A Distributed Paging RAM Grid System for Wide-Area Memory Sharing

1. A Distributed Paging RAM Grid System for Wide-Area Memory Sharing Rui Chu, Yongzhen Zhuang, Nong Xiao, Yunhao Liu, and Xicheng Lu Reporter : Min-Jyun Chen Submission year :2006

2. Abstract • We propose a service-oriented grid memory sharing scheme, Distributed Paging RAM Grid (DPRG). • We study the properties and criteria of large scale memory sharing, and then design major operations and optimizations to fit the usage of grid systems.

3. Outline • Introduction • Overview • System Design • Performance Evaluation • Conclusion

4. Introduction • Clusters that use network memory mechanisms to share memory between cluster nodes have long been considered to be the best computing facilities for memory-intensive applications. • DPRG adopts a service-oriented architecture and provides memory service based on the wide-area distributed computing technology.

5. Overview • System assumption • We make several reasonable assumptions in the design of a prototype of a RAM Grid system - DPRG, through which we separate sub-problems (mutual trust) and throw away the trivia (zero disk cache). • Criteria • We extract two system criteria, which are the basic premises of DPRG.

6. System Assumption • Security and mutual trust • In DPRG, all nodes joined in the system are considered to be trustworthy. • Presently, we assume that data transmission is secure and all nodes in the system are trustworthy. • Zero disk cache • Each hard disk includes an inner disk cache, whose size is usually in the range of several megabytes. • We can treat the memory and inner disk cache as equivalent devices with the same access speed.

7. Criteria • Single service offering • Each grid node can only offer service to one user. • For example, if node x is storing page frames for node y, it cannot store page frames for any other node. • Exponential request • When a user needs memory, it requests M, 2M, 4M, …, M of remote memory gradually until its need is satisfied, where M is the amount of local memory of the node.

8. System Design • Paging Service and Deputy Service • Node Sets and Node States • Paging Service Operations

9. Paging Service and Deputy Service • Paging serviceallows other nodes in the system to remotely store a page in its shared memory and fetch the page at any time. • Deputy service acts as an agent that assists the service requestor by discovering paging services.

10. Node Sets and Node States

11. Node Sets and Node States (cont.)

12. Paging Service Operations • Put Page and Get Page

13. Paging Service Operations (cont.) • Paging Service Subscription • The paging service subscription operation is used toinform an available node that its service may be used inthe near future by a head node. • When the available nodechanges states, it should send a cancellation message toall the head nodes on its subscriber list.

14. Paging Service Operations (cont.) • Paging Service Release

15. Paging Service Operations (cont.) • Paging Service Withdrawal

16. Performance Evaluation • RAM Grid V.S. network memory when the heterogeneous factor is changing.

17. Performance Evaluation(cont.) • RAM Grid V.S. network memory when the dynamic factor is changing.

18. Conclusion • We propose RAM Grid, a grid memory sharing mechanism. • We design the DPRG scheme, which is composed of two major services: paging service and deputy service. • Experimental results show that DPRG significantly outperforms existing remote memory sharing schemes and effectively supports grid computing applications.

19. Thank You!