Miller, J., Sheth, A., Kochut, K., and Wang, X., "CORBA-Based Run-Time Architectures for Workflow Management Systems," Journal of Database Management, Special Issue on Multidatabases, Vol. 7, No. 1, 1996, pp. 16-27.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....most often tools are communicating directly; and only use adapters and wrappers to adapt as much as possible the communication. In the high end they consider process based approaches, but where the process controller directly drives the real tools. In our approach, the Corba (or RMI) layer [7], the event layer like [8] 11] the different technology around communication (XML and others) 7] and the different technology and patterns for interfacing tools (mediators, wrappers and other proxies[3] are simply technology means, they are not concepts. We strongly believe that a real ....

....much as possible the communication. In the high end they consider process based approaches, but where the process controller directly drives the real tools. In our approach, the Corba (or RMI) layer [7] the event layer like [8] 11] the different technology around communication (XML and others)[7], and the different technology and patterns for interfacing tools (mediators, wrappers and other proxies[3] are simply technology means, they are not concepts. We strongly believe that a real solution can only emerge from a higher level view of the problem to solve and the identification of the ....

J.A.Miller,A.Sheth,K.J.KochutandX.Wang. CORBA-Based Run-Time Architectures for Workflow Management Systems. Journal of Database Management, Special Issue on Multidatabases, 7(1):16-27.

....reactive components has been proposed in [32] The model is open but focuses only on tool integration; it does not deal with interoperability at concept and model levels nor on the issues of simplicity and reusability. The Corba technology has been used in many work including workflow support [28]. Here the distribution of an application at run time is the main issue. Interoperability at concepts and model level is not addressed. Federation of distributed process engines has been addressed in a some of work. In Oz [6] the objective is to support interoperability among autonomous and ....

J.A. Miller, A. Sheth, K.J. Kochut and X. Wang. CORBA-Based Run-Time Architectures for Workflow Management Systems. Journal of Database Management, Special Issue on Multidatabases, 7(1):16-27.

....the need of a new development process [14] 16] the new focus on vendor customer relationships[15] the impact of not controlling the rate and content of changes, the impact of not owning the source code for critical applications [19] andsoon. Interoperability In our approach, Corba or RMI [5], events [6] 8] communication standards (XML and others) 5] as well as mediators, wrappers and other proxies[2] are simply technology means, they are not concepts. EAI The Enterprise Application Integration (EAI) domain, addresses the same issue [2] they have explicitly identified the same ....

....focus on vendor customer relationships[15] the impact of not controlling the rate and content of changes, the impact of not owning the source code for critical applications [19] andsoon. Interoperability In our approach, Corba or RMI [5] events [6] 8] communication standards (XML and others)[5], as well as mediators, wrappers and other proxies[2] are simply technology means, they are not concepts. EAI The Enterprise Application Integration (EAI) domain, addresses the same issue [2] they have explicitly identified the same problems. Unfortunately, in EAI, the level of abstraction is ....

J.A.Miller,A.Sheth,K.J.KochutandX.Wang. CORBA-Based Run-Time Architectures for Workflow Management Systems. Journal of Database Management, Special Issue on Multidatabases, 7(1):16-27.

....the [17] but a full specification is not given. Since the security reference model is not yet implemented and not even accepted, one can resort to existing CORBA services to implement our model. One such approach can follow the scheme suggested by Sheth in his CORBA based Workflow architecture [12]. In this architecture, there is a Task manager associated with every task (object in our case) which executes the interface code defined in the IDL file. We will need to add to such a task the active security checks and the ability to re initialize its parameters each time it receives a message ....

Miller, J.A., Sheth, A.P., Kochut, K.J., and Wang, X., "CORBA-based run-time architecture for Workflow management systems," Journal of Database Management, Vol 7, No. 1, Winter, 1996, pp. 16--27.

....heterogeneity of each tool (formalism, platform, The tools services are defined in a common formalism, a Process Interface Description Language. In this way, a tool can call another one, whatever their respective formalisms and the communication technology used. It is a Corba like philosophy [28][30] A basic tool provides the services (sub processes) defined in its interface (in PIDL language) A tool (T0 in Fig 1) plays the role of supervisor, and calls the others (tools) The supervisor model expresses formally the relative ordering of sub processes to be executed by the other tools; ....

J.A. Miller, A. Sheth, K.J. Kochut and X. Wang. CORBA-Based Run-Time Architectures for Workflow Management Systems. Journal of Database Management, Special Issue on Multidatabases, 7(1):16-27.

