Navigators' Current Projects

CORTEX - CO-operating Real-time senTient objects: architecture and EXperimental evaluation
DEFEATS - Distributed Fault and Attack Tolerant Systems Configuration
MAFTIA - Malicious- and Accidental-Fault Tolerance for Internet Applications
MICRA - A Model for the Development of Mission Critical Applications
ARTIST - NoE in Advanced Real-Time Systems
COPE: Secure and Reliable Parallel Processing


Navigators Past Projects

Here you may find information about the following projects:

Delta-4 - Definition and Design of an open Dependable Distributed Architecture
CoDiCom - Distributed Real-time Computer Control System
BROADCAST - Basic Research On Advanced Distributed Computing: from Algorithms to SysTems
DINAS - DQS - Design and Implementation of CNMA-based Networks for CIME Applications in SMEs
GODC - Group-Oriented Distributed Computing
MOOSCo - MOO with Separation of Concerns
SHIFT - Group Communication with Differetiated Messages
TOPCOM - Topology-Aware Reliable Group Communication in Geographically Large-Scale Systems
DEAR-COTS - Distributed Embedded Architectures using Commercial Off-The-Shelf Components


Project Title: TOPCOM: Topology-Aware Reliable Group Communication in Geographically Large-Scale Systems
http://topcom.di.fc.ul.pt/ 

Sponsoring bodies: FCT (PRAXIS/P/EEI/12202/1998)
Total award amount: 23,500 Euro
Coordinator: FCUL
Partners: FCUL
Start date: September 1999
Duration: 2 years
Keywords: Large-Scale Distributed Systems, Group-Communication,
Fault-Tolerance, Protocols

Abstract: 

The goal of the project is twofold: in first place, it intends to implement and test a mature distribution of the Navigators' protocols and, in second place, to contribute to the validation the Ensemble framework. Since there are several technical differences between the protocol designed by the Navigators and the protocols currently implemented in Ensemble, this experiment will emphasize the generic aspects of the framework and reveal its potential limitations. The project will gather feedback from protocol implementors in order to improve the framework and, hopefully, to support other research groups in adopting Ensemble for their projects.


Aims: 

The project pretends to mature some of the topological protocols previously developed by the team and to test their implementation in the Ensemble platform. It also intends to study novel architectures to support the implementation and execution of configurable protocol stacks.

Approach and Methods: 

The project intends to develop and evaluate prototypes and use the experience gained to refine the models, algorithms, protocols and implementations.

Progress and Results: 

Part of the project was dedicated to the implementation of a Light-Weight Groups Layer in the Ensemble system. This experiment helped to get insights on the tradeoffs involved in the design of a platform to implement and execute configurable protocol stacks.

The project also investigated the developemnt of a protocol composition framework able to support inter-QoS constraints. A prototype of this platform, called Appia, has been implemented.

Indication of project size at FCUL: 

5 Researchers. 

Latest publications:

H. Miranda e L. Rodrigues. Flexible Communication Support for CSCW Applications. In Proceedings of the 5th International Workshop on Groupware, pp. 338-342, Cancún, México, Setembro de 1999.

H. Miranda e L. Rodrigues. Communication support for multiple QoS requirements. In Third European Research Seminar on Advances in Distributed Systems (ERSADS'99), Madeira Island, Portugal, 23-28 April 1999.

L. Rodrigues e K. Guo. Partitionable Light-Weight Groups. In Proceedings of the 20th IEEE International Conference on Distributed Computing Systems, pp. 38-45, Taipe, Taiwan, Abril de 2000.

L. Rodrigues, R. Baldoni, E. Anceaume, M. Raynal, Deadline-Constrained Causal Order. In Proceedings of The 3rd IEEE International Symposium on Object-oriented Real-time Distributed Computing, pp. 234-241, Newport Beach, California, USA, Março de 2000. 


Project Title: SHIFT: Group Communication with Differetiated Messages
http://shift.di.fc.ul.pt/ 

Sponsoring bodies: FCT (Sapiens 32869/1999)
Total award amount: 23,500 Euro
Coordinator: FCUL
Partners: FCUL, U. Minho
Start date: Approevd, to be started soon.
Duration: 2 years
Keywords: Semantic Reliability, Group-Communication, Fault-Tolerance


Abstract: 

The project intends to study the use of knowledge on the application semantics to improve the efficiency of group communication systems. The starting point of the project is the definition of semantic reliability, recently introduced by the project partners.

Aims: 

The project intends to design and implement new algorithms and protocols that exploit the notion of semantic reliability. The project aims to study the use of this concept under different system assumptions and for different application classes with diverse consistency requirements.

Approach and Methods: 

The project will first design models, create the algorithms and implement the protocols to offer services based on the notion of semantic reliability.

Progress and Results: 

The project has not started yet, but there is ongoing preparation work.

Indication of project size at FCUL: 

3 Researchers. 

Latest publications:

(Preliminary work)

Semantically Reliable Multicast Protocols José Orlando Pereira, Luís Rodrigues and Rui Oliveira IEEE Intl. Symp. on Reliable Distributed Systems (SRDS'2000), October 2000.

Semantically Reliable Multicast: Current Status and Future Work José Orlando Pereira, Luís Rodrigues and Rui Oliveira 14th International Symposium on DIStributed Computing (DISC'2000), Brief Announcement,
October 2000.

Fault-Tolerant Replication of High Throughput Services José Orlando Pereira IEEE Intl. Conf. on Dependable Systems and Networks (FTCS-30 and DCCA-8), Student Forum, June 2000.


