Efficient Survivable Provisioning for Bulk Data Transfers in Grid Networks

1. Efficient Survivable Provisioning for Bulk Data Transfers in Grid Networks 施清棋 2011-04-20

2. Outline • Background • Network Model • Bulk Data Transfer • Multipath with Reliable Bandwidth • MPRB algorithm (ILP & Heuristic) • Reservation Cancellation • Simulation • Conclusion

3. Background • Grid Network is a promising infrastructure to support many advanced data-intensive applications.

4. Network Model • The physical topology is denoted as where is the set of nodes and is the set of links. Each link is associated with a bandwidth and a delay .

5. Bulk Data Transfer (BDT) Request • Each BDT request is denoted as: where , are the source and sink respectively. is the arriving time, and is the deadline. is the file size. is the differentiated delay requirement. • Every request which arrives at time asks for whether a file with size is able to tranfer fromto before deadline . The difference of different routed packets must be bound by .

6. Survivable Provisioning for BDT • We define the survivable provisioning for BDT as the reservation of network resources such that, using reserved resources, the deadline requirement will still be met even when network failure occurs. • In the following, we will focus on single link failure since it’s the dorminant failure in grid networks. • However, it’s possible to extend our scheme to deal with other failure scenarios.

7. Survivable Provisioning: Methodology • Two link disjoint paths, working path & backup path. • >100% over-provisioning (no backup sharing) • x% over-provisioning (backup sharing) • When actually no failure occurs, the backup resources are wasted. • Multiple working paths with reliable bandwidth (our scheme). • Efficient provisioning with theoretic no over-provisioning.

8. Multipath with Reliable Bandwidth • For a BDT request , we denote the set of all paths from to as . We choose a subset as the set of working paths. Each path is assigned a bandwidth for request . And the differentiated delay for any must be bound by . • The total bandwidth:

9. Multipath with Reliable Bandwidth • Vulnerable bandwidth : the maximum of bandwidth that will be affected under any failure scenario (single link failure). • Reliable bandwidth (the minimum bandwidth remains under any failure scenerio): • If , then the provisioning is survivable. And we reserve the bandwidth by .

10. Multipath with Reliable Bandwidth • If no failure occurs, the request will transmit its file by, • If any failure occurs at time , the request will transmit its file before, • If no failure occurs, the bandwidth reserved between and can be re-allocated to other requests, resulting no over-provisioning.

11. MPRB problem • Multipath with Reliable Bandwidth (MPRB) problem: • Given , , and , and , the MPRP problem seeks for a set of s-d path with each reserved with bandwidth such that, • Delay difference is bound by DD • The reliable bandwidth of is at least

12. MPRB problem (extension) • The above MPRB problem assume that is constant over time. In fact is a function of time. • For is a function of time, we choose

13. Reservation Cancellation • Given request , with the set of working paths , reserved bandwidth , and reliable bandwidth , if no failure happens, at time (), the amount of data transmitted is, . • The remaining file size is , and is guaranteed to transmit at reliable bandwidth in the future. Thus, the request is guaranteed to finished by, • Thus, the reservation after this time instant can be cancelled for other request.

14. Reservation Cancellation • When a request arrives, we first cancel the unnecessary bandwidth reservation for all requests, and then run the MPRB algorithm.

15. 谢 谢！