Flow Networking in Grid Simulations - Grid Computing: Infrastructure, Service, and Applications - page 378

principles behind modeling network trafi c and transfers as l ows or
“l uid,” rather than discrete packets. The bandwidth-sharing model utilized
in our l ow-level networking model is then described. The new l ow-level
networking implementation for the GridSim toolkit is then introduced,
highlighting the additions made to GridSim in order to support the l ow-
based networking paradigm. We then describe the l ow tracking and man-
agement algorithms required to compute the durations of network l ows
and to update them when conditions change during a simulation run. The
performance improvements gained from the l ow-networking model over
existing packet-based implementation are highlighted. Finally, we con-
clude the chapter by taking a macroscopic view of the potential applica-
tions of l ow-level networking in large-scale grid simulations.

15.2 The GridSim Toolkit
GridSim is a grid simulation toolkit for resource modeling and applica-
tion scheduling for parallel and distributed computing [2]. The GridSim
toolkit has been used extensively by researchers across the globe [3] to
model and simulate data grids [4], failure detection [5], differentiated ser-
vice [6], auction protocols [7], advanced reservation of resources [8], and
computational economies in grid marketplaces.
GridSim has been designed as an extensible framework by following
a multi-layer architecture as shown in Figure 15.1. This allows new
components or layers to be added and integrated into GridSim easily.
GridSim implementations use SimJava [9], a general purpose discrete-
event simulation package for handling the interaction or events among
GridSim components.

Grid scenario User requirements Application configuration

User
code

Grid resource brokers or schedulers

Data
grid
Compu-
tational
grid
Core
elements

Dataset Replica catalogue Replica manager

Grid
information
service

Job
management

Reservation Resource allocation Workload traces

Tra c generator Network Resource (Clusters, SMPs)

SimJava simulation kernel

FIGURE 15.1 The GridSim architecture.