Project Title: MOOSCo: MOO with Separation of Concerns
http://www.esw.inesc.pt/moosco/ 


Sponsoring bodies: FCT (Sapiens 33127/1999)
Total award amount: 23,500 Euro
Coordinator: INESC
Partners: INESC, FCUL
Start date: Approved, to be started soon.
Duration: 2 years
Keywords: Multi-user Object Oriented Environement, Separation of
Concerns, Configurable Systems

Abstract:

The MOOSCo project, Multi-user Object-Oriented environments with Separation of Concerns, addresses the difficulties in applying a component-based approach in a vertical and integrated manner, from analysis to implementation, to the design of this class of systems. The project will define an architecture that will be applied in the MOOs context. MOO environments constitute a challenge for object-oriented distributed systems theory and practice due to its unique requirements for dependability, scalability, adaptability, usability, dynamic changes, non-functional domains to be considered, and efficiency.

Aims: 

The project intends to design and implement an architecture to the support of multi-user object-oriented environments. The architecture is based on component composition and addresses three abstraction layers: user models, middleware abstractions, and infrastructure communication protocols.

Approach and Methods: 

The project workplan is divided into several parts:

  1. Identify the user models that are relevant for MOOs in order to classify the variabilities inherit to the MOO applications.
  2. Design composible and customizable middleware abstractions to support user models and their variabilities and allow the construction of MOO application that are easily tuned and can evolve. Implement those abstractions as an object-oriented framework.
  3. Design composible and customizable infrastructure protocols, offering different quality of
    service, to be used by the middleware abstractions.
  4. Integrate the results from the previous tasks in a coherent architecture.
  5. Validate the results applying it to a concrete MOO system.


Progress and Results: 

The project has not started yet, but there is ongoing preparation work.

Indication of project size at FCUL: 

4 Researchers. 

Latest publications:

(Preliminary work)

Separating Replication from Distributed Communication: Problems and Solutions. Miguel Antunes, Hugo Miranda, António Rito Silva, Luís Rodrigues and Jorge Martins. International Workshop on Distributed Dynamic Multiservice Architectures, in conjunction with ICDCS2001. Accepted for publication.

Using Separation and Composition of Concerns to Build Multiuser Virtual Environments Miguel Antunes and António Rito Silva IEEE Proceedings of the 6th International Workshop on Groupware October 2000 Madeira Island, Portugal

Group Communication Support for Dependable Multi-User Object-Oriented Environments Hugo Miranda, Miguel Antunes, Luís Rodrigues and António Rito Silva Presented at SRDS Workshop on Dependable System Middleware and Group Communication (DSMGC 2000) October 2000 Nürnberg, Germany


Project Title: GLOBDATA
http://globdata.iti.es/


Sponsoring bodies: Esprit (IST-1999-20997)
Total award amount: 1.094.281 Euros 
Coordinator: ITI
Partners: FFCUL, UPN, GFI, EIKON
Start date: November 1999.
Duration: 2 years
Keywords: Database replication, consistency, fault-tolerance

Abstract: 

The overall objective of the project is to design an efficient software development tool and support system to provide application developers with a global view of an object database repository with transactional access to geographically distributed persistent objects independent of their location.

Aims: 

The aim is to create a set of mechanisms to handle replica consistency maintenance, data distribution, and transaction commitment and synchronization. These mechanisms are provided in a coherent tool called COPLA.

Approach and Methods: 

COPLA makes use of standard proposals for distributed application creation like those on OMG's CORBA. At the level of communication support, COPLA will rely on a configurable group communication tool.

Progress and Results: 

The project is started recently. Currently the programming interface is being designed and specified.

Indication of project size at FCUL: 

8 Researchers. 

Latest publications:

Not available yet.


Project Title: Delta-4 - Definition and Design of an open Dependable Distributed Architecture

Sponsoring body: CEC-DGXIII, Esprit
Coordinator: Ferranti Computer Systems Ltd
Start date: March 1986
Duration: 69 months, ended
Keywords: distributed systems, fault-tolerance, real-time, open distributed processing, reliable broadcast

Abstract:

The Delta-4 project is concerned with the achievement of dependability in open distributed systems, including real-time systems. The project has developed a distributed fault-tolerant architecture for the support of dependable applications for computer integrated manufacturing, process control, office systems, etc.

Aims:

The aim of the Delta-4 project is to provide a computational and communication infrastructure for application domains that require distributed system solutions with various dependability and real-time constraints. The scale of distribution in the targetted application domains is commensurate with the distances that can be covered by local area networks.

Approach and Methods:

To be able to satisfy a large range of application requirements in a cost-effective manner, the Delta-4 architecture can provide various degrees of dependability and performance. Fault-tolerance is based on the replication of components of run-time software. Replicas are allocated to distinct nodes of a local area network.

The Delta-4 architecture offers two variants (both based on sub-systems presenting a high degree of commonality):

(a) the Delta-4 Open System Architecture (D4-OSA) which, as its name suggests, is an open architecture able to accommodate heterogeneity,

(b) the Delta-4 Extra Performance Architecture (D4-XPA) which provides explicit support for assuring timeliness.

Progress and Results:

The project has developed and demonstrated prototypes of the architecture at yearly intervals throughout the project. Two pilot demonstrators were implemented: a payment card authorization centre (Credit Agricole) and a computer-integrated manufacturing system for the Renault automobile company. The project ended in December 1991.

Main contributions of INESC:

Indication of project size at INESC:

6 researchers

Latest publications:

D. Powell (Ed.),
"The Delta-4 Architecture Guide",
Lecture Notes in Computer Science, Springer Verlag, Heidelberg, Germany, 1991 (to appear).

