The main objective of the research is to formalize an abstract architecture for the alternative data source that is meant to be used during system availability under intrusion threat. For this purpose, three possible designed semantics have been identify and considered. The security and performance parameters that are required to be exhibited by the alternative data source have been identified. Qualitative analysis is carried out in terms of the identified security and performance parameters, among the considered design semantics to select the potentially secure and suitable design semantic. The selected design semantic becomes the basis of formalizing an abstract architecture for the alternative data source during system availability under intrusion threat scenario.