The Distributed Data Access Schemes in Lambda Grid Networks

Transcription

1 The Distributed Dt Access Schemes in Lmbd Grid Networks Ryot Usui, Hiroyuki Miygi, Yutk Arkw, Storu Okmoto, nd Noki Ymnk Grdute School of Science for Open nd Environmentl Systems, Keio University, Jpn

2 Agend. Bckground - Grid computing - Dt Grid. Prllel downloding - File division method - Server selection. Proposed scheme 4. Performnce evlutions 5. Conclusion

3 . Bckground Growth of opticl network technologies High performnce computing Grid Computing High performnce virtul mchine by combining PCs, dt storges nd etc. Execution of lrge scle jobs High speed processing cpbilities

4 Dt Grid The Dt Grid is technology tht logiclly integrtes the dt geogrphiclly distributed to the server. Lmbd Grid -An increse in connection cpcity b c -Gurntee of bndwidth Opticl Pths Distribute the lod of servers Reduce the influence of file dmge Replic files re stored in mny servers. b c Fig. Lmbd Dt Grid c 4

5 Dt Grid Lmbd Grid High-cpcity of dt files block Execution trnsmission dt by lightpths Replic files re stored in mny servers Opticl Pths Prllel downloding cn reduce the downloding time of the file. File File division method Server selection method Fig. Prllel downloding 5

6 . Prllel downloding File division method server Downloding smll block from server. When downlod of block from server completes, we clculte the throughput from elpsed time nd piece size. Allocte the block of size ccording to the rtio of throughput Others clculte the throughput from own dt size nd elpsed time File File File client File Fig. File division method Block size ccording to bndwidth nd distnce 6

7 Servers re selected by shortest pth serch. Server selection method File, b nd c re downloding from neighboring servers. Lightpths concentrtes on certin link. Server A Client X b Server B b b c Server C c Server D Client Z b c Bottleneck link fctor Client Y Fig.4 exmple of Server selection method 7

8 Problem of server selection The stte of the network is not considered in the server selection lgorithm. The stte of the network is considered. To distribute the lod of server which hve the file, Client need not select the nerest servers. Decresing bottleneck links The proposed scheme Server A Client X Considering the the wvelength vilbilities of of ech link to to decrese bottleneck links nd to to enhnce the the network efficiency. b Server B bc Client Y Fig.5 exmple of the stte of the network considered b Server C b c Server D Client Z 8

9 . Proposed Scheme Method of setting cost of ech link Link cost α + ( α ) Mx link cost Numberof Used Wvelength Numberof Mximum Wvelength Wvelength level chnges by vlue of α ex. α = 6 5 Number of prtitions = Server A Server B 6 47 Server Server Server Server Server A= =. B= =. 4 C = =. D= =. 4 E = = 7 Client X 8 Server C 4 Client Y Server E 4 Fig.6 exmple of the proposl scheme Server D 9

10 4. Performnce Evlution Tble. Prmeters Server Opticl cross Connect Number of wvelength (Access Link) Number of wvelength (Others) Mx link distnce (km) Number of link File size Gbyte Opticl Pths Opticl Network 図 0 想定ネットワーク Access Link OXC Fig.7 lmbd grid network Block size: considering bndwidth nd distnce 0

11 The blocking probbility for α α = (Only originl cost) Blocking probbility is high. Simultion Results It is no considertion of the network stte. α = 0 (Only number of wvelength) Blocking probbility is high. The downloding time is long. α = 4 (Number of wvelength +originl cost) Blocking probbility is low. It is considertion of the network stte Fig.8 the blocking probbility for α (Lod=04) Block: ll of lightpth cn t set in prllel downloding Lod: the rtio of request for one client in one second α

12 The blocking probbility The conventionl scheme chieves higher blocking probbility for no considertion of network stte. The proposed scheme chieves lower blocking probbility for distribute the lod of servers. Simultion Results conventionl proposed OECC Decresing bottleneck links lod Fig.9 the blocking probbility for lod

13 Averge downloding time The conventionl scheme is shorter bout verge downloding time thn the proposed scheme. but The difference t the verge downlod time hs contrcted s the number of prtitions increses. The Allocted block size is smll. Simultion Results verge downloding time(sec) conventionl proposed It is no problem becuse the proposed scheme cn number of prtitions increse the number of prtitions thn the conventionl scheme. Fig.0 verge downloding time

14 Conclusion The file is reproduced nd high-cpcity in dt grids Prllel Downloding File division method Server selection method The Distributed Dt Access Schemes for prllel downloding in WDM network which considers the wvelength vilbilities of ech links in Lmbd Grid Networks hs been proposed By computer simultions The proposl cn reduce the blocking probbility compred with conventionl scheme. The proposed scheme cn relize more efficient lmbd grid networks. 4