presentation on an agent based approach for invoking service in environments with limited network...

Introduction Related Work Redundant Data Stripping Agent-Based Invoking Architecture Experiment Results Conclusion

An Agent-based Approach for Invoking Service inEnvironments with Limited Network Bandwidth

Xiaotao Li* 1 Xiaohui Hu 2

1Beijing University

2Chinese Academy of Sciences

[email protected], [email protected]

August 9, 2016

Presented by: Fajar Purnama Computer Science and Electrical Engineering, HICC LAB

Kumamoto University, International Conference on Web Services (ICWS) 2015


Outline

Introduction

Related Work

Redundant Data StrippingRequest Message StrippingResponse Message Stripping

Agent-Based Invoking ArchitectureAdaptive Data CompressionService Invoking Process

Experiment ResultsStripping Ratio PerformanceResponse Time Performance

Conclusion




Background

Web Service are services that is available on the world wide web onThe Internet. A web service to search:




Background

A web service to chat, mail, and socialize:




BackgroundVirtual machine an advance web service:




IssueHow Web Services Works (simple explanation):

I Uses EXtensible Markup Language (XML) to tag data.

I Uses Simple Object Access Protocol (SOAP) to transfer message.

I Uses Web Service Definition Language (WSDL) to describe theavailability of services.

.

Problem:

I SOAP for application integration consumes high network bandwidth.

I XML documents are huge in size and verbose.

I Web services suffers bottlenecks and congestions due to XML messages.

I Overall its invokation is time consuming especially on limited bandwdithnetwork.




Solution

Reduce the volume of communication data betweenservice requesters and invokers (client and server).

I Strip off redundant data.

I Apply adapative compression strategy (ACS) tocompress the data.

I Apply agents in between client and serverto execute above statements.

I Use Apache Axis2 to invoke web services due toits simplicity and stability.




Summary (TAKE NOTE OF THESE 2 SLIDES)

Problem illustration example: google translate buffering.




Summary (TAKE NOTE OF THESE 2 SLIDES)Method illustration, reduce transmission on low speed network.

CLIENT AGENT SERVER

Low Speed

Network

High Speed

Network

Core MessageComplete Message

Redundant Data

Data Stripping

Core Message

Compression

Compressed Message Transmission

Decompression

Core Message

Reconstruction

Core Message Core Message

Transmission

AND VICE VERSA




List of Related Work

I Seperate XML tags from payload, then distribute in differentcontainer and compress.

I Differential encoding between message and skeleton onWSDL.

I Use short tags.

I Dictionary compression schema A-SOAP.

I Indexed tag names.

I Tree structure on XML.

I Fixed-length encoding and Huffman encoding on tags.

I Fractal Clustering Model.

I Change SOAP message structure.




Request Message Stripping

Service Key Information (SKI) Values

I Through Axis2 service can be invoked using SKI as on Table 1instead of full SOAP message.

I WSDL describes how service can be called, what parameters itexpects, data structures it returns.

I Tags on Figure 1 are simplified i.e. remove duplicate tags:





I n s t e a d o f :<categoryName>One</categoryName><categoryName>Two</categoryName><categoryName />

I t i s b e t t e r :<c a t e g o r i e s >

<name>One</name><name>Two</name><name />

</ c a t e g o r i e s >





Request Message

I Other stripping method were used but not clearly stated, it also saidthat all the value can be extracted as on Table 1 using Dom4j.




Response Message Stripping

Response Message

I Like on the request message, stripping operation is performedas well, but with 3 different stripping strategies.

I Depending on the return value it can be divided into 3strategies: simple, array, DataSet.

I For array type there are many duplicate tags, the array flagname is defined in WSDL so it is extracted.

I This erases duplicates, only extract the content of each arraytag and group them.

I The DataSet structure is not provided in WSDL so it isanalyzed, is like a data table.




Response Message Stripping

Response Message




Adaptive Data Compression

Adaptive Compression Strategy (ACS)

I The messages became lighter after the strippingprocess, compression reduce the message sizefurther.

I ACS chooses an optimal compression strategy dependingon nominal transmission time, message size, and networkbandwidth.

I The operation can either be no compression, orcompression using Snappy or Zlib which are libraries ofGoogle.

I Snappy has very high speed and reasonable compression.

I Zlib has a maximum compression ratio but cost moretime.




Service Invoking Process

Protocols

I WPP (WSDL parse protocol): This protocol is a ruleto send WSDL parsing request from the client to agent.

I WRP (WSDL response protocol): This protocol isresponsible for returning the WSDL parsing results to theclient.

I SIP (service invocation protocol): This protocol isused to inform the agent invoke an operation of a service.

I SRP (service response protocol): This protocol isused to return the service response result to client.





Illustration

I The stripping and compression is on the limited bandwidth network.

I The agent then returns them to the original before sending to the server(high bandwidth network).





SIP structure




Stripping Ratio Performance

Stripping Ratio = Original / Stripped




Response Time Performance

On network speed 9.6KB/s and 64KB/sNative SOAP vs Variable Length Coding (VCT) vs Fixed Length Coding (FCT)vs This Method.




Response Time Performance

On network speed 200KB/s and 1MB/s




Agent Based Solution was Proposed

EnvironmentAll PCs are Intel dual-core P9600 2.53GHz, 2GB RAM, WindowsXP Proffesional, JDK 1.6.1, MyEclipse 10.0 development platform,experimented on weather service web service”http://webservice.webxml.com.cn/WebServices/WeatherWS.asmx”.

ConclusionBy stripping off redundant data and applying adaptive datacompression, improved the service invocation performance in theenvironments with limited network bandwdith, and evaluationshows good performance on stripping ratio and response time.




Thank youAny comments or questions?



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