P.A. Barrett, A.M. Hilborne, P.G. Bond, P. Verissimo, L. Rodrigues, N.A. Speirs,
"The Delta-4 XPA Extra Performance Architecture", in Proc. 20th. Int. Symp. on Fault-Tolerant Computing Systems (FTCS-20), (IEEE), pp.481-488, Newcastle upon Tyne, UK, June 1990.

P. Verissimo, L. Rodrigues,
A posteriori Agreement for Fault-tolerant Clock Synchronization on Broadcast Networks. In Digest of Papers, The 22th International Symposium on Fault-Tolerant Computing, July 1992, Boston - USA.

L. Rodrigues, P. Verissimo,
xAMp: a Multi-primitive Group Communications Service. In 11th Symposium on Reliable Distributed Systems, Houston, Texas, October 1992.

P. Verissimo, L. Rodrigues,
Reliable multicasting in high-speed lans. In High-Capacity Local and Metropolitan Area Networks, pages 397-412, Springer Verlag, NATO ASI Series, Volume F72, 1991

 


Project Title: CoDiCom - Distributed Real-time Computer Control System

Sponsoring bodies: STRIDE - Jnict, since 1993.
Coordinator: INESC
Consultants: Prof. H.Kopetz, T.U. Vienna; Prof. R.Schlichting, U. Arizona.
Start date: October 1991
Duration: 3 years
Keywords: real-time; reliable multicast; fault-tolerance; I/O; control.

Abstract:

Distributed real-time system architectures are still in fast evolution. Still, there are challenging fields yet unexplored: the most efficient combination of time-triggered and event-triggered behaviours; highly concurrent and decentralised real-time processing, based on object-oriented paradigms other than client-server via RPC (eg. reliable Casts, peer object conversations); the application of distributed fault-tolerance techniques (eg. those pursued in Delta-4) to fault-tolerant I/O processing, exploring different flavours of synchronism and the advantages of taking an embedded approach.

Aims:

Exploring concepts which may open unexpected doors in fields such as manufacturing, process control, real-time cooperative work, transactional systems, etc.

Developing fault-tolerant input-output solutions relying on techniques otherwise used for distributed computation, based on the paradigms of groups and reliable multicast.

Approach and Methods:

Look at architecture from the viewpoint of an embedded distributed real-time system, to match the kind of applicationms typically found in field-buses.

Progress and Results:

Definition of the system architecture. Development of a PC-farm style testbed with remote download. Work published on the underlying concepts expressed above.

Potential:

The issues under research in this project may lead to the development of new techniques in process control and automation.

Indication of project size at INESC:

4 researchers

Latest publications:

P. Verissimo, H. Kopetz. Part V - Real Time and Dependability, in Distributed Systems, edited by Sape Mullender, ACM-Press. Addison-Wesley, 1993.

P. Veríssimo. Causal Delivery Protocols in Real-time Systems: a Generic Model. Journal of Real-Time Systems, to appear 1995.

P. Veríssimo. Ordering and Timeliness Requirements of Dependable Real-Time Programs. Journal of Real-Time Systems, Kluwer Eds., 7(2):105--128, September 1994. Also as INESC AR/14-94.

J. Rufino and P. Veríssimo. A Study on the Inaccessibility Characteristics of the Controller Area Network. In Proceedings of the 2nd International CAN Conference, London, England, October 1995. CiA. (to appear).

Carlos Almeida and Paulo Veríssimo. An adaptive real-time group communication protocol. In Proceedings of the First IEEE Workshop on Factory Communication Systems, Lausanne, Switzerland, October 1995.

L. Rodrigues, A. Casimiro, and P. Veríssimo. Priority-based totally ordered multicast. In Proceedings of the 3rd IFAC/IFIP workshop on Algorithms and Architectures for Real-Time Control (AARTC'95), Ostend-Belgium, May 1995. IFAC.

L. Rodrigues, P. Veríssimo, and J. Rufino. A low-level processor group membership protocol for {LAN}s. In Proceedings of the 13th International Conference on Distributed Computing Systems, pages 541-550, Pittsburgh, Pennsylvania, USA, May 1993. Also as INESC AR/30-93.

P. Veríssimo and L. Rodrigues. A posteriori Agreement for Fault-tolerant Clock Synchronization on Broadcast Networks. In Digest of Papers, The 22th International Symposium on Fault-Tolerant Computing, Boston - USA, July 1992. INESC AR/65-92.

J. Rufino and P. Veríssimo. A study on the inaccessibility characteristics of ISO 8802/4 Token-Bus LANs}. In IEEE INFOCOM'92 Conference on Computer Communications, IEEE, Florence, Italy, May 1992.

 


Project Title: BROADCAST - Basic Research On Advanced Distributed Computing: from Algorithms to SysTems

Sponsoring bodies: Esprit BRA
Coordinator: U. Newcastle
Partners: EPF de Lausanne, INESC, INRIA, INRIA-IRISA, Un. de Bologna, Un. Joseph Fourier, Un. of Newcastle, Un. Twente
Start date: October 1992
Duration: 3 years
Keywords: groups; distributed systems; large scale; CSCW.

Abstract:

Large-scale distributed systems comprising several thousands to millions of individual computer systems (nodes) are coming into existence both as a consequence of technological advances and the demands placed by applications. The increase in scale adds a new dimension to the problems of building distributed systems, and requires rethinking of many of the existing computational paradigms, algorithms and structuring principles for distributed computing. The objective of the BROADCAST project is to develop the principles for understanding, designing, and implementing LSDCS. The project will address the following tasks: Fundamental Concepts; Systems Architecture; Systems Engineering.

