**2. Approaches to resource allocation of tasks on grids**

Different researchers have taken various approaches to resource allocation of Tasks on Grids. The approaches to allocate resources in Grids can be divided into three broad categories.


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

management middleware which has led to the creation of various efficient technologies. In order to provide a satisfactory performance, these systems must optimize the overall execution time (or makespan) of the resource-intensive tasks. This requires efficient allocation of the resources for the sub-tasks (called jobs in this paper) of the PBDT tasks at

The problem of optimally scheduling these sub-tasks is a well-known NP complete problem [12]. To tackle it, various heuristics-based algorithms that can generate near-optimal solutions to optimization problems in polynomial times are devised. In this chapter a Bilevel Grid Resource Management System abbreviated as BiLeG is presented, in which the decision-making module is divided into two separate sub-modules. The upper level decision-making module is called the Task & Resource Pool Selector (TRPS). It selects a task from the given bag-of-tasks for which resources are to be assigned and chooses a partition of resources available for this chosen task (called the resource-pool of this task) which is typically a subset of all the resources available. The lower level decision-making module is called the Resource Allocator (RA), which uses an assignment algorithm to decide how the resources(from the chosen resource-pool) are allocated to the jobs, in a given task. Various algorithms can be used at RA whereas various policies can be deployed at TRPS. A particular combination of a TRPS policy and a RA scheduling algorithm deployed at a time is called an allocation-plan which determines the resource allocation for each task in the given bag-of-tasks. The following notation is used in this paper to write an allocation-plan: TRPS Policy, RA-Algorithm>. Investigating the choice of the most appropriate allocationplan under a specific set of workload and system conditions is the focus of this chapter.

1. It proposes the ATSRA algorithm and two extensions based on constraints relaxation

2. The experimental results capture the trade-off between accuracy in resource allocation and scheduling overhead both of which affect the overall system performance. The chapter discusses under which circumstances the proposed original algorithm or its

The rest of the paper is organized as follows. In Section 2, different approaches to resource allocation of tasks on Grids are presented. In Section 3, PBDT tasks are described. In Section 4, the problem being solved is defined and an overview of the proposed system is presented. In Section 5 policies are described. In Section 6, the concept of Architectural Templates is described. In Section 7, a Linear Programming (LP) based algorithm and its extensions are described that can be used to perform PBDT tasks. In Section 8, experimental results are

Different researchers have taken various approaches to resource allocation of Tasks on Grids. The approaches to allocate resources in Grids can be divided into three broad

Based on simulation, it analyses the performance of the proposed algorithms for

the individual machines of the network of nodes.

The main contributions of this paper are summarized.

different number of available Grid nodes.

presented. Finally, in Section 9, the chapter is concluded.

**2. Approaches to resource allocation of tasks on grids** 

extensions should be used.

technique.

categories.

3. Workflow based Resource Allocation

Each of these approaches is discussed in a following subsection.
