**2.2 Management Agents System (MAS)**

136 Grid Computing – Technology and Applications, Widespread Coverage and New Horizons

This book chapter introduced a Parallel Cache Model Based on Grid Memory (PCMGM) in the dynamic network environment (DNE). Through building an open grid environment, using the idle memory resources of DNE, adopting the multi-agents, the fuzzy theory and the self-learning methods, we designed the PCMGM model that can support the concurrent peak access for the hot segments in large scale internet applications, such as the large scale VOD system. The experimental results show that PCMGM can improve response time of the large scale application system for hot segments. It can be fit for the grid computing and the

PCMGM includes two parts: one is DNE that is the physical computing devices for the parallel cache, and DNE is composed of computer clusters connected through LAN and Intranet, and all the cache computers are not special, the other is the agent system, and we call it GMG (Global Management Group). GMG is composed of a management agent system (MAS), the application agent (AA), and a lots of cache agents (CA). The architecture is presented in figure1, and the definitions of NA, CA, CN, GA, SA are described as the

> *GA SA*

CC LC

*GMG*

C

*DN*

Internet

**Definition.1.** Cache node (CN) is a computer and it is defined as CN (id, AS, RSV, st), where id is the identifier of CN; AS is the set of agents running on CN; RSV(rcpu, rmem, rdisk, rnet) denotes its resource support vector, rcpu is the power of its CPU, rmem is the power of its memory storage, rdisk is the power of its hard-disk , and rnet is the power of its network adapter; st{"Local", "Idle", "Caching"} is its states, "Local" denotes that this computer is working for local tasks, "Idle" denotes that this computer is not working , and "Caching"

Intranet

denotes that this computer is working for Grid in the form of cache.

*AA*

*Server*

*Server*

CC

*NA CA*

large scale VOD system in internet.

**2. Architecture of PCMGM** 

definition 1 ~7 and the section 3.

*CN*

Fig. 1. The architecture of PCMGM

**2.1 DNE** 

The main functions of MAS are the computation resource management, the DNE monitoring and the task scheduler. MAS include four parts: The first part is the global control agent (GA) for managing PCMGM. The second part is the agent for managing one file server, and it is called as the server agent (SA). The third part is the agents for managing the cache nodes, and they are called as the node agents (NA), and each cache node has a NA. The last part is the application agent (AA) that is the connection manager between the users and PCMGM. The MAS structure is presented in figure 1.

The main functions of GA are as follows: (1) Control and manage DNE; (2) Receive and dispatch the caches; (3) control and monitor the file access process; (4) load balance; (5) Control all the cache nodes in DNE; (6) Calculate the idle resources; (7) Monitor the states all computing nodes and node agents;

The main functions of SA are as follows: (1) File operations; (2) The hot segment 27 management; (3) File transfer;

The main functions of NA are as follows: (1) Control the cache node to join or disjoin the DNE in dynamic; (2) Calculate the idle resources, and report them to GA; (3) Monitor the states and events in CN, and make the response adjustments; (4) Control the cache agents (CA) to complete the file access task.
