Efficient Distributed Control of Enterprise-Wide and Cross-EnterpriseWorkflows

In large workflow management systems (WfMS), it is particularly important to control workflows (WF) in an efficient manner. A very critical factor within this context is the resulting communication overhead. For this reason we have developed an approach for distributed WF control, which tries to keep the communication overhead low. In this paper, this approach is described and examined by means of a simulation

Dynamic Change of Server Assignments in Distributed Workflow Management Systems

Workow management systems (WfMS) offer a promising approach for realizing process-oriented information systems. Central WfMS, with a single server controlling all workow (WF) instances, however, may become overloaded very soon. In the literature, therefore, many approaches suggest using a multi-server WfMS with distributed WF control. In such a distributed WfMS, the concrete WF server for the control of a particular WF activity is usually dened by an associated server assignment. Following such a partitioning approach, problems may occur if components (WF servers, subnets, or gateways) become overloaded or break down. As we know from other elds of computer science, a favorable approach to handle such cases may be to dynamically change hardware assignment. This corresponds to the dynamic change of server assignments in WfMS. This paper analyses to what extend this approach is reasonable in such situations

Adding Virtualization Capabilities to Grid'5000

Ce rapport révisé a fait l'objet d'une publication, voir hal-00946971Almost ten years after its premises, the Grid'5000 testbed has become one of the most complete testbed for designing or evaluating large-scale distributed systems. Initially dedicated to the study of High Performance Computing, the infrastructure has evolved to address wider concerns related to Desktop Computing, the Internet of Services and more recently the Cloud Computing paradigm. This report present recent improvements of the Grid'5000 software and services stack to support large-scale experiments using virtualization technologies as building blocks. Such contributions include the deployment of customized software environments, the reservation of dedicated network domain and the possibility to isolate them from the others, and the automation of experiments with a REST API. We illustrate the interest of these contributions by describing three different use-cases of large-scale experiments on the Grid'5000 testbed. The first one leverages virtual machines to conduct larger experiments spread over 4000 peers. The second one describes the deployment of 10000 KVM instances over 4 Grid'5000 sites. Finally, the last use case introduces a one-click deployment tool to easily deploy major IaaS solutions. The conclusion highlights some important challenges of Grid'5000 related to the use of OpenFlow and to the management of applications dealing with tremendous amount of data.Dix ans environ après ses prémisses, la plate-forme Grid'5000 est devenue une des plates-formes les plus complètes utilisée pour la conception et l'évaluation de systèmes distribués à grande échelle. Dédiée initialement au calcul à haute performance, l'infrastructure a évolué pour supporter un ensemble de problèmes plus vaste liés au calcul de type Desktop, l'internet des objets et plus récemment l'informatique dans les nuages (aussi appelé Cloud Computing). Ce rapport présente les améliorations récentes apportées au logiciels et pile de services pour supporter les expérimentations à grande échelle utilisant les technologies de virtualisation comme blocs de base. Nos contributions incluent le déploiement d'environnements logiciels customisés, la réservation de domaines réseaux dédiés et la possibilité de les isoler entre eux, et l'automatisation des expérimentations grâce à une API REST. Nous illustrons l'intérêt de ces contributions en décrivant trois expériences à large échelle sur la plate-forme Grid'5000. La première expérience utilise des machines virtuelles pour conduire des expérimentations de grande taille sur 4000 pairs. La seconde expérience décrit le déploiement de 10000 instances KVM sur 4 sites Grid'5000. Enfin le dernier exemple présente un outil de déploiement simple pour déployer des solutions de Cloud de type IaaS. La conclusion discute de prochains défis importants de Grid'5000 liés à l'utilisation d'OpenFlow et à la gestion d'applications gérant des grandes masses de données

Adding Virtualization Capabilities to Grid'5000

Ce rapport révisé a fait l'objet d'une publication, voir hal-00946971Almost ten years after its premises, the Grid'5000 testbed has become one of the most complete testbed for designing or evaluating large-scale distributed systems. Initially dedicated to the study of High Performance Computing, the infrastructure has evolved to address wider concerns related to Desktop Computing, the Internet of Services and more recently the Cloud Computing paradigm. This report present recent improvements of the Grid'5000 software and services stack to support large-scale experiments using virtualization technologies as building blocks. Such contributions include the deployment of customized software environments, the reservation of dedicated network domain and the possibility to isolate them from the others, and the automation of experiments with a REST API. We illustrate the interest of these contributions by describing three different use-cases of large-scale experiments on the Grid'5000 testbed. The first one leverages virtual machines to conduct larger experiments spread over 4000 peers. The second one describes the deployment of 10000 KVM instances over 4 Grid'5000 sites. Finally, the last use case introduces a one-click deployment tool to easily deploy major IaaS solutions. The conclusion highlights some important challenges of Grid'5000 related to the use of OpenFlow and to the management of applications dealing with tremendous amount of data.Dix ans environ après ses prémisses, la plate-forme Grid'5000 est devenue une des plates-formes les plus complètes utilisée pour la conception et l'évaluation de systèmes distribués à grande échelle. Dédiée initialement au calcul à haute performance, l'infrastructure a évolué pour supporter un ensemble de problèmes plus vaste liés au calcul de type Desktop, l'internet des objets et plus récemment l'informatique dans les nuages (aussi appelé Cloud Computing). Ce rapport présente les améliorations récentes apportées au logiciels et pile de services pour supporter les expérimentations à grande échelle utilisant les technologies de virtualisation comme blocs de base. Nos contributions incluent le déploiement d'environnements logiciels customisés, la réservation de domaines réseaux dédiés et la possibilité de les isoler entre eux, et l'automatisation des expérimentations grâce à une API REST. Nous illustrons l'intérêt de ces contributions en décrivant trois expériences à large échelle sur la plate-forme Grid'5000. La première expérience utilise des machines virtuelles pour conduire des expérimentations de grande taille sur 4000 pairs. La seconde expérience décrit le déploiement de 10000 instances KVM sur 4 sites Grid'5000. Enfin le dernier exemple présente un outil de déploiement simple pour déployer des solutions de Cloud de type IaaS. La conclusion discute de prochains défis importants de Grid'5000 liés à l'utilisation d'OpenFlow et à la gestion d'applications gérant des grandes masses de données

