Paper8: The Next Step in Web Services

Paper Title:

Three Critical Questions

Group 1:

Member Name: Bokka Satya Saradhi

1)In interaction between a BPEL composition the parents will exchange their message as a peer to peer service and he again told that it acts like Client/Server model for it , how is it possible for a single system can attain the roles of both peer to peer , Client/Server architecture , do they have followed a different architecture?

2)There is no fault handling mechanism in other latest paradigm i.e in Virtualization but it works fine how it can be happened ? what makes this system need Fault handling as a main event?

Member Name:Fazlun

1) In the BPEL process the web services which are atomic are reusable, but parts of the BPEL cannot be reused because they donot have WSDL descriptions associated with them. This is a disadvantage of using BPEL. This has not been discussed. To solve this what we can do is we can define the part of the process before hand , i.e the part that we intend to reuse.
2) Another weak point of the BPEL is that the concept that defines the components is not explicitly defined. One approach to solve this is we can craete instances of this component by constructing super BPEL and sub BPEL files.
3) Most of the organizations follow the BPEL but in practical companies have there own definitions for the standard based on their necessities, they donot follow the W3C standards, so how exactly will this emerge to be standardized.
4) The applications which operate in a SOC need to define the nonfunctional and functional aspects in such a manner that they must be readable by a machine format, to provide documents which are rich in the way that they explain this terminologies is difficult, the feasibilty has not been discussed.
5) Correlation cannot be uniquely determined, it may lead to different interpretations

Group 2:

Member Name: Chiranjeevi Ashok Puvvula

Critical Questions:
1.How can extendibility be achieved in this type of service composition? Because extendibility does allow reuse of some services, we need to write lots of code in designing subservices and make those works properly.
2.Do you think that BPEL is confined only to the business processes, because in the whole paper it emphasized more on the business processes?
3.Is there any mediator that does the validation of models (here models of different services), process transformation as these were not discussed using BPEL? Because BPEL concentrated more on how a service can be called and how these services be communicated?
4.There is no concept of components in service composition, so how can two services be combined together or communicated with out the concept of components?

Member Name: Anuradha Pathuri

1.How would the model come across the issue of concurrency of the transactions in order to maintain the state of the process? The paper talks about a concept called “Compensation” where in it deals with the compensatory steps that are taken when an error has occurred while execution of a process. But meanwhile when another application performs an action and modifies the same data which is accessed by this process, then how does the model come across this issue?
2.Is this model going to be more user-friendly when compared to the web-services oriented model? If so, how is the feature going to be helpful in the present scenario? I doubt that the introduction of fault handling might lead to un-necessary components for the users of the service, since the users of the service might not have in-sight into the service that they are using.
3.Is the message correlation part of the model automated or implemented manually? What kinds of tools are used in order to identify the key fields among the interacting data messages? Are the keywords being identified syntactically or semantically?
4.How does the proposed model achieve access to a service by multiple protocols?
5.By providing multiple protocol access to a service, is the model not complicating the service from the user point of view? For example, the set-up part of the service would be more complicated now, because the user would also have to set up that service to the protocol.

Group 3:

Member Name: Bindu

1. It is stated in paper that for the applications to be operating in a SOC environment the functional and non functional requirements and capabilities should be agreed. What if after the agreement the requirements of the application change?
2. On what basis is it said that Peer-to-Peer way of communication between the Business Process Execution Language partners is more efficient than the usual way of communication?
3. Why was the process oriented composition chosen and not the structure oriented composition? What are the advantages of choosing a process oriented composition over a structure oriented compostion?

Member Name: RamB

1) How far is it efficient to use implicit instance identifier in BPEL than traditional explicit instance identifier or factory instances? Implicitly way of correlating fields doesn’t seems to be effective for me.
2) Can the peer-to-peer fashion of communication between BPEL partners is more efficient (even secure) than general way of communication?
3) The writer says that the primitive activities are combined in to complex algorithms. How far is it worth to define algorithms using structured activities than the traditional calling of different functions or services at the time of their need?

Group 4:

Member Name:SrikanthVoruganti

1) How can one undo the effect of actions once passed? In SOC, services once deployed can never be got back. So how will the fault handling be done?
2) Are these specifications enough to meet the robust business requirements? A wide variety of business requirements persist. How well are they accomplished by these techniques?
3) Is there any specific reason to compensate the faults in reverse order of completion or simply is it that they are checking the faults more precisely?

srujan kumar swarna

1. In WS-Transaction there are two models AT and BA. So which one is better for making transaction in intraorganisation SOA?
2. When we are developing our own protocols for our own web services. How can we make reliable composition with the other services developed by other companies?
3. For reliable messaging, how can we make best fit to the BPEL protocols developed by using different protocol types?

Group 5:

Member Name: Sunil Kakaraparthi

1. BPEL uses a concept of using other web services to include in our systems. How can it be a reliable method to combine the outside web services?
2. The BPEL process involves more than a set of correlation fields. Is it conceivable to create more sets of correlation fields rather than to use interfaces to access services?
3. In WS-Transaction we use Atomic Transaction and Business Activity coordination types. Which one will be more effective transaction method in Service-Oriented Computing?

Group 6:

Member Name: Bhargav Sandeep Ramayanam

1. As BPEL4WS is an orchestration language but not a choreographic language, then how can it support the peer-to-peer communication between the BPEL composition and its partners where an orchestration language can't?

