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48 2012 Issue 01 | dell.com/powersolutions

Cloud computing

Reprinted from Dell Power Solutions, 2012 Issue 1. Copyright © 2012 Dell Inc. All rights reserved. Reprinted from Dell Power Solutions, 2012 Issue 1. Copyright © 2012 Dell Inc. All rights reserved.

Cloud-based operations and service

delivery can support a wide range of

business and commerce applications

including invoice and payment

systems; on-demand ordering systems; data

storage, backup, and control systems; and many

other possibilities. Organizations of many stripes are

taking steps to transition to cloud computing–based

models to provide business and organizational

units with a highly responsive infrastructure while

helping to reduce IT operational costs with lean,

agile data centers. This approach offers innovative

prospects for transitioning operations to on-

premises, private cloud platforms or for extending

services delivery to off-premises, third-party public

cloud hosting facilities.

Many organizations moving to cloud-

based deployments need to be up and running

quickly, and they are looking to utilize existing

infrastructure to help reduce costs and maximize

their technology investment. A key consideration

in these transitions is the capability to enable

authorized end users and IT administrators to

create and deploy resources and workloads rapidly

and automatically. Automating the management of

workloads throughout their life cycles is one way

to free IT resources to focus on strategic initiatives.

Dell VIS Creator, a key component of the

Dell Virtual Integrated System (VIS) portfolio,

provides an automated workload deployment

and management platform that unifies the

management ecosystem for private and public

cloud environments. The platform provides end-

to-end governance and self-service capabilities

for authorized users in a policy-driven approach

designed to control virtual machine sprawl and

automate the process of deploying, reducing,

reusing, and recycling compute resources

in shared virtual environments. Life-cycle

management policies control how long virtual

machines can exist, and process automation

orchestrates the decommissioning and reuse

upon lease expiration of those virtual machines.

Moreover, reclamation workflows can be

customized to meet the requirements of each

business or organizational unit.

In addition to providing the necessary

capabilities to deliver a private cloud platform, VIS

Creator offers an open and extensible design that

enables IT organizations to go beyond out-of-

the-box functionality and enhance their existing

data center ecosystems. VIS Creator architecture

modules, technology, and utilities are designed

to deliver the speed and simplicity necessary to

maximize the extensibility of VIS private cloud

capabilities and integrate them with external

platforms. VIS Creator extensibility features also

help both administrators and developers create

their own custom workflows.

Implementing a model-driven architecture

The Dell VIS Creator extensibility architecture

is based on a model-driven approach that

IT organizations can deploy to design and

Agile, responsive infrastructure for IT resources can be a huge

motivator for transitioning to cloud computing. The Dell™ VIS Creator

platform enables enterprises to transform existing IT infrastructure

into an on-demand cloud environment in just days.

By Kailas Jawadekar

Extending private cloud capabilities into the data center ecosystem

dell.com/powersolutions | 2012 Issue 01 49

Cloud computing


implement capabilities for integrations into

third-party or external systems. At its core,

VIS Creator implements a model manager

that enables administrators to define, modify,

and update any part of a model; inject new

models into the model manager; or update

legacy models with simple configuration tasks.

Each VIS Creator data model is made

up of the following five model elements

(see Figure 1): data models, workflows

and activities, event triggers, distributed

execution, and security and role-based

access control (RBAC). Together, these

elements present a unified view of VIS

Creator data models with integrated security,

helping ensure end users have access only to

the data and tasks they have been assigned.

Data models

A data model is a logical representation

of related data. VIS Creator exposes data

models through a Representational State

Transfer (REST) architecture through an

application programming interface (API).

Data models can be defined by connecting

to an existing external database and

selecting either a subset of the data or the

entire database, or by creating new data

from scratch and specifying new entities,

attributes, and relationships. (For more

information on REST, see the sidebar,

“Web-like interfaces for data access.”)

