大连交通大学云计算全部简答题.doc

1. how many types of scaling? What are they?
Answer: 2 types,
（1）Horizontal Scaling – scaling out and scaling in,
（2）Vertical Scaling – scaling up and scaling down
2. what are Cloud Characteristics?
Answer:
（1）on-demand usage
（2）ubiquitous access
（3）multitenancy (and resource pooling)
（4）Elasticity
（5）measured usage
（6）Resiliency
3.How many Cloud Delivery Models? What are they?
Answer: 3 types,
（1）Infrastructure-as-a-Service (IaaS)
（2）Platform-as-a-Service (PaaS)
（3）Software-as-a-Service (SaaS)
1. Explains the difference between the concept of Multitenancy and Virtualization.
• With virtualization: Multiple virtual copies of the server environment can be hosted by a single physical server.
• With multitenancy: A physical or virtual server hosting an application is designed to allow usage by multiple different users.
2. What industry standards are represented the core technologies behind Web services?
Web Service Description Language (WSDL)
XML Schema Definition Language (XML Schema) 
SOAP – Formerly known as the Simple Object Access Protocol
Universal Description, Discovery, and Integration (UDDI)
3.Describing the active and passive service agents.
Active service agents perform an action upon intercepting and reading the contents of a message. The action typically requires making changes to the message contentsor changes to the message path itself.
Passive service agents, do not change message contents. Instead, they read the message and may then capture certain parts of its contents, usually for monitoring, logging, or reporting purposes.
4. Description the Modern data centers.
Modern data centers exist as specialized IT infrastructure used to house centralized IT resources,
such as servers, databases, networking and telecommunication devices, and software systems.
5. What is called server consolidation ?
The coordination function that is provided by the virtualization software allows multiple virtual servers to be simultaneously created in the same virtualization host. Virtualization technology enables different virtual servers to share one physical server. This process is called server consolidation 
6. Which categories for Networked storage devices usually fall into?
• Storage Area Network (SAN) 
connected through a dedicated network
provide block-level data storage access
using industry standard protocols
• Network-Attached Storage (NAS) –
Hard drive arrays are contained and managed by this dedicated device,
connects through a network
using file-centric data access protocols like the Network File System (NFS) or Server Message Block (SMB).
6. Data centers require extensive network hardware in order to enable multiple levels of connectivity. the data center is broken down into five network subsystems,What is these ?
Carrier and External Networks Interconnection
Web-Tier Load Balancing and Acceleration
LAN Fabric
SAN Fabric
NAS Gateways
7. Three fundamental elements comprise the technology architecture of the Web, Which is these?
Uniform Resource Locator (URL) 
 Hypertext Transfer Protocol (HTTP)
 Markup Languages (HTML, XML) 
1. About the threat agents. ( 8 points )
Questions:
a) What is a threat agent ？( 2 points )
Answer: A threat agent is an entity that poses a threat because it is capable of carrying out an attack.
b) fill in the table. ( 6 points )
threat agent
Defintion
An anonymous attacke
 is a non-trusted cloud service consumer without permissions in the cloud. 
A malicious service agent
 is able to intercept and forward the network traffic that flows within a cloud.
A trusted attacke
shares IT resources in the same cloud environment as the cloud consumer and attempts to exploit legitimate credentials to target cloud providers and the cloud tenants with whom they share IT resources 
Malicious insiders
 are human threat agents acting on behalf of or in relation to the cloud provider.
2. When does the following cloud security threat occur?( 8 points )
a) Traffic eavesdropping
b) Malicious intermediary threat
c) Denial of service (DoS) attack
d) Insufficient authorization attack
Answer:
a) Traffic eavesdropping occurs when data being transferred to or within a cloud is passively intercepted by a malicious service agent for illegitimate information gathering purposes. 
b) The malicious intermediary threat arises when messages are intercepted and altered by a malicious service agent.
c) The denial of service (DoS) attack occurs when a targeted IT resource is overloaded to the point where they cannot function properly.
d)The insufficient authorization attack occurs when access is granted to an attacker erroneously or too broadly, resulting in the attacker getting access to IT resources that are normally protected.
1. About the ready-made environment mechanism.
Questions:
a) What is the  ready-made environment mechanism？
Answer: The ready-made environment mechanism represents a pre-defined, cloud-based platform comprised of a set of already installed IT resources, ready to be used and customized by a cloud consumer.
b) Which cloud delivery model is it a defining component?
Answer:PaaS
c) What do the cloud consumers utilize these environments to do?
Answer:These environments are utilized by cloud consumers to remotely develop and deploy their own services and applications within a cloud.
2. About Cloud Usage Monitor.
Questions:
a) What is the Cloud Usage Monitor?
Answer: The cloud usage monitor mechanism is a lightweight and autonomous software program responsible for collecting and processing IT resource usage data.
b) please describe three common agent-based implementation formats.
Answer:
A monitoring agent is an intermediary, event-driven program that exists as a service agent and resides along existing communication paths to transparently monitor and analyze dataflows
A resource agent is a processing module that collects usage data by having event-driven interactions with specialized resource software.
A polling agent is a processing module that collects cloud service usage data by polling IT resources. 
c) fill in the table.
agent-based implementation format
usage
monitoring agent
be used to measure network traffic and message metrics
resource agent
be used to monitor usage metrics, such as initiating, suspending, resuming, and vertical scaling.
polling agent
be used to periodically monitor IT resource status, such as uptime and downtime

1、Beyond simple division of labor algorithms ，load balancers can perform a range of specialized runtime workload distribution functions that include:
（1）
（2）
（3）
2.In the pay-per-use monitor mechanism，what are Some typical monitoring variables ？
2、 What are the common resource cluster types ？
4、What is the function of a failover system mechanism？How many configurations of failover system ?
答案：1、（1）Asymmetric Distribution 
（2）Workload Prioritization 
（3）Content-Aware Distribution 
2、（1） request/response message quantity
（2）transmitted data volume
（3）bandwidth consumption
3、 （1）Server Cluste （2）Database Cluster （3） Large Dataset Cluster
4、The failover system mechanism is used to increase the reliability and availability of IT resources by using established clustering technology to provide redundant implementations.
two basic configurations:
（1）Active-Active （2）Active-Passive
1：Which management-related mechanisms are described in this book？
答案：The resource management system mechanism
The SLA management system mechanism
The remote administration system mechanism
T he billing management system mechanism
1. What is the role of the Cloud Balancing Architecture? What are the function of cloud balancing?
The cloud balancing architecture establishes a specialized architectural model in which IT resources can be load-balanced across multiple clouds.
Cloud balancing functionality is based on the combination of the automated scaling listener and failover system.
2. What is the capacity watchdog system comprised of?
The capacity watchdog system is comprised of a capacity watchdog cloud usage monitor, the live VM migration program, and a capacity planner. 
3. Which architecture establishes a resilient watchdog system? What are the functions of resilient watchdog system?
Dynamic failure detection and recovery architecture establishes a resilient watchdog system.
Five functions of resilient watchdog system: watching, deciding upon an event, acting upon an event, reporting, escalating .