Similarly, in this research we treat them as synonyms and consider Inter-cloud as the worldwide association of clouds. According to the discussion, cloud aggregation can be considered as a prerequisite for the ultimate goal of Inter-cloud. Current cloud and inter-cloud aggregation projects, as shown in Figure 3, follow one or a combination of these two methods.
Although one of the main features of cloud computing is the illusion of infinite resources, capacity in cloud providers' data centers is limited and can eventually be fully utilized [Calheiros et al. It is also seen as one of the current disadvantages of cloud computing [Armbrust et al.
Multicloud Scenario
Aggregated Service by Broker
INTER-CLOUD CHALLENGES AND ENABLING APPROACHES
- Provisioning
- Portability
- Service-Level Agreement
- Security
- Monitoring
- Economy
- Network
- Autonomics
Cloud customers require choosing the best possible application deployments in the cloud according to their goals and constraints for QoS. Another important issue in the federated cloud environment is how to enforce SLAs in a federation where there are conflicting policies and goals of different members versus the goals of the federation as a whole. There are some works in the literature that have addressed SLA management in the context of the federated cloud environment.
They provide extended SLA management functionality by integrating the SLA management approach of the SLA@SOI19 project into the federation architecture. These certificates are issued by the certificate authorities (CAs) that are part of the IGTF. Monitoring of cloud-based applications can be achieved at two separate levels of the infrastructure and the application.
Computing as a tool can be considered one of the main goals in federated cloud computing, where resources on multiple cloud platforms are integrated into a single set of resources. Federated cloud providers require a clear understanding of the consequences of any decision they make regarding the sale/purchase of resources to/from other providers. How providers price their services in the federated cloud marketplace requires deep considerations to ensure provider profitability.
Accounting and Billing. In a federated cloud environment, accounting and billing must be done in a way that meets the requirements of the cross-cloud scenario. The focus of the work is on the design of the accounting and billing system, using existing alternatives, for the RESERVOIR [Rochwerger et al. To enable the effective identification of the required service, its capabilities and required features, auditing capabilities are required in the design of a cloud naming system [Bernstein et al.
All these real or abstracted entities are presented to users and can be seen as entities of the cloud [N ´u ˜nez et al. In heterogeneous and dynamically interconnected cloud environments, the system must continuously adapt itself to the current state of the system.
STANDARDS
Autonomic computing refers to the self-managing principles of computer-based systems while hiding the inherent complexity of the system. Self-management of cloud services minimizes user interactions with the system and represents challenging research questions. That is, autonomous systems can be used for various aspects of interconnected cloud environments, such as SLA management, delivery, security, market, and so on.
That is, due to a large variety of services and offerings in cloud environments, matching between user requirements and services is a difficult task. Relevant advances in autonomous cloud computing have been achieved by Kim and Parashar in the CometCloud project [Kim and Parashar 2011]. CometCloud is an autonomous computing engine developed for cloud and grid environments that supports highly heterogeneous infrastructures, integration of public and private clouds, and dynamic application scaling.
Other approaches apply principles of autonomous computing to specific aspects of cloud computing, such as market management [Breskovic et al. A common and widely accepted solution requires a significant amount of work and research to overcome existing differences. There are several barriers and problems in applying standard APIs and protocols in cloud environments [Petcu 2011]. Standards Development Organization (SDO), when technically involved in developing and publishing standards for cloud computing and cloud interoperability;
Consortia bring together organizations, businesses, academia, and government institutions to collaborate on the goal of wider adoption and development of cloud computing technologies, and they are interested in reaching consensus on solving technical problems in cloud computing. The efforts of consortia and SSOs speed up the standards development process, or even in cases where they are widely accepted by cloud computing stakeholders, they are converted into standards. A more detailed review of the current standard protocols and interfaces that facilitate cross-cloud realization can be found in Supplementary Appendix B.