Figure 1. Model elements in a VIS Creator data modelModel

elementsWorkflowsand activities

Data models

Security and RBAC

Event triggers Distributed execution

Web-like interfaces for data accessRepresentational State Transfer (REST)

is an architecture style that leverages

a stateless access model in which a

Web service can be viewed as a

resource and identified by its URL.

REST is experiencing rapid adoption

in the software industry because it

provides a simple and consistent

HTTP- and URL-based approach to

access and manipulate Web-based

resources. It also can be described as

a style of mapping information and

standardizing the methods to interact

with that information.

URLs function in the REST

architecture similarly to the way they

function for Web pages, by providing

a defined method to access data. A

specific URL provides access to

a resource that follows a defined

architecture, or Web page. For example,

Yahoo.com and Facebook.com

return very different information,

but they are built on the same

expectation of resources in response

to HTTP requests.

Connecting to a REST URL

presents a set of defined resources,

and in the case of VIS Creator,

authorized end users see a

dynamically generated set of

resources that are secure for

their credentials. The VIS Creator

self-service portal, or a custom

application, can connect to the VIS

Creator manager and repository

through the REST interface—

enabling secure access to VIS

Creator data models using access

control rules and filters.


Cloud computing


Workflows and activities

Business logic can easily be implemented

by creating custom workflows that leverage

a library of existing activities. These

activities include utilities for data and model

management and integrations with external

systems. Administrators can associate a

different custom task for each read, write,

and delete operation on any data element in

the model. For example, administrators can

execute a custom logging workflow every

time a new request is submitted, or execute a

custom approval workflow every time a virtual

machine delete request has been received.

A data event is created when an

operation occurs against a data element

in a model. This data event can trigger

the start of a workflow or some other

process. The following examples

describe workflows:

• When a virtual machine changes state,

an administrator can execute an external

workflow to perform any custom task

such as adding a custom log entry.

• A dynamic menu can be associated with

a virtual machine to execute a workflow

by right-clicking the virtual machine.

• Authorized end users can interact with

a VIS Creator server from an external

application or Web page.

• A Microsoft® .NET framework programming

language plug-in, encapsulated as a

dynamic link library (DLL), can be executed

when VIS Creator triggers an action.

Event triggers

The VIS Creator automation engine manages

different types of events and associates them

with the execution of one or more workflows

(see Figure 2). Workflows can be executed

when certain events are triggered. The

following examples describe event triggers:

• Data event: Creating, updating, or

deleting data in the data model triggers a

data event.

• Schedule event: Specifying an absolute

time, relative time, or recurrent interval

triggers a schedule event.

• User event: Associating a dynamic menu

with a virtual machine triggers a user event.

• External event: Initiating a provisioning

or configuration change indicated by an

external application during a specified

change window triggers an external event.

Distributed execution

Any standard or custom workflow managed

by the model manager is executed in a

distributed execution environment. The VIS

Creator runtime environment consists of

one or more Distributed Execution Manager

(DEM) engines. A DEM can execute any

workflow managed by the model manager,

and one or more DEMs can be added

as needed for scalability, availability, and

distribution (see Figure 3).

A DEM pings the VIS Creator server to

see whether there are workflows waiting

to be executed. If a workflow is pending,

the DEM downloads the workflow from the

model manager and executes it.

A DEM can be assigned skills and

location restrictions. These restrictions limit

the DEM to executing only workflows of

Figure 2. Event triggers associated with workflow execution

Events

Dataevent

Scheduleevent

Userevent

Externalapplication

Change lease

Power o� virtual machine

Destroy

RE

ST

Business logic

Figure 3. DEMs for executing workloads managed by the model manager

Developer

Productionadministratorin New York

Productionadministrator

in London

VIS Creator

RE

ST

Secu

rity

Model manager

Dat

a ac

cess

laye

r

Database

DEM DEM DEM

Connectionbrokers

Applicationdeployment

Imagedeployment

Hypervisors

Physicalservers

dell.com/powersolutions | 2012 Issue 01 51

Cloud computing


the appropriate type—as referenced by the

skill value—and in the appropriate location.

