AN OCCI COMPLIANT INTERFACE FOR IAAS PROVISIONING
AND MONITORING
Salvatore Venticinque, Alba Amato and Beniamino Di Martino
Dep. of Information Engineering, Second University of Naples, Aversa, Italy
Keywords:
Cloud Agency, Negotiation, Monitoring.
Abstract:
In the Cloud scenario provisioning and monitoring play an important role giving the possibility to maintain
always the best resources configuration that satisfies the application requirements. Dynamic Cloud provision-
ing and monitoring allow for the possibility of getting resources in a way that is suited especially well to
the business model of IT companies, which can adapt their costs to the current needs continuously and eas-
ily. A solution for Cloud resource provisioning and monitoring should also be vendor independent, platform
neutral to choose the best proposal among a collection of business offers the widest it is possible. One of
the first proposals of standard in Cloud is represented by OCCI (Open Cloud Computing Interface) that is a
protocol and API for all kinds of management tasks. In this paper we describe a proposal of extension of
OCCI to support provisioning, monitoring and reconfiguration. Furthermore we introduce Cloud Agency, a
software platform that complements the common IAAS management facilities with a set of advanced services
for dynamic provisioning and monitoring of Cloud resources.
1 INTRODUCTION
Cloud computing represents an opportunity for IT
users to reduce costs and increase efficiency providing
an alternative way of using IT services. For big com-
panies, which own large physical infrastructures, it al-
lows for high utilization. On the other hand it gives to
small and medium enterprises the possibility of us-
ing services and technologies that were prerogative of
large ones, by paying only for the resources needed
and avoiding upfront investment. In fact both costs
estimation and provisioning can be delayed . But if
there are many advantages for the users, there are also
problems that, if not resolved, can vanish the benefits.
A well known problem is the vendor lock-in, that is
the risk for the user of being locked to a provider find-
ing very difficult to migrate its application to other so-
lutions when is not satisfied about the service level or
about its cost. This is due to the absence of standards
for Cloud solutions that ensure portability among dif-
ferent vendors’ technologies. To overcome this prob-
lems it is fundamental to have a general purpose set of
specifications and facilities for cloud that are vendor
independent, platform neutral and can be extended to
solve a variety of problems in Cloud computing. One
of the first proposal of standard in Cloud is represent-
ed by OCCI
1
(Open Cloud Computing Interface) that
is a protocol and API for all kinds of management
tasks. This solutions is aimed at the fulfillment of
three requirements: integration, portability and inter-
operability for common tasks including deployment,
autonomic scaling and monitoring still offering a high
degree of extensibility. In this paper we describe
a proposal of extension of OCCI to support provi-
sioning, monitoring and reconfiguration. Furthermore
we introduce Cloud Agency, a software platform that
complements the common IAAS management facili-
ties with a set of advanced services for dynamic pro-
visioning and monitoring of Cloud resources.
2 RELATED WORK
According to (Buyya et al., 2009) a market-oriented
resource management is needed in order to regulate
the supply and demand of Cloud resources. The cur-
rent Cloud computing technologies offer a limited
support for dynamic negotiation of SLAs between
participants. A Cloud multi-agent management archi-
tecture is proposed in (Cao et al., 2009; You et al.,
2009). Preliminary investigations by the authors on
1
http://occi-wg.org/
163
Venticinque S., Amato A. and Di Martino B..
AN OCCI COMPLIANT INTERFACE FOR IAAS PROVISIONING AND MONITORING.
DOI: 10.5220/0003932101630166
In Proceedings of the 2nd International Conference on Cloud Computing and Services Science (CLOSER-2012), pages 163-166
ISBN: 978-989-8565-05-1
Copyright
c
2012 SCITEPRESS (Science and Technology Publications, Lda.)
related topics have been presented in (Aversa et al.,
2010). SLA@SOI is the main project that aims (to-
gether with other relevant goals) at offering an open
source based SLA management framework. It will
provide benefits of predictability, transparency and
automation in an arbitrary service-oriented infrastruc-
ture, being compliant with the OCCI standard. In or-
der to check or guarantee an agreed SLA at IAAS
level, it is necessary to monitor performance and qual-
ity indexes, to enforce the agreed service terms. Tra-
ditional monitoring technologies for single machines
or Clusters are restricted to locality and homogeneity
of monitored objects and, therefore, cannot be applied
in the Cloud in an appropriate manner (Emeakaroha
et al., 2011). In (Andrew et al., 2011) an extension
of OCCI for IAAS provisioning is described, but it
doesn’t add new functionalities.