Aims:

The main objective of the BROADCAST project is to develop the underlying principles of designing and implementing large scale distributed computing systems (LSDCS). We expect LSDCS to exhibit great diversity of node and communications capability. Nodes will range from (mobile) laptop computers, workstations to supercomputers.

In order to meet the main objective of the BROADCAST project, it is necessary then to understand the impact of two main factors responsible for the growth of interest in LSDCS: (i) application requirements; (ii) user expectations on technology.

Approach and Methods:

It is intended to investigate the adequate properties of: multicasting communication; group communication protocols; group management services, such as membership, replication and cooperation; global time services. Investigation will be also directed towards the development of suitable CSCGW paradigms, in imbrication with the more fundamental group activity paradigms mentioned above. Prototyping in later stages is considered paramount, to test in a real world the techniques to be developed.

Progress and Results:

Several papers, reports and surveys produced in the three streams of project activity: concepts and paradigms; architecture and protocols; applications. Main results of INESC: survey on groupware; framework for reliable LSDCS, leading to the design of NavTech.

Potential:

It is expected that research in this area will lead to an innovative system, to support large scale distributed applications, such as CSCGW or on-line transactions.

Indication of project size at INESC:

6 researchers

Latest Publications:

François J.N. Cosquer, Luís Rodrigues, and Paulo Veríssimo. Using Tailored Failure Suspectors to Support Distributed Cooperative Applications. In Proceedings of the 7th International Conference on Parallel and Distributed Computing and Systems, October 1995.

François Cosquer and Paulo Veríssimo. The impact of group communication paradigms on groupware support. In Proceedings of the 5th IEEE Workshop on Future Trends of Distributed Computing Systems, pages 207-214, Seju Island, Corea, August 1995.

L. Rodrigues, H. Fonseca, and P. Veríssimo. Reliable computing over mobile networks. In Proceedings of the 5th Workshop on Future Trends of Distributed Computing Systems, pages 488-494, Cheju Island, Korea, August 1995.

L. Rodrigues and P. Veríssimo. Causal separators for large-scale multicast communication. In Proceedings of the 15th International Conference on Distributed Computing Systems, pages 83-91, Vancouver, British Columbia, Canada, May 1995. IEEE. Also as INESC AR/05-95.

L. Rodrigues, E. Siegel, and P. Veríssimo. A Replication-Transparent Remote Invocation Protocol. In Procs. of the 13th Symp. on Reliable Distrib. Systems, Dana Point, California, Oct. 1994.

L. Rodrigues and P. Veríssimo. How to avoid the cost of causal communication in large-scale system. In Procs. of the 6th ACM-SIGOPS Europe Workshop, Dagstuhl, Germany, September 1994.

François Cosquer and Paulo Veríssimo. Survey of selected groupware applications and supporting platforms. Technical Report RT-21/94, INESC, September 1994. (also available as Broadcast Technical Report 2nd year deliverables, 1994).

P. Veríssimo, Werner Vogel, and Luis Rodrigues. A Framework for Structuring Group Support in LSDCs. BROADCAST REPORT, INESC, Lisboa, Portugal, September 1993. Expanded version of a paper in procs. 4th IEEE Workshop on Future Trends of Distr. Comput. Syst., Lisboa-Portugal, 1993. Also as INESC AR/15-94.

Paulo Veríssimo and Luís Rodrigues. Group Orientation: a Paradigm for Modern Distributed Systems. In Proceedings of the 5th ACM SIGOPS European Workshop, Mont Saint-Michel, France, September 1992. Extended and revised version as INESC RT/20-94.

L. Rodrigues and P. Veríssimo. Replicated object management using group technology. In Procs. of the 4th Workshop on Future Trends of Distributed Computing Systems, pages 54--61, Lisboa, Portugal, September 1993. Also as INESC AR/28-93.

 


Project Title: DINAS - DQS: Design and Implementation of CNMA-based Networks for CIME Applications in SMEs

Sponsoring bodies: Esprit
Coordinator: Intracom
Partners: Intracom, Intrasoft, IPK-Berlin, INESC, Hyperion
Start date: October 1992
Duration: 2 years, ended
Keywords: CIM, quality management, distributed systems, real-time networks, MAP.

Abstract:

Several ESPRIT projects have produced architectures and technologies for the interconnection of nodes in distributed systems: protocols, communication stacks. Some of these technologies have not solved all the problems encountered in their target environments: - the difficulty of integrating with efficiency different cell network technologies; - the lack of integration of cell networks with high-speed backbones such as FDDI; - the achievement of reliable real-time operation, namely in the input/output part of the system.

DINAS will address these problems in the scope of a distributed quality control application in a large-scale factory setting. Technology emerging from the ESPRIT project CNMA will be used wherever possible, being complemented with customs developments or other off-the-shelf components when necessary.

Aims:

In the area of integration, it is wished to provide interoperation and intercommunication of a set of selected communication architectures susceptible of being used in a target factory automation scenario: CNMA, MAP; proprietary LANs; defacto standards, like TCP/IP.

The current standard network protocols are not fit for highly concurrent and interactive applications across LAN borders. This may imply new protocols that handle LAN interconnection transparently and at the same time provide reliability and powerful addressing schemes. Some implementations of reliable multicasting protocols fit this description.

With regard to reliable real-time operation and performance, its achievement has to do with architectural properties that affect the system vertically, that is, justifiably obtaining reliable real-time behaviour of MAP-type cell networks.

Finally, the overall goal is to design a scalable distributed industrial information system.

Approach and Methods:

Determining user requirements.

Definition of the overall system architecture, namely, the interworking aspects, and distribution support. Definition of information flow model, from SCADA to DBMS. Definition of the quality applications.

