[Mochi-devel] An overview of application usage scenarios

[Srinivasan Ramesh]

Hi team,

@Mattheiu: Thanks for the wiki tutorial for Mochi. I found it extremely 
useful for my understanding and tried out the hands-on tutorials.

I re-read the PDSW "Methodology for rapid development..." paper and 
installed HePNOS locally on my laptop. A few questions come to mind:

1. For each of the popular data-services mentioned in the paper 
(Framestore, HePNOS, SDSKV), what is the model of usage/topology? 
Specifically:
    a. Are these services part of a workflow? Meaning, a node allocation 
is managed, and the services are long-running for the duration of the 
workflow. Jobs within the workflow come and go, and use the service 
during their execution.
    b. Are these services part of the application itself? Meaning a 
"regular" MPI job where the service is built into each MPI process and 
loaded as a library local to the process.
    c. Is it possible that certain services are long-running on the 
system "forever" (reduces to (a) I guess?)

The methodology paper hints at the topology but doesn't really provide a 
concrete description. With regard to performance measurement,
I am fully aware that data-services can span the entire range of 
possibilities. However, I think it may not be a bad idea to start with 
specific scenarios in mind and then go from there onto more general 
cases once we have a grasp on the problem.

2. Can I get access to a high-energy physics code that actually uses the 
HepNOS service? Can I run this setup on my laptop?

3. @Phil: I remember you mentioning that you had a branch where you had 
developed a dapper-like request tracing infrastructure? Could you kindly
point me to this?

Regards,
-- 
Srinivasan Ramesh