Types of Web Services and Their Components

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2 Outline Host Host: QoS extensions Host in P2P networks Realization of MWSMF Conclusions and future research directions 2/18

3 3/18 Wireless developments Host web services [LA, OMA] web service provisioning Implementation details Implemented in PersonalJava Uses ksoap2 SOAP over HTTP Upgraded to J2ME Performance analysis UDDI Registry Find Service Requester SOAP Acceptable performance levels for service delivery The WS processing time at the Host (< 10%) Directly proportional to achievable transmission rates High data transmission rates with 3G & 4G Refers Publish WSDL Describe WS Host

4 Host QoS extensions Security issues Security breaches End-to-end security Security Standards for web services XML Encryption [W3C] XML Signature [W3C] WSSE (WS-Security Standard) [OASIS] 4/18 SAML (Security Assertion Markup Language) [OASIS] Adaptability of WSSE for mobile web services Bouncy Castle Lightweight cryptographic API

5 Security results 5/18 Confidentiality & Integrity can be provided for reasonable message sizes of 2kb Extra time to the WS invocation cycle is ~ 2 sec with Confidentiality Integrity latency is 2 sec Signing on top of encryption ~3.5 sec Best scenario (Highly secured and better performance) AES-256 Symmetric key encryption RSA 1024 bit key exchange RSAwithSHA1 signature Best scenario forces the need for a mediation framework

6 Host QoS extensions Scalability issues Scalability aspects To achieve less data to transmit Significant for Host Transmission time constitutes 90% of invocation cycle latency Improves battery life Size of MWS message B msg = B tp + B mtp + B soap + B app Minimal encoding is not always the best option XML Compression XMill [Liefke and Suciu, 1999] 6/18 Fast Infoset [Sandoz et al., 2004] Efficient XML [AgileDelta]

7 Scalability analysis 7/18 BinXML [Ericsson and Levenshteyn, 2003] XML tags replaced by Unique byte value 6 reserved bytes (0x00-0x03, 0xFE, 0xFF) Effective for SOAP messages Analysis BinXML enabled MH Message size 5 kb ~ 15% gain (1.3 sec) MWS compression gain: Comparision of mobile web service invocation times with and without BinXML compression T mwscg = δt reqt + δt rest T reqenc T reqdec T resenc T resdec Time in Milliseconds Total time at client Server processing time Client processing time Transmission time WithoutBinxml WithBinxml

8 Host in JXTA network JXTA Network JXTA Rendezvous WS JXTA Super (Relay & Rendezvous) BTS1 Operator Network BTS2 BTS3 Virtual P2P Network JXTA Rendezvous WS WS JXTA Relay 8/18 Technical advantages to Host Eliminating the need for Public IP Better identification/access mechanisms (Peer ID) Better service discovery

9 web service discovery issues 9/18 Web service discovery Huge number of services are possible with Hosts Centralized UDDI not the best solution Problems with bottlenecks nodes are dynamic Binding information changes regularly Services are to be published again and again Dynamic service discovery mechanisms Announce listen model (e.g. Jini) Distributed P2P WS registry (VISR) [Dustdar and Treiber, 2006] Konark [Lee et al., 2003] UPnP

10 web services discovery 10/18 Publishing mobile web services in JXTA / JXME JXTA Modules Life time of advertisements <jxta:msa> <MSID>... </MSID>... <Parm> <WSDL>... <WSDL> </Parm>... </jxta:msa> MSAs advertise mobile web services Discovery of MSAs with name & description Works, but not very precise Module class Advertise the existence of a service Module Specification Advertise how to access a Service (API, messages) Module Implementation Advertise a platform specific implementation Service Interface Service Implementation UDDI Registry WSDL

11 Advanced mobile web service discovery 11/18 Categorization using MCA MCAs simulate Category bags & tmodels in UDDI Peer Groups simulate business groups Post-filtering of mobile web services Search can also extend to WSDL information Search should be based on weight of keywords Apache Lucene tool Based on indexing Advanced Matching of Services (AMS) Context-aware service discovery [WSTalk] To achieve very precise results Ontology based context engine

12 How to integrate mobile web services and P2P domains taking care of QoS? MWSMF BTS2 BTS3 UDDI WS Client Internet BTS JXTA Super QoS Provisioning JXTA Relay Virtual P2P Network 12/18 JXTA Network JXTA Rendezvous JXTA Rendezvous WS Accessible to IP network

13 MWSMF realization 13/18 Why Enterprise service Bus (ESB)? Any SOA should be sufficient for the purpose Web services are best means of realizing SOA Latest developments in web services domain Enterprise service Bus (ESB) Enterprise Service Bus provides a set of infrastructure capabilities, implemented by middleware technology, that enable the integration of services in an SOA [Gartner, Inc.] Java Business Integration (JBI) ServiceMix

14 MWSMF - Components 14/18 WS Client Internet MWSMF HttpReceiver Broker Binary Transformer XSLT Transformer P2PMapper N o r m a li z e d M e s s a g e R o u t e r HttpInvoker ContentBased Router QoS Verifier SAAJBinding Context Engine Host WS

15 Message flows in MWSMF 15/18 web service message optimization scenario Supplementary features of MWSMF Hosts a UDDI registry Supports automatic startup of Hosts PushRegistry feature of WMA MWSMF Broker HttpReceiver 1 12 Internet JBI Container N M R 5 Binary Transformer HttpInvoker 6 7 Host WS

16 Performance evaluation of MWSMF ApacheBench load generator Established on a laptop Successful in handling 110 concurrent requests Mean value of handling a client ~ 130 ms Evaluation proved that MWSMF can handle large number of concurrent clients Time-Diagram TPS-Diagram 35, Time to handle single client (ms) 30, , , , , , Time Transactions per second (TPS) TPS 16/ No of concurrent requests No of concurrent requests

17 Conclusions 17/18 QoS aspects for MWS are discussed Alternatives for mobile web services discovery are identified Architecture, features and realization details of MWSMF are identified Discussed mobile web service message optimization scenario Evaluation proved MWSMF deployment scenario is feasible Remaining components of the MWSMF are to be realized P2P Mapper ContextEngine Further scenarios can be envisioned

18 Thank you 18/18