Tobias Binz

Portable Cloud Services Using TOSCA

For cloud services to be portable, their management must also be portable to the targeted environment, as must the application components themselves. Here, the authors show how plans in the Topology and Orchestration Specification for Cloud Applications (TOSCA) can enable portability of these operational aspects.

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.

OpenTOSCA --- A Runtime for TOSCA-Based Cloud Applications

TOSCA is a new standard facilitating platform independent description of Cloud applications. OpenTOSCA is a runtime for TOSCA-based Cloud applications. The runtime enables fully automated plan-based deployment and management of applications defined in the OASIS TOSCA packaging format CSAR. This paper outlines the core concepts of TOSCA and provides a system overview on OpenTOSCA by describing its modular and extensible architecture, as well as presenting our prototypical implementation. We demonstrate the use of OpenTOSCA by deploying and instantiating the school management and learning application Moodle.

TOSCA: Portable Automated Deployment and Management of Cloud Applications

Portability and automated management of composite applications are major concerns of today’s enterprise IT. These applications typically consist of heterogeneous distributed components combined to provide the application’s functionality. This architectural style challenges the operation and management of the application as a whole and requires new concepts for deployment, configuration, operation, and termination. The upcoming OASIS Topology and Orchestration Specification for Cloud Applications (TOSCA) standard provides new ways to enable portable automated deployment and management of composite applications. TOSCA describes the structure of composite applications as topologies containing their components and their relationships. Plans capture management tasks by orchestrating management operations exposed by the components.This chapter provides an overview on the concepts and usage of TOSCA.

Winery --- A Modeling Tool for TOSCA-Based Cloud Applications

TOSCA is a new OASIS standard to describe composite applications and their management. The structure of an application is described by a topology, whereas management plans describe the applications management functionalities, e.g., provisioning or migration. Winery is a tool offering an HTML5-based environment for graph-based modeling of application topologies and defining reusable component and relationship types. Thereby, it uses TOSCA as internal storage, import, and export format. This demonstration shows how Winery supports modeling of TOSCA-based applications. We use the school management software Moodle as running example throughout the paper.

Combining Declarative and Imperative Cloud Application Provisioning Based on TOSCA

The automation of application provisioning is one of the most important issues in Cloud Computing. The Topology and Orchestration Specification for Cloud Applications (TOSCA) supports automating provisioning by two different flavors: (i) declarative processing is based on interpreting application topology models by a runtime that infers provisioning logic whereas (ii) imperative processing employs provisioning plans that explicitly describe the provisioning tasks to be executed. Both flavors come with benefits and drawbacks. This paper presents a means to combine both flavors to resolve drawbacks and to profit from benefits of both worlds: we propose a standards-based approach to generate provisioning plans based on TOSCA topology models. These provisioning plans are workflows that can be executed fully automatically and may be customized by application developers after generation. We prove the technical feasibility of the approach by an end-to-end open source toolchain and evaluate its extensibility, performance, and complexity.

Vino4TOSCA: A Visual Notation for Application Topologies Based on TOSCA

A major difficulty in enterprise computing is the modeling of complex application topologies consisting of numerous individual components and their relationships. Especially in the context of cloud computing, the Topology and Orchestration Specification for Cloud Applications (TOSCA) has been proposed recently for standardization to tackle this issue. However, TOSCA currently lacks a well-defined visual notation enabling effective and efficient communication in order to transport the semantics of the encoded information to human beings. In this paper, we propose a visual notation for TOSCA based on established usability research which provides additional concepts for visual modularization and abstraction of large application topologies.

CMotion: A framework for migration of applications into and between clouds

The number of applications and services hosted in the cloud grows steadily, because of significant advantages in cost, flexibility, and scale compared to traditional IT. However, major difficulties in this field are (i) the migration of existing applications into the cloud and (ii) the increasing vendor lock-in which denotes the inability to leave a certain cloud provider without significant effort. Current approaches do not offer a holistic solution: Either they require the user to provide the application in a certain standardized way or they are only able to migrate one specific type of component. As a consequence, the migration of composite applications with different types of components is not supported. To overcome this limitation we propose the Cloud Motion Framework (CMotion) which leverages existing application models and provides support to migrate composite applications into and between clouds. Based on the application model, the framework evaluates alternative ways to host each component. CMotion assumes that the dependencies of components are modeled explicitly and the components are self-contained.

BPMN4TOSCA: A Domain-Specific Language to Model Management Plans for Composite Applications

TOSCA is an upcoming standard to capture cloud application topologies and their management in a portable way. Management aspects include provisioning, operation and deprovisioning of an application. Management plans capture these aspects in workflows. BPMN 2.0 as general-purpose language can be used to model these workflows. There is, however, no tailored support for management plans in BPMN. This paper analyzes TOSCA with the focus on requirements on workflow modeling languages to come up with a strong link to the application topology with the goal to improve modeling support. To simplify the modeling of management plans, we introduce BPMN4TOSCA, which extends BPMN with four TOSCA-specific elements: TOSCA Topology Management Task, TOSCA Node Management Task, TOSCA Script Task, and TOSCA Data Object. Portability is ensured by a transformation of BPMN4TOSCA to plain BPMN. A prototypical modeling tool supports the strong link between the management plan and the TOSCA topology.

Unified Invocation of Scripts and Services for Provisioning, Deployment, and Management of Cloud Applications Based on TOSCA

There are several script-centric approaches, APIs, and tools available to implement automated provisioning, deployment, and management of applications in the Cloud. The automation of all these aspects is key for reducing costs. However, most of these approaches are script-centric and provide proprietary solutions employing different invocation mechanisms, interfaces, and state models. Moreover, most Cloud providers offer proprietary Web services or APIs to be used for provisioning and management purposes. Consequently, it is hard to create deployment and management plans integrating several of these approaches. The goal of our work is to come up with an approach for unified invocation of scripts and services without handling each proprietary interface separately. A prototype realizes the presented approach in a standards-based manner using the Topology and Orchestration Specification for Cloud Applications (TOSCA).