POSTECH DP & NM Lab. (1)(1) Policy Driven Management (1)(1) Policy Driven Management for Distributed Systems Mi-Joung Choi DP&NM

POSTECH DP & NM Lab. (2)(2) Policy Driven Management Contents Introduction –Definition, Architecture, Advantages Policy Classification Policy as Relationship Objects Example Policy Objects –Access Rules, Domain Membership Policy, Security Administrator, Responsibility Consideration Issues for policy Conclusions References

POSTECH DP & NM Lab. (3)(3) Policy Driven Management Introduction (1) Distributed System Management –monitoring the activity of a system –making management decision –performing control actions to modify the behavior of the system Policy –a relationship between a domain of subjects (managers) and a domain of target managed objects –one aspect of information which influences the behavior of objects within the system Policy Driven Management –perform management based on policy

POSTECH DP & NM Lab. (4)(4) Policy Driven Management Introduction (2) Managed Object Management Interface Normal Functionality Interfaces Management Policies Management Policies Managers Interprets Monitor Control Figure 1. PDM Architecture Interpreter

POSTECH DP & NM Lab. (5)(5) Policy Driven Management Introduction (3) Advantages –facilitates the dynamic change of behavior of a distributed management system –permits the reuse of the managers in different environments

POSTECH DP & NM Lab. (6)(6) Policy Driven Management DMS Architecture

POSTECH DP & NM Lab. (7)(7) Policy Driven Management Policy Classification (1) Authorization policies –define what an manager is permitted or not permitted to do –the operations they are permitted to perform on managed objects –considered target based Obligation Policies –define what a manager must or must not do –guide the decision making process –considered subject based

POSTECH DP & NM Lab. (8)(8) Policy Driven Management Policy Classification (2) Figure 2. Policies Influence Behavior of Object within System

POSTECH DP & NM Lab. (9)(9) Policy Driven Management Policy Classification (3) Positive Policy : permitting or must Negative Policy : prohibiting or must not Activity Based : the simplest policies State Based : include a predicate based on object state (ex) - John is permitted to read file F1(authorization & positive & activity based) –John is prohibited to read personnel records where employment grade > 10 (authorization & negative & state based) –Manager must perform reset on links with error count > 50 (obligation & positive & state based) –The standby manager must not perform any control actions (obligation & negative & activity based)

POSTECH DP & NM Lab. (10) Policy Driven Management Terminology Management domain : a collection of managed objects to which policies apply (subdomain, direct member, indirect member, parent) Constraints : specification to restrict the applicability of the policy (temporal constraints, parameter value constraints, preconditions) Propagation : policy applying to a parent domain, should propagate to member subdomains of parent Figure 4. Policy Propagation

POSTECH DP & NM Lab. (11) Policy Driven Management Policy as Relationship Objects Figure 3. Typical Management Relationship

POSTECH DP & NM Lab. (12) Policy Driven Management Example Policy Objects (1) Access Rules

POSTECH DP & NM Lab. (13) Policy Driven Management Example Policy Objects (2) Domain Membership Policy : – specify membership of a domain by specifying an object selection predicate & creating & deleting (Ex) – A+ any {include X, create X} Dt when X.type=T (any subject is permitted to include or create objects of type T in target domain Dt) – A- any {remove, delete} Dt when Dt.membernum > 2 (any subject is prohibited to remove or delete domain Dt when the member number is more than 2)

POSTECH DP & NM Lab. (14) Policy Driven Management Example Policy Objects (3) Security Administrator

POSTECH DP & NM Lab. (15) Policy Driven Management Example Policy Objects (4) Responsibility

POSTECH DP & NM Lab. (16) Policy Driven Management Consideration Issues of Policy Policy Implementation Issues : Policy Dissemination Function – transforms policies into a form suitable for interpretation – sends obligation policies to managers in subject domain – sends authorization policies to reference monitors associated with objects in the target domain Form : O+ | O- [on ] {actions} [when ] Policy Hierarchy – Policy Goals – Policy Rules – Policy Mechanism Information Policy Analysis – Coverage – Missing Obligation/Authorization – Conflicts

POSTECH DP & NM Lab. (17) Policy Driven Management Conclusions PDM provides the basis for dealing with automated & dynamic & reusable management Policy specification language should produce a set of rules which can be interpreted by managers Domains are used to specify the scope for applying the policy Important Issues : policy analysis, conflict detection & resolution

POSTECH DP & NM Lab. (18) Policy Driven Management References Morris Sloman, “Policy Driven Management for Distributed Systems,” Journal of Network and Systems Management, Plenum Press. Vol.2 No.4, 1994.