A method for load sharing and high availability in a cluster of computers. The cluster includes a first computer and a second computer which perform a task An active application runs in the first computer and a standby application is installed in the second computer. The active application and the standby application are included in an application group. A first plurality of applications is installed in the first computer; the first plurality includes the running active application. The active application performs the task and stores in memory of the first computer state parameters and a policy. A synchronized copy of the state parameters and the policy pertaining to the task is maintained by storing in memory of the second computer. Preferably, the cluster is in a security gateway between data networks and performs a task related to security of one or more of the networks.