Sharing Science Gateway Artefacts Through Repositories - Science Gateways for Distributed Computing Infrastructures - page 123

including upload, upgrade, and delete workflow operations and use workflows
including browse, search, and download workflow operations.
Repository users : There are three types of repository users: domain researchers,
workflow developers and repository system administrators. Workflow developers are
familiar with workflow systems and infrastructures where workflows are executed.
They can create workflows and can support researchers to run these workflows. To
achieve this, ne and publish workflows in the workflow repository.

Researchers can browse/search the workflow repository, select and download
workflows from the repository, and run these workflows on DCIs. The repository
system administrators manage the repository. They have the highest privileges
among the repository users.
Work fl ow data : The repository manages four data entities: abstract workflows (or
workflows), concrete workflows (or implementations), con

they de

gurations and workflow
engines. The abstract workflow describes the workflow behavior. It speci es the

workflow graph, including workflow nodes and edges, node inputs and outputs.
However, it does not actually specify any binaries or data needed to run the
workflow because any abstract workflow may have been implemented in different
workflow systems. Concrete workflows strictly follow the de

nitions of the abstract
workflow. They contain binaries/executables, and input data or references for input
data are de gurations contain data, parameters,

and files, for example, default or sample data or references to these data entities.
The workflow engine includes or references

ned by the con gurations. The con

files and any other data required to
execute a workflow engine on an infrastructure.
Repository domains : The repository has a private and public domain. In the
private domain developers can manage workflows having both read and write
access rights. They can specify, upload, modify and delete them. The content of this
domain is available only for registered users. In contrast, the public domain does
not require any registration. It allows browsing/searching workflows in the repos-
itory, and also downloading them.
Repository views : The SHIWA Workflow Repository offers two views:
researcher (or browse) and developer (or table) views. The researcher view
(Fig. 9.3 ) presents workflow data assuming a basic user-level understanding of
workflows. It enables users to c experi-

ments. In this view the repository displays the summary (domain, application,
owner, description, graph, etc.), the number and types of inputs and outputs, data
sets, and details of the existing concrete workflows. Users can search workflows,
either selecting a domain via the domain list or by specifying workflow names. The
developer view allows workflow developers to upload workflows manually, edit
workflow data, and delete workflows. This view displays the name, owner, status,
and description of the workflow, and also the group to which the workflow belongs
in a table format. After selecting a particular abstract workflow, further details such
as attributes and its implementations are also displayed.
Repository usage scenarios : Users can use the repository in three scenarios. In

find workflows they need to run scienti

the first scenario workflow developers can upload, upgrade, and delete workflows.

They can publish workflows either automatically or manually. In the rst case they