingo]

Database is only changed by Vensim and the php-based website, but maybe that causes the problem. VDO in your Inbox.

[Administrator]

Thanks, I have it.

How many users do you have? I'll set up an experiment here.

My guess is that one copy of Vensim is read/writing at the same time to/from the database which is causing problems.

[lingo]

At the moment, there's only one person who operates Vensim but the web-Interface reads and writes to the same database as Vensim does. Could that be it?

[Administrator]

I'm working on the assumption that it's reading/writing by Vensim at the same time that is causing problems. It's difficult to replicate though (but I am trying).

[Administrator]

ok, I've managed to replicate this by doing things too quickly (pressing the go button twice).

I'll see if I can produce a fix as it should be possible to wait until the database commands have finished before allowing a 2nd click.

Tony.

[lingo]

Great, thanks a lot!