2. The new version of the BPEL is 2.0. Can all the features that are mentioned in the paper are compatible with the new version or not?

3. In the WS-Transaction specification there are two coordination types AT and BA. Among these which one is better for the intra-enterprise application?

Member Name: Debargh Acharya

1) Although the author says that the web service framework mainly intend to provide standard based realization of the service oriented computing paradigm but on the contrary he also states that only SOAP is a W3C standard but WSDL and UDDI are not.

2) In his paper the author stress on the need for security but he fails to mention anything about WS-security and WS-Reliable messaging. The paper doesn't explain anything regarding them.

3) While mentioning WS-security and WS-Reliable messaging the author doesn't mention performance and scalability issues.

Group 7:

Member Name:Sandeep Kumar Yarala Padmarao

Critical Questions:

1)Why did the author prefer BPEL, a process oriented composition?Why not structure oriented composition?The author did not speak about the reason of choosing process oriented over
structure oriented.

2)What is the message format and how is it processed?The paper gives an overview of the how the entire procedure goes on but does not describe in depth how the working is taking place.For example the message is sent to the partner using a invoke actvity and the process getting invoked by recieve activity.
How is the message understood,its format,how the process is invoked?

3)How does BPEL provide actions for signaling faults,process termination and manipulating data?How are these issues addressed and what is the mechanism involved in it.

4)How is the system secure?The journal does not speak about the security aspects.How authentication,data confidentiality are achieved? Security is an imporatant aspect in QoS protocol and a crucial element in SOA.

5)The journal express WS-Coordination in simple steps .Does this mechanism be extended for large and complex compostion of components?If so how well can it manage?

6)Can this sytem be fully automated?Fully automating the SOA is the overall aim in SOA.

Name: Rajanikanth Beesabathini

Critical Questions:

1. Here BPEL provides a mechanism for defining services composition in the form of choreography mechanism. What is choreography? Why only choreography is used by BPEL?
2. From figure 2, the interaction between the BPEL composition and its partners like a peer-to-peer conversational one. Here what about the security? How the valid partners can be identified from unauthorized parties? How the authentication and data integrity take place so that the particular partner is communicating among a group of partners and the data is safe?
3. The BPEL processes by declaring the WSDL interfaces definitions for the partners for the partners whose definitions are defined in the WSDL it is OK. But if the new partner would like to access the service from the Process, What is the process behind that?
4. In WS Transactions, two types of transaction coordinates are mentioned like the AT and BA. So how can we estimate the life time of the transaction?

Member Name: Shaiv

1. It has been given that service composition can be accomplished by combining services with some composition pattern. What compostion patterns are used in order to build a useful service composition?
2. The author intends that services are combined following certain business rules. What kinds of business rules are used?
3. Roll backs are carried out whenever there is an error in the process. Are the checkpoints inserted at appropriate points to reduce the time taken for a roll back?

Member Name: Rameshwaram Karunapriya

CriticalQuestions:

1. The article discusses that the services can be merged by a service composition using a composition pattern, but what pattern is actually to be followed?

2. SOC is still in the initial phase of progression, how far will SOC model be implemented in the self-motivated business interfaces?

3. Is the co ordination context broadcasted all along with message of the application when the web service is being invoked by the client's initiation?

Group 8:

Member Name: Harsha

1. It is sated in the paper that during the service composition a process may have more than one correlation fields for different partners and at different times. How is it that this functionality where for each partner a different set of correlation fields are used, is going to be implemented?
2. In the paper it is said that when using the compensation mechanism under fault handlers, all the activities in the scope where this fault occurs, will be disabled. How this scope for a particular fault be decided? Does this involve extra mechanism to be implemented?
3. Why do the long-lived business activity type compositions need less resources to function?

Member name : Nikhilesh Katakam
1) The paper discusses about fault handling and compensating by simply undoing the completed action. This might not always be correct as not all the actions in a given scope are faulty ? So when we undo a particular scope even the actions that might have been successfully completed are also taken as faults , how far is this measure correct?
2) Is it not difficult for the BEPL to compose a set of existing web services to a new web service.?
3) The paper claims that WS- coordination and Ws-transactions can be used individually or can be combined with BEPL . Which way would yield better results? And why?

Group 9:

Member Name:Muppalla Durga Maheswari

1. As enterprise are giving way to applications managed by business partners why BPEL uses traditional partner roles.

2. It is said that the choreography consist of aggregation to certain business rules how are these choreographies defined

3. How the key fields with in data messages are identified to maintain the state of interaction.

4. How coordination protocols address the problem of correct execution of activities to reach an outcome.

Group 10:

Member Name:manasa chennamaneni

1. As given BPEL uses some key fields to correlate the messages from a particular conversation to a partner and for example it mentioned the invoice number is used to identify the conversation but it did not explain how it will identify the process?
2. BPEL provides some activities like signaling faults, manipulating data to perform some actions but to what extent these are helpful and succeeded?
3. Security is very important factor in every software we should mainly concentrate on that but this paper did not explain about how the data will be secured and transmitted between the partners?

Member Name: Gayathri Devi Bojja
1. The interaction with each partner has a different correlation set. Why does it require different correlation sets at different times?
2. AT supports atomicity that is all or nothing during execution of distributed web services. But sometimes it might require executing some web services. What action should be taken in such case?
3. The SOC to be developed requires to be improvised in terms of security and standards. How secure is the soc being used?

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License