Basile Michel

Territorialised or without commitment: An in-depth analysis of 'cultural and creative' activities in a post-industrial neighbourhood in Grenoble

Keywords: art, creativity, culture, neighbourhood, worker

In the context of fusion of cultural and economic spheres, cultural and creative activities are increasingly seen as a homogenous whole despite persistent differences. In order to examine the relevance of this classification, this paper aims to examine the spirit of cultural and creative workers behind their participation in the social life of the urban neighbourhoods where they spatially agglomerate. Based on the research carried out in the post-industrial district of Berriat in Grenoble, an analysis of the cultural and creative workers' actions and networks leads to two distinct categories. Linked by common characteristics and a similar attachment to their neighbourhood, cultural workers on one hand and creative workers on the other are distinguished by the relations that they have with their home territory.

Introduction

Several researchers have analysed the spatial agglomeration processes of the socalled "cultural and creative" activities 1 in former industrial neighbourhoods [START_REF] Bell | City of Quarters. Urban Villages in the Contemporary City[END_REF][START_REF] Evans | From cultural quarters to creative clusters: Creative spaces in the new city economy[END_REF][START_REF] Ambrosino | Portrait de l'artiste en créateur de ville. L'exemple du quartier artistique de South Shoreditch à Londres[END_REF]Liefooghe, 2015a;Michel, 2018a). These neighbourhoods generally underwent radical changes spurred on by a combination (or not) of forces: urban renovation operations carried out by local authorities, development strategies of real estate professionals and establishment of activities related to the fields of culture, creation and creativity [START_REF] Liefooghe | Économie créative et développement des territoires : enjeux et perspectives de recherche[END_REF]. These territories thus occupied by artists, cultural players, facilities and entrepreneurs and subsequently, by various so-called "creative" organisations are often described indiscriminately as cultural (and/or creative) quarters (or clusters) [START_REF] Roodhouse | Cultural Quarters. Principle and Practice[END_REF][START_REF] Musterd | Accommodating Creative Knowledge. A Literature Review from a European Perspective[END_REF][START_REF] Zarlenga | Cultural clusters and social interaction dynamics: The case of Barcelona[END_REF]. A case of unstable vocabulary that certain researchers have incidentally attempted to resolve by trying to typify either the governance (public or private), the function (creative production, industrial reproduction or cultural and recreational consumption), or the level of intervention of the public sector (planned or otherwise) specific to each of the territories involved [START_REF] Mommaas | Cultural clusters and the post-industrial city: Towards the remapping of urban cultural policy[END_REF][START_REF] Debroux | Les territoires créatifs : quelques notions théoriques et une analyse bruxelloise[END_REF].

There are fewer studies nevertheless which, instead of looking into the coordination modes of agglomerated players in these quarters, focused on the desire of the workers involved in "cultural and creative" structures to go beyond their professional obligations and engage in their neighbourhood territory to contribute to its unfolding social life. Apart from the analysis using the lens of gentrification [START_REF] Zukin | Loft Living. Culture and Capital in Urban Change[END_REF][START_REF] Grésillon | Berlin, Métropole culturelle[END_REF][START_REF] Vivant | La gentrification et ses pionniers : le rôle des artistes off en question[END_REF] or that of the connection between "neo-bohemia" and commerce [START_REF] Lloyd R | Neo-Bohemia. Art and Commerce in the Postindustrial City[END_REF][START_REF] Cohendet | The Anatomy of the creative city[END_REF], there are, in fact, few studies on this specific issue. This is precisely one of the objectives of this paper. Clustering of the so-called cultural and creative activities into neighbourhoods whose image and life is fashioned by these very activities leads us to question the relations that these activities have with one another as well as with area where they are located. How do the cultural and creative workers interact with the neighbourhood where they work and in particular with their inhabitants? Do these workers wish to engage in the social life of the neighbourhood where they are established? Is there a difference in the relations that cultural workers on one hand and creative workers on the other have with the urban territories that they are involved in on a daily basis?

1 Cultural activities: performing arts, visual arts, cinema, publishing, video games, music, heritage, radio, television and video. Creative activities: architecture, design, digital sector, advertising [START_REF] Kea | The Economy of Culture in Europe[END_REF].

3 With these questions, the second objective of this paper is to examine the merit of these workers gathering together to form a single category, as is the case in several institutional reports promoting "cultural and creative industries" (DCMS, 1998;HKU, 2010). What is the pertinence of distinguishing or on the contrary, grouping together the so-called "cultural and creative" activities into one single category to analyse them? To get a better insight on this issue, involvement in the neighbourhood's social life, which qualifies as a form of openness to the local territory, is considered in this paper as a key analytical criterion that needs to be tested in order to highlight the similarity or difference between the cultural and creative workers. This paper does not by any means consider it morally and politically necessary for these workers to show this involvement. In addition, the level of commitment of these workers to their neighbourhood and the networks that they develop at this scale will be analysed.

In an attempt to throw light on these issues, we propose a micro-level analysis of the professional practices and relational networks of the cultural and creative workers in a neighbourhood, which is identified as being cultural and creative at the same time. This input makes it possible to highlight dimensions that are rarely the focus of research work on territories and cultural and creative fields [START_REF] Comunian R | Exploring the role of networks in the creative economy of North East England: Economic and cultural dynamics[END_REF]. It also makes it possible to raise the issue of government policies: to what extent does supporting and promoting these forms of activities (mostly as part of knowledge economy) become an opportunity for the authorities to participate in the development of social life in peri-central urban territories? The analysis will be based on studies carried out in Berriat (Grenoble). This former industrial and working-class neighbourhood has the advantage of currently agglomerating several cultural and creative activities after having hosted a number of alternative initiatives and players who were initially living in art squats. This paper has three parts. The first one lays theoretical foundations to the existing debate about the notions of creative economy and cultural and creative industries before highlighting territorial dynamics that are specific to these with the category of "cultural and creative quarters". After a box specifying the methodology used and the studies carried out, the second part presents the way culture finds itself at the core of Berriat's social life as a result of art squats since the 1980s followed by the way in which the neighbourhood changed to become a "creative quarter" during the course of the 2000s. The third part shows how the cultural activities on one hand and the creative ones on the other differ with respect to openness to Berriat's social life.

Cultural and creative industries in cultural and creative quarters: Theoretical framework

Creative economy and cultural and creative industries: Categories in question

Since early 2000s, creative activities have been considered as belonging to the artistic sector to form a vast group labelled as cultural and creative industries [START_REF] Scott | The Cultural Economy of Cities[END_REF][START_REF]The Cultural and Creative Industries: A Literature Review[END_REF]. It is the British Labour government which is partly responsible for the emergence of this categorisation and more generally, of the concept of creative economy through the publication of several reports on the topic (DCMS, 1998 and[START_REF]Creative Industries Mapping Documents 2001[END_REF]. The main objective was to overcome the industrial crisis by highlighting the "cultural and creative" sectors identified as vectors of a possible economic revival and improve the country's image [START_REF] Garnham | From cultural to creative industries. An analysis of the implications of the 'creative industries' approach to arts and media policy making in the United Kingdom[END_REF]. Thus, activities as varied as theatre, visual arts, design, publishing, architecture and music formed a homogeneous socio-economic group for the promoters of such labelling.

