Grid computing systems are increasingly growing importance in the present world with advances in the network technology. Grids are composed of many geographically disturbed resources, each having its own administration domain. Grid computing involves decentralized heterogeneous, geographically distributed resources that can work on a job together. Since the resource availability is dynamic in nature, the grid infrastructure is prone to failure of job lose or delay. So in order to adapt to the failure, fault tolerant mechanism must be implemented. Commonly used techniques for fault tolerance are check pointing and load replication or job migration mechanism.