ECOO

Environments for COOperation

Inria Lorraine

Objectives

• Coordination of a virtual team (people distributed in time, space and organizations, with a common objective)

– Flexible and reliable process management– Replica management with operational

transformations – Group Awareness

Composition of the team

• 10 + 1 academic people (C. Godart (head), P. Molli (vice-head), K. Benali, N. Boudjlida, G. Canals, F. Charoy, P. Molli, O. Perrin, H. Skaf, P. Urso)(J.C. Derniame)

• 5+7 Phd Students (K. Baina, J. Bitcheva, C. Bouthier, D. Grigori, S. Tata)(S. Alshattnawi, D. Cheng, W. Gaaloul, K. Gaaloul, A. Guabtni, M. Rouached, U. Yildiz)

• 2 post-doctoral fellow (S. Bhiri, G. Oster)• 5+1 engineers (G. Bort, R. Chabald, S. Jourdain,

M. Patten, M. Valdes Faura)(F. Jouille)

Plan

• Results– Flexible and reliable process management

• Flexible process (Highlight 1: the Bonita WfMS)• Reliable process (Highlight 2: Service composition with transactional

guarantees)

– Operational transformations• Safe and generic transformation (Highlight 3: the Vote proof system)• From synchronous to asynchronous work (Highlight 4: the

LibreSource environment)

– Group awareness

• Perspectives– Process engineering– Collaborative editing

Process management topics

• Flexible processes– How to better support the subtlety of human interactions

than traditional workflow systems do ?– Highlight 1: Bonita, a flexible a WfMS

• Reliable processes– How to provide (transactional) guarantees for long term,

with proper internal control, semi-atomic, with user defined correctness … activities ? … in SOA architecture !

– Highlight 2: Service composition with transactional guarantees

Operational transformations

• OT framework allows anyone to edit anytime any kind of data without locking, turn taking or serializing

• Shared data are replicated. Local operations are broadcasted to others sites to be re-executed after transformation

• The system is correct if it eventually converge towards a common state that ensures intentions of users

• Intention are represented as constraints

OT: topics

• Safe and generic synchronization– It appears to be very difficult to write safe OT– Highlight 3: Tombstone Transformation Functions (TTF

)

• From synchronous to asynchronous work– Configuration management system based on OT

technology: you no longer check-out, update, commit file versions, but logs of operations

– Highlight 4: implemented in So6, a safe and generic synchronizer, heart of LibreSource, [Group03]

Group Awareness

• If people receive the right information at the right time, they communicate and coordinate

• Large sets of shared artefacts, large groups of participants, complex organizational structures: many different collaborative situations; loosely coupled groups

• Topics– Awareness visualization– Context-based awareness adaptation

Perspectives

Process EngineeringCooperative processes, Composition of services with properties, Process discovery, Decentralized

control, Process awareness

Collaborative editingPeer-to-peer editors, Beyond linear structures, Massive collaborative editing (process,

awareness)

Keyword: decentralized control and organization

Process engineering (1)

• Composition of services with properties– Questions: How to abstract a process ? Which

properties? How to abstract them ? How to compose process fragments ? How the semantic Web can help ?

– Application: Many, Service Oriented Architecture …– Context: in the vein of work on Trans. Com. Ser., ARA

Cops (Composition of Policies and Services), Regional Cows (Constraint reasoning for the safe composition of WS), French WG « Web Services »

Process engineering (2)

• Process discovery– Objectives: control flow discovery, properties discovery– Applications: process discovery, process group enactment, trust

(when I expose some knowledge, what can be mined concerning my know–how ?) …

– Context: in the vein of initial results (control flow discovery, transactional properties discovery), cooperation with TU Eindhoven (Web process discovery)

• Distributed control– Objective: More distributed control! how to do? Process

delegation, the role of process patterns, the role of trust– Application: towards peer-to-peer processes, trust (When I

delegate an “activity”, how can I trust my supplier ?) …– Context: in the vein of work on Trans. Com. Ser.

Collaborative editing (1)

• Peer-to peer editors– Objectives: OT approach is decentralized but

designed for closed network, need for new algorithms that tolerate the churn of peer-to-peer network

– Applications: P2P group text editor such as a P2P Wiki

– Context: the Woot approach (designed for linear structures, based on a monotonic linearization function of partial orders, does not require vector clocks nor site number knowledge), ARC Recall

• Collaborative editing, beyond linear structures

Collaborative editing (2)

• Massive collaborative editing– Objectives: collaborative editing community

always handles small groups of users (2-50)..., what about tens or hundreds of users? Need to imagine new consistency management, processes and awareness

– Application: e-learning environment, Wikipedia

– Context: ARC Recall

Questions ?

1

• Flexible cooperative workflow management system– Flexible execution of activities– Dynamic process definition– Web services ready

• Built on the Jonas ObjectWeb J2EE Application Server• Proposed by Bull in their Open Source Software

Solution "Open Service"

Composition of services with …

How to ensure correct reliable executions ? (application dependent, user defined, easy to do)

Reliability choices

Composed service

Registry of services Designers

Define correctness: Accepted Termination States: the configurations of terminal states (completed, compensated, aborted …) in which

designers accept the activities of a process to terminate

Extend service description with simple properties : retriable, compensatable, pivot

Extend TCS withdependencies :compensation,alternative …

2

Using the provided information,either we validate the model

or we provide hints for correction

Tombstone Transformational Functions

• Writing a set of Operational Transformation is difficult. – C1: op1.T(op2,op1)≡op2.T(op2,op1)– C2: T(op3,op1.T(op2,op1))=T(op3,op2.T(op1,op2))

• All existing OT were false !• The TTF transformation functions are proved safe

!• Key of success: the VOTE environment that

automatically and quickly proves that a set of OT verifies correctness conditions [TCS06]

Begin

SPIKEAutomated

Proof

Formal Specification & C1 - C2 & Properties (SPIKE)

Formal Specification & Properties (VOTE)

Translation & Completness

ScenarioExtraction

IncrementalVerification

End

[Failure]

Correctness of a set of OT3

3