FAULT TO-LERANCE IN TCP USING PROCESS CHECKPOINTING

Abstract

Today's Internet services are commonly built over TCP, the standard Internet connection-oriented reliable transport protocol. TCP, based on network layer (IP) addresses, creates an implicit binding between a service and the IP address of a server providing it, throughout the lifetime of a client connection. This makes a TCP client prone to all adverse conditions that may affect the server or the inter network in between, after the connection is established: congestion or failure in the network, server overloaded, failed or under DoS attack. As a result, although highly available servers can be deployed, sustaining continuous service remains a problem. Fault tolerance support at the TCP layer can be very advantageous, and can prove to be more effective than at the application layer. It is often desirable to hide server failures from the clients. Various techniques and solutions exist to survive fault tolerance in TCP, but all needs to change TCP code on server side. FTTCP using wrappers had given a solution to this but it uses normal checkpoint which increases overhead of the server. In this work, "fault tolerance in TCP using process checkpointing", a new way of implementing checkpoint/restart mechanism is proposed. This method saves only core file of a process rather than complete process. Core file contains a complete memory dump of the process and register values. This shows that it reduces overhead of the server