How To Make A Network Overlay More Efficient

Transcription

1 Corporate Technology Service Layer Components for Resource Management in Distributed Applications Fabian Stäber Siemens Corporate Technology, Information and Communications Copyright Siemens AG Alle Rechte vorbehalten.

2 Introduction Peer-to-Peer Computing A peer can be summarized as a node which can: act as both a client and server make local resources available to the network search for resources in a cooperative group of peers Key Properties of a peer-to-peer network include: flexibility, scalability and self-organization resilience (normally via redundancy) the efficient use of existing storage and computing resources overlay protocols which work on top of TCP/UDP the shifting of data and computation from a centralized client-server based model to decentralized cooperation Seite 2 8. März 2007 Fabian Stäber, CT IC 6

3 Introduction Architecture of Peer-to-Peer Applications Applications use services provided by the service layer Service layer provides features like confidential communication, range query support,... Peer-to-peer layer is wellresearched, lot of algorithms File Sharing/ VoIP service layer components Resource Discovery/ Routing Application Layer Service Layer Overlay Layer Network layer is commodity Sensor Networks/ TCP/IP Network Layer Seite 3 8. März 2007 Fabian Stäber, CT IC 6

4 Introduction Architecture of Peer-to-Peer Applications Application Requirements do not match properties of raw overlay. Research on service layer is unstructured, not generic. The gap on service layer yields to low number of applications actually using peer-to-peer. File Sharing/ VoIP service layer components Resource Discovery/ Routing Sensor Networks/ TCP/IP Application Layer Service Layer Overlay Layer Network Layer Seite 4 8. März 2007 Fabian Stäber, CT IC 6

5 Synopsis Close the gap on the service layer and enable more applications to benefit from peer-to-peer based network overlays. Methodology 1.Identify and analyze use cases. 2.Implement and evaluate missing service layer components. 3.Create a map and classification of service layer components. Seite 5 8. März 2007 Fabian Stäber, CT IC 6

6 Use Cases Criteria for the Choice of the Use Cases 1. Business Relevance. All use cases are part of the Siemens business. That way, the identified requirements can be discussed and verified with experienced professionals from the chosen application domains, and the results can be applied in future Siemens projects. 2. Diversity. The use cases are chosen from a wide range of applications, covering very different application domains. That way, as many aspects as possible are taken into account on the service layer. 3. Multiple Impact. The service layer components implemented in the use cases must be transferable to other applications and other application domains. That way, the overall contribution to the service layer is maximized. Seite 6 8. März 2007 Fabian Stäber, CT IC 6

7 C Use Cases Use Case 1: Collaborative Product Design (CPD) in the Automotive Industry Developed in the ATHENA IP. Step 1: OEM (FIAT) issues Request for Quotation (RfQ) to its First Tier supplier (Siemens). Well structured, highly integrated environment Process-Centric communication using Web Services Standard Protocols Request For Quotations RfQs Seite 7 8. März 2007 Fabian Stäber, CT IC 6

8 Use Cases Use Case 1: Collaborative Product Design (CPD) in the Automotive Industry Developed in the ATHENA IP. Step 2: Siemens issues RfQs to the Second Tier Suppliers Event-based coordination Document-centric communication Dynamic set of partners s RfQs Common Peer-to-Peer Information Space Seite 8 8. März 2007 Fabian Stäber, CT IC 6

9 Use Cases Use Case 1: Collaborative Product Design (CPD) in the Automotive Industry Developed in the ATHENA IP. Step 3: Second Tier Suppliers place their bids. s Quote Common Peer-to-Peer Information Space Seite 9 8. März 2007 Fabian Stäber, CT IC 6

10 Co Use Cases Use Case 1: Collaborative Product Design (CPD) in the Automotive Industry Developed in the ATHENA IP. Step 4: Siemens makes proposal for OEM Request For Quotations Quote Seite März 2007 Fabian Stäber, CT IC 6

11 Use Cases Use Case 2: Distributed Phone Book for VoIP Applications Searchable for the user s last names Storing user entries directly in the overlay causes hot spots: Too many people called Müller in Germany Developed the Extended Prefix Hash Tree, which is a service-layer component enabling scalable range queries Evaluated with the phone book of Munich ( entries): nearly all peers store less than 3 entries, maximum load: 150 entries. Reduced network traffic through caching. Seite März 2007 Fabian Stäber, CT IC 6

12 Use Cases Use Case 3: Routing and Aggregation of Sensor Data in Decentral Power Generation Power supply company use Web-based infrastructure to control small power generators Queries and threshold violations are routed through several levels of aggregation to reduce network traffic. Aggregation tree supports push- and pull-mode Benefit from locality preservation Seite März 2007 Fabian Stäber, CT IC 6

13 Evaluation of new Service Layer Components The following new service layer components are evaluated: Confidential Communication, for peer-to-peer based auction scenarios. An Index Tree, contributing scalable range queries for user data A Routing Infrastructure, providing reliable aggregation for sensor data done. done. to do. Seite März 2007 Fabian Stäber, CT IC 6

14 Map of Service Layer Components (ToDo) See how service layer components have impact on each other, which requirements can be combined easily, and which cannot. Requirement Area Service Layer Component Example: Requirement area: Limited network bandwidth per peer Service layer component: Replication Impact: Positive, because replication facilitates load balancing. Seite März 2007 Fabian Stäber, CT IC 6

15 Summary Overall contribution of the thesis 1. Enabling peer-to-peer in three new scenarios. 2. Classification of service layer components makes peer-to-peer integration more approachable. 3. New service layer components narrow the gap on the service layer. Seite März 2007 Fabian Stäber, CT IC 6