Implementation of the prototypes. Validation and performance measurement on an experimental platform (phase 1) and on the pilot site at the factory (phase 2).

Progress and Results:

The pilot manufacturing cell quality control was successfully achieved.

Main role of INESC:

Potential:

It is expected that research in this area will unveil new techniques to support distributed quality management systems, and distributed SCADA systems in general.

Indication of project size at INESC:

6 researchers

Latest publications:

P. Verissimo et al. Dinas - user requirements on networks and services. Technical Report RT-60/93, Esprit Proj. Dinas-DQS 6779, February 1993.

P. Verissimo et al. Dinas - internetworking architecture and service specification. Technical Report RT-59/93, Esprit Proj. Dinas-DQS 6779, June 1993.

 


Project Title: GODC - Group-Oriented Distributed Computing

Sponsoring bodies: ESPRIT BRA (and USA NSF), since 1993
Coordinator: INESC
Partners: Cornell Univ.
Start date: November 1993
Duration: 2 years
Keywords: groups; distributed systems; large scale; CSCW.

Abstract:

Increasing use of distributed systems, with the corresponding decentralization of activities, stimulate the need for structuring those activities around diverse groups of interested participants. The building blocks for group activity are currently the subject of great interest. The notion pervades all layers of a distributed architecture, from multicasting communication infrastructures and group communication protocols, to group management services. Operating system and networking support should evolve to accommodate this reality.

Aims:

Both the Navigators team at INESC and the ISIS group at Cornell have a track record of producing group-oriented technologies. They propose to cooperate in order to exchange ideas about their respective work, and possibly open the way for reuse of technologies each one develops. Understanding the requirements of the user applications on one side, and the constraints of the environment on the other, are fundamental pre-conditions to establish: the most adequate group activity building blocks; the functional and correctness dependencies among them; and their efficient implementation in the operating system, from network to applications support environment.

Paradigms and algorithms to assist the solution of these distributed problems have been presented in the recent years. A systematics of group orientation in distributed systems is yet to be developed. It is hoped to achieve results in this area. In particular, about its adaptability to large scale distributed computing systems.

Approach and Methods:

This is a strategic research action, where the teams will merge and discuss their experiences in g-o technology. As far as INESC is concerned, this will work both internally to group, from the several ongoing projects (NavTech, NavCim, CoDiCom), and externally, with the BROADCAST (cf. project synopsis elsewhere) partners and Cornell. It is intended to investigate around the 'group' paradigm, in order to discover the adequate properties and structure of each of the building blocks of a g-o system, to respond to the new challenges in distributed computing.

Progress and Results:

The cooperation has focused on: (i) models and frameworks for large-scale group support; (ii) a few key technologies - remote and reliable client-server access; group membership and addressing; lightweight groups. In the course of the cooperation, several visits have taken place. Several papers and reports on models and frameworks have been produced. Both have influenced the production of several papers on particular technologies.

Potential:

It is expected that research in this area will unveil new techniques to support construction of systems and applications, based on the group paradigm.

Indication of project size at INESC:

6 researchers

Latest publications:

P. Veríssimo. Causal Delivery Protocols in Real-time Systems: a Generic Model. Journal of Real-Time Systems, to appear 1995.

François J.N. Cosquer, Luís Rodrigues, and Paulo Veríssimo. Using Tailored Failure Suspectors to Support Distributed Cooperative Applications. In Proceedings of the 7th International Conference on Parallel and Distributed Computing and Systems, October 1995.

Carlos Almeida and Paulo Veríssimo. An adaptive real-time group communication protocol. In Proceedings of the First IEEE Workshop on Factory Communication Systems, Lausanne, Switzerland, October 1995.

L. Rodrigues, A. Casimiro, and P. Veríssimo. Priority-based totally ordered multicast. In Proceedings of the 3rd IFAC/IFIP workshop on Algorithms and Architectures for Real-Time Control (AARTC'95), Ostend-Belgium, May 1995. IFAC.

François Cosquer and Paulo Veríssimo. The impact of group communication paradigms on groupware support. In Proceedings of the 5th IEEE Workshop on Future Trends of Distributed Computing Systems, pages 207-214, Seju Island, Corea, August 1995.

L. Rodrigues, H. Fonseca, and P. Veríssimo. Reliable computing over mobile networks. In Proceedings of the 5th Workshop on Future Trends of Distributed Computing Systems, pages 488-494, Cheju Island, Korea, August 1995.

L. Rodrigues and P. Veríssimo. Causal separators for large-scale multicast communication. In Proceedings of the 15th International Conference on Distributed Computing Systems, pages 83-91, Vancouver, British Columbia, Canada, May 1995. IEEE. Also as INESC AR/05-95.

L. Rodrigues, E. Siegel, and P. Veríssimo. A Replication-Transparent Remote Invocation Protocol. In Procs. of the 13th Symp. on Reliable Distrib. Systems, Dana Point, California, Oct. 1994.

L. Rodrigues and P. Veríssimo. How to avoid the cost of causal communication in large-scale system. In Procs. of the 6th ACM-SIGOPS Europe Workshop, Dagstuhl, Germany, September 1994.

François Cosquer and Paulo Veríssimo. Survey of selected groupware applications and supporting platforms. Technical Report RT-21/94, INESC, September 1994. (also available as Broadcast Technical Report 2nd year deliverables, 1994).

L. Rodrigues, P. Veríssimo, and J. Rufino. A low-level processor group membership protocol for LANs. In Proceedings of the 13th International Conference on Distributed Computing System}, pages 541-550, Pittsburgh, Pennsylvania, USA, May 1993. Also as INESC AR/30-93.

