Contact Point:

Heiko Schuldt ( )

University of Basel
  

Technical Contact Points:

Paola Ranaldi ( )
Michael Springmann ( )
Gert Brettlecker ( )
 

Type of Software:

STABLE PROTOTYPE 
 

Descriptive Keywords:

Windows, C++, Process Management, Scalability, Reliability, Replication, Service Oriented Architecture
  

Potential Use and Applications:

Standards like SOAP, WSDL, and UDDI facilitate the proliferation of services. Based on these technologies, processes are a means to combine services to applications and to provide new value-added services (“programming in the large”). For large information systems, a centralized process engine is no longer appropriate due to limited scalability. Instead, OSIRIS offers a distributed and decentralized process engine that routes process instances directly from one node to the next ones. Such a Peer-to-Peer Process Execution (P3E) promises good scalability characteristics since it is able to dynamically balance the load of processes and services among all available service providers. OSIRIS is the process execution engine of the DelosDLMS.
  

General description:

OSIRIS, short for Open Service Infrastructure for Reliable and Integrated process Support has been developed at the ETH Zurich, and continued at UMIT in Hall in Tyrol and now at the University of Basel. OSIRIS combines the benefits of several existing infrastructures, namely: i.) discovery and invocation of web services from frameworks, ii.) process support and execution guarantees from workflow management systems, iii.) late binding of service calls and load balancing from grid infrastructures, and, finally, iv.) Peer-to-Peer Processes Execution (P3E) in analogy to peer-to-peer file systems. An interesting characteristic of P3E in OSIRIS is that process navigation costs only accumulate on nodes of the community that are directly involved in the execution of a process. Especially, there is no central component in charge with process execution. Therefore, and in contrast to a centralized process engine, P3E bears the potential to scale well with the number of concurrent processes and the number of service providers. However, this requires sophisticated strategies for the replication of meta information for P3E. Especially, replication mechanisms should avoid frequent accesses to global information repositories. OSIRIS deploys a clever publish/subscribe based replication scheme together with freshness predicates to significantly reduce replication costs.

An online demonstration is available at http://isisdemo.cs.unibas.ch (username / password upon request).
  

Technical Description:

OSIRIS is implemented completely in C++ based on the Windows API. At a basic level it offers a generic message-oriented middleware which allows exchange of messages in an efficient proprietary way based on TCP socket connections. Based on the messaging system, OSIRIS offers a component (service) framework which allows for configuration, lifecycle management, and service execution. Additionally, a replication framework allows for sophisticated replication of meta-data between services (components). Message processing at component level is done in a service based concept, where service interaction is in request-response style. Moreover, OSIRIS offers a dedicated agent component, which is responsible for communication between OSIRIS providers and offers pipeline based message processing. The agent has an incoming and outgoing message processing pipeline which also for arbitrary plugging of dedicated pipeline handlers. An example of a pipeline handler is the process execution engine running on each provider. Additional pipeline handlers are e.g., responsible for message routing and load balancing. This pipeline based message processing allows to easily extend OSIRIS. A dedicated gateway component offers the ability to integrate non OSIRIS services, like standard WSDL/SOAP services in a loosely coupled way. The OSIRIS infrastructure offers a generic web-based user interface, which allows taking control of participating providers and their services (components). Newly integrated services are easily to adapt to this generic user interface by applying a web templates by using XSLT. Moreover, process execution is monitored and the web interface allows investigating the process logs. Finally, O’GRAPE (OSIRIS GRAphical Process Editor) is accessible via the web interface in order to create and modify workflows to combine services into processes.

Detailed information about ISIS and OSIRIS is presented in “The OSIRIS Process Support Middleware and the ISIS Process-Based Digital Library Application”

(http://dbis.cs.unibas.ch/delos_website/jpa2/osiris.pdf).
  

Required User Skills:

Fair knowledge of C++ and Windows programming, conceptual knowledge of message-oriented middleware, SOA, and process management is recommended in order to be able to fully understand the source code and implement new tightly coupled (OSIRIS) services. For the integration of WSDL/SOAP based services (loosely coupled) into custom processes no knowledge of C++ and the OSIRIS source code is needed.
  

Pre-Requisites for Installation:

At least one PC with Microsoft Windows 2000 or newer and an available SQL Server database server preferable at the same machine is needed to run the OSIRIS platform. Additional, memory and disc requirements are mostly demanded by the services one wants to install. The OSIRIS core services and the middleware layer itself are not resource demanding.
  

Conditions of use:

Contact the authors.