Challenges for the comprehensive management of cloud services in a PaaS framework

The 4CaaSt project aims at developing a PaaS framework that enables flexible definition, marketing, deployment and management of Cloud-based services and applications. The major innovations proposed by 4CaaSt are the blueprint and its lifecycle management, a one stop shop for Cloud services and a PaaS level resource management featuring elasticity. 4CaaSt also provides a portfolio of ready to use Cloud native services and Cloud-aware immigrant technologies

Enabling horizontal scalability in an open source enterprise services bus

Cloud computing is a recent paradigm which describes a new way of consuming and delivering IT Services. In the Platform as a Service (PaaS) model, an underlying infrastructure such as network, operative system or server is provided to the Cloud consumers for either deploying their own applications, or applications supplied by the Cloud provider. In effect, Cloud computing modifies how applications should be built, provided, and consumed, as they may provide or be totally exposed as services, or consume existing third party applications services. The main advantages in Cloud computing are related to dynamic scaling of resources which are able to adapt to changes based on demand of resources and the use of multi-tenancy techniques in order based on sharing of resources between different users towards achieving the economy of scale. The Enterprise Service Bus (ESB) is essential as an integration middleware between application and services within and between multiple Cloud infrastructures. Different communication protocols might be used by application services and it is therefore necessary to have a mediator between them. Several challenges might arise when using an ESB as communication mediator between applications in cloud when to scale in and scale out to optimize resource consumption. The number of ESB instances should vary depending on the load in the Cloud infrastructure. This can be achieved by dynamically scaling in and out multiple ESB instances which constitute the horizontal ESB cluster. In this Master Thesis we focus on enabling horizontal scalability support for an open source multi-tenant aware Enterprise Service Bus (ESB). The investigation is based on two possible scenarios for enabling horizontal scalability: interconnected vs. non interconnected ESB instances. Therefore, in this work we investigate their advantages, disadvantages, and possible challenges and solutions. Based on previous investigations, a realization approach for enabling multi-instance management of a multi-tenant aware ESB is provided

Integration of different aspects of multi-tenancy in an open source enterprise service bus

The EU project 4CaaSt aims to create an advance PaaS Cloud platform which supports the optimized and elastic hosting of composite Internet-scale multi-tier applications. Cloud computing is essentially changing the way services are built, provided and consumed. Nowadays applications are composed out of multiple reusable services consisting of newly developed services as well as legacy applications made available as services. These services do not necessarily use the same protocols for communication. So a component for the mediation between various protocols, dynamic service selection and routing based on non-functional requirements is needed. Nowadays an Enterprise Service Bus (ESB) is used in Service-Oriented Architectures (SOAs) to serve precisely these objectives. One important aspect of bringing an ESB as building block into the Cloud is to enable multi-tenancy. This includes multi-tenant aware management and administration of the ESB as well as multi-tenant aware messaging. In this student thesis we design and implement the extensions of the ESB and the components needed for the integration and evaluation of two approaches to extend an open source ESB for multi-tenancy support: the first covers the multi-tenant aware administration and management and the second covers the multi-tenant aware messaging. Both approaches require the extension of the ESB, which implements the Java Business Integration (JBI). As a result, we provide an integrated prototype based on a scenario emerged from the EU project 4CaaSt and a performance's evaluation of the extended JBI Components in the ESB

Enabling the compatible evolution of services based on a cloud-enabled ESB solution

Software services are susceptible to changes because of the rapid growth and challenges in business environment. Business operations offered by service providers have to able to cope with various and countless service demands from service consumers. Such a case could also be experienced in cloud environment. As cloud platform, the Platform-as-a-Service (PaaS) platform allows application developers as tenants to deploy and configure their service artifacts in cloud infrastructure. A multi-tenant aware Enterprise Service Bus (ESB) as applications integrator is introduced to serve tenants in terms of management and administration. The purpose is to ensure data isolation between tenants. The goal of this diploma thesis is to extend an open source multi-tenant aware ESB with service version control management framework so that the ESB can facilitate the version management of service providers and consumers in a transparent manner, and ensure service compatibility among tenants. The extension can be further decomposed in terms of management and administration, as well as message flows in versions inside the multi-tenant ESB

Extending an open source enterprise service bus for cloud data access support

In the last years Cloud computing has become popular among IT organizations aiming to reduce its operational costs. Applications can be designed to be run on the Cloud, and utilize its technologies, or can be partially or totally migrated to the Cloud. The application's architecture contains three layers: presentation, business logic, and data layer. The presentation layer provides a user friendly interface, and acts as intermediary between the user and the application logic. The business logic separates the business logic from the underlaying layers of the application. The Data Layer (DL) abstracts the underlaying database storage system from the business layer. It is responsible for storing the application's data. The DL is divided into two sublayers: Data Access Layer (DAL), and Database Layer (DBL). The former provides the abstraction to the business layer of the database operations, while the latter is responsible for the data persistency, and manipulation. When migrating an application to the Cloud, it can be fully or partially migrated. Each application layer can be hosted using different Cloud deployment models. Possible Cloud deployment models are: Private Cloud, Public Cloud, Community Cloud, and Hybrid Cloud. In this diploma thesis we focus on the database layer, which is one of the most expensive layers to build and maintain in an IT infrastructure. Application data is typically moved to the Cloud because of , e. g. Cloud bursting, data analysis, or backup and archiving. Currently, there is little support and guidance how to enable appropriate data access to the Cloud. In this diploma thesis the we extend an Open Source Enterprise Service Bus to provide support for enabling transparent data access in the Cloud. After a research in the different protocols used by the Cloud providers to manage and store data, we design and implement the needed components in the Enterprise Service Bus to provide the user transparent access to his data previously migrated to the Cloud

