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

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 ChenSubmission year :2006

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.

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Outline

IntroductionOverviewSystem DesignPerformance EvaluationConclusion

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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.

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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.

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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.

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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.

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System Design

Paging Service and Deputy ServiceNode Sets and Node StatesPaging Service Operations

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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.

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Node Sets and Node States

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Node Sets and Node States (cont.)

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Paging Service Operations

Put Page and Get Page

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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.

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Paging Service Operations (cont.)

Paging Service Release

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Paging Service Operations (cont.)

Paging Service Withdrawal

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Performance Evaluation RAM Grid V.S. network memory when the

heterogeneous factor is changing.

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Performance Evaluation(cont.)

RAM Grid V.S. network memory when the dynamic factor is changing.

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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.

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Thank You!