Since then, the category of cultural and creative industries has been re-used in several reports aiming to emphasize their economic importance in France [START_REF] Jauneau | Le Poids économique direct de la culture en[END_REF]Ernest Young, 2015), Europe [START_REF] Kea | The Economy of Culture in Europe[END_REF] and in the world (UNCTAD, 2010). The increase in the number of reports presenting these industries as one of the motors of economy in addition to the publication of books proposing "creative" development solutions for cities [START_REF] Landry | The Creative City. A Toolkit for Urban Innovators[END_REF][START_REF] Ponzini | The Rise of the Creative Class[END_REF], generated interest among academic researchers who took on the subject using the same terminology [START_REF]The Cultural and Creative Industries: A Literature Review[END_REF][START_REF] Comunian R | Exploring the role of networks in the creative economy of North East England: Economic and cultural dynamics[END_REF]Liefooghe, 2015b). Combining cultural and creative activities is based on the idea that the act of creation which characterises them constitutes a "work" [START_REF] Menger P-M | La création comme un travail. Qu'est-ce que la sociologie de l'art, II[END_REF] in its own right marked by the importance of the workers' creativity [START_REF]Cities and the Creative Class[END_REF][START_REF] Liefooghe | Économie créative et développement des territoires : enjeux et perspectives de recherche[END_REF], small size of the concerned companies [START_REF] Greffe | La survie des nouvelles entreprises culturelles : le rôle du regroupement géographique[END_REF], employment conditions which are temporary, precarious and unstable all at the same time [START_REF] Menger P-M | Portrait de l'artiste en travailleur. Métamorphoses du capitalisme[END_REF], promotion of personal dimensions in professional exchanges [START_REF] Comunian R | Exploring the role of networks in the creative economy of North East England: Economic and cultural dynamics[END_REF], permanent "self-staging" [START_REF] Vivant | Travail créatif, emplois précaires[END_REF] and a strong capacity of adaptation shown by the players involved when faced with a competitive and uncertain context [START_REF] Caves R | Creative Industries. Contracts between Art and Commerce[END_REF].

Artists, cultural and creative entrepreneurs: Converging professional trajectories?

Research on the professional trajectories of artists, cultural and creative entrepreneurs reinforces the motives behind such a merger. For example, Ann Markusen and David King (2003) demonstrate how certain artists (from the fields of performing arts, visual arts, literature or music) trade their skills and their ideas for use in design, multimedia, communication and advertising sectors in the United States. In the same way, several case studies in Montreal in the field of digital art [START_REF] Charrieras | Trajectoires, circulation, assemblages. Des modes hétérogènes de la constitution de la pratique en arts numériques à Montréal[END_REF], design [START_REF] Yagoubi | Cooperation and knowledge exchanges in creative careers: Network support for fashion designers' careers[END_REF] and video games (Roy-Valex, 2010) -fine-tune this perspective of inter-sector relations in metropolitan areas. The 5 logic of project-based work, competition for getting orders and an increase in the number of constraints thus pushes several creators and creative people to show entrepreneurial skills, which become necessary for their professional mobility. Despite this convergence of professional trajectories in the cultural and creative sectors, differences continue to exist between the fields of creation and creativity.

Art versus cultural industries versus creative industries?

This is the reason why certain authors try on the contrary to deconstruct this merger of artistic, cultural and creative work. For example, Boris [START_REF] Grésillon | Géographie de l'art. Ville et création artistique[END_REF] proposes to consider separately arts (performing arts and plastic arts), cultural industries (cinema, publishing, recorded music, etc.) and creative industries (architecture, design, etc.). According to him, the differences between these three types of activities in terms of the how coherent they are with market-oriented rationale justify the need to examine and analyse then separately. Though they are affected by the economic dynamics of the art market and money-related issues, artists focus on the creation of unique works of art without considering the sale or the consumption of the said work as the primary objective. They have a certain amount of freedom in their work and set up art projects [START_REF] Paris | Organisation, processus et structures de la création[END_REF]. As for the cultural and creative companies, they try to create more reproducible products with the objective of selling them and getting a monetary profit. They function mainly in response to external client orders. This categorisation has its limitations: not all the artists are committed to creating non-reproducible works without any business intent and not all cultural companies cater to external orders. However, the advantage is that it allows us to shift away from the broad typology of creative industries initially proposed by the British Labour government. For Gaëtan [START_REF] Tremblay | Industries culturelles, économie créative et société de l'information[END_REF], this typology validating the consolidation of the cultural and creative activities is a ploy that allows the creative sector companies to benefit from the aura and prestige of arts and even apply for public aid on the same account as artistic activities. It would also correspond to the desire of its promoters (European Commission, United Nations, etc.) to artificially increase the economic weight of the cultural and creative sectors through a broad and disparate amalgamation with the final aim of accentuating creativity as the primary driving force behind current and future economic development. In doing so, a positive image of the "creative industries" is propagated, often hiding the fragility and uncertainty characterising artistic, cultural and creative professions [START_REF] Vivant | Travail créatif, emplois précaires[END_REF].

Cultural quarters versus creative quarters

Grouping together numerous activities under the label of creative economy adversely affects the analysis of the spatial and territorial dimensions of these activities. The notion of cultural or creative quarter is thus developed to characterise the spatial agglomeration of activities in specific urban neighbourhoods [START_REF] Montgomery | Cultural quarters as mechanisms for urban regeneration. Part 1: Conceptualising cultural quarters[END_REF][START_REF] Bell | City of Quarters. Urban Villages in the Contemporary City[END_REF][START_REF] Evans | From cultural quarters to creative clusters: Creative spaces in the new city economy[END_REF]. This spatial agglomeration can be combined with relational networks connecting activities with one another [START_REF] Vivant | Qu'est-ce que la ville créative ? Paris: Presses universitaires de France, coll[END_REF]Michel, 2018a), turning "cultural" or "creative" quarters into cluster entrenchment places [START_REF] Roodhouse | Cultural Quarters. Principle and Practice[END_REF]. These quarters are distinguished on the basis of three main criteria. First of all, the process of construction of creative quarters may correspond to top-down planning by the authorities or result from a bottom-up spontaneous agglomeration [START_REF] Mommaas | Cultural clusters and the post-industrial city: Towards the remapping of urban cultural policy[END_REF]. Secondly, the position on the activity value chain pushes some quarterstowards creation and production while others are committed to consumption and cultural dissemination [START_REF] Mommaas | Cultural clusters and the post-industrial city: Towards the remapping of urban cultural policy[END_REF][START_REF] Evans | From cultural quarters to creative clusters: Creative spaces in the new city economy[END_REF]. Thirdly, because of the nature of the live events, the type of the products generated in the quartervary between artistic creations (art works), industrial reproductions (films, books, design objects, etc.) and production of creative goods and services (architectural projects, web design, etc.) [START_REF] Debroux | Les territoires créatifs : quelques notions théoriques et une analyse bruxelloise[END_REF].

The combination of the last two criteria allows us to distinguish between "cultural quarters" and "creative industry quarters" with different functioning principles (Evans, 2009, p. 39). The former are mainly focused on local cultural development while the latter are oriented towards production and innovation in the creative sectors. The two principles may intersect in a territory such that the distinction between cultural and creative activities is blurred. Hence, the question arises about the impact of these activities on the functioning of cultural and creative quarters. Is the role played by cultural activities on one hand and creative activities on the other in these neighbourhoods similar? Do the differences between these activities as pointed out in the literature lead to different positions with respect to their desire to open up to the neighbourhood? Are their contributions to local social life thus different? The analysis of the Berriat district should allow us to shed some light on the question.

Berriat: From art squats to a creative quarter

The Berriat district is interesting for this research as it was at the core of a spatial agglomeration of artists, cultural players and creative industries which led today to the copresence of cultural activities and creative activities. The methodology and studies carried out on this district are explained in detail in the box below (Box 1).

