Distributed Computing Environment (DCE) Presenter: Zaobo He Instructor: Professor Zhang Advanced Operating System Advanced Operating System

Outline  Fundamental Knowledge  Current Technology  Future Research

Concept of DCE What is Distributed Computing Environment (DCE)?  The DCE supplies a framework and toolkit for developing client/server applications A remote procedure call (RPC) A naming (directory) service A time service A authentication service A distributed file system (DFS)

Why use DCS  Harnesses available computing resources  Accommodates heterogeneous data  Facilitates collaborative work and minimizes storage limitations  Protects distributed resources  Helps maintain distributed applications  Tracks data and programs that move around

DCE Services

Framework and Toolkit DCE RPC Distributed File Services Directory Services Distributed Time Services DCE Security services Threads

DCE RPC  The fundamental communications mechanism  Allows direct calls to procedure on remote systems as if they were local procedure calls  Masks differences in data representations on different hardware platforms, allowing distributed programs to work transparently across heterogeneous systems

Directory services  DCE Cell Directory Service (CDS) is the mechanism for logically naming objects within a DCE cell (a group of client and server machines)  Applications identify resources by name, without needing to know where the resources are located

Distributed File Service  DCE Distributed File Service (DFS) is a high- performance, scalable, secure method for sharing remote files  DFS includes many advanced features not found in traditional distributed file systems, including caching, security, and scalability over wide-area networks

Distributed Time Service Provides a way to synchronize the clocks on the different machines in a distributed system Threads DCE supports multi-threaded applications i.e., programs that use “lightweight” processes to perform many actions concurrently DCE Threads are based on the POSIX threading standard

Security Service  DCE Security Service provides the mechanisms for writing applications that support secure communications between clients and servers  enables processes on different machines to be certain of one another’s identities (authentication)  allows a server to determine whether a given user is authorized to access a particular resource (authorization)  supports several protection levels for messages as they travel across the network

DCE Cells The Domain of the Distributed Environment  a cell is the basic unit of operation and administration  a cell is a group of users, hosts, and resources that share common DCE services

Cell configurations At a minimum, a cell includes CDS, Security Service and Time Service Distributed Operation in a DCE Cell

A simple DCE cell

Outline Fundamental Knowledge Current Technology Future Research

Grid Space GridSpace is a novel virtual laboratory framework enabling researchers to conduct virtual experiments on Grid-based resources and other HPC infrastructures.

Atmosphere The Atmosphere platform is responsible for maintaining an interface between the end-user tools developed in the VPH- Share project and the underlying hardware resources required to perform complex computations in a distributed Cloud environment.VPH- Share project

Outline Fundamental knowledge Current Technology Future Research

Big Data and Cloud Computing With the rapid development of microelectronics, embedded computing techniques, integrated circuits and wireless communication techniques, the wireless sensor networks (WSNs) enter into our lives. Since a WSN always has a large amount of sensed data, it costs lots of energy to transmit the raw sensed data to the sink and process them centrally. Thus, the distributed in-network algorithms are very important for WSNs. Distributed Computation in Nodes

Future work Distributed in- network algorithms Approximate Aggregation Algo-rithm in Static Sensor Networks Aggregation Algorithms in Dynamic Sensor Networks

Reference [1] K. Rycerz, M. Bubak, E. Ciepiela, D. Harezlak, T. Gubala, J. Meizner, M. Pawlik: Composing, Execution and Sharing of Multiscale Applications, submitted to Future Generation Computer Systems, after 1st review (2013) [2] A. Wibisono, R. Koning, P. Grosso, A. Belloum, M. Bubak, C. de Laat: OIntEd: online ontology instance editor enabling a new approach to ontology development, Software: Practice and Experience, DOI (2013)DOI [3] Siyao Cheng, Jianzhong Li, Zhipeng Cai: O(ε)- Approximation to physical world by sensor networks. INFOCOM 2013: Jianzhong LiZhipeng CaiINFOCOM 2013

Thank You ！