Interactive Parallel Simulations with the Jane Framework

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Interactive Parallel Simulations with the Jane
Framework

• Richard M. Fujimoto
• Kalyan S. Perumalla
• Presented by Ricardo Riveros

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Abstract
3 main reasons for the Jane framework

• Graphical user interfaces to support various
  phases of the modeling and simulation process
• User that do not have access to parallel
  computers must be able to access parallel
  computing resources elsewhere.
• These type of collaborative simulations are
  important because expert modelers and parallel
  simulation experts may be geographically
  dispersed.

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Introduction
Approaches one must take to implement an ideal
Interface

• Approach 1 The interface must be independent
  of the parallel simulation software.
• Why ?
• Parallel Simulation Kernels are complex, hence
  adding a GUI interface to any part of that
  software adds additional complexity.
• Language used for Kernel (I.e. C for GTW) may not
  be ideal for creating powerful GUIs.

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Introduction (cont..)

• Approach 2 Simulation models must be
  independent of particular views used to visualize
  and control the models
• Why ?
• Different user can develop different
  visualizations of same model.
• Approach 3 Nature of the large scale model
  development has to be considered.
• Why ?
• E.g Many systems used layered approach.
• Approach 4 It is important for interactive
  systems to provide factilities for geographically
  distributed users to collaborate during model
  developments and simulation execution.

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Overview

• Jane provides default controls and displays
• Jane provides robust and extensible mechanism for
  users to provide their own model-specific views
• Based on the client-server architecture

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Jane intended Capabilites

• Remote Control of parallel simulations over the
  internet
• Default graphical views for runtime
  visualizations of modeling systems(TeD)
• Easy development of application-specific
  animations(such as TeD)
• Scripting for programmatic control of parallel
  simulations
• Pre- and post-simulations analysis of multiple
  simulation
• Capability to interface with larger design tools

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Client-Server Architecture for a simulation
seesion in Jane
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• Jane supports the use of simulation in a larger
  design problem
• (I.e. network design and optimization) in
  which simulation is
• just a subcomponent.
• Used for programmatic design of experiments,
  automatically
• running multiple sequential or concurrent
  simulations and for
• analysis of simulation results.
• In general, a client can connect to serveral
  servers at once, and
• a server can run many clients. Several clients
  may collaborate
• on one simulation

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Software

• Server (daemon process) written in C
• Client written in Java
• -Simulation display and control
• -TeD or RTI-kit display and
  control
• -Model-specific display and
  control
• A model instumentation API in C/C
• Simulation-control and model-specific
  visualization API in Java
• Communication between clients and servers is via
  the TCP protocol and communications between
  servers and simulations is via UNIX pipes.

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Implementation

• Instrumentation
• -the process of augmenting the
  otherwise pure model with
• additional statements to instruct the
  runtime system to
• display model-specific views.
• In TeD, instrumentation is supported naturally
  using the same event-sending primitives as used
  to define the TeD model behavior. Sent over an
  STDOUT channel
• Events captured by the runtime system and
  submitted to Jane client
• Using a simple API, the users can define their
  own classes that receive the instrumentation
  events and overide Jane client display views.
• Jane provides the user with default views,
  controls and other features common to most
  simulations and models.
• Categorized into debugging, progress and
  performance monitoring, visualization of model,
  etc..

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Synchronization

• Interface between the parallel simulation and
  interactive system must address synchronization
  issues like time advances and the exchange of
  instrumentation data.
• In Jane, clients are conservative so no rollbacks
  occur. Instrumentation events are sent to Jane
  clients using conservative I/O mechanisms of GTW.
• So event data from simulation is sent to Jane
  clients only when GVT reaches receive-timestamp
  of event.

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Security

• Jane server limits client sessions to 5
• Jane limits the maximum elapsed/CPU time utilized
  by any simulation run.
• Connections can be denied if they originate from
  unauthorized machines.

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THE END !!!!