Box 1/ Methodology and field studies

This paper is based on qualitative research work carried out in two distinct periods in the Berriat district (in 2005, and subsequently in 2016)* with a mix of semi-directive interviews, analysis of social networks, documentary research (archives, local press, etc.) and observation (in the cultural and creative activity work places and during cultural events). The 43 interviews were carried out in the neighbourhood (with an average duration of one hour and ten minutes): 11 development officials and residents and 32 cultural and creative workers, defined in this paper as individuals working in cultural and creative sectors associations and industries. The interviews of these workers aimed to explore the following: the reasons for their choice of location; characteristics of the activity; the actions initiated at the neighbourhood level; relations with other players in this area (other cultural and creative activities, residents, etc.); their practices and representations of the neighbourhood. Following the interviews, an analysis of social networks was carried out in order to identify the personal and professional social relations developed at the neighbourhood level by each worker interviewed (use of Ucinet and Netdraw software). The observation phases and the analysis of the documentary sources (internet sites of the activities, etc.) allowed us to expand the research and confront the players' discourses interviewed with factual evidence.

In order to select players for the interviews, it was decided to include in the target population, all the activities grouped under cultural and creative sectors as defined in the institutional reports [START_REF] Kea | The Economy of Culture in Europe[END_REF] in order to be able to explore its pertinence. Secondly, we distinguished cultural activities from creative activities by considering that the former are composed of companies and associations from the art sector (independent artists, artistic companies, theatres, etc.) while the latter included those from the cultural and creative "industries" (architects, designers, etc.). This classification does not correspond to an analytical framework laid down before carrying out the fieldwork. On the contrary, it emerged while analysing the interviews and was defined a posteriori in order to characterise the differences observed between these activities in terms of openness to the neighbourhood and its residents.

The sample of cultural and creative workers interviewed was chosen such that they were representative of the type of cultural and creative activities present in Berriat with 38 % of the persons working in the art sector, 25 % in architecture and 13 % in graphic design. They are composed of mainly young (57 % 20-39 years of age) women (69 %) and men (31 %). They live in the Berriat district (42 %) or elsewhere in Grenoble (42 %) and in the agglomeration (16 %). *The main author carried out field interviews in 2016 while the second author carried out the ones in 2005. These two studies were carried out among the same types of players and with the same methodological tools. Pooling the material gathered during the course of these studies allowed us to retrace the evolutionary path of Berriat and led to a reflection about the interactions developed by the cultural and creative workers with their professional neighbourhood.

Berriat: A creative quarter in the scientific metropolis of Grenoble

Historically speaking, Grenoble is characterised by a development focused on technology and science, which made it a technopolitan city or even a scientific metropolis (Novarina, Seigneuret, 2015). In France, the city is reputed to be the second technological and scientific hub behind Paris [START_REF] Courlet | L'Économie territoriale[END_REF]).

Grenoble appears today at the forefront in microelectronics, nanotechnologies and biotechnologies with the presence of multiple players of these two sectors. Grenoble has in fact research organisations2 , training institutes (Minatec campus, for example), a fabric of micro enterprises, major corporations (Hewlett-Packard, STMicroelectronics, etc.) and structuring facilities such as the synchrotron (particle accelerator).

The importance of technopolitan and scientific approach of the city is coupled with a strong development of cultural initiatives. Grenoble is known for its numerous festivals (Détours de Babel, Grenoble Jazz Festival, etc.) and cultural venues in the field of music as well as the presence of Musiciens du Louvre (an orchestra with an international reputation) and National Centre of Contemporary Art (Centre national d'Art contemporain or CNAC), Le Magasin (Photo 1). Generally speaking, Grenoble's inhabitants are satisfied with the local cultural events on offer [START_REF] Bozonnet J-P | Pratiques et représentations culturelles des Grenoblois[END_REF]. However, the degree of satisfaction varies significantly depending on the neighbourhood of residence. Berriat emerges as the most appreciated geographical sector for its diversity and abundance of cultural events as compared to Teisseire and Très-Cloître. 9 Photo 1/ National Centre of Contemporary Art: Le Magasin in Berriat Photo taken by Michel B, 2016. This popularity rating of the neighbourhood in terms of cultural events is explained by the concentration of the cultural players and facilities in this area as compared to the rest of Grenoble. For example, 8 of the 32 theatres and performance venues listed by the Town hall are located in Berriat, which makes it the main hub ahead of the city centre, which has only 7 such venues. A statement by the Project Manager at the city's Department of Cultural Affairs (Direction des Affaires culturelles or DAC) illustrates this concentration:

"If we take Berriat: a concert hall with a capacity of 800 seats, two theatres, two small modern music venues, well three if we include Le 102 plus the collective Mann'Art(e), I mean its incredible. In a neighbourhood like Berriat in a city like Grenoble, it is totally amazing so we are going to do everything to preserve it"interview in April 2016.

Because of this concentration, the neighbourhood is identified as a "cultural" or "creative" quarter in Grenoble. This image is the result of historical anchorage of artistic dynamics in this area. The local authorities are well aware of this: "Berriat has always been a cultural district in Grenoble" -Project Manager at the DAC of Grenoble, interview in April 2016. 10 It is hence important to analyse the historical dynamics, which make Berriat a neighbourhood known today as a "cultural" or "creative" place in Grenoble.

Art squat maze: Culture at the core of social life in Berriat

In the 19 th century, Berriat flourished with the establishment of industrial activities: food industries, glove industries, mechanical and metallurgical industries [START_REF] Giroud | Résister en habitant ? Renouvellement urbain et continuités populaires en centre ancien (Berriat Saint-Bruno à Grenoble et Alcântara à Lisbonne)[END_REF][START_REF] Ambrosino | Le cluster culturel, un artefact conceptuel pour mieux comprendre la ville contemporaine. L'exemple du quartier Berriat à Grenoble[END_REF]. It emerged as the main industrial and working-class neighbourhood of Grenoble with 75 % of the workers and employees in 1930 (Barou, Duclos, 2003) notably employed in the penstock company Bouchayer-Viallet established in 1870.

The decline of industries in Berriat started in the 1950s and led to wasteland situations [START_REF] Ambrosino | Friches en ville : du temps de veille aux politiques de l'espace[END_REF]. The slow and gentle urban transformation launched by the socialist government of Hubert Dubedout in the municipality in 1965 allowed conservation of empty spaces in the neighbourhood3 . Located close to the city centre and the basic cultural infrastructure4 , these empty spaces attracted several artists. In the early 1980s, they started settling here randomly before changing subsequently into "a true movement of invasion" (Ambrosino, Andres, 2008, p. 42). The artists emerged by way of collective art squats. Various places were occupied such as 102 rue d'Alembert (former cardboard factory), Frise brewery and Terray factory before the wasteland resulting from the departure of Bouchayer-Viallet company was occupied by several collectives. Thus, the neighbourhood emerged as the place with a high concentration of art squats in the city:

"We called it the squat maze"-artist member of a squat in the 1990s, interview in June 2016.

This spatial concentration of Grenoble's informal artistic players was coupled with a local social network connecting them with one another through informal exchanges and mutual aid [START_REF] Ambrosino | Le cluster culturel, un artefact conceptuel pour mieux comprendre la ville contemporaine. L'exemple du quartier Berriat à Grenoble[END_REF]. The players of this cultural cluster developed relations with the Berriat district. Culture was at the core of the social life of the neighbourhood with the presence of artists and the activities that they undertook [START_REF] Ambrosino | Le cluster culturel, un artefact conceptuel pour mieux comprendre la ville contemporaine. L'exemple du quartier Berriat à Grenoble[END_REF]. The case of Brise-Glace, one of the most important art squats in the history of Berriat illustrates the case in point.

