You can use the pub.storage or pub.cache service to code flow services to store state information and other pertinent information in the short-term data store. If a flow service fails because a server becomes unavailable, the flow service can be restarted from the last checkpoint rather than at the beginning. For more information about pub.storage and pub.cache services, see the webMethods Integration Server Built-In Services Reference. You can use both checkpoint restart services with stateful clusters. For stateless clusters, use the pub.storage service to use checkpoint restart.