P. Verissimo, H. Kopetz. Part V - Real Time and Dependability, in Distributed Systems, edited by Sape Mullender, ACM-Press. Addison-Wesley, 1993.

P. Veríssimo, Werner Vogel, and Luis Rodrigues. A Framework for Structuring Group Support in LSDCs. Technical Report BROADCAST REPORT, INESC, Lisboa, Portugal, September 1993. Expanded version of a paper in procs. 4th IEEE Workshop on Future Trends of Distr. Comput. Syst., Lisboa-Portugal, 1993.

Paulo Veríssimo and Luís Rodrigues. Group Orientation: a Paradigm for Modern Distributed Systems. In Proceedings of the 5th ACM SIGOPS European Workshop, Mont Saint-Michel, France, September 1992. Extended and revised version as INESC RT/20-94.


Project Title: DEAR-COTS: Distributed Embedded Architectures using Commercial Off-The-Shelf Components

http://dear-cots.di.fc.ul.pt/

 

Sponsoring bodies: FCT (PRAXIS/P/EEI/14187/1998)
Total award amount: 38,750 Euro
Coordinator: FCUL
Partners: FCUL, IST, ISEP, FEUP
Start date: October 1999
Duration: 2 years
Keywords: Real-Time, Fault-Tolerance, Computer Aided Manufacturing, COTS

Abstract:

The main purpose of the DEAR-COTS project is the specification of an architecture based on the use of commercial off-the-shelf (COTS) components, able to support distributed computer controlled systems where safety and timeliness are major requirements.

Aims:

The DEAR-COTS project will address two main problems:

Approach and Methods:

A structured approach to the first problem needs to address several non-trivial issues, both at the communication and processing levels, such as: the impact of real-time and dependability requirements on the field-bus architecture, distributed fault-tolerant concurrent applications and the real-time support environment. 

In order to solve the second problem, the proposal foresees the use of emerging information technologies to cope with heterogeneity issues while providing a dependable user-friendly man-machine interface. This calls for innovative solutions addressing issues such as replica determinism of WWW servers, the use of object oriented technologies, the downloading/uploading within field-bus clusters and ensuring fault-containment between the field-bus and the "open network" domain. The DEAR-COTS proposed architecture will be validated through the development and test of a prototype, which will be integrated in a semi-industrial environment, with stringent safety and timeliness requirements. 

Progress and Results:

Significant progress has been made during the first project year, namely by defining a suitable DEAR-COTS architecture. Several results have been published and two project workshops have been made. Cooperation among the several teams involved in the project has been carried out with evident success.

Indication of project size at FCUL:

1 Researcher.

Latest publications:

P. Veríssimo, A. Casimiro, L. M. Pinho, F. Vasques, L. Rodrigues, E. Tovar. Distributed Computer-Controlled Systems: The DEAR-COTS Approach. In Proceedings of the16th IFAC Workshop on Distributed Computer Control Systems. Sydney, Australia, November 2000.

António Casimiro and Pedro Martins and Paulo Veríssimo. How to Build a Timely Computing Base using Real-Time Linux. In Proceedings of the 2000 IEEE International Workshop on Factory Communication Systems, Porto, Portugal, September 2000.

Pedro Martins and António Casimiro. Event Timestamping Tool: a simple PC based Kernel to timestamp distributed events. Technical Report DI/FCUL TR-00-4, Department of Informatics, University of Lisboa, July 2000.

Paulo Veríssimo and António Casimiro and Christof Fetzer. The Timely Computing Base: Timely Actions in the presence of Uncertain Timeliness. In Proceedings of the 1st International Conference on Dependable Systems and Networks. New York, USA, June 2000.


Project Title: MICRA: A Model for the Development of Mission Critical Applications

http://micra.di.fc.ul.pt/

 

Sponsoring bodies: FCT (PRAXIS/P/EEI/12160/1998)
Total award amount: 39,500 Euro
Coordinator: FCUL
Partners: FCUL, DSG/UC
Start date: September 1999
Duration: 2 years
Keywords: Real-Time Systems, Fault-Tolerant Systems, Distributed Systems, Timeliness constraints

 

Abstract:

The growth of networked and distributed systems in several application domains has been explosive in the past few years. This has changed the way we reason about distributed systems in many ways. One issue of definitive importance is the following: what model to use for large-scale interactive or mission-critical applications? The MICRA project intends to study, propose, and validate an adequate model to address this problem.

Aims:

This project aims to investigate, in the first place, the steps needed for the definition of a new model suitable for mission-critical applications. The crucial aspect is timing fault-tolerance in the context of real-time systems. We intend to formalize assumptions about system timeliness, and then develop what we call a Timing Failure Detector, in order to perfectly detect all violations of timeliness. There are several ways to treat the problem afterwards, but we plan to study the use of replication to mask timing faults. Previously known failure detectors were of the crash type only, our detectors are more accurate. Besides, replication has not been used previously in the context of timing faults, and as such, this approach is innovative. Our research will therefore concentrate on the definition of a set of basic services (a Timing Failure Detection Service -- TFDS, and a Replica Management Service -- RMS) which aim at providing the functionality just described, by means of a suitable programming interface, with provisions for timeliness specifications.

Approach and Methods:

The project is structured around three main lines of action: i) basic research in the area of synchrony models for distributed systems, including the work required for the definition of a generic model suitable for MICRA; ii) definition of middleware architecures and platforms to support the development of mission-critical applications, including the definition of a Timing Failure Detection service and an adaptation or replication service; iii) implementation of a small demonstration prototype to validate the model and the services. 