In 1995, this former building of the Société dauphinoise d'Études et de Montages is occupied by around ten artists who formed a collective association. Common events such as Open Doors were organised. This allowed them to open the place to local 11 people especially those living in the neighbourhood. In the collective, the company Ici-même developed an interactive and participative approach:

"We shifted from performances where the public is expected to watch and listen to performances where they interact. The interactive dimension is present all the time in all our events from the 2000s. That is, we ask the public to walk with us, to share an experience where we are side-by-side, where without the public, our performances do not exist" -founding artist of the company, interview in June 2016.

This approach was concretised in the company's art events. In 2000, with the project "Ici comme ailleurs vous êtes ici chez vous" [Here as elsewhere you are at home here], the artists proposed a survey of the Berriat district by following various art events. The objective was to encourage the residents and other users of Berriat to take ownership of public space. The events interlinked the neighbourhood and took on various forms: dances, readings, organisation of debates, film projections, etc. In 2001, the project "Espace à saisir" proposed a free visit of the Bouchayer-Viallet wasteland to the public while access to the place was legally prohibited. This visit was dotted with various artworks and gatherings: botanical garden, sound installations, etc. The participants were encouraged to lose themselves in the place and feel the state of abandonment. Through their actions, the artists of Brise-Glace and other Berriat squats rehabilitated an abandoned land. They gave back life to it by taking over the spaces present in the area. They associated the residents with it and created new practices of the wasteland. They belonged to the figure of the "geoartist" who "shifts the centralities, contributes to the recreation of public space and participates in the emergence of a new ergonomics of the city" (Gwiazdzinski, 2014, p. 176).

From art squats to creative quarter: What is the continuity of the relationship with the neighbourhood?

Since 1983 and the arrival of Alain Carignon (Rally for the Republic) municipality's Mayor, urban renovation operations increased in the neighbourhood: Europole urban project, construction of a tramway line, reconversion of the Lustucru factories, etc. [START_REF] Giroud | Résister en habitant ? Renouvellement urbain et continuités populaires en centre ancien (Berriat Saint-Bruno à Grenoble et Alcântara à Lisbonne)[END_REF]. Following the change of Mayor with the election of Michel Destot (Socialist Party) in 1995, this pattern of urban revitalization was continued with, for example, the establishment of the urban planning area of Bouchayer-Viallet. New housing and office buildings were thus constructed with the price of real estate among the highest in the Grenoble agglomeration in the early 2000s [START_REF] Giroud | Résister en habitant ? Renouvellement urbain et continuités populaires en centre ancien (Berriat Saint-Bruno à Grenoble et Alcântara à Lisbonne)[END_REF]. They replaced spaces left as wasteland with the departure of the industry. In this context, the population of the neighbourhood evolved. Formerly a working class neighbourhood, Berriat underwent a gentrification process symbolised by an increase in the number of executives among the residents (from 14 % of the 12 population to 23 % between 1990 and 2013) and a decrease in that of workers (from 20 % to 7 % of the population between 1990 and 2013) 5 . A form of continuity of the working-class nature of neighbourhood is identified with the continuance of a strong cultural diversity and low-income groups [START_REF] Giroud | Résister en habitant ? Renouvellement urbain et continuités populaires en centre ancien (Berriat Saint-Bruno à Grenoble et Alcântara à Lisbonne)[END_REF].

Tolerated during the wasteland time, and even heard during M. Destot's first term (1995)(1996)(1997)(1998)(1999)(2000)(2001), the squat artists see free and re-adoptable places get reduced with progress in the renovation of Berriat neighbourhood, leading to the shift to the postwasteland stage 6 . Henceforth, the underground cultural dynamics declined with the closure of several squats (Mandrak in 2003, Brise-Glace and the 400 covers in 2005, etc.). However, the activist movement of artists and historical cultural players such as the Cap Berriat association allowed them to restrict this decline (Photo 2). Some squat artists were rehoused in the neighbourhood by the city of Grenoble while others remained in their initial location by capitalising on an occupancy agreement. In addition, institutional and intermediary cultural players were retained in the neighbourhood (concert halls, theatres, CNAC) and were joined by Scène de musiques actuelles (SMAC) La Belle électrique in 2015 (Photo 3). Finally, numerous so-called "creative" enterprises were established in the neighbourhood in the 2000s. These enterprises were attracted by the combination of centrality, real-estate prices lower than the city centre and the artistic and industrial vibe inherited from the neighbourhood's history. Some of them were grouped together in private shared work spaces 7 and in the former chocolate factory Cémoi which was bought back by the city in 1979 and transformed into a business and association centre 8 (Photo 4).

INSEE figures.

6 Some art squat collectives were able to benefit from a convention of precarious occupation accorded by the Town Hall, sometimes after strong protests by the artists and the residents (For example, Le 102 under Alain Carignon). Under Michel Destot, collectives like Brise-Glace benefitted from political attention through Deputy Mayors in charge of culture and economic development. In the early 2000s, the renovation of the last wastelands along with the change of Deputy Mayor in charge of culture following the re-election of M. Destot in 2001 made it more difficult to keep these collectives in Berriat. 7 These spaces are offices shared by several independent small companies and associations which want to pool material, exchange or even cooperate with one another. These are coworking spaces used exclusively by permanent workers, that is, with an office assigned to the place (Michel, 2018c). 8 The rates for renting proposed by Grenoble-Alpes Métropole are attractive in comparison to the private market as the objective is mainly to support the projects of young entrepreneurs.

14 Photo 4/ The renovated Cémoi building in Berriat Photo taken by Michel B, 2016. Thus, the evolution of Berriat district follows the oft-observed trajectory of former industrial neighbourhoods occupied by artists followed by cultural and creative enterprises [START_REF] Lloyd R | Neo-Bohemia. Art and Commerce in the Postindustrial City[END_REF]Liefooghe, 2015a). While the alternative artistic dynamics declined because of the renovation projects, the cultural dimension of the neighbourhood did not disappear and was followed by a "creative" development.

Berriat emerged as a neighbourhood with a "creative" image with a combination of cultural activities and creative activities (Fig. 1). The process of clustering these activities is mainly part of a spontaneous dynamics (bottom-up) though the municipality also played a role in the establishment of certain cultural venues in Berriat (for example, for La Belle électrique). In 2018, 174 cultural and creative activities were established in the neighbourhood, including 47 % in the former Bouchayer-Viallet wasteland which has now been renovated. These activities belong mainly to the sectors of art (41 %), architecture (26 %) and graphic design (9 %). Like the configuration of the cultural and creative sectors (HKU, 2010), they are characterised by a high number of very small-sized structures (81 % of the activities surveyed have less than five workers). In the Berriat district, these activities are mixed with economic players of other sectors. In Bouchayer-Viallet, major corporates of management and innovations in information technology (Atos, Bonitasoft, etc.) as well as players in entrepreneurships (Chambre de Métiers et de l'Artisanat, Réseau Entreprendre Isère, etc.) were established. Several local businessmen, restaurant owners and bar managers are also present, particularly in Cours Berriat and Saint-Bruno Square. Their presence offers sites suitable for the development of a vibrant social life in the neighbourhood. Consequently, it is often called a "village" by its residents and other users (Szántó, 2004;[START_REF] Michel | Mythe et réalités du quartier-village des travailleurs créatifs à Berriat (Grenoble)[END_REF].

