Quiz 5 Flashcards
A Distributed Hash Table can provide the following:
Availability
Scalability
Fault-tolerance
Security
Availability
Scalability
Fault-tolerance
One major challenge with home-based approach is:
Poor geographical scalability
Home address of an entity cannot be registered with a naming service
Broken links because of long chains of pointers
Poor geographical scalability
Scalability issues are addressed in DNS system by:
Replicating higher level DNS servers
Using flat naming scheme
Caching at the local DNS servers
Replicating higher level DNS servers
Caching at the local DNS servers
Names can be resolved iteratively and recursively in DNS. Which of the statements is/are correct:
In recursive resolution, higher-level servers may have too much load
In iterative resolution, communication distance is not an issue
In recursive resolution, communication distance may not be an issue
In iterative resolution, communication latency can be an issue
In recursive resolution, higher-level servers may have too much load
In recursive resolution, communication distance may not be an issue
In iterative resolution, communication latency can be an issue
A name space contains:
All valid names recognized and managed by a service
All names that a designer can think of
Unbounded names making it possible to pick any arbitrary name
All valid names recognized and managed by a service
You are tasked to design a lookup for a chord system that can scale, which lookup algorithm would you recommend:
An approach where each node can use a routing table containing references to a few exponentially distant nodes
An algorithm where each node can multicast the request to all nodes and get back the address
An algorithm where queries can be looked up from one node’s successor to another until the address is found
An approach where each node can use a routing table containing references to a few exponentially distant nodes
The Domain Name System (DNS) is used to map the hostname to the IP address. Which of these statements is/are correct:
An authoritative name server is the server that stores and provides the actual IP address of the hostname to the local DNS server
The DNS is hierarchically organized where the root node is contacted to start the name resolution
The root server contains the records of the authoritative name servers
An authoritative name server is the server that stores and provides the actual IP address of the hostname to the local DNS server
The DNS is hierarchically organized where the root node is contacted to start the name resolution
A Distributed Hash Table uses 8bits to define its address space. What is the size of the address in this space?
8
64
128
256
2^8 = 256
An example of a location independent name is:
A telephone number
A domain name
All of the options
An IP address
A domain name
A DHT chord ring has 3 active peers; P1, P2, and P3. P1 has an address 20, P2 has an address 10 and P3 has an address 30. Which of the peers is/are responsible for the files with the following identifiers: 5, 12, 31, and 1?
P1 holds 12, P2 holds 1, 5, and P3 holds 31
P1 holds 12. P2 holds 1, 5, 31
P1 holds 1, 5, 31. P2 holds 12
P3 holds 1, 5, 31. P2 holds 12
P1 holds 12. P2 holds 1, 5, 31