For example, restrictions can be assigned to

a DEM to run a workflow only in a specific

location or require an environment that

supports a specific API the workflow is using.

Security and role-based access control

A key VIS Creator differentiation is its

governance model and its simplicity in

granting rights to end users and groups

based on their role. The three elements

that define a security context are role, task,

and permission.

A role represents the access required

for an end user to perform the tasks

associated with the role. A task represents

the access required for an end user to

perform the specific actions associated

with the task. And the permission element

grants access at a granular level to specific

model entity types. Any given task may be

associated with one or more permissions,

and any given role may be associated with

one or more tasks.

Security and RBAC helps ensure that

even if an end user has more than one role,

the access granted is kept in the context

of its related resource, instead of a blanket

access assignment that could potentially

allow an unintentional grant of access to

other resources.

Designing custom workflows

VIS Creator gives IT organizations the

opportunity to create workflows that

automate many of the tasks associated

with services delivery. Although standard

workflows are designed to be up and

running quickly, administrators can

customize workflows that require tasks such

as integrating processes across multiple

systems or accelerating private cloud or

virtual desktop infrastructure deployments.

The Creator Workflow Designer feature

enables IT organizations to create custom

workflows intended for use with the VIS

Creator model manager.

The Creator Workflow Designer feature

can be used to customize workflows

created using an extensibility framework

based on the Microsoft .NET framework

and Windows® Workflow Foundation. This

approach enables administrators to design

and manage custom workflows. Workflows

determine the steps and sequence of

each operation within VIS Creator. Each

provisioning method uses both the

master workflow and a provisioning-

specific workflow that together determine

which information and commands are

sent to the virtualization platform, cloud

service, physical server, or software

management system involved, and in

what sequence (see Figure 4).

Administrators can add two types

of custom workflows to VIS Creator:

custom state transition and custom

machine menu. Custom state transition

workflows are invoked before the VIS

Creator master workflow enters one of

the following six states: BuildingMachine,

MachineProvisioned, MachineRegistered,

MachineExpired, UnprovisionMachine,

and MachineDisposing. For example,

administrators can create a custom workflow

to add information such as machine owner

and approvers to an external database

before the master workflow enters the

MachineProvisioned state.

Custom machine menu workflows are

invoked by selecting a custom entry in the

dynamic menu for virtual, cloud, or physical

machines in the VIS Creator console.

A machine must be provisioned using a

custom property for the menu entry to

appear. Custom machine menu entries are

available for selection on the Security tab of

the service blueprints page. IT organizations

can also create a custom workflow to add

a snapshot entry that provides the capability

to take a snapshot of a virtual machine.

After clicking this option, administrators can

specify appropriate tasks in the workflow to

take a snapshot of a virtual machine.

Dell provides a library of activities to

help simplify the workload customization

Master workflow

DecommissionManageProvisionApproveRequest

Custom property bag

Virtual.Machine.CPU.Count = 1

Virtual.Machine.Memory.Size = 512

Virtual.Machine.Lease.Days = 14

Virtual.Machine.Storage.Name = san-4.train_virtual_machines

VMware.VirtualCenter.OperatingSystem = winXPProGuest

My.New.Custom.Property = My New Custom Property Value

PreActivityExecution

Power on

Power o�

Custom machine menu

PostActivityExecution

Figure 4. Master workflow for a VIS Creator operation

Dive deeper

As enterprises transition to converged infrastructures, administrator tasks will evolve toward setting up automation for cost-effective, agile IT environments. View this video to learn more about how the journey to the cloud provides opportunities for self-service provisioning, capacity monitoring, and efficient management of data in a fluid architecture.

dell.to/converged-infrastructure

http://dell.to/converged-infrastructure


Cloud computing


Author

Kailas Jawadekar is a technical marketing

manager on the Virtualization Solutions Marketing

team at Dell.

