CS-3310 - 06 Multiprocessing - RPC, Distributed Systems, and Middleware

What is the goal of RPC?

Make remote calls resemble local calls.

What is a client stub?

Code that packs arguments and sends RPC.

What is a server stub?

Code that unpacks and invokes server function.

What is marshalling?

Packing parameters into a message.

What makes RPC tricky with pointers?

Addresses meaningless on remote machines.

Why can global variables break RPC?

Client and server do not share memory.

What is DSM?

Distributed shared memory abstraction.

How does DSM fetch remote pages?

Page fault triggers remote fetch.

What is false sharing in DSM?

Unrelated variables share a page and cause page thrashing.

Why do writable replicated pages cause issues?

Difficult to maintain consistency.

Why is scheduling easier on multicomputers?

Processes tied to local memory.

Why must process placement be chosen carefully?

Impacts communication and load.

What is a graph-based load balancer?

Partitions processes to minimize communication.

What is a sender-initiated algorithm?

Overloaded node sends excess work away.

What is a receiver-initiated algorithm?

Idle node requests work from others.

What is a distributed system?

Collection of independent machines acting as one.

What is middleware?

Software layer for uniform distributed access.

How does Ethernet avoid collisions?

Carrier sense and binary exponential backoff.

What is a router?

Specialized device forwarding packets between networks.

What is a protocol stack?

Layered network protocols cooperating together.

What is IP?

Unreliable connectionless datagram protocol.

What is TCP?

Reliable connection-oriented transport protocol.

What is DNS?

Name-to-IP address directory service.

What is the Web model?

Document-based client/server architecture.

What is location transparency?

File path gives no indication of physical location.

What is location independence?

Files can move without name change.

What is session semantics?

Changes visible to others only after close.

What is CORBA?

Object-based distributed middleware.

What is IDL?

Interface Definition Language for CORBA.

What is publish/subscribe middleware?

Producers publish tuples; subscribers receive matching ones.