I'm getting the following notice:

"Your app_info.xml file doesn't have a useable version of MilkyWay@Home N-Body Simulation"

Can someone please provide me with the proper lines to add?

Nick

I have one which works correctly (which is more than can be said for the implementation on the server here), but following an exchange of private messages with one of the researchers here last week, I'd prefer to wait until they get the server sorted out before adding to the general confusion. If you think you've got a convincing case for adding yourself to the pool of testers, send me a PM.

No, I don't have a convincing case, but it worked last night.

Is there a FAQ somewhere which explains these things?

Well, app_info.xml is designed for people who write/compile their own applications, so you're very much into "roll your own" territory.

There's a formal specification for the elements you need at http://boinc.berkeley.edu/wiki/Anonymous_platform

You need to know the name by which the server knows the application, and the names of the individual files which comprise it - one exe and two dlls. The easiest way to get those (and the files themselves) is to run the application once on a machine of comparable specification without app_info.xml - see what's downloaded, and how it's written up in client_state.xml

And finally, you need to write the 'glue' which holds it all together, in the <app_version> section of app_info.xml. This is where you're really on your own, because the N-Body application is designed to work with an MT (multi-threaded) plan class, and that's the bit which this project haven't cottoned on to yet (so you won't find it in client_state.xml).

Some months ago, I did post an example of the sort of thing you'll be looking for (in message 56259), copied from another project. Do note that all the file names, version numbers etc. in that thread will have to be updated to the current 1.08 to meet the needs of the current test tasks.

Richard, I'm not rolling my own. I wouldn't even know how. I'm just running Milkyway@home and it's giving me that notice message.

You say I need to be running version 1.08. Version 1.08 of what and how do I get that version?

I would think that an FAQ would go a long way to help people here.

Well, you can only be getting the message "Your app_info.xml file doesn't have..." if you already have the file - either you rolled your own, or somebody rolled it for you and should have explained what you were getting in to.

There is no obligation on you to run the N-Body application. If you're interested, feel free to climb aboard: if you prefer not to bother, just ignore the message and carry on running the application(s) that you specified with your existing app_info.xml file.

How does one get the N-Body application?

How does one get the N-Body application?

It downloads automatically and you already have some in your cache. They are cpu units, not gpu units.

Thanks to all who tried to help. Maybe someday someone can post the app_info.xml to allow N-Body to work when also using a GPU. It's too confusing for me to figure out.

Nick

Thanks to all who tried to help. Maybe someday someone can post the app_info.xml to allow N-Body to work when also using a GPU. It's too confusing for me to figure out.

Nick

Here is one from Poem:
<app_config>
<app>
<name>poemcl</name>
<gpu_versions>
<gpu_usage>0.25</gpu_usage>
<cpu_usage>1.0</cpu_usage>
</gpu_versions>
</app>
</app_config>

ADD before the last line above to run cpu units too!
<app>
<name>poempp</name>
<max_concurrent>8</max_concurrent>
</app>

Change the lines to MilkyWay file stuff and get the right n-body line for the cpu units and you will be good to go. It is set to run 4 gpu units at once and 8 cpu units at once, edit those as to your own needs.

App_info.xml files are becoming a thing of the past in Boinc, they require specific file names and as the projects upgrade to newer versions they become obsolete so require constant updating. App_config.xml files use generic names so should work pretty much forever. They are saved in the same place so it becomes a direct replacement. To use an app_config.xml file you DO need to be running Boinc version 7.0.40 or higher though.

Nick is already running the N-Body application successfully on his host 482724, but he's getting the message "Using OpenMP 1 max threads on a system with 8 processors". He can fine-tune some aspects of the application via app_config.xml, but the particular one he needs to make N-Body work properly:

<cmdline>--nthreads 8</cmdline>

isn't available that way. [I did ask David Anderson to add it, but unfortunately he refused - he didn't believe my assertions, from testing here, at AQUA, and at BURP, that it would be useful and possible]

Nick's other machine, host 480295, already has an app_info.xml file (you can tell from the words 'Anonymous platform' in the right-hand column), so he will be unable to run N-Body on that machine unless he either modifies the existing file (by adding the extra elements for N-Body), or removes it entirely.

I said in my first contribution to this thread that I have a tried and tested app_info.xml file prepared, but that I'm unwilling to post it in public while the project's whole position on N-Body seems - I'm sorry to say - so chaotic. If a project developer or administrator wants to come on board and ask for a leg-up, and says that publishing my app_info.xml file would be a useful contribution towards the development of the project, I'd be delighted to help.