| dc.description.abstract | Grid computing, emerging as a new paradigm for next-generation computing, enables the sharing, selection, and aggregation of distributed resources for solving large-scale problems in science, engineering, and commerce. The resources in the Grid are heterogeneous and geographically distributed. The resources in the Grid are dynamic in nature. Resource owners are at discretion to submit/donate the resources in to the Grid environment. A Web Services is a network-enabled entity accessed using the standard web protocols. Web Services are basically stateless in nature and there is a need to maintain state across the transactions based on Web Services. Grid Services is an extension of Web Services in a Grid environment having statefulness as a key feature. State of any Grid Services is exposed with the help of Service Data Elements. Grid Services may fail during its life cycle due to failure of a resource or a withdrawal of a resource by the resource owner. Thus, there is a need to provide a reliable solution in the form of Grid Service instance migration to protect the work of the users, which was carried out. This thesis proposes a model that supports Grid Services instance migration. Migration of an instance can take place based on the failure of resource, increase in load at the resource, change in the policy of the domain in which resource resides, user specified migration, or migration due to withdrawal of a resource by the resource owner. It enables the users to specify the migration if (s) he does not trust the domain in which instance is running. The model includes an incremental checkpointing mechanism to facilitate migration. Thesis shows the study of checkpointing mechanism in various resource managers: condor, condor-G and LSF. It narrates the different economic models prevalent in distributed computing field. The need for dynamic scheduler for Grid is also discussed. A model for instance migration for a task having parallel independent subtask is also proposed. A proposal to modify existing Globus-GRAM protocol to support Grid Service instance migration is also suggested. | |
