CROWN: A Service Grid Middleware for e-Science - Grid Computing: Infrastructure, Service, and Applications - page 10

show current runtime information using maps and charts. We can also
adjust the parameters of the tool to change the monitor behavior of the
target service grid systems.
Based on these middleware modules, the CROWN middleware is
designed as shown in Figure 1.3. There are three layers in a service grid.
CROWN middleware connects resources in a resource layer. The appli-
cation grid uses Web portals or other customized client interfaces to
submit jobs and solve the user's problem. First, the node server should
b e de ploye d o n e ac h r e s ou r c e t o s up p o r t s e r v ic e de ploy m e nt a nd r u nt i m e
management; second, all the grid resources should be divided into
multiple domains, at least one RLDS instance should be deployed into
each domain, and all the RLDS instances have to be coni gured into a
predei ned heretical architecture to form a distributed information
systems; third, the CROWN scheduler will be deployed into the grid, to
get the job request from the user and to i nd the proper services for each
job; i nally, monitoring and developing tools simplify the building of a
service grid and its applications.

1.2.4 Main Features

CROWN adopts an OGSA/WSRF-compatible architecture, with the
following features.

App App App App App

Application layer

Rich client framework Portals

Scheduler

Set event

Query info

CROWN

JDT PDE

RLDS

RLDS RLDS Designer

Eclipse

Resource

RLDS RLDS

RLDS

Generate

Register to ... Register to ...

WFS
Workflow engine S S S S

Node server Sec Node server Sec Node server Sec

Middleware layer

Install/config Install/config Install/config

Resource layer

PC Cluster front end Device host

Resources Cluster nodes

Devices

FIGURE 1.3 Service grid design principle based on CROWN middleware.