3 OCCI EXTENDED
Obtaining a common interface is the focus of the
OCCI group that defined a model for Cloud manage-
ment at IAAS. OCCI defines entities, API and pro-
tocol. The specification of Cloud API is a Resource
Oriented Architecture (ROA) that uses REpresenta-
tional State Transfer (REST)protocol. The OCCI core
meta-model (Metsch et al., 2011) is shown in the
left part of the Figure 1. It provides means of han-
dling abstract Cloud resources. Any resource exposed
through OCCI is a Resource or a sub-type thereof.
A resource can be e.g. a virtual machine, a job in
a job submission system, a user, etc. The Resource
type is complemented by the Link type which asso-
ciates one Resource instance with another. Entity is
an abstract type, which both Resource and Link in-
herit. Each sub-type of Entity is identified by a unique
Kind instance. The Kind type is the core of the type
classification system built into the OCCI Core Model.
Kind is a specialization of Category and introduces
additional resource capabilities in terms of Actions.
An Action represents an invocable operation appli-
cable to a resource instance. The last type defined
by the OCCI Core Model is the Mixin type. An in-
stance of Mixin can be associated with a resource
instance, i.e. a sub-type of Entity, to ”mixin” ad-
ditional resource capabilities at run-time. Resources
can be managed using a set of operations create, re-
trieve, update and delete. Currently three types of re-
sources are considered: storage, network and com-
pute resources. It is also possible to manage state
(start, stop, restart) and create new resources using
actions. In order to extend the OCCI model by auto-
nomic and dynamic services, it is necessary that new
Figure 1: OCCI Extended model.
functionalities can be deployed in user’s Cloud. To
be compliant with the standard it is necessary to ex-
tend the core model using inheritance of MIXIN to
provide IAAS resources with monitoring and provi-
sioning capabilities, and ENTITY, to represent those
new concepts, which are introduced by the services
we are going to describe. In Figure 1 the new entities
and mixin, an their relationship with the OCCI core
model are shown. Among the entities, a Call for Pro-
posal (CFP) describes the list of resources which are
necessary to run a Cloud application. A Cloud cus-
tomer defines the values of those attributes of OCCI
Compute, Storage and Links which are significant for
his application requirements. A CFP will include also
the negotiation rules to select the best offer among
the ones proposed by providers. A Proposal is a can-
didate for a Service Level Agreement(SLA). It in-
cludes an instance for each resource in the CFP with
all the attribute specified, including other informa-
tion such as the cost and service levels. It can be
accepted or refused by the customer. An SLA is an
accepted proposal, it is agreed by the customer with
one provider. Among the new mixin, a Vendor is com-
mitted to get an offer for resource provisioning, to ac-
cept or refuse that offer, to get information about a
resource or to perform an action on it against a spe-
cific Cloud provider or technology. A Broker is an
intermediary that provides information and assists in
finding the right cloud-based solution. It receives a
CFP, ask to vendors for available offers, brokers the
proposal that best serves the user and allows to close
the transaction. The Meter is a mixin that monitors
some parameters chosen by user and gives the mea-
sure of performance indexes for those parameters. It
can be deployed into the Cloud, within a Virtual Ma-
chines, to dynamically complement the user’s Cloud
resource with this new capability. We need to run
Meter instances on any resource to perform locally
specialized algorithm to take measures. An Archiver
collects measures from Meters and stores them in a
CLOSER2012-2ndInternationalConferenceonCloudComputingandServicesScience
164
knowledge base. It provides metrics and performance
statistics computed on the knowledge base. A Tier is
a mixin that use statistics provided by the Archiver, it
detects critical conditions such as SLA violations, re-
source saturation or underutilization and then informs
the user or autonomically performs required reaction
as new provisioning or management.
4 CLOUD AGENCY DESIGN
Cloud Agency uses the agents technology to imple-
ments the OCCI extended model. Each mixin pre-
sented before will be implemented by a software
agent. According to our extended OCCI model Cloud
Agency is both a mixin itself and a collection of those
mixin presented before. It can run anywhere, also in
an user’s Resource, if it has been implemented as a de-
ployable software component. Cloud Agency can ac-
cess, on behalf of the user, the utility market of Cloud
computing to maintain always the best resources con-
figuration that satisfies the application requirements.
This system is being designed and developed within
the research activities of the FP7 mOSAIC project.
It is in charge to provide the collection of Cloud
resources, from different vendors, that continuously
meets the requirements of users applications. Ac-
cording to the available offers, it generates a service
level agreement that represents the result of resource
brokering and booking with available providers. The
user is able to delegate to the Agency the monitor-
ing of resource utilization, the necessary checks of the
agreement fulfillment and eventually re-negotiations.