.... that have been pointed out recently [3,10,28,29] three are worth mentioning: the adoption of distributed architectures instead of client server architectures [4,11,12,14] the utilisation of middleware platforms, such as CORBA and WWW, to provide enterprise and inter enterprise interoperability [12,14,26,27,30], and the integration of workflow systems with the Internet [2,22,36] However, despite all the work that has been carried out by the WfMC, interoperability among existing WFMS is hardly achieved [10] Two important classes of protocols can be distinguished, viz. application protocols and data ....

J. Miller, A. Sheth, K. Kochut and X. Wang, CORBA-Based Run-Time Architectures for Workflow Management Systems, Journal of Database Management (Special Issue on Multidatabases) Vol. 7 no. 1 (1996) 16--27.

....engine. It is not likely that a centralized workflow engine can cope with this additional load and deliver the required performance for interactive applications. Therefore, scalability of this approach is bad. As an alternative, workflow systems can be realized in several more decentralized ways [4]. An architecture can consist of several interoperating workflow engines whose realizations are central. The coupled system is also an architecture in which workflow systems interoperate. However, the systems are not equivalent but specialized for a certain purpose. Another architecture, a fully ....

J. A. Miller, A. P. Sheth, K. J. Kochut, and X. Wang. Corba--based Run--time Architecture for Workflow Management Systems. Journal of Database Management, 7, 1996. Special Issue on Multidatabase.

....architectures need to be designed with this in mind. It does not suffice to have a common model (like the one proposed by the Workflow Management Coalition [Hol94] as the problem involves much more complicated issues. In this area, technology like CORBA or OLE may have a considerable impact [MSKW96] ffl Availability: very large workflow management systems will involve several thousand users, hundreds of thousands of concurrently running processes and several thousand sites distributed over wide area networks [KAGM96] In these environments continuous availability is crucial, in the same ....

J.A. Miller, A. Sheth, K.J. Kochut, and X. Wang. Corba-based run-time architectures for workflow management systems. Journal of database Management, 7, 1996.

....Management System WfMS) that matches resources (including human resources) with tasks, and to which programs as well as employees report back. Although some work was done towards distributing the workflow control mechanism to avoid bottlenecks [4] and to overcome intra enterprise heterogeneity [13], a direct consequence of having such a control system is an axiomatic framework which ensures collaboration, where all parts of the system work together for achieving the same goal, and submission, where a central mechanism provides instructions to be followed by the various parts of the system. ....

J. Miller, A. Sheth, K. Kochu, and X. Wang. CorbaBased Run-Time Architecture for Workflow Management Systems. Journal of Database Management, 7(1):16--27, 1996.

....power and should have a formal foundation. Workflow management research has received much attention in recent years. In [GHS95] an up to date high level overview of the current workflow management methodologies and software products is provided. Research prototypes, such as e.g. described in [MSKW96, KS95], concentrate on concurrency, correctness, and recovery of workflows while commercial products pay more attention to user friendly workflow specification tools leaving aspects like recovery and correctness to designers. Some WFMS have not given much attention to the conceptual level [RS94] As ....

J.A. Miller, A. Sheth, K.J. Kochut, and X. Wang. CORBA-Based Run-Time Architectures for Workflow Management Systems. Journal of Database Management, 7(1):16--27, 1996.

.... workflows [17] Further research has built upon this concept by implementing advanced transaction models in commercial WFMSs [2, 3] The Workflow Interface Definition Language (WIDL) has been presented as a method of specifying workflows by adding intertask dependency specifications to CORBA s IDL[13]. This paper builds on the foundation of this previous research by further modifying IDL in order to accommodate relaxed transactional workflows. 2.1 Semantic Failures Since workflows typically execute in a distributed computing environment, the potential for system downtime exists at numerous ....

....skeletons are are basically templates generated by the IDL compiler from user supplied IDL statements. These templates provide the framework from which object requests can be physically implemented. 3. 2 CORBA Based Architecture Five different run time CORBA based architectures are presented in [13]: Highly Centralized, Synchronous Centralized, Asynchronous Centralized, Semi Distributed, and Fully Distributed. Each architecture is classified by its scheduler implementation. The main entities in these architectures are task, task manager, scheduler, monitoring service, and dispatching ....

