120 likes | 235 Views
Communication. Networking RPC and Relatives Distributed Objects Message- & Stream-Oriented Communication. Layered Protocols. Low-level layers Transport layer Application layer Middleware layer. Basic Networking Model. Layers, interfaces, and protocols in the OSI model. Low-Level Layers.
E N D
Communication Networking RPC and Relatives Distributed Objects Message- & Stream-Oriented Communication
Layered Protocols • Low-level layers • Transport layer • Application layer • Middleware layer
Basic Networking Model • Layers, interfaces, and protocols in the OSI model
Low-Level Layers • Physical layer: contains the specification and implementation of bits, and their transmission between sender and receiver • Data link layer: prescribes the transmission of a series of bits into a frame to allow for error and flow control • Network layer: describes how packets in a network of computers are to be routed
Transport Layer Important: the transport layer provides the actual communication facilities for most distributed systems Standard Internet Protocols: • TCP: connection-oriented, reliable, stream-oriented communication • UDP: unreliable (best-effort) datagram communication
Client-Server TCP • TCP for transactions (T/TCP): A transport protocol aimed to support client-server interaction
Application Layer Observation: Many application protocols are directly implemented on top of TP, doing a lot of app-independent work
Middleware Layer Observation: Middleware is invented to provide common protocols and services that can be used by many different applications • A rich set of communication protocols to allow different apps. to communicate • Marshaling and unmarshaling of data, necessary for integrated systems • Naming protocols, so that different apps. can easily share resources • Security protocols, to allow different apps. to communicate in a secure way • Scaling mechanisms, such as support for replication and caching Note: what remains are truly application-specific protocols
Middleware Protocols • An adapted reference model for networked communication.
Papers Presented • G. Eisenhauer, F. E. Bustamante and K. Schwan, Native Data Representation: An Efficient Wire Format for High-Performance Computing, IEEE Transaction on Parallel and Distributed Systems, 13 (12), pp 1234-1246, 2002. (Tuesday 1/13 - presented by Stefan Birrer) • A. D. Birrell and B. J. Nelson, Implementing Remote Procedure Calls, ACM Transaction on Computer Systems, 2(1), Feb. 1984, pp 271-290. (Tuesday 1/13 - presented by James Newell) • M. D. Schroeder and M. Burrows Performance of the Firefly RPC, in Proc. of the 12th Symposium on Operating System Principles, 1989. (Thursday 1/15 - presented by Stefan Birrer) • G. Banaver, T. Chandra, R. Strom, D. Sturman, A Case for Message Oriented Middleware, in Proc. 13th International Symposium on Distributed Computing (DISC) (invited lecture), Sep. 1999, pp 1-18. (Thursday 1/15 - presented by Ashish Gupta)
Implementing RPC • A. D. Birrell and B. J. Nelson – 1984 • Presented by: James Newell