On-demand computing refers to a delivery model where computing resources are made available to users as needed. These resources can be maintained within a user's enterprise or provided by a cloud service provider, in which case it is referred to as cloud computing. Effective use of cloud computing requires properly provisioning resources to avoid over-provisioning, which wastes money, and under-provisioning, which hurts performance. Efficient resource provisioning in the cloud is challenging due to the variety of VM types, pricing models, demand and cost uncertainties, and the need to balance multiple objectives like cost and quality of service.

1. ON DEMAND PROVISIONING

2. DEFINE
On-demand computing is a delivery model in
which computing resources are made available
to the user as needed.
The resources may be maintained within the
user's enterprise, or made available by a cloud
service provider.
When the services are provided by a third-
party, the term cloud computing is often used
as a synonym for on-demand computing.

3. Effectively using of cloudcomputing
 Over-provisioning: purchased resources are not fully
utilized cost more thannecessary.
 Under-provisioning: purchased resources are not
sufficient to meet the actual demand hurts application
performance.

4. Efficient resource provisioning: challenge #1:
Various cloud providersoffering
multiple Virtual Machine (VM)types
Virtualization technologies help providers
pack their hardware resources into different
type of VirtualMachines
The end-users encounter a complicated
decision making problem for choosing the
right mix ofVMs!
6/1
6

5. Efficient resource provisioning: challenge
#2 : Multiple pricingmodels
7/1
6

6. Efficient resource provisioning: challenge #3
: Dealwith COSTandDEMAND
uncertainty
 The application’s demand is not
known in advance
e.g. online video streaming
applications, like YouTube
Channel
 The cost of instances in
both on- demand and spot
isvarying!
8/1
6

7. Efficient resource provisioning: challenge #4:
Multi-objectiveproblem
9/1
6
 Costisnot the only objective forthis problem
 The trade-off among cost and QoS must also be
handled
 Forexampleresponsetime is very critical in latency
sensitive applications , online gaming services,as the users
tend to beveryimpatient

9. REFERENCE
• Mastering Cloud computing foundation and
application programming rajkumar
buyya,christian vecchiola,s.Tamarai selvi