[Article contains additional citation context not shown here]

J. Miller, A. Sheth, K. Kochut, and X. Wang. CORBA-based run-time architectures for workflow management systems. Journal of Database Management, Special Issue on Multidatabases, 7(1):16-- 17, 1996.

....products are available that can provide object oriented access to this data. If the data is in an object oriented database (OODB) then object adapters may be available in a CORBA Object Request Broker (ORB) that permit the database objects to integrate seamlessly with the implementation objects, [20,21]. Application program interface (API) More usually perhaps, the databases would be protected by an application layer that is designed to help keep them in a consistent state. If an application program interface (API) is provided, it should be possible for a task object wrapper to ....

Miller J., Sheth A., Kochut K., Wang X., "CORBA-Based Run-Time Architectures for Workflow Management Systems", University of Georgia, 1995.

No context found.

J.A. Miller, A. Sheth, K.J. Kochut, and X. Wang, "CORBA-based run time architectures for workflow management systems," Journal of Database Management, Special Issue on Multidatabases, vol. 7, no. 1, pp. 16--27, 1996.

No context found.

Miller, JA, A Sheth, KJ Kochut, and X Wang 1996. "CORBA-Based Run Time Architectures for Workflow Management Systems", Journal of Database Management, Special Issue on Multidatabases, Vol. 7, No. 1 Winter 1996) pp.16-27.

....workflow. A human task typically has a worklist which organizes work items as a sort of to do list. Task scheduling, data flow, control flow, exception handling, recovery and monitoring 2 functions are provided by task managers, schedulers and auxiliary enactment service processes. Sheth, 1996, Miller et al. 1996, Miller et al. 1998, Kochut et al. 1999] There are many potential threats for Web based workflow: Not everyone is allowed to execute certain workflow tasks. Not every one is allowed to access all information. We do not want information sent over the network to be stolen. We do not want ....

Miller, J. A., Sheth, A. P., Kochut, K. J., and Wang, X. (1996). CORBA-based Run-Time Architectures for Workflow Management Systems. [Dogac, 1996], 7(1):16--27.

....is geared towards developing a multi paradigm transactional WFMS capable of supporting large scale, mission critical, inter enterprise workflow applications in HAD environments. Several workflow enactment services have been designed and implemented based on various scheduling paradigms [Wan95, MSKW96, SKM 96] These range from highly centralized ones to fully distributed implementations using CORBA and Web technologies (either exclusively, or in combination) as infrastructure for workflow enactment. In this paper, our focus is on the error handling support provided in ORBWork, a reliable ....

....we discuss the aspects of these 6 components of the METEOR 2 WFMS that are useful in explaining error handling discussed in the subsequent sections. 5. 1 The METEOR 2 Workflow Model In this section, we review the basic components of the METEOR 2 workflow model as discussed in [KS95] and [MSKW96] These include interfaces, processing entities, tasks, task managers, and the workflow schedulers. Figure 2 describes the high level modeling units of the METEOR 2 workflow model using Unified Modeling Language (UML) notation [Rat97] Control Dependency State Control Flow Scheduler Task ....

[Article contains additional citation context not shown here]

J. A. Miller, A. P. Sheth, K. J. Kochut, and X. Wang. CORBA-based Run-Time Architectures for Workflow Management Systems. [Dog96], 7(1):16--27, Winter 1996. 26

....what to do when they fail and where to send their output. To establish global control as well as facilitate recovery and monitoring, the task managers communicate with workflow schedulers. It is possible for schedulers to be either centralized or distributed, or even some hybrid between the two [Miller et al. 1996]. 1 2 Error Handling and Recovery WebWork supports the development of workflow applications that can run in heterogeneous and distributed environments. Any number of organizations can be easily incorporated into a workflow a Web server at an organization accesses its local database(s) using ....

Miller, J. A., Sheth, A. P., Kochut, K. J., and Wang, X. (1996). CORBA-based Run-Time Architectures for Workflow Management Systems. [Dogac, 1996], 7(1):16--27.

....developing a multi paradigm transactional WFMS capable of supporting large scale, mission critical, inter enterprise workflow applications in HAD environments. Various task models have been defined to support integration of heterogeneous task types into the workflow model [KS95, Wan95, Mur95, MSKW96] Task models include models for transactional, non transactional, user and two phase commit types of tasks. Graphical workflow designers have been developed to enable graphical representation of the workflow process, associated workflow data, and task models that map to actual user and ....