Progress and Results:

The definition a a generic system model,  the Timely Computing Base model, has been successfully accomplished during the first project year. Also some development work has been done, with results published in international workshops. 

Indication of project size at FCUL:

2 Researchers.

Latest publications:

António Casimiro and Pedro Martins and Paulo Veríssimo. How to Build a Timely Computing Base using Real-Time Linux. In Proceedings of the 2000 IEEE International Workshop on Factory Communication Systems, Porto, Portugal, September 2000.

Pedro Martins and António Casimiro. Event Timestamping Tool: a simple PC based Kernel to timestamp distributed events. Technical Report DI/FCUL TR-00-4, Department of Informatics, University of Lisboa, July 2000.

Paulo Veríssimo and António Casimiro and Christof Fetzer. The Timely Computing Base: Timely Actions in the presence of Uncertain Timeliness. In Proceedings of the 1st International Conference on Dependable Systems and Networks. New York, USA, June 2000.


Project Title: MAFTIA: Malicious- and Accidental-Fault Tolerance for Internet Applications

http://www.newcastle.research.ec.org/maftia/

Sponsoring bodies: European Commission - IST Programme
Project Number: IST-1999-11583
Total award amount: 5,100,000 Euro
Coordinator: Univ. Newcastle upon Tyne
Partners: Univ. Newcastle, FCUL, DERA, Univ. of Saarlandes, LAAS, IBM ZRL
Start date: January 2000
Duration: 3 years
Keywords: Dependability, Security, Large networks
 

Abstract:

The MAFTIA project will investigate the dependability of large distributed applications thus addressing one of the four key issues of the IST Programme and in particular the main objectives of CPA2. Its major innovation is a comprehensive approach for tolerating both accidental faults and malicious attacks in such systems, including attacks by external hackers and by corrupt insiders. The objectives of the project will evolve under the guidance of an Industrial Advisory Board, representing a cross-section of the industrial organizations which can best exploit MAFTIA's ideas. Board members will provide "use cases" based on actual or planned major systems and on realistic threat scenarios; as the project progresses they will play an ever-increasing role in providing exploitation routes for the results. Deliverables will include demonstrations and prototypes of several accident- and attack-tolerant security mechanisms and services.

Aims:

MAFTIA will investigate the 'tolerance paradigm' systematically, to propose an integrated architecture built on this paradigm, and to realise a concrete design used to support the dependability of many applications. Therefore, we will work on three broad categories of objectives related to, (i) the architecture of MAFTIA: providing a framework that ensures the dependability of distributed applications in the face of a wide class of faults and attacks, (ii) the design of mechanisms and protocols: providing the required building blocks to implement large scale dependable applications: this will be addressed by means of four subclasses of objectives, dependable middleware, large scale intrusion detection systems, dependable trusted third parties and distributed authorisation mechanisms (iii) the assessment of our work: rigorously defining the basic concepts developed by MAFTIA and verifying results of the work on dependable middleware.

Approach and Methods:

MAFTIA is structured into six technical Workpackages (WP). WP1 will concentrate on the conceptual model and architecture of attack tolerance. The largest body of work will be carried out in designing mechanisms and protocols. This constitutes the next four work packages. The first two are dealing with enabling technologies while the last two are concerned with application-level technologies. WP2 will develop a modular and scalable cryptographic group-oriented middleware suite, suitable for supporting reliable multi-party interactions under partial synchrony models and subject to malicious as well as accidental faults. We will also develop a framework for building attack-tolerant transactional systems that are as resilient to attacks as they are to accidental faults. WP3 will investigate how Intrusion Detection Systems (IDSs) can benefit from fault injection methods, diversity from combining several systems, and distributed reasoning. The design of an IDS that is itself secure and attack-tolerant will be addressed building on results of WP2. In WP4 we will design a generic architecture for dependable TTP services based on results from WP2. We will specify the necessary services that the TTP needs to provide, then we will implement the protocols in the first prototype and finally provide an integrated demonstrator for the TTP in the PKI scenario and in the fair exchange scenario. In WP5, we will define a framework for access control and authorisation in a distributed environment where the access control decision is distributed among parties that might not trust each other completely. We will design and prototype flexible authorisation schemes, adapted to multi-party transactions. The assessment part forms WP6, in which we plan to work towards formalisation of the MAFTIA conceptual model, employ existing methods and tools to assess new MAFTIA mechanisms, and develop a novel combination of existing approaches to the validation of cryptographic mechanisms.

Progress and Results:

Indication of project size at FCUL:

6 researchers

Latest publications:

 


Project Title: DEFEATS - Distributed Fault and Attack Tolerant Systems Configuration
http://defeats.di.fc.ul.pt/

Sponsoring bodies: FCT (POSI/1999/CHS/33996)
Total award amount: 29,500 Euro
Coordinator: FCUL
Partners: FCUL
Start date: January 2001
Duration: 3 years
Keywords:  Distributed systems, Configuration, Intrusion tolerance, Fault tolerance, Security, Reflection, Groups

Abstract:

With the increasing experience with applications running in a large-scale asynchronous network such as the Internet, the need for dependability properties in that environment has become evident. For example, E-commerce services have to be secure, reliable and available. There has been research in those properties for a couple of decades now, but their implementation is still not simple for the average system architect.

Faults in critical systems have been handled by a number of techniques, from prevention to fault tolerance mechanisms based on replication. On the other hand, security is still mostly obtained through prevention, although it is possible to characterize the malicious faults involved in attacks, which can then be handled using fault-tolerance techniques. This issue, attack tolerance, only recently started to receive attention.