Fig. 1/ Location of the cultural and creative activities of the Berriat district

In this new context, what has happened to the relations developed with the neighbourhood by squat artists during the wasteland period? Did the subsequent cultural and creative activities have the same role of creating spaces for meeting and exchanging with Berriat residents?

Engagement with the social life of Berriat. The difference between "cultural and creative" activities

The two distinct sub-networks of the cultural and creative cluster of Berriat

In the Berriat district, the cultural and creative activities build collaborative relations. They exchange information, loan equipment to one another and set up projects together. A true local collaborative network is built on the basis of a strong spatial proximity (location in the same neighbourhood) and affinity-based proximity (affiliation to the same networks) among the workers. The cooperation and the products resulting from this clustering are divided into two main categories. Firstly, the artists and the cultural structures create collaborations based on the showing of the artistic creations. Collective events are organised and help to provide visibility to the local cultural program and attract public. Secondly, architects, designers and other creative industries collaborate in a business-to-business model without any direct link with the public or the consumers. The objective of the relations is the production of "creative" goods and services.

Thus the cultural and creative cluster embedded in Berriat is in reality made up of two distinct sub-networks that co-exist with limited interactions: one composed of cultural activities (71 activities) and the other of creative activities (103 activities). The internal relational network in each of these sub-networks is dense with a respective average of 5.3 and 4.1 relations per activity. The density of the networks connecting the two sub-networks is significantly lower because the average number of relations per activity is 0.8. The existence of these sub-networks connected internally but partly isolated from one another is highlighted by Figure 2.

The presence of these two distinct sub-networks in Berriat demonstrates a difference in the position taken by the cultural activities on one hand and the creative activities on the other with respect to their openness to the neighbourhood.

Cultural activities: A commitment to Berriat neighbourhood's social life

The majority of the cultural activities in Berriat stand up for a philosophy of opening culture and cultural places to the neighbourhood residents and users (75 % of the interviewed cultural workers). It is manifest in the importance of the structures that are part of social economy (économie sociale et solidaire -ESS) in the neighbourhood's cultural activities (75 % of the associations for the survey sample). Social economy is presented as an alternative to capitalism whereby organisations try not to follow the logic of economic profit, function democratically and develop an activity for general interest [START_REF] Laville | Agir à gauche. L'économie sociale et solidaire[END_REF]. However, recourse to the status of an association, which is a part of social economy, is an operational and a nearly mechanical choice in the cultural sector [START_REF] Hearn | Sur le développement de l'entrepreneuriat dans le secteur culturel en France. Paris: La Documentation française[END_REF]. For some project initiators, it seems to be the easy solution and does not correspond to a political and social commitment. Thus, in the case of Berriat, opening up to the local territory advocated by cultural activities is part of a strategy seeking visibility as well as to attract and retain local audience. However, it also corresponds to their desire to be involved in ensuring local entertainment in order to blend in and play a social and cultural role. One of the founding members of the artist collective, Barbarins Fourchus, established in Berriat since 1999, talks about this commitment:

"We saw some places that were not open to the outside at all, which are open from 8pm to 10pm and that's it. That's not how we saw things, we thought "no no, we have to be open, meals, public rehearsals, etc." -Interview in June 2016. This commitment is concretised by means of several actions aiming to create moments for meetings and exchanges in the neighbourhood. In the venue managed by them, Barbarins Fourchus create writing workshops, concert-cocktails, music workshops, ball dances, film projections, neighbourhood feasts, public rehearsals, etc. They facilitate interactions between their cultural project and the Berriat neighbourhood. These actions are merged with initiatives developed by other cultural workers in the neighbourhood. The Mann'Art(e) collective organises several open events for the inhabitants such as Christmas in the Balcony. The associations Histoires De created a board game "Memory of my neighbourhood" with students and old people in the neighbourhood, followed by a multimedia guide "Raconte-moi Berriat Saint-Bruno"9 . All these actions illustrate the manner in which cultural activities are introduced in the neighbourhood and help to enliven the local social life. Like the association Et à Fond dedicated to batucada practice 10 and which organises concerts and shared meals in neighbourhood public places, cultural workers integrate the Berriat neighbourhood in their project and professional practices:

"Since several years, the association Et à Fond had the intention of adhering to this area [Berriat]. It's something we repeat often and we have put it into practice by creating and developing meetings with individuals as well as practice venues for the local people" -manager of the association Et à Fond, interview held in April 2016.

The collective dynamics that links the local cultural activities with one another reinforces the scale of the actions developed. The neighbourhood's annual feast is an example. The cultural association Le Stud which manages the performance hall Ampérage, coordinates this gathering in partnership with Union du Quartier (resident association). The association calls for proposals whereby all the cultural activities of Berriat are requested to help in providing entertainment at this festive event taking place in public places and markets. This way of functioning generates a single cooperation mode based on the participation of the community of cultural workers in the organisation and production of cultural events open to one and all. Other events of this type emerge from the collaboration of cultural activities. As part of the Day and Night Festival that it organises, La Belle électrique develops concerts in Berriat's cultural places (Salle Noire, CNAC Le Magasin, Ampérage), creates a discovery tour of the neighbourhood with Histoire De and organises meets between Cap Berriat's graffiti artists and the residents.

In the end, the involvement of cultural workers in opening up to Berriat's inhabitants results in an attachment to this neighbourhood. The long work of integration in the area carried out daily helps to create a lasting connection between the cultural players and the neighbourhood. It is this connection that led Barbarins Fourchus to remain in Berriat despite having been forced to change their location:

"For a performing arts company, to arrive in a neighbourhood, it takes years of work because things don't happen fast and because we don't just land up at someone's place and say "Hi, its me, come see how amazing what I do is". And as we worked our asses off for a certain number of years to open this famous Théâtre 145 by saying "but look, there is nothing sacred inside, everyone can come, we can do things", we wanted to pursue the work here (in Berriat)" -the collective's founder, interview in June 2016.

Creative activities: A more limited involvement in the neighbourhood

The majority of the creative workers based in Berriat do not have any connection with the local residents and do not express any desire to develop one (64 % of the creative workers interviewed11 ). This finding is based on the nature of the activity of these workers. Architects, designers and graphic artists are engaged in professional projects, which demand a lot of investment in terms of time and economic gains without having to develop relations with the local population. Hence, openness to the neighbourhood is not a concern. The absence of structures belonging to social economy in the local creative activities symbolises the difference in the objective differentiating them from cultural activities. Priority is given to the development and the survival of the enterprise, especially in the case of very small structures. In order to survive in the context of uncertainty and competition that characterises the "creative" sectors [START_REF] Caves R | Creative Industries. Contracts between Art and Commerce[END_REF][START_REF] Menger P-M | Portrait de l'artiste en travailleur. Métamorphoses du capitalisme[END_REF], the latter are encouraged to cluster and join peer networks [START_REF] Greffe | La survie des nouvelles entreprises culturelles : le rôle du regroupement géographique[END_REF]. The aim of these networks is to stimulate innovation and growth of the companies and not of opening out to a local 20 area with a purely social objective. The presence of a sub-network of creative activities collaborating on a business-to-business model in Berriat fits into this framework.

Collaborations developed between the local creative activities aim to produce "creative" projects. An independent graphic artist is, for example, sought after by a communication agency on occasional projects in order to produce exhibition panels, brochures, corporate identity graphics, etc. Another independent graphic artist produces illustrations of real estate projects secured by an architect. The most common case is the association of several architects and landscape architects of the neighbourhood to respond collectively to calls for proposals in the building construction sector and complete the projects obtained:

"When there is a call for proposals, we make teams and there you go, it's smooth, it's fast. In two minutes, the team is created and we are ready!"architect, interview held in June 2016.

