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. 2

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

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. 4

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. 5

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. 6

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. 7

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

9. Paging Service and Deputy Service  Paging service allows 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. 9

10. Node Sets and Node States 10

11. Node Sets and Node States (cont.) 11

12. Paging Service Operations  Put Page and Get Page 12

13. Paging Service Operations (cont.)  Paging Service Subscription  The paging service subscription operation is used to inform an available node that its service may be used in the near future by a head node.  When the available node changes states, it should send a cancellation message to all the head nodes on its subscriber list. 13

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

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

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

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

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. 18

19. 19 Thank You!