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 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 SQL statement transformation to enable cloud data access

Cloud computing has gained tremendous popularity in the past decade in the IT industry for its resource-sharing and cost-reducing nature. To move existing applications to the Cloud, they can be redesigned to fit into the Cloud paradigm, or migrate its existing components partially or totally to the Cloud. In application design, a three-tier architecture is often used, consisting of a presentation layer, a business logic layer, and a data layer. The presentation layer describes the interaction between application and user; the business layer provides the business logic; and the data layer deals with data storage. The data layer is further divided into the Data Access Layer which abstracts the data access functionality, and the Database Layer for data persistence and data manipulation. In various occasions, corporations decide to move the their application's database layer to the Cloud, due to the high resource consumption and maintenance cost. However, currently there is little support and guidance on how to enable appropriate data access to the Cloud. Moreover, the diversity and heterogeneity of database systems increase the difficulty of adaption for the existing presentation layer and business layer with the migrated database layer. In this thesis, we focus on the heterogeneity of SQL language across different database systems. We extend an existing open source Enterprise Service Bus with Cloud data access capability for the transformation of SQL statements used in the presentation and business layer, to the SQL dialect used in the Cloud database system back end. With the prototype we develop, we validate it against real world scenario with Cloud services, such as FlexiScale and Amazon RDS. Besides, we analyze the complexity of the algorithm we realized for parsing and transforming the SQL statements and prove the complexity through performance measurements

Extending a multi-tenant aware ESB solution with evolution management

Services have been improved over time to meet the increasing demand of service consumers. A service could be changed at any state in service life cycle. An inefficient service version management with arbitrary decisions could lead to disconnections between service consumers and service providers. A service version control management system is therefore necessary. The goal of this thesis is to specify, design and implement a service evolution management system for a multi-tenant aware ESB solution, so that the ESB could have the capabilities to manage the changes of multiple service versions between service consumers and service providers in a transparent manner. Furthermore, a function should be provided to check the compatibility between service versions, and, moreover, the calculation of service identifiers should be executed automatically, because service descriptions do not contain version-related information

Development of a Java library and extension of a data access layer for data access to non-relational databases

In the past years, cloud computing has become a vital part of modern application development. Resources can be highly distributed and provisioned on-demand. This fits well with the less strict data model of non-relational databases that allows better scaling. Many cloud providers have hosted NoSQL databases in their portfolio. When migrating the data base layer to a NoSQL model, the business layer of the application needs to be modified. These modifications are costly, thus it is desirable to design an architecture that can adapt to changes without tight coupling to third party components. In this thesis, we extend a multi-tenant aware Enterprise Service Bus (ESB) with Data Access Layer, modify the management application and implement a registry for the NoSQL configurations. Then, we design an architecture that manages the database connections that adds a transparency layer between the end-user application and non-relational databases. The design is verified by implementing it for blob stores including a Java access library that manages the access from local applications to the ESB. Additionally, we evaluate component by measuring the performance in several use scenarios and compared the results to the performance of the vendor SDKs

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

Comparison of composition engines and identification of shortcomings with respect to cloud computing

Most workflow engines are currently not Cloud-aware. This is due to multiple reasons like no support for transparent scalability, no multi-tenancy support, no ability to store process related data in a Cloud storage, or no support for quality of service enforcements. Recently Cloud based workflow services appeared in the workflow landscape and promise to run workflows in the Cloud. This student reports evaluates current state of the art BPEL and BPMN workflow engines and Cloud based workflow services according to their Cloud- awareness and general workflow functionalities. Identified shortcomings are described and prioritized. As a result of this evaluation the workflow engine WSO2 Stratos is best suited for running workflows in the Cloud, but it lacks native clustering support and quality of service enforcement

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

Extending an open source BPEL engine for multi-tenancy support

WS-BPEL is the de-facto standard for orchestrating Web services into business processes. Workflow engines can execute WS-BPEL processes. Furthermore, workflow engines handle the communication with external service partners providing the Web services. One future goal is to achieve tenant-aware Web services and thereby tenant-aware workflow engines to handle Web services. These tenant-aware Web services are specifically configured for the tenants, and the tenant-aware engines are able to configure such a process instance and offer them on a per-tenant basis. This reduces provider costs and efforts. The goal of this diploma thesis is to describe how workflow engines can support multitenancy, especially in the area of communication, and how this is of advantage for providers who offer their services over the Web using such a workflow engine. The providers should be able to offer tenant specific instances of applications on one workflow engine. In this diploma thesis, a concept to extend a workflow engine to handle a tenant context is developed. It is therefore an extension of the workflow engine in the area of communication. The concept is implemented by extending the open source WS-BPEL engine OW2 Orchestra