webMethods Integration Server provides a number of built-in services (in the pub.cache and pub.storage folders) that you can use to make your flows more robust. With these services, you can write state information and other pertinent data to a data store in the Integration Server short-term data store. If the webMethods Integration Server on which your flow is executing becomes unavailable, when your flow restarts it can check the state information in the data store and begin processing at the point where the flow was interrupted. For more information about pub.cache and pub.storage services, see the webMethods Integration Server Built-In Services Reference.