These different examples show that the issue of openness to the neighbourhood and its residents does not appear in the reality of the networks of creative activities. In this perspective, some of the creative workers do not develop any specific attachment with the neighbourhood. For them, Berriat is neither more nor less than the place where their office is located: "I just cross the neighbourhood when I am going to work or I go to buy something to eat at noon. So, I don't take part in the neighbourhood life […] I am just a neighbourhood passenger" (architect, interview held in June 2016).

However, this position remains that of a minority (46 % of the creative workers interviewed). Most of the creative workers are interested in the neighbourhood. They are concerned by the place in which they are professionally rooted and are attached to it, which tends to bring them closer to the cultural workers in terms of relationship with the neighbourhood. The key words12 that they use to define Berriat, which are identical to the ones cited by the cultural workers, demonstrate this fact. For them, this neighbourhood is a "convivial" and "lively" "village" marked by a "cultural diversity". A landscape architect speaks of this attachment: "In fact, I started having roots in the neighbourhood and then finding it quite nice […] personally, I like the social diversity here" -interview held in April 2016.

While the involvement of the cultural workers in the social life of Berriat is not present among the creative workers, the latter nevertheless develop an attachment with the neighbourhood, which softens the opposition between cultural and creative activities with respect to their position regarding this neighbourhood.

Conclusion

The case of Berriat illustrates the dynamic trajectories that former working-class neighbourhoods might undergo after artists settle in following the industrial decline in the second half of the twentieth century. As is the case of the Olivettes neighbourhood in Nantes [START_REF] Michel | Les quartiers créatifs : une dynamique de club. Analyse croisée des quartiers des Olivettes (Nantes), du Panier (Marseille) et Berriat[END_REF] and Poblenou in Barcelona [START_REF] Ballester | Quartier d'artistes versus cluster numérique. Entre conflit foncier et production d'un nouvel espace créatif : le 22@ de Poblenou à Barcelone[END_REF], the underground artistic dynamics which emerged during the wasteland time and which led to the revival of enthusiasm for the spaces, becomes weak as urban renovation progresses, but not without opposition. Continued presence of artists and the arrival of creative companies thus create a co-presence of workers from the worlds of culture and creativity whereby tentative connections between them are forged.

The analysis of professional practices and relational networks of these workers, carried out at a micro-level in this paper, makes it possible to streamline elements of comprehension of post-industrial dynamics at play in this type of neighbourhood. In the case of Berriat, this analysis throws light on the different positions of cultural workers on one hand and the creative workers on the other in terms of openness to the neighbourhood:

1) The former are involved in the creation of place and time for exchanges with the residents and develop collaborative networks aiming to amplify their own individual actions13 . Over time, the initiatives led by them are territorialised and end up influencing the neighbourhood's identity.

2) By the very nature of their work, the latter are focused on the production of goods, services and creative projects without any direct link with the neighbourhood residents and users. For all that, their anchorage is not less (partially) local, but it is deployed via peer networks that are activated with the aim of developing projects and ensuring the survival of companies subject to an extremely competitive economic system. While the spatialisation of these activities is evident, their embedding in the neighbourhood social structures remains more tenuous and selective14 .

22

Thus the development model of the cultural and creative quarters appears better integrated in its immediate environment with the presence of cultural activities in that more connections are developed with the local territory (residents, users etc.) by the latter than by the creative companies. With the aim of promoting social life in the neighbourhoods, support for cultural activities, in particular those coming under social economy, thus appears to be a possible lever for the authorities while support for creative activities falls more under the domain of economic development.

The case of Berriat helps us to distinguish the cultural activities and the creative activities clearly in terms of interactions with the neighbouring territory. From this point of view, these activities belong to two distinct categories, which should be considered separately and not as a homogeneous group. The co-presence in the neighbourhood of two networks that are partially isolated from one another provides an additional element for their distinction. The common points connecting these activities are based on the importance of creation work, their tendency to be spatially present in the same neighbourhood and develop a form of attachment with it.

On the basis of these common points, various studies have analysed these activities together, more or less highlighting their differences [START_REF] Scott | Les ressorts géographiques de l'économie culturelle : du local au mondial[END_REF][START_REF] Foord | Strategies for creative industries: An international review[END_REF]Michel, 2018a). In view of the conclusions of this paper, and with the objective of pursuing research on the topic, it seems necessary not to assimilate them into a unified group. It also seems essential to systematically question the pertinence of the classifications applied to these activities by taking into consideration the general data on the cultural and creative sectors as well as the specific contexts on the field.

Fig. 2 /

 2 Fig. 2/ Collaborative network of the cultural and creative activities in the Berriat district

Commissariat à l'énergie atomique et aux énergies alternatives [Nuclear and Renewable Energy Commission], laboratoire d'électronique des technologies de l'information [Electronics and Information Technology Research Institute]…

© Basile MICHEL

The municipality wanted to rehabilitate the neighbourhood by giving priority to preserving the existing urban fabric and retaining its residents.

Le Centre dramatique national des Alpes [National Drama Centre of the Alps] was established in Berriat in 1982 before being joined in by the CNAC Le Magasin in 1986.

The guide is available online: http://www.histoiresde.fr/raconte-moi-Berriat-Saint-Bruno/, consulted on 23/01/2018.

The remaining 36 % of the creative workers have informal relations developed spontaneously with the local residents (mutually beneficial neighbourhood relations, friends living in the neighbourhood).

At the end of the cultural and creative workers' interviews, they were asked to list some key words defining the Berriat district according to them.

This position is of course not shared by all the cultural players but by a large majority (75 % in the case of Berriat).

The absence of involvement by the creative workers in the social life of their work neighbourhood has some exceptions such as creative enterprises with the status of social economy (ESS) dedicated to social entertainment in the creative quarters of Les Olivettes and Le Panier[START_REF] Michel | Les quartiers créatifs : une dynamique de club. Analyse croisée des quartiers des Olivettes (Nantes), du Panier (Marseille) et Berriat[END_REF].


Riadh Ben

Emna Fki
email: fkiemna@yahoo.fr

Khalil Drira
email: khalil@laas.fr

Mohamed Jmaiel
email: mohamed.jmaiel@enis.rnu.tn

Experiments Results and Large Scale Measurement Data for Web Services Performance Assessment

, we defined and implemented a generic architecture applicable for different services within different business activities. Our approach is based on meta-level communications defined as extensions of the SOAP envelope of the exchanged messages, and implemented within handlers provided by existing web service containers. Using the web services technology, we implemented a complete prototype of a service-oriented Conference Management System (CMS). We experienced our monitoring and measurement architecture using the implemented application and assessed successfully the scalability of our approach under the French grid5000. In this paper, experimental results are analyzed and concluding remarks are given.

Introduction

Internet progress has enabled data exchange between remote collaborators and the multiplication of on-line services. Several platforms of services are available today to support the design, the deployment and the implementation of these services in reduced scales of time. However, users require more exigencies. They dislike to encounter problems while using a service. Such as, waiting for a long time in order to book a room, checking whether the crashed rent car service is restored, searching for services with improved QoS. Therefore, we have to deal with these problems at the design time, and provide a strategy for recovery in order to satisfy users requirements. Such systems, have to inspect their behavior and change it when the evaluation indicates that the intended QoS is not achieved, or when a better functionality or performance is required. This implies the need of deploying entities for supervising traffic between web service providers and requesters in order to act for healing or preventing [START_REF] Kephart | The vision of autonomic computing[END_REF].

