《分布式系统原理与范型：第2版》原书课件第5章.ppt

DISTRIBUTED SYSTEMSPrinciples and ParadigmsSecond EditionANDREW S. TANENBAUMMAARTEN VAN STEENChapter 5Naming Names, Identifiers, And Addresses Properties of a true identifier: An identifier refers to at most one entity. Each entity is referred to by at most one identifier. An identifier always refers to the same entity Forwarding Pointers (1) Figure 5-1. The principle of forwarding pointers using (client stub, server stub) pairs. Forwarding Pointers (2) Figure 5-2. Redirecting a forwarding pointer by storing a shortcut in a client stub. Forwarding Pointers (3) Figure 5-2. Redirecting a forwarding pointer by storing a shortcut in a client stub. Home-Based Approaches Figure 5-3. The principle of Mobile IP. Distributed Hash TablesGeneral Mechanism Figure 5-4. Resolving key 26 from node 1 and key 12 from node 28 in a Chord system. Hierarchical Approaches (1) Figure 5-5. Hierarchical organization of a location service into domains, each having an associated directory node. Hierarchical Approaches (2) Figure 5-6. An example of storing information of an entity having two addresses in different leaf domains. Hierarchical Approaches (3) Figure 5-7. Looking up a location in a hierarchically organized location service. Hierarchical Approaches (4) Figure 5-8. (a) An insert request is forwarded to the first node that knows about entity E. Hierarchical Approaches (5) Figure 5-8. (b) A chain of forwarding pointers to the leaf node is created. Name Spaces (1) Figure 5-9. A general naming graph with a single root node. Name Spaces (2) Figure 5-10. The general organization of the UNIX file system implementation on a logical disk of contiguous disk blocks. Linking and Mounting (1) Figure 5-11. The concept of a symbolic link explained in a naming graph. Linking and Mounting (2) Information required to mount a foreign name space in a distributed system The name of an access protocol. The name of the server. The name of the mounting point in the foreign name space. Linki