Extending an open source enterprise service bus for multi-tenancy support

Within the Cloud computing approach, Platform as a Service is a way to provide customers with the capability to deploy acquired or consumer-created applications onto the Cloud infrastructure. It relieves these of the need to install and run their own infrastructure or to manage and control the underlying Cloud infrastructure. Whereas providers of such services try to serve as many customers as possible to exploit economies of scale, especially small and medium businesses profit from this approach, because they can save the high up front and administrative cost of installing and running their own processing systems and applications. In order to offer an Enterprise Service Bus as a proven technology known from the field of Service-Oriented Architectures as a Platform in the Cloud it has to be made multi-tenant aware. This fulfills the Platform as a Service providers' need to raise the overall utilization and to maximize revenue by serving multiple customers from one system instance. This master's thesis develops a concept to extend an Enterprise Service Bus by multi-tenancy support with respect to communication and implements this concept in an open source product. The concept and implementation are evaluated by application to a scenario originating from the European project 4CaaSt

Extending an open source enterprise service bus for multi-tenancy support focusing on administration and management

As part of cloud computing, the service model Platform-as-a-Service (PaaS) has emerged, where customers can develop and host internet-scale applications on cloud infrastructure. The Enterprise Service Bus (ESB) is one possible building block of a PaaS offering, providing integration capabilities for service-oriented architectures. Bringing the ESB to the cloud requires scalability and multi-tenancy support. When applied, these characteristics lead to economies of scale, reducing the costs per customer. In this diploma thesis we specify, design, and implement a multi-tenant management application for an existing open source ESB. The management application grants tenant users limited configuration access to the ESB’s connectivity and integration services. A tenant registry and a service registry serve as platform-wide databases. We ensure data isolation between tenants for the management application and ESB message flows. Furthermore, the management application can control clusters of ESB instances, retaining elasticity. These goals also involve extensions to the ESB itself, which implements the Java Business Integration (JBI) specification. As a result, an integration scenario emerged from the EU-funded project 4CaaSt was applied to the system

Extending an open source enterprise service bus for PostgreSQL statement transformation to enable cloud data access

Cloud computing has enabled a new era in the IT industry and many organizations are interested in moving their business operations to the Cloud. This can be realized by designing new applications that follow the prerequisites of the Cloud provider or just by migrating the existing applications to the Cloud. Each application follows a multi-layered architecture defined by its design approach. Application data is of utmost importance and it is managed by the data layer, which is further divided into two sublayers, the Data Access Layer (DAL) and the Database Layer (DBL). The former abstracts the data access functionality and the latter ensures data persistence and data manipulation. Application migration to the Cloud can be achieved by migrating all layers it consists of or only part of them. In many situations it is chosen to move only the DBL to the Cloud and keep the other layers on-premise. Most preferably, the migration of the DBL should be transparent to the upper layers of the application, so that the effort and the cost of the migration, especially concerning application refactoring, becomes minimal. In this thesis, an open source Enterprise Service Bus (ESB), able to provide multi-tenant and transparent data access to the Cloud, is extended with PostgreSQL transformation functionality. Previously the ESB could only support MySQL source databases. After the integration of two new components, a PostgreSQL proxy and a PostgreSQL transformer, we provide support for PostgreSQL source databases and dialects. Furthermore, we validate and evaluate our approach based on the TPC-H benchmark, in order to ensure results based on realistic SQL statements and appropriate example data. We show linear time complexity, O(n) of the developed PostgreSQL transformer

Extending an open source enterprise service bus for dynamic discovery and selection of cloud data hosting solutions based on WS-policy

As part of Cloud computing, the service model Platform-as-a-Service (PaaS) has emerged, where customers can develop and host internet-scale applications on Cloud infrastructure. The Enterprise Service Bus (ESB) is one possible building block of a PaaS offering, providing integration capabilities for Service-Oriented architectures. Dynamic service discovery and selection support for an ESB increases flexibility of the application composed of reusable services in the Cloud and gives providers the possibility react faster on changes in the market. In this master's thesis we specify, design and implement Dynamic Discovery and Selection of Cloud Data Hosting Solutions for an open-source ESB. Provided dynamic service discovery and selection endpoint/service allows users of tenants to send requests with attached policies, while tenants register Cloud Data Hosting Solutions with the policies that describe their capabilities. To provide uniform policy language a new WS-Policy Assertion Language is created and specified that is used to express functional and non-functional properties of Cloud Data Hosting Solutions. By matching a policy in a request and policies of Cloud Data Hosting Solutions, a suitable Cloud data store service is discovered. Moreover, we ensure data isolation between tenants while providing dynamic service discovery and selection