PRIN 2007: D-ASAP project

Transcription

1 PRIN 2007: D-ASAP project Roma Tor Vergata Unit D-ASAP meeting Feb Name Vincenzo Grassi Salvatore Tcci Francesco Lo Presti Valeria Cardellini Emiliano Casalicchio Effort (m/y) Stefano Ianncci Lca Silvestri D-ASAP meeting Feb

2 Or involvement in D-ASAP WP s WP 1, WP 2, WP 5 (+ WP0 and WP6) general framework : rntime adaptable systems or focs is on the Service Oriented (SOA) domain architectral featres applications bilt sing loosely copled services dynamic discovery, selection and composition» different services with same fnctionality and different QoS/cost contractally specified QoS/cost reqirements: Service Level Agreement (SLA) provider role, reqester role both roles in case of composite service D-ASAP meeting Feb Otline (this talk) an exploration of the rntime adaptation problem space focsed on the SOA domain MOSES : or approach to rntime adaptation of SOA systems methodology ongoing work (next talk) MOSES: architectre and implementation stats D-ASAP meeting Feb

3 Model-based rntime self-adaptation self-adaptive systems based on one or more closed loops feedback from both the system self and context play a significant role here! which? targeted to specific isses the why, when, where, what, how, who qestions tailored for particlar domains (and regions within them) the case of the service-oriented (SOA) domain D-ASAP meeting Feb (domain independent) basic isses When? Where? What? How? Why? Who? D-ASAP meeting Feb

4 (possible) answers for the SOA domain why? flfillment of fnctional reqirements flfillment of non fnctional reqirements (QoS, cost) stated in SLAs» average vales» higher moments, percentiles Why? D-ASAP meeting Feb (possible) answers for the SOA domain when? reactive approaches, pon detecting : service availability/navailability delivered QoS level variation load variations proactive approaches model-based predictions When? D-ASAP meeting Feb

5 (possible) answers for the SOA domain where? / what? level fringes of the service composition» implementation of the reqired fnctionalities (abstract tasks) whole service composition» modification of the overall workflow scope granlarity» single reqest» flow of reqests no. of systems» single system» mltiple systems Where? What? D-ASAP meeting Feb (possible) answers for the SOA domain how? fringe-oriented approaches service tning (re-)selection of single services (re-)selection of coordination patterns whole composition approaches compensating workflows workflow replanning How? D-ASAP meeting Feb

6 (possible) answers for the SOA domain who? centralized coordination single athority (service broker) distribted coordination mltiple cooperating athorities mltiple non cooperating athorities» non cooperative game Who? D-ASAP meeting Feb how? a region in the SOA domain why? where? / what? flfillment of fnctional reqirements flfillment of non fnctional reqirements (QoS, cost) stated in SLAs» average vales» higher moments, percentiles when? scope reactive approaches, pon detecting : service availability/navailability delivered QoS level variation load variations proactive approaches model-based predictions fringe-oriented approaches service tning (re-)selection of single services (re-)selection of coordination patterns whole composition approaches compensating workflows workflow replanning level fringes of the service composition» implementation of the reqired fnctionalities (abstract tasks) whole service composition» modification of the overall workflow granlarity» single reqest» flow of reqests no. of systems» single system» mltiple systems D-ASAP meeting Feb who? centralized coordination single athority (service broker) distribted coordination mltiple cooperating athorities mltiple non cooperating athorities» non cooperative game

7 The MOSES framework MOSES: MOdel-based SElf-adaptation of SOA systems Rntime monitoring Modeling Adaptation mechanisms Implementation Rntime Off line ed parameters Workflow validation and model generation Adaptation actions Workflow (BPEL, ) D-ASAP meeting Feb How to adapt at rntime a SOA system two viewpoints for the implementation of each reqired fnctionality (abstract service) WHICH concrete service shold I select at rntime to implement it? a single concrete service for each abstract service service selection problem most existing approaches adopt this viewpoint a set of concrete service for each abstract service arranged according to different coordination patterns (retry, 1-otof-N, ) pattern selection problem HOW shold I arrange at rntime different concrete services to implement it? D-ASAP meeting Feb

8 the MOSES approach based on both viewpoints for each abstract service, we determine at rntime... the best set of concrete services... more flexibility!... and the best coordination pattern.. to flfill the QoS/cost reqirements of different (classes of) sers concerning the average vale of QoS/cost attribtes response time, dependability, cost (others cold be added) and the overall flow of service reqests for each ser D-ASAP meeting Feb MOSES adaptation: basic idea S4 k i2 k i3 k i1 k i3 S1 S3 {OR} S2 S5 S6 S4 = switch(par_or(ki2,ki3), single(ki1), single(ki3)) C = seq(loop(par_and(seq(s1,s2),s3),s4,sel(s5,s6))) D-ASAP meeting Feb

