Steve Strauch

How to adapt applications for the Cloud environment Challenges and solutions in migrating applications to the Cloud

The migration of existing applications to the Cloud requires adapting them to a new computing paradigm. Existing works have focused on migrating the whole application stack by means of virtualization and deployment on the Cloud, delegating the required adaptation effort to the level of resource management. With the proliferation of Cloud services allowing for more flexibility and better control over the application migration, the migration of individual application layers, or even individual architectural components to the Cloud, becomes possible. Towards this goal, in this work we focus on the challenges and solutions for each layer when migrating different parts of the application to the Cloud. We categorize different migration types and identify the potential impact and adaptation needs for each of these types on the application layers based on an exhaustive survey of the State of the Art. We also investigate various cross-cutting concerns that need to be considered for the migration of the application, and position them with respect to the identified migration types. Finally, we present some of the open research issues in the field and position our future work targeting these research questions.

Business Compliance Governance in Service-Oriented Architectures

Governing business compliance with regulations, laws, best practices, contracts, and the like is not an easy task, and so far there are only limited software products available that help a company to express compliance rules and to analyze its compliance state. We argue that today’s SOA-based way of implementing and conducting business (e.g., using Web services and business process engines) lends itself very well to the development of a comprehensive compliance government solution that effectively aids companies in being compliant. In this paper, we contextualize the compliance problem in SOA-based businesses, we highlight which are the most salient research challenges that need to be addressed, and we describe our approach to compliance governance, spanning design, execution, and evaluation concerns.

An Integrated Solution for Runtime Compliance Governance in SOA

In response to recent financial scandals (e.g. those involving Enron, Fortis, Parmalat), new regulations for protecting the society from financial and operational risks of the companies have been introduced. Therefore, companies are required to assure compliance of their operations with those new regulations as well as those already in place. Regulations are only one example of compliance sources modern organizations deal with every day. Other sources of compliance include licenses of business partners and other contracts, internal policies, and international standards. The diversity of compliance sources introduces the problem of compliance governance in an organization. In this paper, we propose an integrated solution for runtime compliance governance in Service-Oriented Architectures (SOAs). We show how the proposed solution supports the whole cycle of compliance management: from modeling compliance requirements in domain-specific languages through monitoring them during process execution to displaying information about the current state of compliance in dashboards. We focus on the runtime part of the proposed solution and describe it in detail. We apply the developed framework in a real case study coming from EU FP7 project COMPAS, and this case study is used through the paper to illustrate our solution.

Fragmento: Advanced Process Fragment Library

Reuse is a common discipline for decreasing software development time and for improving overall quality, independent from the domain. As business processes represent a fundamental asset of an organization, several concepts for enabling reuse during process modeling have been proposed. However, only few concrete examples for reusable process artifacts have been discussed so far. In this paper, we present the concept of process fragments and an example collection of process fragments for illustrating our reuse concept and for showing that it can actually be applied in practice for an easier and faster development of process-based applications. The fragment examples demonstrate different characteristics such fragments may exhibit. We also argue that this work will encourage reuse of process logic in terms of fragments, since it also provides an opportunity to design and develop a process fragment library for collecting process logic explicitly. As technical enabler for the approach we present a prototype called Fragmento.

Measuring Performance Metrics of WS-BPEL Service Compositions

In this paper we present an approach to the development of monitoring solutions for processes implemented as WSBPEL service compositions. The approach allows modeling of process performance metrics in a platform-independent manner and then generating an event-based monitor model for a specific WS-BPEL process engine. We create a metamodel which enables modeling of different types of process performance metrics. In particular, our approach supports modeling of metrics related to correlated processes. In the deployment phase, we generate a monitor model based on a proprietary event metamodel of a process engine. In addition, we determine which events are needed for the calculation of PPMs, and generate corresponding deployment information for the process engine.

ESB MT : Enabling Multi-Tenancy in Enterprise Service Buses

Multi-tenancy is an essential property of Cloud computing. It helps service providers to maximize resource utilization and reduce servicing costs per customer. It is therefore important for key components of the contemporary enterprise environment like the Enterprise Service Bus (ESB) to support and enable multi-tenancy. For this purpose, in this work we investigate the requirements for multi-tenant ESB solutions, propose an implementation-agnostic ESB architecture that addresses these requirements, and discuss our proof-of-concept realization of this architecture.

Enabling tenant-aware administration and management for JBI environments

Enterprise Service Buses (ESBs) constitute a core middleware technology for each modern Service-Oriented Architecture (SOA) solution. Given the popularity of the Cloud paradigm, which is based on fundamental SOA concepts, it is only therefore natural to look into how ESBs can be transformed into native building blocks for Cloud platforms. As a first step of this effort, in this work we investigate how ESBs can become multi-tenant aware, i.e. able to support multiple tenants and their users sharing the same ESB instance. A generalized architecture based on the JBI specification implemented by a number of open source ESBs is presented for this purpose. We demonstrate the feasibility of our proposal by means of a proof of concept realization and we evaluate the performance of our solution against a non multi-tenant ESB that was used as the baseline for our implementation.

A Taxonomy for Cloud Data Hosting Solutions

Cloud computing allows reducing capital expenditure by using resources on demand. We investigate how to build a database layer in the Cloud and present pure and hybrid Cloud data hosting solutions. The solutions are organized in a taxonomy. The properties used for organization are: application layer, deployment model, location, service model, data store type, and compatibility. Using the taxonomy, existing Cloud data hosting solutions are categorized.

Non-functional data layer patterns for Cloud applications

Cloud services allow for hosting applications partially or completely in the Cloud by migrating their components and data. Especially with respect to data migration, a series of functional and non-functional challenges like data confidentiality arise when considering private and public Cloud data stores. In this paper we identify some of these challenges and propose a set of reusable solutions focusing on the non-functional aspects, organized together as a set of Cloud Data Patterns.

Migrating enterprise applications to the cloud: methodology and evaluation

Migrating existing on-premise applications to the cloud is a complex and multi-dimensional task and may require adapting the applications themselves significantly. For example, when considering the migration of the database layer of an application, which provides data persistence and manipulation capabilities, it is necessary to address aspects like differences in the granularity of interactions and data confidentiality, and to enable the interaction of the application with remote data sources. In this work, we present a methodology for application migration to the cloud that takes these aspects into account. In addition, we also introduce a tool for decision support, application refactoring and data migration that assists application developers in realising this methodology. We evaluate the proposed methodology and enabling tool using a case study in collaboration with an IT enterprise.