Three main steps are distinguished in the self-healing process [START_REF] Benhalima | A qos-oriented reconfigurable middleware for self-healing web services[END_REF]: Monitoring to extract information about the system health (using knowledge about the system configuration), Diagnosis & Planning to detect degradations and generate repair plans, and Repair to enforce reconfiguration actions in order to heal the system. In this paper, we focus on QoS monitoring of a web service-based application. We are achieving experiments on the cooperative reviewing system which is developed in the framework of the WS-DIAMOND European project. We carry out experiment on the "conference search" web service. The monitoring is carrying out while using monitors-based approach. We present the performance measurement values and analyze experiment results. The measurement is fulfilled under the grid5000 which is an experimental grid platform gathering 3000 nodes over 8 geographically distributed sites in France.

This paper is organized as follows. Section 2 describes our self-healing architecture. Section 3 presents the monitoring framework. Section 4 details experiments and gives concluding remarks. Section 5 presents related works. The last section concludes the paper.

Self-Healing Architecture

Figure 1 shows the different self-healing modules interaction within the dynamically reconfigurable web services bus. The bus offers a flexible framework for invoking services and managing QoS.

In the following, we describe the self-healing compo-

….

….

Requester-Side Monitoring

Requester-Side Monitoring …. -Reconfiguration Enforcement: It enforces repair plans by rerouting requests to the suitable web service provider.

In the sequel, we present the interaction messages exchanged between the web services and the self-healing components. The WS Requester sends a request message M1. This message is intercepted by the RSM. Message M1 is then extended by the first QoS parameter value (QoSP1) in the output message M2. For example, QoSP1 may represent the invocation time of the service by the requester. Message M2 is intercepted by the PSM for a second time. M2 is extended by the QoS parameter value (QoSP2) in the output message M3. To illustrate this, QoSP2 may represent the communication time spent by the message to reach the provider-side network. The current bound WS Provider executes the request. The message response M4 is intercepted by the PSM for a third extension by the QoS parameter value (QoSP3) in the output message M5. For example, QoSP3 may represent the execution time associated with the request. Message M5 is intercepted by the RSM. It is then extended by the fourth QoS parameter value (QoSP4). For example, QoSP4 may represent the time spent by the response to reach the requester-side. The QoS data is extracted at this connector-level and sent to the Logging Manager which is a web service responsible of saving data in a log. The Diagnostic Engine questions periodically the Logging Manager, analyzes statistically QoS values (Messages ReqMes and RespMes), and sends alarms and diagnostic reports (Message Report) to the Reconfiguration Decision Planner. When a QoS degradation is detected, the Reconfiguration Decision Planner plans a reconfiguration and solicits REC for enforcement (Message Decision). For example, the Reconfiguration Decision Planner can ask for leaving WS Provider 1 and binding requesters to WS Provider 2. Consequently, requests will be routed to WS Provider 2 instead of WS Provider 1.

QoS Monitoring Framework

Monitoring Approach

Our Monitoring approach is based on Monitor which is a software entity used to intercept and to enrich SOAP messages with QoS information. A SOAP message is encapsulated in a SOAP Envelop which is divided into two parts: The Header and the Body. The SOAP Body element provides a mechanism for exchanging mandatory information like method name, parameters, and invocation result while the SOAP Header allows extension of SOAP messages [START_REF] Gudgin | Object Access Protocol (SOAP)[END_REF]. The Monitor intercepts a SOAP message and enriches its Header with QoS information.

In the following:

• t1 represents the time at which the request has been issued by the service requester. It denotes the value of QoSP1,

• t2 represents the time at which the request has been received by the service provider. It denotes the value of QoSP2,

• t3 represents the time at which the response has been issued by the service provider. It denotes the value of QoSP3, and

• t4 represents the time at which the response has been received by the service requester. It denotes the value of QoSP4.

We interrogate the log and measure QoS values, namely: Execution Time, Communication Time, Response Time, Throughput, Availability and Scalability, according to formulas shown below:

Execution Time: The time spent by the service to execute a request;

T exec = t3 -t2
Response Time: The time from sending a request until receiving a response; T resp = t4 -t1

Communication Time: The transport time of the request and the response;

T comm = T resp -T exec
Throughput: The number of requests served in a given period [START_REF] Patel | Provisioning resilient, adaptive web services-based workflow: A semantic modeling approach[END_REF] which is calculated through this formulas; Throughput = Number of requests/period of time Availability: This parameter is related to the number of failures of a service in a time interval [START_REF] Patel | Provisioning resilient, adaptive web services-based workflow: A semantic modeling approach[END_REF]. It is calculated through this formulas:

Availability = Number of successful responses/Total number of requests)

Scalability: A web service that is scalable, has the ability to not get overloaded by a massive number of parallel requests [START_REF] Rosenberg | Bootstrapping performance and dependability attributes ofweb services[END_REF] (see table 3).

Conference Management System

The Cooperative Management System is concerned with a multi-services application involving massively cooperating web services. Its architecture aims to ensure data exchange flexibility between system components. It includes three tiers composed of the following components:

Requesters: They are composed of system actors namely: administrators, authors, reviewers and chairmen.

The self-healing components: They manage QoS degradation between each pair of requester/provider.

Web services:

They include requester-side and provider-side web services. The requester-side web services are used by requesters to dynamically explore and invoke specific services. Provider-side web services offer functionalities related to cooperative reviewing.

The cooperative reviewing process starts by searching a suitable conference for authors. So, they send requests to the ConfSearch web service across the bus looking for appropriate conferences (topics, publisher, deadline, etc.). In this paper, we monitor QoS of the web service based Conference Management System. We interest mainly in the measurement and evaluation of QoS presented in section 3.1 for the ConfSearch web service.

Experimental Environment

To perform QoS tests of the ConfSearch web service, we used the French grid5000. The deployment architecture is shown in figure 2. The grid5000 is composed of several nodes operating with fedora linux (see table 1).

T l Sit

P id WS

WS

Toulouse Site

Provider WS

WS

Log

Lille Site

Dynamically Reconfigurable Substitutable WS Bus

WS

Substitutable WS Bus

REC PSM

Logging Manager

Requester nodes g

Grid5000

Lyon Site

Figure 2. Infrastructure of experiments

The network configuration for the experimental environment is illustrated in table 1. We reserved nodes located in different sites. We run two nodes for servers. The first for CMS web services and the second for the Logging Manager web service. We reserve and run respectively 1, 3, 5, 10, 25, 50, 75, 100, 200, 350, and 500 requesters1 . We use Apache Tomcat5.5 as a web server, Axis1.4 as a SOAP engine, Java1.5 as a programming language, and MySQL5 as a database management system.

Using unix shell scripts, we can build and run multiple requesters at the same time. Each requester sends SOAP requests to the ConfSearch web service. The requester continuously invokes the services during 10 minutes. The experiments are carried out more than 10 times. Each request will be intercepted four times in order to enrich it with QoS values. Before the response reaches the requester, the RSM runs a thread which logs QoS values. Based on formulas shown in section 4, we interrogate log and compute the response and execution times, as well as availability and throughput.

Table 2 shows experiment results of the ConfSearch web service. The first line shows that 1 requester invokes the ConfSearch web service for 6193 times in 10 minutes. At 500 concurrent requesters, about 50% of requests failed. We remark that the growth of requesters number leads to overload the server and to turn down the performance. However, The execution time value is monotonically increasing while the communication time is varying due to the traffic injected by other users of grid5000. Figure 3.a displays the communication time variation according to the requester number growth. The curve keeps growing until the level of 100 requesters. After that level, it stills around 1,7 second. The communication time varies between about 100ms for 10 requesters to about 2000ms for 100 requesters. It increases highly with the number of requesters showing the importance of this parameter in response time observed by the requesters. Such information is being analyzed and modelled to support a correct monitoring and diagnosis for this application.