9 MOSES adaptation: rntime model we bild at rntime a linear programming optimization model model parameters based on SLA parameters and sage profile parameters sage profile: V i : nmber of reqests to Si for each client reqest» pdated by monitoring activity the soltion drives the system implementation new soltion calclated at each environment change ser profile change arrival/departre of sers component services change Constrained mlti-criteria optimization problem S1 S3 S4 QoS constraints S2 S5 S6 Fnctional constraints C D-ASAP = seq(loop(par_and(seq(s1,s2),s3),s4,sel(s5,s6))) meeting Feb MOSES adaptation: rntime model jst a taste of the nderlying mathematics max F(x) = w r R max R(x ) D(x) D +w min R max R d +w min D max D c min sbject to: C (x) Cmax, U D (x) Dmin, U R (x) Rmax, U R l' (x) R l (x), l' d(l), l Π, U R l (x) = + ipdd l h Π,hpdd l U x ij 0, V h V h V i V l R h x J Ii ij (x) l Π, U R(Si;J) x ij Vi L L ij, 1 i m, J Ii C max C(x ) C max C min D-ASAP meeting Feb J I x ij = 1, 1 i m, U

10 MOSES adaptation: fnctional architectre Rntime monitoring Modeling Adaptation mechanisms Implementation Rntime ed parameters Adaptation actions Off line S1 S3 S4 Workflow validation and model generation Workflow (BPEL, ) goal management change management plan reqest G1 P1 G P2 G2 change plans change actions S2 S5 S6 Component C1 C2 D-ASAP meeting Feb C = seq(loop(par_and(seq(s1,s2),s3),s4,sel(s5,s6))) control 19 stats MOSES : present and ftre present a methodology for QoS-driven reactive adaptation of SOA systems (jst presented) flow based mltiple QoS classes stateless/statefl services SLA : average vales of QoS attribtes a simlator for validation prposes a real prototype (next presentation) rnning, bt not yet experimented modlar ongoing work tighter SLA : percentile-based monitoring and proactive adaptation admission control distribted (and cooperative) MOSES real world experiments prototype implementation : continos pdate D-ASAP meeting Feb

11 collaborations Poli MI CNR PI D-ASAP meeting Feb pblications (1) E. Casalicchio, D.A. Menascé, V. Dbey, L. Silvestri, Optimal service selection heristics in service oriented architectres, Proc. of 3rd Int l Workshop on Advanced Architectres and Algorithms for Internet DElivery and Applications (AAA-IDEA 2009), Las Palmas de Gran Canaria, Spain, Nov (2) Grassi V., Mirandola R., Randazzo E., Model-Driven Assessment of QoS-Aware Self- Adaptatio n in Software Engineering for Self-Adaptive Systems (Betty H.C. Cheng, Rogerio de Lemos, Holger Giese, Paola Inverardi, Jeff Magee eds.), LNCS 5525, Springer-Verlag (2009), pp (3) V. Cardellini, E. Casalicchio, V. Grassi, F. Lo Presti, R. Mirandola Towards QoS aware selfadaptation in service oriented systems in Architecting Dependable Systems 6 (R. de Lemos, J.-C. Fabre, C. Gacek, F. Gaddcci, M. H. ter Beek eds.), LNCS 5835, Springer-Verlag (2010) (4) V. Cardellini, E. Casalicchio, V. Grassi, F. Lo Presti, R. Mirandola QoS-driven Rntime Adaptatio n of Service Oriented Architectres Joint 12th Eropean Software Engineering Conference and 17th ACM SIGSOFT Symposim on the Fondations of Software Engineering (ESEC-FSE 2009), Agst 26-28, 2009, Amsterdam, The Netherlands, pp (5) Valeria Cardellini, Emiliano Casalicchio, Vincenzo Grassi, Francesco Lo P resti, Raffaela Mirandola A Scalable Approach to QoS-Aware Self-Adaption in Service-orien ted Architectres Proc. of QShine 2009, The Sixth International ICST Conference on Heterogeneos Networking for Qality, Reliability, Secrity and Robstness, Las Palmas de Gran Canaria, Spain, November (6) S. Casolari, M. Colajanni, F. Lo Presti "Rntime state change detector of compter system resorces nder non stationary conditions", Proc 17th IEEE.ACM International Symposim on Modelling, Analysis and Simlation of Compter and Telecommnication Systems, London, Sept , (7) Daniel A. Menasce, Emiliano Casalicchio, Vinod Dbey, On optimal service selection in Service Oriented Architectres, Performance Evalation, In Press, Corrected Proof, Available online 17 Jly 2009, DOI: /j.peva D-ASAP meeting Feb