Design of Cooperative Load Distribution for Addressing Flash Crowds Using P2P File Sharing Network

Design of Cooperative Load Distribution
for Addressing Flash Crowds
Using P2P File Sharing Network

Transcript

1. Design of Cooperative Load Distribution for Addressing Flash Crowds Using P2P File Sharing Network Network Media Group Department of Intelligence Science and Technology Graduate School of Informatics, Kyoto University Hiroki OKAMOTO, Ryosuke MATSUMOTO, Yasuo OKABE 1
2. Flash Crowd Website A Server Features • The duration is relatively short • The traffic will be 10 to 100 times bigger than normal • It will be occurred by links from popular website, TV, etc Website A is Good !! Website A is introduced by a TV show Concentration of accesses on Website A Website A is Temporarily unavailable 2 A problem that a website will be temporarily unavailable by suddenly high loads 1 2 3
3. Estimates loads and prepare appropriate infrastructures Problems of Conventional Method 3 Additional administrative and operational effort Costs for new Infrastructures Possibility to waste resources Additional Infrastructure Additional Infrastructure … … In conventional methods… Non-for-profit organizations and persons cannot address flash crowds For addressing flash crowd, we need to prepare appropriate infrastructures flexibly
4. A solution using cooperation 4 Help! When a server suffers flash crowd Other servers has idle resources Website A Server ♪ ♪ • To address flash crowds as a small website… Website B Server Website C Server Servers have other’s data each other • Problem 2 servers 5 servers The numbers of servers increases The number of replicas will be huge We need to increase the number of replicas according to demands Cooperate with other web servers
5. Peer to Peer (P2P) • Peer to Peer o One of the architecture of communication between some computers o A client has a role of both server and client o High scalability and fault tolerance • P2P File Sharing Network o Exchange files between peers without servers using P2P 5 Client-Server Peer to Peer • Download from a Server • Loads concentrate on the server • Download from peers • Increase replicas according to demands • Distribute loads to many peers
6. Proposed Method • Cooperative load distribution for addressing flash crowds 6 Web servers automatically lend idle resources each other Load distribution and Data dissemination to Clients using P2P File Sharing Network P2P Usable Client P2P Unusable Client P2P File Sharing Network Web Server P2P Usable Client P2P Unusable Client
7. Related Works 1. Load distribution to clients by proxy servers [Yokota et al. 2011] o Place a reverse proxy in front of web servers o Detect flash crowds by reverse proxies and route requests to a client 2. Load distribution to proxy network [C.Pan et al. 2006] o Load Distribution to an overlay network that constructed by proxy servers o The overlay network will be constructed dynamically when a flash crowd occurs o Web server handles ordering and controlling to construct the overlay network 7 Web server Proxy server Flash crowd Client that has replicas Overlay network constructed by proxy servers Web Server Flash crowd
8. Conceptual Diagram of Proposed Method 8 P2P Usable Client P2P Unusable Client P2P File Sharing Network P2P Usable Clients P2P Unusable Clients ① P2P Usable Client and P2P Unusable Client ② Web servers call for help from other servers when flash crowd occurs ③ The other server downloads the data from P2P ④ The other server provide the data instead of original server Help! 1 2 3 4 OK! 1 Other Web Server Original Web Server
9. Details of Proposed Method 9 • Cooperation with other servers Redirect requests to cooperative servers when flash crowd occurs P2P File Sharing Network P2P Usable Clients P2P Unusable Clients Help! Cooperative Server Original Server HTTP Redirect Download from P2P Provide the data instead of original server Cooperative Server
10. Details of Proposed Method 10 By web servers joining to P2P file sharing network... The number of replicas increases automatically according to demands Original Server P2P Usable Clients • Join to P2P File Sharing Network Accesses via P2P Network Accesses via P2P Network Spreading replicas to some clients Cooperative Server Cooperative Server
11. Details of Proposed Method 11 P2P File Sharing Network P2P Unusable Client P2P Usable Client Help! Original Server Download via P2P File Sharing Network Flash crowd Need not to download from a crowded server If all servers downed clients can download from other clients • Join to P2P File Sharing Network 1 2 2 3 Cooperative Server Cooperative Server
12. Features of Proposed Method • Cooperation with other servers o Create cooperative relationship with other servers o Cooperative relationship is a relationship to give each other help o Cooperative server must be a reputable server • P2P File Sharing Network o Publish websites to P2P file sharing network Exchange data with other servers via P2P file sharing network o We use BitTorrent because the overhead by joining a P2P network is low o We can use other P2P file sharing network as same role 12 Your Server Other Server
13. Design of Proposed System - Overall structure - • Components of our system ① Original Server ② Cooperative Server ③ DNS 13 Cooperative Server P2P Unusable Clients ④ Clients ⑤ BitTorrent Tracker Original Server DNS BitTorrent Tracker P2P Usable Clients Administrate BitTorrent Network 1 2 3 5 4 4 Name resolving and DNS round robin Cooperative Server 2
14. • Detecting flash crowds o Properties inside Web servers o Server state o Mutual periodically health checking • State transition of web server o Idle state o Flash crowd state o Rescue state • Distribution of requests o HTTP Redirect o DNS Round Robin 14 • The number of clients • The number of processes and threads • The number of connections in backlog • CPU utilization • Memory usage Web servers automatically lend idle resources each other Design of Proposed System - Cooperation -
15. • Example of guiding to Bittorrent 15 Original Server Cooperative Server P2P usable client that has the data P2P usable Client HTTP Request HTTP Redirect HTTP Request Return .torent file (HTTP response) BitTorrent Download BitTorrent Upload Help! Design of Proposed System - P2P Usable Client-
16. • Example of guiding to Bittorrent 16 Original Server Cooperative Server P2P usable client that has the data P2P Unusable Client HTTP Request HTTP Redirect HTTP Request Return contens data (HTTP response) BitTorrent Download BitTorrent Upload Help! Design of Proposed System - P2P Unusable Client-
17. • An example how our system works 17 Flash crowd state ＋ Access via HTTP + Original Server is not down Original Server Server C Server A Server B Server D Sever E Cooperative Server DNS ・ ・ ・ www IN A Server C Zone file Cooperative Server BitTorrent Tracker Server C Client B Peer List P2P Unusable Client that came to the new 2. HTTP 3. Redirect 7. Add record 6. Send data P2P Usable Client that has the data 5. Download the data 4. Acquire Peer List 1. Name resolving Design of Proposed System - P2P Unusable Client -
18. Summary • Summary o Considered problems of conventional methods as a method for addressing flash crowds o Proposed a load distribution method for addressing flash crowd by cooperation with other servers and P2P file sharing network o Designed a system using proposed method • Future work o Implement the system and evaluate the performance o Consider how to handle contents using server side programs o Consider how to delete contents that is disseminated on some clients by P2P file sharing network If you have a detailed question, Please send mail to first author, Hiroki OKAMOTO okamoto@net.ist.i.kyoto-u.ac.jp 18