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Name Services

Name Services. Johanna Hultin Carina Höglund. Name services. Introduction General Terms Name Services Name Space Name Resolution Caching. Introduction. Names Fundamental in distributed systems Facilitates communication and resource sharing

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Name Services

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  1. Name Services Johanna Hultin Carina Höglund

  2. Name services • Introduction • General Terms • Name Services • Name Space • Name Resolution • Caching

  3. Introduction Names • Fundamental in distributed systems • Facilitates communication and resource sharing • A consistent naming system is required • Adresses: locations of objects, not identifiers

  4. Introduction • Name service • Translates a human-readable name into a system-internal identifier • Ex human readable names: http://www.facebook.com URL www.facebook.com Internet Domain Name /etc/passwd File name • Ex system-internal name: 123.25.7.34 IP address

  5. General terms • Resolution • Translation of a name into data • Binding • Association between an object and a name • Context • Set of bindings • Attributes: value of property of an object • Ex: address • Ex Name Service: • Domain Name System (DNS)

  6. Name Service • A name service stores the collection of one or more naming contexts • Major operation: Look at attributes of a given name • Other operations required • Adding/deleting bindings • Listing bound names • Adding/deleting context • Name management is separated from other services • Unification: use the same naming scheme • Integration: Openness

  7. Ex: Reaching a file from URL address • Domain Name Server • Name service used by webbrowsers to interpret URL and e-mail addresses

  8. Name spaces • All valid names recognized in a particular service • Ex: URL in DNS • DNS name space • Hierarchical structure • Alias • Possible to use a simple name instead of a complicated one • Provides for transparency. • www.example.net is an alias for www.johanna.example.net

  9. Name Resolution • Iterative navigation • DNS

  10. Caching • Holds names that has previously been looked up • Consulted during name resolution • Availability

  11. Questions?

  12. Thanks for listening!

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