Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Grid and Cloud Computing > Exam Questions (from protocols) > Flashcards

Exam Questions (from protocols) Flashcards

1
Q

Definition of Grid Computing by Len Kleinrock (1969) and Ian Foster (2002).

A

Len Kleinrock: visionary definition. Spread of computer utilities serving homes and offices like electric and telephone utilities. He addresses utilities and social value. Ian Foster: more technical definition. Coordination, non-centralized control, open standards and interfaces and quality of service are the main issues here.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

In the definition of Grid Computing by Ian Foster. What does it mean “non-trivial qualities of service”?

A

It refers to achievement of desired throughput, response time, co-allocation of multiple resources to meet an application requirement, availability, security.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the memory models for parallel systems and their advantages?

A

Shared memory: global address space. Physical memory can be distributed (but interconnect via bus). It is easier to use and fast. Distributed Memory: each processor has its own memory. Communication via explicit messages over the network. Easier to build and cheaper.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is GSI?

A

GSI stands for Grid Security Infrastructure. Set of tools, libraries and protocols to support:- security across organization boundaries- single sign-on- secure communication- delegation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is PKI? How it works?

A

PKI stands for Public Key Infrastructure. It is a set of entities need to manage digital certificates. Based on asymmetric cryptosystem. 1. The user gets a related key pair.2. Trusted authority binds public key to digital identity of the owner.3. The digital certificate is retrieved from trust authority.Consists of CA, RA, Central Directory, Digital Certificates, Entities and Management.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can a sporadic user make use of a Grid?

A

Delegation. It is not good for a user of the grid to share his private key with you. Proxy certificate! Alternate private key with limited lifetime and limited capability. Stored unencrypted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which are the Grid layers? Explain them.

A

From bottom to top:Fabric: control resources locallyConnectivity: communication and securityResource: negotiate access and control use of single resource.Collective: coordinate multiple resources.Application: execute the grid applications.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How does a Web Service simulate state in the client side? (tricky)

A

Cookies in a browser, maybe.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain the different kinds of SSO?

A

Single Sign-On.Client-based: using client-side cached credentials.Server-based: using secondary credentials returned from primary authentication.Service-based: using temporary ID (token based or PKI-based (certificate)) from primary authentication.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does the Fabric Layer classifies networks?

A

By number and proximity of devices: On-Chip Networks, System/Store Area Networks, LAN, WAN.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain the Cloud Stack.

A

Cloud Stack from bottom to top:Hardware (HaaS)Software KernelCloud Software Infrastructure (IaaS, DaaS, CaaS)Cloud Software Environment (PaaS)Cloud Application (SaaS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain MapReduce. What are its uses?

A

MapReduce is an algorithm/framework for simplifying parallel programming and apply operations on large data sets. Based on functional programming.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How to calculate PI using MapReduce?

A

Monte-Carlo algorithm. Square dartboard with circle inscribed. N throws. Each Map() throws N/p and calculate the hits. Reduce() adds up the count for hits and misses. PI = 4 * (hits/N).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the points in the checklist by Ian Foster?

A
  1. … coordinates resources that are not subject to centralized control,2. using standard, open, general-purpose protocols and interfaces,3. to deliver nontrivial qualities of service.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the difference between Grid and Cloud?

A

Grid: complex scientific work, batch job scheduling, sharing of resources. Best for large computations with performance requirements.Cloud: no upfront investment, illusion of infinite scale, resources on-demand. Best for small, irregular and unpredictable computations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Definition of SOA and how is it related with Grid.

A

Service Oriented Architecture is used to build software systems with autonomous loosely coupled components that provide their functionality via a standardized interfaces in the form of services. (broker, requester, provider). Grid is similar in the mode of operation and needs to integrate heterogeneous grid nodes. SOA is stateless but Grid must be statefull!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is the problem of authentication and authorization solved in Grid?

A

Cryptography, digital signature, digital certificates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How can the software be distributed in a Grid environment (licence issues)?

