TU Wien:Verteilte Systeme UE (Lachner)/Prüfung 2022-01-28

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Ein Auszug der Fragen vom Multiple-Choice-Test:

Asymmetric cryptography: The only way to encrypt a message is to use the public key, while the private key can only be used for decryption.

  • Wahr
  • Falsch

How can you make an object which implements java.rmi.Remote remotely accessible through RMI?

  • I let its class extend java.rmi.remote.UnicastRemoteObject.
  • It is already remotely accessible, because of the implemented java.rmi.Remote interface.
  • I use the static exportObject method of java.rmi.remote.UnicastRemoteObject.
  • It is sufficient to bind the object in the RMI Registry.

Java RMI communication is encrypted.

  • Wahr
  • Falsch

What happens when the close() method of a ServerSocket is called?

  • All socket connections that were accepted by the ServerSocket are closed.
  • The ServerSocket stops listening to new connection requests.
  • The connected clients receive an exception that the ServerSocket was closed.

Which types of objects can be passed as parameters to a method defined by an RMI remote object (suppose both client and server have access to the same code).

  • Any primitive data type.
  • Any object that does not use other complex types (like collections).
  • Any fully serializable object.
  • Any object that only has primitive members.
  • References to other remote objects.

Which properties does the DMAP (DSLab Message Access Protocol) protocol have?

  • Stateless
  • Plain-text
  • Stateful (Aufgrund des Logins ist diese Antwort korrekt!)
  • Binary

Similar to java.net.Socket, the input/output streams of java.net.DatagramSocket have to be closed.

  • Wahr
  • Falsch

Which properties does the DMTP (DSLab Message Transfer Protocol) protocol have?

  • Binary
  • Plain-text
  • Asynchronous
  • Synchronous

Which statements about Java RMI are correct?

  • It is the object-oriented equivalent of remote procedure call (RPC). (Diese Antwort ist korrekt.)
  • It relies on the publish/subscribe messaging pattern.
  • It simplifies the coordination of multi-threaded programs.
  • It simplifies data exchange between Java programs.

Which statements about Base64 encoding are correct?

  • Base64 adds a layer of security.
  • Base64 translates binary data to ASCII printable characters.
  • Base64 is necessary to send binary data over TCP channels.
  • Base64 encoded channels exhibit higher network traffic. (Diese Antwort ist korrekt.)