....workflow designers have been developed to enable graphical representation of the workflow process, associated workflow data, and task models that map to actual user and application tasks. The design process is followed by semi automatic code generation of an executable workflow application [KS95, MSKW96] Several enactment systems have been designed and implemented based on various scheduling paradigms [Wan95, MSKW96, SKM 96] These range from highly centralized ones to fully 2 distributed implementations using CORBA and Web technologies (either exclusively, or in combination) as ....

[Article contains additional citation context not shown here]

J. A. Miller, A. P. Sheth, K. J. Kochut, and X. Wang. CORBA-based Run-Time Architectures for Workflow Management Systems. citedogac, 7(1):16--27, Winter 1996. 22

....recovery and failure atomicity. In addition, the workflow could exhibit transactional properties for parts of its execution. It might use transaction management technology such as transactionalRPC between two components of a WFMS (e. g, scheduler and task manager) an extended commit coordinator [Miller et al. 1996], or a transactional protocol (XA) between a task manager and a processing entity. In our view, the scope of transactional workflows extends beyond the purview of database transactions and ATMs. Workflow executions include tasks that might involve database transactions; however, large scale ....

....Groups of tasks along with their inter task dependencies can be modeled as compound tasks. The compound tasks have their task structures too. Transactional workflows can be modeled using transactional tasks and transactional compound tasks as the basis of the workflow model. The METEOR 2 WFMS [Miller et al. 1996, Sheth et al. 1996b] is based on the METEOR model. It extends the model in terms of providing better supy METEOR refers to the project carried out at Bellcore. METEOR 2 is its follow on at the LSDIS Lab of the University of Georgia. TRANSACTIONS IN TRANSACTIONAL WORKFLOWS 13 port for failure ....

[Article contains additional citation context not shown here]

Miller, J. A., Sheth, A. P., Kochut, K. J., and Wang, X. (1996). CORBA-based Run-Time Architectures for Workflow Management Systems. Journal of Database Management, Special Issue on Multidatases, 7(1):16--27.

No context found.

Miller, J., Sheth, A., Kochut, K., Wang, X. (1996). CORBA-based run-time architectures for workflow management systems. Journal of Database Management, 7, 16-27.

....Scheduler, Task Managers and Tasks (see Figure 3) To establish global control, as well as facilitate recovery and monitoring, the task managers communicate with a scheduler. It is possible for the scheduler to be either centralized or distributed, or even some hybrid between the two [Wan95, MSKW96] WORKFLOW MODEL REPOSITORY DESIGNER MONITOR AND TASK TASK TASK TASK WEB DB TASK MANAGER TASK MANAGER TASK MANAGER TASK MANAGER AUTOMATIC CODE GENERATION Figure 3: Meteor 2 Run Time Model To facilitate monitoring and control of tasks, each task is modeled using a well defined task structure ....

....of object implementations throughout the lifetime of an object. This inherent fault tolerance of CORBA makes it superior to the Web for designing robust distributed applications. 5 CORBA based Implementation of the Workflow System We have designed and implemented several CORBA based WFMS [MSKW96] Here we discuss the fully distributed implementation that is used for the application under consideration. 5.1 Distributed Scheduler Architecture The idea behind the creation of the fully distributed runtime for a WFMS is simple. The main principle is that every task manager should ....

J. A. Miller, A. P. Sheth, K. J. Kochut, and X. Wang. Corba-based run time architectures for workflow management systems. Journal of Database Management, Special Issue on Multidatases, 7(1), 1996.

No context found.

Miller, J., Sheth, A., Kochut, K., and Wang, X., "CORBA-Based Run-Time Architectures for Workflow Management Systems," Journal of Database Management, Special Issue on Multidatabases, Vol. 7, No. 1, 1996, pp. 16-27.

No context found.

J.A. Miller, A. Sheth, K.J. Kochut and X. Wang. CORBA-Based Run-Time Architectures for Workflow Management Systems. Journal of Database Management, Special Issue on Multidatabases, 7(1):16-27.

No context found.

Miller, J. A.; Sheth, A. P.; Kochut, K. J. ; Wang, X.: "CORBA-Based Run-Time Architectures for Workflow Management Systems" Journal of Database Management, Special Issue on Multidatabases, 7(1) (1996), pp. 16-27.

No context found.

J.A. Miller, A. Sheth, K.J. Kochut, and X. Wang. Corba-based runtime architectures for workflow management systems. Journal of database Management, 7, 1996.

First 50 documents

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC