Policy Driven Management for Distributed Systems

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Policy Driven Management for Distributed Systems
Mi-Joung Choi mjchoi_at_postech.ac.kr DPNM
(1)
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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

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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

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Introduction (2)
Management Policies
Interprets
Interpreter
Monitor
Control
Figure 1. PDM Architecture
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Introduction (3)

• Advantages
• facilitates the dynamic change of behavior of a
  distributed management system
• permits the reuse of the managers in different
  environments

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DMS Architecture
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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

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Policy Classification (2)
Figure 2. Policies Influence Behavior of Object
within System
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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 gt 10 (authorization
  negative state based)
• Manager must perform reset on links with error
  count gt 50 (obligation positive state based)
• The standby manager must not perform any control
  actions (obligation negative activity based)

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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
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Policy as Relationship Objects
Figure 3. Typical Management Relationship
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Example Policy Objects (1)

• Access Rules

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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.typeT
• (any subject is permitted to include or create
  objects of type T in target domain Dt)
• A- any remove, delete Dt when Dt.membernum gt 2
  
• (any subject is prohibited to remove or delete
  domain Dt when the member number is more than 2)

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Example Policy Objects (3)

• Security Administrator

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Example Policy Objects (4)

• Responsibility

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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- onlteventgt ltsubjectgt actions
  lttargetgt when ltconstraintsgt
• Policy Hierarchy
• Policy Goals
• Policy Rules
• Policy Mechanism Information
• Policy Analysis
• Coverage
• Missing Obligation/Authorization
• Conflicts

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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

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References

• Morris Sloman, Policy Driven Management for
  Distributed Systems, Journal of Network and
  Systems Management, Plenum Press. Vol.2 No.4,
  1994.