1. Cost-based scheduling algorithm for workflow-based application in optical grid Lingzhi Zhang 2011.10.12

2. Introduction • The mathematical model • The Minimum Cost Based Scheduling Algorithm(MCBS) • Conclusions

3. 1. what is workflow-based application • 2. the background of our research • 3. the problem we want to solve

4. Introduction • The mathematical model • The Minimum Cost Based Scheduling Algorithm(MCBS) • Conclusions

5. The mathematical model workflow application model • scheduling optical grid model system model cost model

6. 1. workflow-based application model • The bottom level of task is the longest path from to the exit task

7. 2. optical grid model • The optical grid is modeled as • a graph • R is the set of grid resources provided by the service providers • L is the set of links including optical links and access links • S is the set of optical switch nodes

8. 3. cost model computation cost • The cost of the workflow execution communication cost • The bandwidth of light-path we can set up is limited to six levels—40G, 10G, 2.5G, GE, 622M, 155M The length of the task • computation cost the service we selected the bandwidth of light-path the distance of light-path • Communication cost the number of hops in light-path reimbursed time

9. Introduction • The mathematical model • The Minimum Cost Based Scheduling Algorithm(MCBS) • Conclusions

10. The scheduling algorithm (MCBS) • 1: query the Grid Market Directoryto obtain available services for each task • 2. sort tasks in a list by non-increasing order of bottom level value • 3. calculate the earliest end time of the application • 4. determine whether we should accept the request • 5. calculate the cost value of each communication task and computation task • 6. distribute the redundancy r to each task according to the cost value and calculate the time interval of each task • 7. minimize the execution cost under the time interval constraint and map the DAG to optical grid

11. simulation • DTL: deadline top level algorithm (proposed by R.Buyya) • SCP: scheduled critical path algorithm

12. Introduction • The mathematical model • The Minimum Cost Based Scheduling Algorithm(MCBS) • Conclusions

13. 1. we propose a new algorithm for workflow scheduling that minimize the execution cost while meeting the deadline defined by the user. • 2. different from the other related algorithms, we take the transmission cost into account when we allocate a grid resource for each task. • 3. The simulation shows that our algorithm reduces the execution cost greatly and has a better performance.

14. Thank You