WS-Policy4MASC - A WS-Policy Extension Used in the MASC Middleware

Abstract

WS-Policy4MASC is a new XML language that we developed for specification of monitoring and control (particularly, adaptation) policies in the Manageable and Adaptable Services Compositions (MASC) middleware. It extends the Web Services Policy Framework (WS-Policy) by defining new types of policy assertions. Goal policy assertions specify requirements and guarantees to be met in desired normal operation. Action policy assertions specify actions to be taken if certain conditions are met or not met. Utility policy assertions specify monetary values assigned to particular situations. Meta-policy assertions are used to specify which action policy assertions are alternatives and which business value-driven conflict resolution strategy should be used. WS- Policy4MASC also enables detailed specification of additional information necessary for run-time policy-driven management. We evaluated feasibility of the WS- Policy4MASC solutions by implementing a policy repository and other modules in MASC. We examined their usefulness on a set of realistic scenarios.