ADEPT2 - Next Generation Process Management Technology

If current process management systems shall be applied to a broad spectrum of applications, they will have to be significantly improved with respect to their technological capabilities. In particular, in dynamic environments it must be possible to quickly implement and deploy new processes, to enable ad-hoc modifications of single process instances at runtime (e.g., to add, delete or shift process steps), and to support process schema evolution with instance migration, i.e., to propagate process schema changes to already running instances. These requirements must be met without affecting process consistency and by preserving the robustness of the process management system. In this paper we describe how these challenges have been addressed and solved in the ADEPT2 Process Management System. Our overall vision is to provide a next generation process management technology which can be used in a variety of application domains

An Approach for Supporting Ad-hoc Modifications in Distributed Workflow Management Systems

Supporting enterprise-wide or even cross-organizational business processes is a characteristic challenge for any workflow management system (WfMS). Scalability at the presence of high loads as well as the capability to dynamically modify running workflow (WF) instances (e.g., to cope with exceptional situations) are essential requirements in this context. Should the latter one, in particular, not be met, the WfMS will not have the necessary flexibility to cover the wide range of process-oriented applications deployed in many organizations. Scalability and flexibility have, for the most part, been treated separately in the relevant literature thus far. Even though they are basic needs for a WfMS, the requirements related with them are totally different. To achieve satisfactory scalability, on the one hand, the system needs to be designed such that a workflow instance can be controlled by several WF servers that are as independent from each other as possible. Yet dynamic WF modifications, on the other hand, necessitate a (logical) central control instance which knows the current and global state of a WF instance. For the first time, this paper presents methods which allow ad-hoc modifications (e.g., to insert, delete, or shift steps) to be performed in a distributed WfMS; i.e., in a WfMS with partitioned WF execution graphs and distributed WF control. It is especially noteworthy that the system succeeds in realizing the full functionality as given in the central case while, at the same time, achieving extremely favorable behavior with respect to communication costs

Towards a New Dimension in Clinical Information Processing (Keynote)

Process-oriented information systems can be very valuable for the clinical personnel since they may actively support the processes in a hospital. By offering tasks right in time and when all information is available to perform them, and by obeying deadlines and other time constraints, it reduces the administrative overhead. Today’s WF technology is still too limited in order to be broadly applicable in this scenario. However, research in WF technology is making quick progress. In the foreseeable future one can expect very powerful WfMS to appear at the market place, offering a powerful platform for implementing process-oriented information systems, also in the clinical domain. This paper sketches the ADEPT WfMS prototype, which is among the functionally most powerful WfMS and proves that one can really build systems of this kind which offer all this functionality within one system

Clinical Workflows - The Killer Application for Process-oriented Information Systems?

There is an increasing interest in changing information systems to support business processes in a more direct way. Workflow technology is a very interesting candidate to achieve this goal. Hence the important question arises, how far do we get using this technology. Is its functionality powerful enough to support a wide range of applications or is it only suitable for rather simple ones? And, if the latter is the case, are the missing functions of the “just to do” type or are more fundamental issues addressed? The paper uses the clinical domain to motivate and to elaborate the functionality needed to adequately support an advanced application environment. It shows that workflow technology is still lacking important features to serve this domain. The paper surveys the state of the art and it presents solutions for some issues based on the concepts elaborated in the ADEPT project

Towards Truly Flexible and Adaptive Process-Aware Information Systems

If current process management systems shall be applied to a broad spectrum of applications, they will have to be significantly improved with respect to their technological capabilities. Particularly, in dynamic environments it must be possible to quickly implement and deploy new processes, to enable ad-hoc modifications of running process instances on-the-fly (e.g., to dynamically add, delete or move process steps), and to support process schema evolution with instance migration (i.e., to propagate process schema changes to already running instances if desired). These requirements must be met without affecting process consistency and by preserving the robustness of the process management system. In this paper we describe how these challenges have been addressed and solved in the ADEPT2 Process Management System. Our overall vision is to provide a next generation process management technology which can be used in a variety of application domains