Thread: Creating a Simulator

Hi All,

This is more in java Theory for java programming, my Question regards to a simulator that i have build now I have to create some way to operate it independently. I already have user inputs, database calls for necessary data (4 different db's). I need to continue with rmi, and messaging UDP protocols. However they(management) threw a damper in my thoughts progress and current running STIM sim (3rd time I reprogrammed it from add on after the fact). They want it to run independent with other simulators (that get users or not) on a timed messaging system. I hope your following me still.



Pen to paper.
create a list of objects that can contain up to 12 hours of data sets. aprox. 3600-20000 objects per hour
I am thinking memory over flow...
hold multiple list to re-use
gui interface to create this list. (my main problem is starting here, or lack of thought)

I can create a new db(database) to hold all the list and not really much of a problem.

I can use the database to help create the 12 hour list. however, where does the heap overflow come in to play. (out of memory).

the list needs to be editable throughout. (this is my kicker, how without overflow memory)

any thoughts on the matter... thanks in advance.

current thoughts
use the database to hold the list and then write to the db every 100 data sets that are created, this way i don't hold a huge list and I can kick off a thread to run the write to db.

editable per 100, call to the db to get new list on review.

the question is more on the out of memory, while creating this list of data. If you base it on my system, its not true it should be on any system machine (weakest link).

Originally Posted by KevinWorkman

First off, are you sure you have to have all of those Objects in memory? Can't you load a subset at a time?

I need 15 minutes of data at any given time, once it is running. Users will determine while in creation mode. I could limit it but not sure how.

Originally Posted by KevinWorkman

Can you write to file or to a database at all?

yes I have made a Database Manager to manage 4 db's that I use, plus I can create another just for this.
not so sure about a file, never thought about it. Write to a file and hold the files in a directory, read from a file. I would think this is similar to the Logger in java?

Originally Posted by KevinWorkman

Does increasing the memory available to the JVM help at all?

I will read up more on this.


Thanks Kevin, Let me do some reading on the JVM, and write a test program for IO read/write.