MODULE 4 Flashcards
(42 cards)
Name:
Denotation to an entity in a distributed system
Identifier:
A name with properties
Access point:
Entities named by means of an address
Pure name:
Random string that has no meaning and is only used for comparisons
Broadcasting:
Using an entity’s ID to request the entity to return its address
Identifier properties:
- An identifier refers to only one entity
- An entity can only be referred to by one identifier
- An identifier always refers to the same entity
Chord organization:
- Each node has a random identifier
- Each entity has a unique key
- An entity is assigned to the node with the smallest ID that is greater or equal to the entity’s key (succ(k))
ARP’s job:
Finding out the MAC address associated with an IP address
HLS stands for _____
Hierarchical Location Services
Geographical scalability problems require separate chain reduction mechanisms because:
- Long chains aren’t fault tolerant
- There’s an increased network latency at dereferencing
ARP stands for _____
Address Resolution Protocol
Chord:
Nodes organized in a ring where each node and entity have unique identifiers in order for nodes to store these entities using their identifiers
HLS organization:
- Address of an entity is stored in a leaf or intermediate node
- Intermediate nodes store a pointer to a child if the child’s subtree contains the entity’s address
- Root knows all entities
HLS:
A search tree with networks divided into domains, and each domain is represented by a directory
HLS lookup operation:
- Start at local leaf
- If the node knows about the entity, follow it’s downward pointer, else go up
- Upward lookup stops at root
HLS insert operation:
- Keep forwarding request till a node that knows about the entity is reached
- Create a chain of pointers to the leaf
Self-certifying name:
Flat names for entities that include a derived value from the entity itself
HLS scaling steps:
- Choose physical servers for the logical server per entity
- Map entities to physical servers in a way that distributes the load of records
Approaches to trust that name-resolution returns what’s associated with a flat name:
- Secure identifier-to-entity associations
- Secure name-resolution process
Naming graph:
A graph where leaves represent named entities
Directory node:
An entity that refers to other nodes
Mounting:
Associating a node identifier of another name space with a node in current name space
Node attributes:
- Entity type
- Entity identifier
- Entity address
- Nicknames
Directory node contains:
- Table of (node identifier; edge label) pairs
- Attributes