Cloud Agency will supplement the common manage-
ment functionalities which are currently provided by
IAAS Private and Public infrastructure with new ad-
vanced services, by implementing transparent layer
to IAAS Private and Public Cloud services. Cloud
Agency will support the Cloud user in two differ-
ent scenarios: Deployment, to discover and buy the
available resources needed to run Cloud applications;
and Execution, to monitor and eventually to reconfig-
ure Cloud resources according the changed require-
ments of the Cloud Application. The following con-
cepts of CA appear in the General Overview of Cloud
Agency. A Call for proposals (CFP) is a document
that define requirements of resource to be acquired,
prices and other information relevant for the negotia-
tion. A Resource List is the part of the CFP where
necessary resources and their attributes are specified.
PolicyLists are different rules to be used for defining
resource brokering strategies that take in input users
requirements and providers offers. Cloud Resources
are the result of the CA Provisioning. They are de-
Figure 2: Cloud Agency Conceptual Model.
scribed, together service levels and other information
in a Service Level Agreement (SLA).
The blue components of Figure 2 represent agents
and provide the necessary facilities to expose Provi-
sioning, Management, Monitoring and Reconfigura-
tion Services. In particular the Vendor implements a
wrapper for a specific Cloud. It is used to get an of-
fer for resource provisioning, to accept or refuse that
offer, to get information about a resource or to per-
form an action on it (start, stop, resume). Brokers re-
ceive a CFP, ask to vendors for available offers, broke
the best one and allow to close the transaction. Me-
ters are deployed on Cloud resources to measure per-
formance indexes. The Archiver collects measures
from Meters and store them in a knowledge base. It
provides metrics and performance figures computed
on the knowledge base. Tiers use reconfiguration
policies to: detect critical events from performance
monitoring of Resource; evaluate critical conditions,
such as SLA violations, saturation or underutiliza-
tion; perform required reaction as new provisioning
or management. The Mediator receives information
and configuration requests directly from the user. It is
in charge of starting new transaction for provisioning
by creating broker agents. It starts also new tiers and
meters, and returns information about CA configura-
tion and services. In Figure 3 the Cloud user prepares
a CFP to be sent to the Cloud Agency. The Cloud
Agency returns a proposal from a Cloud Provider that
satisfies those requirements. If the mOSAIC User
accepts that Proposal an SLA is agreed and the of-
fered resources have been allocated. After that the
User can use the Platform for the application Deploy-
ment. The mOSAIC user exploits an Application Tool
for resource provisioning to define his requirements
at IAAS and to start a transaction. The Mediator re-
ceives the CFP, creates a Broker instance that is re-
sponsible to handle that CFP. The Broker search for
available Vendors and asks for a proposal to each one.
It collects the proposals and performs a brokering to
choice the best one. In an asynchronous way the best
ANOCCICOMPLIANTINTERFACEFORIAASPROVISIONINGANDMONITORING
165
Figure 3: Interaction Model for Provisioning.
proposal is notified to the Application Tool that re-
trieves the proposal details and waits for the Users
agreement. If the user agrees the proposal is amended
and the resources are allocated.
Cloud Agency has been implemented as a Multi
Agent systems. Execution environment for agents
and communication facilities are provided by the Jade
agent platform(Bellifemine et al., 2003). Jade has
been chosen as a platform to provide an execution en-
vironment of software agents, an Agent Communica-
tion Channel (ACC) and some protocol implementa-
tion to support communication. AMS and DF provide
standard services of FIPA compliant agent platforms:
a name server for agents and a yellow pages registry
for publication and discovery of agent base services.
Agents implement the new OCCI MIX-INs defined
in section 3. They embed the interaction protocols of
the deployment and execution scenarios. Agents will
communicate among them via standard ACL (Agent
Communication Language) over HTTP, or over other
transport protocols if it is necessary.
5 CONCLUSIONS
In this paper we presented a proposal of extension of
OCCI to support provisioning, monitoring and recon-
figuration. Standardization will allow user to choose
in cloud without vendor lock-in and to realize porta-
bility giving the possibility to use the cloud services
provided by multiple vendors so enjoying the full ben-
efits of cloud computing. In particular here we de-
signed new runtime capability which can be added
to the Cloud at IAAS for for autonomic provisioning
and monitoring. Finally we introduced the design of
Cloud Agency, an agents based software platform the
implements the proposed model.
ACKNOWLEDGEMENTS
This work has been supported by the FP7-ICT-2009-
5-256910 (mOSAIC) EU project and by the MIUR-
PRIN 2008 Cloud@Home: a New Enhanced Com-
puting Paradigm.
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