analyzing different protocols for e-business 1 fatma sayed gad elrab supervisors prof. dr. ezzat abd...

Analyzing different protocols for E-business

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Fatma Sayed Gad Elrab

Supervisors

Prof. Dr. Ezzat abd El Tawab Korany Dr. Saleh Abdel Shachour El Shehaby

Main topics

What is the E-business

E-business technology Phases

E-business process properties

E-business process technology (WS)

Web Service transaction protocols

Disadvantage WS transaction protocols

Transaction properties ACID

Disadvantage ACID

Problems

Literature review

Contributions2

What is the E-business

E-business is electronically business processes like electronic purchasing ,supply chain management, processing orders electronically, handling customer service, and cooperating with business partners.

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E-business technology phases

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E-business process properties

Loosely coupled

long-running processes

components that do not share data ,location, or administration

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E-business process technology (WS)

A Web service (WS) is mechanism that expose any process that can be integrated into external systems through valid XML documents over Internet protocols.

Organization strive to make by WS their IT resources more effective (performance issue)

Web services environment does not have full control over all the resources. (performance issue)

Web services can compose other Web services in a transactional manner.

Composite Web services require Transactional Properties (TP) so that the overall consistency is ensured.

Invalid Web services is a critical issue . (performance issue)6

E-business process technology (WS) Count

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Web Service transaction protocols

WS-T(web service transaction (coordination ,Business activity).

THP(tentative-hold protocol ).

BTP(Business transaction protocol).

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Disadvantage WS transaction protocols

Mainly based on the database transaction models such as ACID properties and extended advanced transaction models.

They use the Two-Phase Commit (2PC) protocol as underlying protocol to coordinate activities. This lead to lock recourses to protected and ensure data

They do roll back everything even if the first transaction is failing after a lengthy timeout

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Transaction properties ACID

Atomicity :transaction must either appear to execute in its entirety or not at all (ok all or not all )

Consistency :-demands that a transaction must transform a data from one consistent state to another consistent state. and guarantees integrity.

Isolation:- requires that an active transaction cannot expose its intermediate results to other concurrently running ,not make its updates visible to other transactions until it is committed. Durability: Once a transaction commits, the committed changes must never be lost in the event of any failure.

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Disadvantage ACIDACID properties are implemented using various commit protocols such as two-phase commit (2PC) and its variants presumed abort (PA), and presumed commit (PC) protocols.

These are useful in ensuring data consistency and correctness of transactions they result in serious performance problems.

ACID properties are based on the strict atomicity and isolation policy which requires that transactions can not share its data with other concurrently running transactions until it is completed this lead transaction to poor performance, as transactions have to wait for each other until they are completed.

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Problems

consistent outcome and correct execution:- Most business-to-business applications require transactional support in order to guarantee consistent outcome and correct execution (censuses problem ).

loosely-coupled and don`t (ACID)loosely-coupled systems, and components that do not share data, location, or administration. It is therefore difficult to incorporate atomic transactions(ACID)within such architectures (lock resources problem ).

long-running systems and lock recourse :With long-running systems where exclusively locking resources is impossible or impractical. (lock resources problem ).

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Literature review

Muhammad Younas (2006)et.al,” An Efficient Transaction Commit Protocol for Composite Web Services” describe new transaction properties (Semantic Atomicity, Consistency, Resiliency, Durability)and develop a protocol TCP4CWS (Transaction Commit Protocol for Composite Web Services).for implementing this properties in the composite web services(performance issue in case of failure).

An Liu(2009)et,al.” FACTS: A Framework for Fault Tolerant Composition of Transactional Web Services”. Ignore, Notify, Skip, Retry, RetryUntil, Alternate, Replicate, Wait (censuses aoutcome issue in some cases)

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Contribution

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Results

WS-T(BA) BTP My Frame workrespond time per WSlock time resources per WS(lock to commite)respond time to Composit WS

WS-T(BA) BTP My Frame workrespond time per WSlock time resources per WS(lock to commite)respond time to Composit WS

In success cases

In case one Failure

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Description

Build frame work in UDDI server to handle transaction between consumer and provider

New solution ensure atomicity this lead to consuse outcome of composite web service like travel agent.

New solution try to Reduce time of lock resource in case of failure participant .

New solution don`t supposed coordinator failure or crash so it built in UDDI server .

New solution let composite web service to decide second step in case of failure participants (Compensation, abort…etc)

New solution let composite web service , participants to recover them self In their own way.

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Not include in new solution

New solution not cover work flow long running process that wait for days to approve (lock resources ).

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UDDI+ New Frame work

Provider

Consumer

New Web service structure

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UDDI+New FrameworkCmposit WS WS1 WS2 WS3

Request URLs of WSs

Send to it

Call Wss processDo Do

Do

Respond ok in case all success or no in case at least

one abort

respondrespond

respond

Create session

commitcommit commit

New WS structure Steps.Consumer

(composite WS) send soap request

search URLs

UDDI respond

Composit Webservice send Call serquest for this URLs to implentation to

UDDI

If this URL available and

process ok

Send request for each WS include soap request ID

yes

Abort all request +send fail

message to this composite process

NO

Close transaction

UDDI Calculate Max time in all WSs

wanted from WSDL +margine

UDDI wait for max time for all WSs that has the

same id (accept all Wss finished )

If all WSs respond within

time

UDDI respond soap message to Composite WS

yes

No

Creat session between UDDI and Consumer

UDDI set Expire session time =Max time +margine

Send SOAP respond include data from UDDI

to composite

If wait respond message to consumer

or fail sesion

Send abort transaction to

providers WSs to release recourses

and recover

yes

Send ok to WSs to commit

transactionNo

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