A

Dunno.

19
Q

Definition of OSGA.

A

Open Grid Service Architecture is a standard based on SOA for building Grids. WSRF is the foundation (statefull).

20
Q

Definition of WSRF and 5 WS-standards.

A

WS-Resource = stateful resource + Web Service. WSRF is a set of five specifications to model and manage WS-Resources:1. WS-Resource Properties2. WS-Resource Lifetime3. WS-Service Group4. WS-BaseFaults5. WS-Renewable References (WS-Addresses)

21
Q

How SLA’s work?

A

Service Level Agreement is a contract between provider and consumer that explicitly states the terms of agreement.

22
Q

What are the different types of Grids?

A

Grid—> Resource Grid———> Compute Grid———> Data Grid—> Service Grid (uses Resource Grid)

23
Q

How GridFTP works?

A

It is an extension of FTP that uses GSI

24
Q

Definition of ontology and how it is used in the semantic web.

A

Dunno =/

25
Q

What are the LAN technologies for Grid?

A

Ethernet and Myrinet. Myrinet has a better throughput, latency and less interference.

26
Q

What is Flynn’s Taxonomy?

A

SISM, SIMD, MISD, MIMD.

27
Q

How to do SIMD?

A

Processors Array, Vector Pipeline, GPGPU.

28
Q

What are the models for parallel programmin?

A

Shared memory, Threads, Message Passing, Data Parallel Model, Hybrid.

29
Q

Apply the three-point checklist on cloud computing.

A

It does not work because Cloud resources are coordinated by a centralized control (Cloud Provider).

30
Q

Collective Layer: SLAs, Matching, Accounting

A

Dunno

31
Q

Which are the types of virtualization?Explain them.

A

OS Assisted Virtualization: multiple isolated user-space instances.Paravirtualization: simplr hypervisor offers SW interface to virtual machines similar to that of the underlying HW.Full Virtualization: complete simulation of the underlying HW.HW Assisted Virtualization: enhanced version of Full Virtualization. Virtualization supported by CPU. CPU automatically traps sensitive instructions/

32
Q

Define the enablers for Cloud Computing.

A

Secure and efficient hardware virtualization (technological enabler) and datacenter economy, lightweight, contract-less and inexpensive computing (economic enabler).

33
Q

What are the types of hypervisor? What are the advantages of each one?

A

Native hypervisor and Hosted hypervisor. Native is more secure and faster. Hosted has better driver support (because of the OS).

34
Q

What are the Bernstein Conditions? Explain them.

A

Conditions that guarantee that two program fragments can be parallelized.Ij ∩ Oi = 0 (Flow independence)Ii ∩ Oj = 0 (Anti independence)Oi ∩ Oj = 0 (Output independence)

35
Q

Define Transport Level Security and Message Level Security.

A

Dunno

36
Q

Define identification, authentication, authorization, integrity and confidentiality.

A

Dunno

37
Q

What is a critical operation with respect to hardware virtualization?

A

An operation that modifies a unique resource of the host machine, thereby influencing other virtual guest machines.E.g.: memory operations, access to other hardware devices (real-time clock, soundcard, GPU, etc).

38
Q

What are snapshots? What does the system have to do if one is created?

A

Dunno

39
Q

What are the different needs in security for clouds and grids?

A

(grids: multiple organizations, cloud: usually just one)

40
Q

What does Amazon give you to use their services

A

(web service desctiptions).

41
Q

What is the Globus Toolkit and its purpose? What are other approaches?

A

Middleware for development. Unicore and Venice.

42
Q

SLAs, what are they good for? How are they used?

A

Dunno

43
Q

Define Cloud Computing.

A

“Clouds are a large pool of virtualized resources. These resources can be dynamically reconfigured to adjust to a variable load, exploited by a pay-per-use model, and they offer guarantees by means of customized SLAs.”

Grid and Cloud Computing (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions