Documents published to Broker can be stored as volatile documents or guaranteed documents. Volatile documents are stored only in memory and are lost if the host machine loses power or the Broker Server is otherwise restarted. Guaranteed documents are persisted to disk so that they can be recovered in case of a power failure or a restart.

Whether the Broker treats a document as volatile or guaranteed depends on the storage type associated with the document's type and the storage requirements of the client (as specified by the "Queue Type" property in the client's associated client group).

For additional information about storage type, see Document Type Storage Types and Client Queue Storage Type.