INTER-CLOUD PROJECTS 1. RESERVOIR
- mOSAIC
- Contrail
- Cloudbus InterCloud
- OPTIMIS
- Open Cirrus
- Claudia
- Intercloud by Bernstein et al
- Federated Cloud Management (FCM)
- Sky Computing
- STRATOS
One of the main goals of mOSAIC is to allow transparent and simple access to heterogeneous cloud resources and to avoid vendor lock-in. Contrail tries to create an environment that allows cloud customers to exploit resources belonging to different cloud providers through a homogeneous secure interface, regardless of the technology used by the providers. The focus of the toolkit is on cloud service and infrastructure optimization throughout the construction, deployment and operations phases of the service lifecycle.
The main components of the toolkit are the Service Builder, the Basic Toolkit, the Admission Controller, the Deployment Engine, the Service Optimizer and the Cloud Optimizer. Service Builder gives a service programmer access to an integrated development environment. It simplifies both service development and configuration using a new programming model for service development. Therefore, a particular user may not be able to access a particular federation site.
Most of the work regarding the blueprint is focused on concepts, architectures and standards rather than actual system developments. It also includes protocols needed to enable different parts of the Intercloud interactions [Bernstein et al. The core element of the architecture is the Generic Meta Brokering Service (GMBS) component that receives requests from multiple users and can route them to multiple IaaS clouds for execution.
Demonstrations of the feasibility of the approach were performed using various existing open source tools such as Xen, ViNE (for overlay networks), Nimbus and Hadoop. The decision of which providers to use for a specific allocation is determined at runtime. Among the use cases proposed by the authors, the goals of the broker were deadlock avoidance and deployment cost minimization.
TOOLS AND FRAMEWORKS
- Open-Source Cloud Management Platforms
- Client-Side Libraries
- Distributed Programming Languages
- Interoperable Cloud Infrastructure Projects Supporting e-Science
2011] is an architecture that allows the integration of multiple IaaSs to run applications from multiple users. Virtual devices that contain the necessary software to support user requests are kept in a virtual device repository that is part of the FCM architecture. One of the key differences between this work and competing approaches is the consideration of service measurements and KPIs for study selection through the Service Measurement Index (SMI) framework.40.
Open source cloud platforms (OCPs) are important for cloud interoperability not only because of the benefits of open source, but also because they can mitigate the risk of vendor lock-in by providing interoperable cloud environments. 2012] is an open source virtualized data center management platform for enabling IaaS clouds. OpenStack.OpenStack is an open source IaaS Cloud management platform, released under the terms of the Apache License, designed to control large groups of compute, storage and network resources in a data center.
CloudStack.CloudStack is an open source IaaS platform originally developed by Cloud.com and later acquired by Citrix. 2009] is an open source platform, compatible with Amazon Web Services (AWS) APIs, for building private and hybrid cloud computing environments. Currently, Amazon50 is one of the dominant players in the IaaS cloud market, and its service APIs are becoming de facto standards for operating on cloud resources; other vendors therefore offer AWS-compatible APIs for their services.
Not surprisingly, all of the open source platforms we discussed in this section support AWS-compatible APIs, making multicloud deployment scenarios even more achievable. While all previously discussed projects try to build interconnected cloud environments that are independent of the application type, there are projects that focus on forming distributed multiple cloud infrastructures for scientific applications and for research purposes. The European Grid Initiative is also investigating how to create a grid of academic private clouds and virtualized resources (federated clouds) while focusing on the demands of the scientific community.59 Their goal is to provide an e-infrastructure for research based on the federated operations. services.
SUMMARY, DISCUSSION, AND FUTURE DIRECTIONS
Therefore, it is possible that comprehensive and holistic approaches to cloud interoperability will be a result of combining one or more of the ongoing initiatives, either directly or via an extra layer of abstraction that hides the complexities from end users. Furthermore, from the summary of the projects, it is possible to notice that there are currently only a few cloud federation projects and that they mostly mediate technologies for multicloud and aggregated service scenarios. After analyzing ongoing projects, we analyzed the state of the art and the trends in the field of integrated clouds, where we identified that legal issues and meeting regulations are major concerns that are not well studied by the current projects.
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