An efficient algorithm for the bursting ofService-based applications in hybrid Clouds
Abstract
Enterprises
are more and more using hybrid cloud environments to deploy and run
applications. This consistsin providing and managing software and hardware resources
within the enterprise and getting additional resources providedexternally by
public clouds whenever this is needed. In this later case, deployment of new
applications consists in choosing aplacement of some components in the private
cloud and some others in the public cloud. To tackle this NP-hard problem, we
haveproposed in a previous work an approximate approach based on communication
and hosting costs induced by the deploymentof components in the public cloud.
In this paper, we go further and propose a new efficient algorithm adapted for
service-basedapplications modelled that can be not only described as
behavior-based but also as architecture-based compositions of services
Existing System
Scalability
of applicationsand platforms, platform heterogeneity andapplication division
across clouds can be difficultto manage.
In
a previous work, we have proposed an algorithmthat behaves in a polynomial time
and approximatesthe optimal bursting solution. The proposedalgorithm is
efficient when the SBA can be representedby a sparse graph of services. It is
mainly the casewhen the composition of services of the consideredSBA is
behavior-based.
When
we visited existing work on placement ofresources at different levels such as
Software as a Service (SaaS), Platform as a Service (PaaS), Infrastructure as a
Service (IaaS), wefound out that they are not suitable to the consideredproblem
of this paper. Indeed, they do not considercommunication between services or do
not considerhybrid situations
Proposed System
In
this paper, we are interested inapplication division across clouds and
particularly thedivision of service-based applications (SBAs for short)in
hybrid clouds.
When
deploying SBAs in a hybrid cloud, their division (bursting) in the public and
privateclouds consists in choosing components/services tobe deployed in the
public cloud and those to bekept in the private cloud.
Inthis
paper, we are mainly interested in communication
and hosting costs and we do not deal with security,privacy and other
related properties.
Our
proposedefficient algorithm for the bursting of SBAs in hybridclouds
Advantage:
Cloud
environment differs from traditional environmentson the fact that it
(1) is massively scalable,
(2) Can be encapsulated as an abstract
entity that delivers different levels of services to customers outside the
Cloud,
(3) Is driven by
economies of scale,
(4) Can be
dynamically configured (via virtualization or other approaches) and
(5) Can be
delivered on demand
Future Work:
In
our future work, we will consider additional parameters such as security and
privacy of hosting and communications costs as criteria for service bursting of
SBAs in hybrid clouds.
Algorithm:
Forward-Backward-Refinement
(FBR) algorithm
After
the presentation of the procedures Forward,Backward and Refinement and the
first algorithmcalled Forward - Backward, Algorithm 5 presentsour efficient
approach called Forward - Backward - Refinement algorithm (FBR algorithm for
short).It is based on three combinations of the proceduresForward, Backward and
Refinement. The first combinationcalls first the Forward procedure, and then
theBackward procedure and finally the Refinementprocedure (see Algorithm, lines
1-3). The secondcombination calls first the Forward procedure, and thenthe
Refinement procedure and finally the Backwardprocedure (see Algorithm, line 1
and lines 4-5). The third combination places all the application nodes inthe
public cloud then it calls the Backward procedureand finally calls the
Refinement procedure (see Algorithm5, lines 6-9). Finally, our algorithm
choosesthe cheapest solution of these above presented combinations(see
Algorithm, lines 10-12).
Modules:
1.
Hybrid Cloud
Cloud
environments can bepublic, private or hybrid. A public cloud (external cloud) is a cloud that
provides cloud resourcesand services to the public. A private cloud (internal cloud) is an enterprise owned
or leased cloud.In general, a hybrid cloud is a composition of twoor more
clouds of different models. Nevertheless, wedefine, in this paper, a hybrid
cloud as a compositionof one public cloud and one private cloud. Such acloud is
an environment in which an enterprise has itsown private cloud that provides
and manages someinternal resources and only uses external resourcesprovided by
the public cloud when needed.
.
2.
private/public clouds
In public or
private clouds but not for hybrid clouds.Indeed, in hybrid cloud communication
costs betweenservices depend on the placement of services wherepublic and
private communications should be differentiated.Indeed, the placement of
applications inpublic/private clouds is a matter of placement of avirtual
network (that represents an application) ona physical network that represents
the cloud nodesand links. The problem is then to minimize the communication(and
other non-functional properties) inthe placement. The communication is of the
sametype (in a cloud) while in our problem and contextthe communications are of
two types (hybrid communicationand public communication).
3.
Behavior-based compositions
A SBA composed
using a behavior-based specificationcan be described as a structured process
whichconsists of a set of process nodes and transitionsbetween them. A process
node can be service, Or-Join, Or-Split, And-Split or And-Join. And-Joins
andOr-Joins should have at least two ingoing transitionsand at least one
outgoing transition. And-Splits andOr-Splits should have at least one outgoing
transitionand at least two ingoing transitions. Non-initial andnon-final
services have one ingoing transition and oneoutgoing transition.
4.
Architecture-based compositions
A SBA composed
using an architecture-based compositioncan be described as a set of linked
components.A component provides one or more services. It mayconsume one or
several references, which are servicesprovided by other components. Connection
of onereference and one service is realized by a wire.
The example is a
composition of four services. TheStore service provides the interface of the
on-linestore. The Catalog service which the Store service canask for catalog
items provides the item prices. TheCurrency_Converter service does the currency
conversionfor the Catalog service. The Shopping_Cart serviceis used to include
items chosen from the Catalogservice.
5.
SBA and deployed SBA graphs
A SBA like the
one presented in Figure 1 as a graph. Services, Or-Join, Or-Split, And-Split
and And-Join nodes will be represented by graph nodes and connections/
transitions between services will be represented by edges. Nodes are identified
by an ID (a URI or a number) and characterized by an amount of units of hosting
resources. Edges are characterized by an amount of communications units which
refers to the amount of traffic that is transferred on the considered edge.
HARDWARE & SOFTWARE REQUIREMENTS: HARDWARE REQUIREMENTS:
- System : Pentium IV 2.4 GHz.
- Hard Disk : 40 GB.
- Floppy Drive : 1.44 Mb.
- Monitor : 15 VGA Color.
- Mouse : Logitech.
- Ram : 512 MB.
SOFTWARE REQUIREMENT
- S: Operating system : Windows XP Professional.
- Coding Language : ASP.NET MVC
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