Cloud computing can be deployed in many ways and it all depends on the placement of
computing resources at the consumer’s location (on-premise), at cloud service provider’s
location, or at both locations. The current cloud deployment models are as follows:
- Public cloud
- Private cloud
- Hybrid cloud
- Community cloud
Public Cloud
This is most common deployment model. In this model, computing resources are present
in the cloud service provider’s datacenter and are shared with various consumers in a
multi-tenant architecture (Figure 1-2). The major advantage of this deployment model is
that you don’t need to invest in H/W and effort in setting up the cloud. The disadvantage
is that you don’t have full control of your computing resources. You can’t use this model
when there are local laws that prevent you from keeping your data outside your premises.
The public cloud model is good option for startups and any organization that wants
to avoid CAPEX costs related to DB servers.
Oracle database can be run on many public cloud providers; however the prominent
players are as follows:
- Oracle Cloud
- Microsoft Azure
- Amazon Web Services (AWS)
In the public cloud model, database related services are provided in all three service
models (IaaS, PaaS, and SaaS). Oracle provides the following services in Oracle cloud: - Oracle Database Cloud Service, Virtual Image: IaaS offering to run
Oracle database - Oracle Database Cloud Service: IaaS/PaaS offering to run Oracle
database - Oracle Database Exadata Cloud Service: IaaS offering for running
Oracle on Exadata machines - Schema as a Service: SaaS offering to run Oracle database
Microsoft Azure provides IaaS service where you can run Oracle database on virtual
machines hosted in their cloud.
AWS provides the following services for Oracle database: - EC2 Instance: IaaS offering
- Relational Database Services (RDS): SaaS offering to run Oracle
database
Consumer 1
Consumer n
Infrastructure hosted at cloud providers end
Figure 1-2. Public cloud example
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Cloud service providers continuously add enhancements, hence it is recommended
that you check the cloud service provider’s portal to get the latest offerings.
Private Cloud
In this deployment model, computing resources are placed on-premise. There is one
more option here in which computing resources are placed at the cloud provider’s
premises, but all of these are dedicated for consumers (Figure 1-3). The major advantage
of this model is that you have full control of your resources and you can meet any local
laws requiring data be kept in your datacenter. The disadvantage is related to the effort
needed for private cloud setup.
Database private cloud setup is done mostly in house, where companies use
commodity server or converged infrastructures like Oracle Exadata, VCE Vblock, and
IBM Pure app to host DB servers in a consolidated fashion. Oracle OEM 12c/13c cloud
control is used to mimic a cloud-like setup where a self-service portal is created for quick
provisioning and a chargeback module is used for metering and billing. In this model,
planning, implementation, and on-going maintenance is handled by the company itself.
Private cloud is good option for organizations that want to get ROI from their CAPEX
investments done and where hosting in a public cloud is not an option due to compliance
requirements.
Hybrid Cloud
This deployment model provides the best of the public and private cloud options. In
this model, consumers use both a public cloud and private cloud to cater to different
requirements (Figure 1-4). For example, some applications can’t move to a public cloud
since they are running on end-of-life software, so they remain in a private cloud.
Consumer
Infrastructure hosted at customer end and cloud
computing concepts are implemented
Figure 1-3. Private cloud example
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This model is the future of cloud computing and world is moving toward it.
In the hybrid cloud model, some of the databases run on-premise and some are
hosted in a public cloud.
The public cloud does not offer support for all database versions. You can’t run
Oracle 10g on Oracle cloud, so you have to keep such databases in your own private
cloud/datacenter.
Similarly, you might want to keep your extremely complex and mission-critical
databases in your datacenter rather than host them in a public cloud.
A hybrid cloud is good for situations where you can selectively move some of your
workload into a public cloud while retaining others on-premises.