Learn more

Dell VIS Creator:

dell.com/viscreator

process. Part of this process may involve

adding activities to the workflow. The

activity library included with the Creator

Workflow Designer tool provides a base set

of activities for building custom workflows.

The following examples describe commonly

used activities:

• ExecutePowerShellScript: For a

provisioned virtual machine, this activity

allows administrators to invoke a

Microsoft Windows PowerShell™ script

stored in the model manager that uses

properties of the virtual machine.

• InvokePowerShell: This activity invokes

a PowerShell command or script along

with provided arguments and input.

• Get/Set-MachineProperty: For a

given custom property name, this

activity returns or sets the value of a

custom property.

Activities such as these can be used to

write simple or complex workflows and

create custom workflows.

Integrating functionality

into external hosts

Extensibility features enable administrators to

extend Dell VIS Creator beyond out-of-the-

box functionality to allow rapid integration

into external and third-party, cloud-based

hosting environments. However, some

extensible integrations can be complex

to implement. Dell Services consultants

offer in-depth experience with VIS Creator

customizations to help extend service delivery

to implement customized integration into

external or third-party, cloud-based hosting

platforms. Several use case scenarios provide

examples of Dell Services implementations.

Self-service provisioning

Organizations frequently request the

capability to implement the automated,

self-service provisioning functionality of

VIS Creator into their current portal. For

example, integrating VIS Creator into an

existing portal helps mitigate the need for

additional training to use another interface.

VIS Creator RESTful APIs can be used in

this case to obtain data and then project

that data onto the organization’s portal. VIS

Creator extensibility also enables simple

report integration and the ability to request

virtual or physical machines efficiently.

Snapshot management

A virtual machine snapshot is a point-in-time

image of a virtual machine based on a pointer-

based copy of the original virtual machine

image. Snapshots are relatively easy to create,

they initially consume very little additional

storage, and they can be a very powerful tool

for backup and recovery operations. However,

many organizations do not use snapshots

to their full potential; without management

controls in place, unchecked snapshots tend

to accumulate and consume unanticipated

storage capacity. Snapshot accumulation

can leave organizations exposed because

authorized end users can roll back to

obsolete versions that may no longer be

compliant with current system specifications.

To help organizations capitalize on

snapshot capability, VIS Creator can

be extended to implement a snapshot

command as part of a dynamic menu. This

capability allows administrators to take

snapshots of their virtual machines through

this menu. Predefined policies stored in

the virtual machine’s blueprint control the

maximum number of snapshots allowed

as well as the ability to roll forward to and

backward from specific snapshots.

External ticketing system integration

Because various extensibility points are

available for VIS Creator, interfacing with

a ticketing tool such as BMC® Remedy®

Change Management software during

the request, provision, post-provision, or

even the destroy operation can be easily

accomplished. VIS Creator capabilities can

also be extended for creating tickets, updating

existing tickets, and other operations.

Leveraging rapid automation and

response for cloud environments

A key consideration when transitioning

to cloud computing environments is the

ability to use existing IT infrastructure and

resources—enabling organizations to rapidly

implement operations and services delivery

on either on-premises, private cloud

platforms or on external or third-party,

public cloud platforms. Dell VIS Creator

empowers administrators by providing

an open, flexible platform for creating,

deploying, and managing workloads.

VIS Creator enables IT organizations

to efficiently manage the end-to-end

life cycles of workloads. This approach

implements automated workload

governance and self-service provisioning

both of physical and virtual machines in

private cloud environments, and of virtual

machines in public cloud environments.

In addition, VIS Creator can be extended

to offer a self-service front end and

workflow engine for a data center

ecosystem with a single console for

efficient, agile management.

VIS Creator also leverages RESTful APIs

that enable authorized end users to access

dynamically generated resources that are

secured for their credentials and integrate

other self-service portals and automation

engines into the VIS Creator model manager

and repository. The Creator Workflow

Designer feature customizes workflows

using a library of activities, and extensibility

features can be used to extend VIS Creator

capabilities for rapid integration into public

cloud environments.

http://dell.com/viscreator