The composition of medium/large software systems from smaller components has also been an area of research in the last years. The application of these ideas to configuration of distributed systems and processes is a powerful framework. The basic principle is the separation between systems architecture and computation. Computation is done by the components. The architecture of the system can be defined using configuration languages or graphic tools, and changed using a configuration platform.

Project DEFEATS is concerned with studying a configurable framework to build attack and intrusion tolerant systems.

Aims:

Project DEFEATS aims to develop: (1) a framework for the configuration of dependable distributed services (including attack tolerance); and (2) a decomposition of attack tolerance mechanisms in reusable blocks and a set of guidelines for their composition. Other contributions will be the integration of a meta-level scheme with configuration, and the design of a dependable configuration platform. Comprehensive approaches to this set of problems are not known in the literature.

Approach and Methods:

Project DEFEATS has two lines of work. In the first place, the project will research mechanisms to build attack tolerant services and define a set of building blocks and guidelines to compose such services. The set of blocks will include attack-tolerant intrusion detection and attack-tolerant authentication services. Communication will be based on a group communication system, since such systems are particularly well suited for replicated services.

In the second place, the project will define a framework for the configuration of dependable systems resilient to both accidental and intentional malicious faults, using the defined building blocks. There are several issues that will be considered: (1) the definition of a meta-level scheme to transparently configure a service in order that it is dependable; (2) the dependability of the configuration platform itself (including attack tolerance); (3) the interference between the dependability of the platform and the services that run over it. A demonstration prototype of an instantiation of the framework will be implemented and feedback will be taken for its further refinement.

Progress and Results:

The project started on January 2001.

Indication of project size at FCUL:

5 researchers

Latest publications:

 


Project Title: CORTEX: CO-operating Real-time senTient objects: architecture and EXperimental evaluation
http://cortex.di.fc.ul.pt/

Sponsoring bodies: European Commission - IST Programme
Project Number:
IST-2000-26031
Total award amount: 2,094,000 Euro
Coordinator: FCUL
Partners: FCUL, T.C.D., Univ. Lancaster, Univ. Ulm 
Start date: April 2001
Duration: 3 years
Keywords: Large-Scale Distributed Systems, Mobility, Proactive applications, Time and Safety Critical systems, Sentient objects.

Abstract:

We are now at the point where the emergence of a new class of applications that operate independently of direct human control can be envisaged. Future mission-critical computer systems will be comprised of networked components that will act autonomously in responding to a myriad of inputs to affect and control the surrounding environment. Key characteristics of these applications include sentience, autonomy, large scale, time and safety criticality, geographical dispersion, mobility and evolution. The key objective of CORTEX is to explore the fundamental theoretical and engineering issues necessary to support the use of sentient objects to construct large-scale proactive applications and thereby to validate the use of sentient objects as a viable approach to the construction of such applications.

Aims:

The proposed project will undertake:

  1. Design of a programming model that supports the development of applications constructed from mobile sentient objects. The model needs to take into account the provision of incremental real-time and reliability guarantees. This will encompass:

  2. Design of an open, scalable system architecture that reflects the heterogeneous structure and performance of the networks used to support the programming model. This will entail:
  3. Evaluation of the previous results by means of one or more demonstrators that will allow the technology to be assessed.

Approach and Methods:

The CORTEX project is divided into four technical work packages and three other work packages specifically devoted to project management, assessment and dissemination of the results. Upstream is the programming model definition (WP1), which is then refined by concurrently addressing the interaction model and the adequate system architecture (WP2 and WP3), including the necessary middleware services. The demonstrator (WP4) will consolidate the results of the previous work packages, and provide a final evaluation of the project's findings. Due to the nature of this project, specifically oriented to advanced research on new technologies and paradigms, the work will progress accordingly to a spiral methodology, where results are cyclically improved and refined. Therefore, during the course of the project we plan to produce intermediate deliverables with preliminary definitions and specifications, not necessarily coinciding with the end of particular tasks. The other three work packages are obviously outside of this production cycle, at least in the early stages, since they are not concerned with conceptual problems.

Progress and Results:

Indication of project size at FCUL:

4 Researchers

Latest publications:

 


Project Title: ARTIST: Network of Excellence in Advanced Real-Time Systems
http://www.systemes-critiques.org/ARTIST

Sponsoring bodies: European Commission - IST Programme
Project Number:
IST-2001-34820
Total award amount:  
Coordinator: VERIMAG
Partners: INRIA, VERIMAG, TU Wien, Uppsala Univ. Univ. Saarlandes, PARADES, OFFIS, Aalborg Univ, Eindhoven TU, CEA/Saclay, IRISA, Lancaster Univ., ENS Cachan, Univ. Twente, Mälardalen Univ., Univ. York, Univ. Pavia, S.Sup. S.Anna Pisa, Univ. Cantabria, Univ. Aveiro, TU Catalonia, FCUL, Univ. CarlosIII Madrid
Start date: April 2002
Duration: 3 years
Keywords:  

Objectives:

Coordinate the R&D effort in the area of Advanced Real-time Systems so as to :

Actions:

  1. Hard Real-Time Systems
    Consolidate and further improve a strong European competence and know-how that is strategic for safety or mission critical applications (Synchronous languages-TTA- Fixed priority scheduling).
  2. Component-based Design and Development
    Transfer, enhance interaction between teams working on compositionality/composability problems and software and systems engineering teams involved in the definition of standards e.g. UML, SDL.
  3. Adaptive Real-Time Systems for Quality of Service (QoS) Management
    Soft real-time approaches and technology for telecommunications, large open systems and networks Teams with expertise in real-time operating systems and middleware. 

Aims:

Approach and Methods:

Progress and Results:

Indication of project size at FCUL:

2 Researchers

Latest publications:

 


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