Figure 3.b shows the evolution of the execution time while increasing the requester number. It increases continuously from about 20ms at 1 requester to 120ms at 500 concurrent requesters. The growth of requesters number overloads the service and turns down the performance.

Figure 3.c presents the throughput variation from 1 requester to 500 requesters. It allows us to conclude that the web service can respond at the maximum of about 40 requests per second. This threshold is reached with 25 concurrent requesters and remains stable while the requesters number increases.

We have registered the number of triggered exceptions and erroneous service response. After that, we have drawn up the service availability (see figure 3.d). We point out that the 1 requester continuous invocation during 10 minutes may trigger 271 exceptions. The service responds to less than 80% of requests if the simultaneous requesters number exceeds 100. We notice that most error responses were related to "connection refused" exceptions, which means that the application server capacity is exceeded in term of scheduling.

We classified the response time in table 3 into different intervals (in seconds): [0, 1] contains requests that took less than 1s, [START_REF] Benhalima | A qos-oriented reconfigurable middleware for self-healing web services[END_REF][START_REF] Gudgin | Object Access Protocol (SOAP)[END_REF] includes requests that took between 1 and 2 s, etc. We divided the number of requests of each interval by the total number of succeeded requests to get the result of the percentage in different time slots. Those percentages depict the scalability of the ConfSearch web service. The first three lines of table 3 show the execution result of 1, 5 and 10 concurrent clients. Approximately, 100% of requests are served in a response time less than 1 second. When we exceed 50 clients, the web service suffers from the big number of concurrent requests and slows down its response time. For instance, about 80% of requests are completed in a response time more than 1 second at 100 and 200 concurrent requesters. We notice that the performance degrades when the number of requesters growth and the availability turns down to about 20% (see figure 3.d).

In figure 4, we drew up two curves of the response time. In the first curve, the measurement is achieved with monitors. In the second one, the measurement is done in the client code and without using monitors. Less than 50 concurrent clients, both curves are similars and the load of con- 1 99,97% 0,03% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 5 99,96% 0,02% 0,02% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 10 99,24% 0,63% 0,13% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% 25 93,94% 3,84% 2,07% 0,15% 0,00% 0,00% 0,00% 0,00% 0,00% 0,00% nectors is unimportant and about zero. The delay comes to half second when we exceed 50 concurrent clients. This implies that our architecture is very suitable for a service invoked by less than 50 concurrent requesters at the same time and we have to take into account the added load when we exceed 50 concurrent requesters.

Related Work

El Saddik [START_REF] Saddik | Performance measurements of web servicesbased applications[END_REF] addresses the measurement of the scalability and the performance of a web services based e-learning system. He carries out experiments on web service based e-learning system under LAN and DSL environment. He uses multi-clients system simulator which runs concurrent threads requesters. El Saddik interprets collected monitoring data. As a conclusion, he suggests a proxy-based approach for scheduling a massive flow of concurrent requests. But, this delays the problem from the server level to the proxy level.

Table 4. Synthesis of the related work

The work proposed in [START_REF] Repp | A cross-layer approach to performance monitoring of web services[END_REF] presents an approach for monitoring performance across network layers as HTTP, TCP, and IP. It aims to detect faults early and reconfigures the system at real time while minimizing the substitution cost. But, the parsing of many layers takes enough time and consumes resources which will affect the performance. In addition, the experiment is fulfilled only under two nodes which will not reflect the behavior of such system in a large scale use.

Authors of [START_REF] Thio | Automatic measurement of a qos metric for web service recommendation[END_REF] propose a framework for QoS measurement. They extend SOAP implementation API in order to measure and log QoS parameters values. The API modification have to be done in both sides: client and provider sides. This automates the performance measurement values. Also, it allows continuously updating information about QoS of services. An experiment is achieved with available services under the net. They run about 200 requests per day during 6 days and measure only the response time. However, this approach is dependent on the SOAP implementation. The extension have to be set up on the provider SOAP implementation which is difficult.

In [START_REF] Rosenberg | Bootstrapping performance and dependability attributes ofweb services[END_REF] the authors propose both an evaluation approach for QoS attributes of web service, which is service and provider independent, and a method to analyze web service interactions and extract important QoS information without any knowledge about the service implementation. They implement their monitors using the Aspect Oriented Programming (AOP). They alter the behavior of the code base by applying additional behavior at various join points in the program. However, the aspect language is dependent to the used programming language.

Conclusion

In this paper, we presented our experimental results of a large-scale web service-based application implementing the conference management and the cooperative reviewing process. This experiment aims to validate the self-healing architecture that we developed in the context of the IST WS-DIAMOND project. The performance measures how QoS vary under many load conditions, and how to prevent service from QoS degradation.

The monitors load come to 0,5 second when we exceed 50 requesters. Also, when we exceed 50 requesters, the service availability turns down to less than 50%. Consequently, we have to limit the number of concurrent requests addressed to a service to less than 50 requesters.

Figure 1 .

 1 Figure 1. QoS-Oriented, Monitoring-based self-healing architecture

  Figure 3. QoS parameters variation

Figure 4 .

 4 Figure 4. Load of connectors

[

Table 1 . Grid5000 nodes configuration.

 1

	Site Name		Toulouse			Sophia			Bordeaux	Lyon
					Azur (cluster1)	Helios (cluster2)
	Model		Sun Fire V20z		IBM eServer 325	Sun Fire X4100		IBM eServer 325	IBM eServer 325
	CPU		AMD Opteron 248	AMD Opteron 246	AMD Opteron 275	AMD Opteron 248	AMD Opteron 246
			2.2 GHz (dual core)	2.0 GHz (dual core)	2.2 GHz (dual core)	2,2 GHz (dual core)	2.0 GHz (dual core)
	Memory		2 GB		2 GB		4 GB			2 GB		2 GB
	Network speed	Gigabit Ethernet		2 x Gigabit Ethernet	4 x Gigabit Ethernet	Gigabit Ethernet	Gigabit Ethernet
	Requesters	Request	Succeeded	Failed		Experiment	Execution Time (ms)			Communication Time (ms)
	Number	Number	Requests	Requests	duration
							Min	Max	Avg		Min	Max	Avg
	1	6464	6193	271		10Min	10	222	18,163	40	1253	59,767
	3	16285	15368	917		10Min	10	654	22,795	35	2447	71,895
	5	18218	16903	1315		10Min	9	638	28,496	35	155917	99,683
	10	29783	25528	4255		10Min	9	964	55,076	27	5454	128,297
	25	35304	26337	8967		10Min	9	2989	79,059	33	5700	310,039
	50	39087	25563	13524		10Min	9	4903	87,033	35	21554	737,783
	75	42227	24554	17673		10Min	9	6052	95,330	31	185258	1352,367
	100	43118	24380	18738		10Min	9	6021	97,900	39	211162	1780,646
	200	44072	24084	19988		10Min	9	5626	116,434	34	245921	1653,905
	350	44243	24869	19374		10Min	9	6271	116,985	24	489053	1735,029
	500	47981	25736	22245		10Min	9	5919	117,739	24	217436	1660,850

Table 2 .

 2 Performance.

Table 3 . Scalability of the ConfSearch web service.

 3

Experiment data are available at http://www.laas.fr/˜khalil/TOOLS/QoS-4-SHWS/index.html