Supporting Simulations on the Cloud using Workflows & Virtual
Supporting Simulations on the
Cloud using Workflows & Virtual
Machines
Gary Polhill
Macaulay Land Use Research Institute
Edoardo Pignotti
Computing Science, University of Aberdeen
Overview
The SwarmCloud project
Social simulation & the Cloud
A virtualised simulation environment
Facilitating access with workflows
Workflows on the Grid/Cloud
Conclusions
The SwarmCloud Project
Goal: to enable the FEARLUS simulation model to be run on National Grid Service infrastructure
What’s so hard about that?
FEARLUS is written in Obj-C for the Swarm libraries— notoriously difficult to install
Numbers of pre-requisite libraries
Can be sensitive to particular versions of libraries and Unix commands
Typical Grid use-cases involve running a script
e.g. Model calibration
Other software environments for social simulation exhibit the same issues (barrier to adoption)
How can social simulation benefit from the
Cloud?
Enabling large-scale distributed simulations
e.g. Fraser et al. (2009 Science), Birkin et al. (2009
SSCoRe), Tang & Bennett (2009 US-IALE)
More challenging because of managing agent interactions across node boundaries
Enabling multiple runs of smaller-scale models for:
Exploring parameter space
Experimenting with algorithmic variants
Trying different scenarios
Increasing sensitivity (more runs with different seeds)
‘Embarrassingly Parallel’
Software dependencies
Swarm software dependencies shown
‘worst-case’
Java not immune
Pre-requisite jars can be required (with version sensitivity)
JRE version sensitivity
Obvious problems for programs/libraries using
JNI
The solution: A virtualised simulation environment: simulationBox
We used a lightweight version of Centos 5.2 to create a virtualised simulation environment containing
Swarm, MASON and RePast
Compressed image ~1GB in size http://www.simulationbox.net/
The simulation environment was created using Sun’s
VirtualBox virtualisation software
Binaries available under a Personal Use and Evaluation
Licence http://www.virtualbox.org/
Virtualisation on the Cloud
The virtualisation approach relies on the Cloud host making virtualisation facilities available
The National Grid Service is testing a virtualisation service based on Xen/EUCALYPTUS at Oxford
Xen: Open Source standard for virtualisation
http://www.xen.org/
EUCALYPTUS (Elastic Utility Computing Architecture
Linking Your Programs To Useful Systems): Open-source system for implementing clouds
Provides an authentication layer, and manages virtual machines using ec2 tools http://www.eucalyptus.com/
Facilitating access: Workflows
Virtualisation provides a replicable environment for compiling and running a social simulation
‘User interface’ not very friendly
Access via ssh
Kepler workflow tool used to design simulation experiments
Upper Deeside Case-study
Workflows on the CLOUD
We have developed a number of Kepler workflow activities based on the ec2 tools:
Authenticate a user on the Cloud
Upload simulationBox to a node manager
Create instances of simulationBox on the Cloud
Query for available simulationBox instances on the Cloud
Compile a new simulation model on a simulationBox instance
Run the model multiple time across different VM instances
Collect and analyse results, saving them on the local machine
Our Kepler libraries can be downloaded from www.simulationbox.net
Compile a simulation model
Run an experiment
Conclusions
For Cloud infrastructure supplying virtualisation services it is possible to run social simulations with specific computing requirements
Access is facilitated through workflows that can be shared amongst people
Website: www.simulationbox.net
ESSA 2009 Tutorial on simulationBox
Large Scale Social Simulation
Special Interest Group (ESSA)
SwarmFest 2010
