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QQ peer-to-peer Answer

1 Each peer is neither client nor server to other peers. True or False?

2 Pros and cons of P2P

3 What are the 2 main concerns about resources in P2P file sharing?

4 How many views does Gangnam Style have on Youtube?

5 Why did Napster fail?

6 How can I prevent flooding when routing messages in a P2P network?

7 In Gnutella, peer discovery is P2P, not client-server. How do I find peers when I join for the first time?

8 How is resource discovery performed in Skype?

9 Name a type of protocol in sensor networks

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QQ peer-to-peer Answer

1 Each peer is neither client nor server to other peers. True or False?

False. Each peer is both client and server to other peers.

2 Pros and cons of P2P Pros: scaling (more nodes = more hardware), robustness. Cons: complex resource discovery, security.

3 What are the 2 main concerns about resources in P2P file sharing?

Resource location and resource retrieval

4 How many views does Gangnam Style have on Youtube?

Nearly 2 billions

5 Why did Napster fail? Discovery server = single point of failure

6 How can I prevent flooding when routing messages in a P2P network?

Decrease message’s TTL flag every hop

7 In Gnutella, peer discovery is P2P, not client-server. How do I find peers when I join for the first time?

Seeds = list of reliable peers

8 How is resource discovery performed in Skype?

The directory is stored and distributed in super peers.

9 Name a type of protocol in sensor networks Multipath, query-based, QoS-based

3

QQ MVC Answer

1 Describe what MVC is about.

2 In Vanilla (= default) MVC, which component is aware of which?

3 How many components has MVC?

4 In Web MVC (= iOS MVC), what does the controller do?

5 Name a Java tool using web MVC.

6 Why is web MVC not super cool?

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QQ MVC Answer

1 Describe what MVC is about. Separate rendering (V) and user input (C) from state and logic (M).

2 In Vanilla (= default) MVC, which component is aware of which?

M: none. V: model. C: model and view.

3 How many components has MVC? 3? TRICK QUESTION! Can have multiple views, controllers, and models.

4 In Web MVC (= iOS MVC), what does the controller do?

Fetch data from model, select a view, give data to that view.

5 Name a Java tool involved in web MVC. M=Enterprise Java Beans, V=JSP, C=servlet

6 Why is web MVC not super cool? It mixes server code (Java/python/C#/PHP) into client code (HTML, CSS).