Service discovery

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Service discovery

• Melissa Tjiong
• February 16, 2006

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Outline

• Motivation
• Service discovery
• Secure service discovery
• Questions

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Motivation

• Orchestrator needs relevant information about
  services (what, where, how)
• This information is dynamically gathered through
  service discovery

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Service discovery problems

• How to find services in a distributed
  environment?
• Reliable
• Robust
• Scalable
• Secure

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Service oriented architecture
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Entities

• Service provider providing services
• Orchestrator looking for services
• Optional
• Repository gathering information about services
  and exposing it to the network

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Service discovery process
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Service discovery process
1. Finding repository
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Service discovery process
1. Finding repository
2. Advertising services
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Service discovery process
1. Finding repository
2. Advertising services
2. Looking for services
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Service discovery process
1. Finding repository
2. Advertising services
2. Looking for services
3. Query vs services matching
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Review of existing approaches

• Goals to identify
• What are (not) there?
• Are there differences? Why?
• What do we want?
• Do we need a new one?
• What can be reused?
• Whats new?

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Review of existing approaches

• Criteria
• Reliability
• Scalability
• Robustness
• Security
• Portability interoperability

• Samples
• UPnP
• Jini
• SLP
• INS
• Berkeley SDS
• Splendor

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Review results

• Reusable approaches
• For reliability, scalability, and robustness
• Combined broadcast- repository-based
• Distributed replicated repository
• Soft-state registration with periodic triggered
  update
• Still lacking
• Security within the discovery process

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Secure service discovery problems

• In a large network, how to limit the scope of
  service discovery process to authorized parties
  only?
• Scoping parameters Privacy security
• Necessary steps?
• Possible attacks ? required mechanisms?

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Community

• A group of authorized entities
• E.g. services owned by people in the same family,
  services located in the same room
• One of the possible ways virtual community
• Community formed by users
• Membership Users ? Services

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Initial design user level
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Service discovery process
Overlay broadcast
1. Finding repository
2. Advertising services
2. Looking for services
3. Query vs services matching
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Service discovery process
Encrypted, Signed, Certificate-based
1. Finding repository
2. Advertising services
2. Looking for services
3. Query vs services matching
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Initial design

• Similar architecture
• Scope overlay broadcast
• Security encryption, certificate, signed
  messages

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Research questions

• Advantages disadvantages?
• How to deal with overlapping communities?
• Credentials protection
• Requirements consequences?
• Repository Discovery across communities
• Services different access levels
• Orchestrator service access across communities
• Generic approach for different scoping
  parameters?

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Questions?http//www.win.tue.nl/mtjiong/docs/