The sixth International Conference on Service Oriented Computing (ICSOC) is to be held from 1st to 5th of December in Sydney, Australia. In parallel to the main conference there is is a PhD symposium (December 1st) that will discuss the approaches, steps, best practices for PhD student that are exploring the Services Oriented Architecture.
After the main conference there is a summer school too. A good opportunity for students living downunder to learn and discuss the latest concepts and technologies in Services Oriented Computing. That will be held in Friday (5th) and Saturday (6th). The complete program is available in the main conference web site here.
Wednesday, November 26, 2008
Friday, November 21, 2008
Sri Lanka trail guides.
If you are a nature lower and would like to hike in Sri Lanka, have a look at the following web site.
http://www.lakdasun.com
It contains pictures, useful tips and much required trail guides with GPS way points. You may download the trail map and view it on google earth. Thanks Lakdasun team for these useful info. Keep up the good work.
http://www.lakdasun.com
It contains pictures, useful tips and much required trail guides with GPS way points. You may download the trail map and view it on google earth. Thanks Lakdasun team for these useful info. Keep up the good work.
Thursday, November 20, 2008
BPEL from CDL
WS-CDL and WS-BPEL both provide a way to describe how web services should collaborate. But the difference is that WS-CDL gives a global perspective the message exchange whilst the WS-BPEL provides a single participant's perspective.
As some are arguing I do not see a competition between these two specifications. Rather they must co-exist to describe services interactions properly.
Though, WS_CDL is designed to be used in conjunction with the WS-BPEL, one limitation of the WS-CDL specification is that a clear mapping with BPEL is missing. I agree that the intention of WS-CDL is not to be depend on WS=BPEL but there are advantages of having such a clear mapping.
From the engineering perspective such a mapping could be automated. Also such a defined approach would minimize the inconsistent mappings by different parties coming in to collaboration.
This paper presents how BPEL process definitions are derived from the global WS-CDL model. Authors have done this by defining a set of transformation rules.
For example
The complete mapping is available in the section 5.
The paper addresses a much required issue by not altering the existing standards or without introducing new standard, which is a plus point. The approach seems straightforward and not requiring intermediated mapping like in the approach here[4] where the mapping is into Communicating Sequential Processes. Also authors have implemented a prototype of the mapping as a proof of concepts.
Saying that, one limitation of the paper is that there is no reference on how to verify the generated BPEL stubs over the original CDL. Generated stubs may be correct for the given example or could be verified manually for simple scenarios. But it is required to have a formal mechanism to verify more complex scenarios. That is not in future work section too. And the verification need to be integrated to the BPEL stub generation or it should be done after generating BPEL stubs but before the populating them with application logic.
Also it is not clear how the mapping from BPEL processes to CDL is done. Which also an interesting issue (as far as ROAD is concerned ). May be we might be able to complete that part. We can map several processes to a common choreography by projecting them over a ROAD Self Managed Composite. In other words by overlapping several processes we might be able to define the choreography. Syntactical transformations might use the same discussed in the paper. Sure need to think and discuss more about that.
As some are arguing I do not see a competition between these two specifications. Rather they must co-exist to describe services interactions properly.
Though, WS_CDL is designed to be used in conjunction with the WS-BPEL, one limitation of the WS-CDL specification is that a clear mapping with BPEL is missing. I agree that the intention of WS-CDL is not to be depend on WS=BPEL but there are advantages of having such a clear mapping.
- Choreographies can be defined in WS-CDL first by business partners and then generate BPEL process stubs for each party
- A party who’s having an internal business processes may need to publish the interface to its processes to attract business partners by generating the choreography. This could be done using a BPEL to CDL mapping.
From the engineering perspective such a mapping could be automated. Also such a defined approach would minimize the inconsistent mappings by different parties coming in to collaboration.
This paper presents how BPEL process definitions are derived from the global WS-CDL model. Authors have done this by defining a set of transformation rules.
For example
- Each party participated in CDL choreography a separate BPEL stub is generated
- One cdl:relationshipType maps to one bpel:partnerLinkType and the bpel:role with its bpel:portType is generated from the referenced cdl:roleType declaration
- Generate separate property files for each cdl:roleType including only those bpel:properties that are relevant for a party.
- BPEL basic activities are directly mapped to CDL basic activities
- Work units in CDL are related to scopes in BPEL
The complete mapping is available in the section 5.
The paper addresses a much required issue by not altering the existing standards or without introducing new standard, which is a plus point. The approach seems straightforward and not requiring intermediated mapping like in the approach here[4] where the mapping is into Communicating Sequential Processes. Also authors have implemented a prototype of the mapping as a proof of concepts.
Saying that, one limitation of the paper is that there is no reference on how to verify the generated BPEL stubs over the original CDL. Generated stubs may be correct for the given example or could be verified manually for simple scenarios. But it is required to have a formal mechanism to verify more complex scenarios. That is not in future work section too. And the verification need to be integrated to the BPEL stub generation or it should be done after generating BPEL stubs but before the populating them with application logic.
Also it is not clear how the mapping from BPEL processes to CDL is done. Which also an interesting issue (as far as ROAD is concerned ). May be we might be able to complete that part. We can map several processes to a common choreography by projecting them over a ROAD Self Managed Composite. In other words by overlapping several processes we might be able to define the choreography. Syntactical transformations might use the same discussed in the paper. Sure need to think and discuss more about that.
Friday, November 14, 2008
How to pronounce a word like a native?
Ever imagined how to pronounce a word correctly like a native? For example how the word for home in Sinhala language be pronounced in English properly? Is it "Gedara" or "Gethara"? Or something in between "da" and "tha" sounds? Well… now we have the chance to make the correct pronunciation available for non-Sinhala speaking community by recording them via Forvo’s web database.
Forvo’s goal is to collect proper pronunciations of every word in every language on the plant. Sounds bit dotty yeah…? But I think it’s a matter of time. I have already included some words in Sinhalese to the database and will contribute in the future as well.
So if you need to contribute for your language or like to learn how to pronounce a word in another language like French, Spanish or Japanese (as of now 195 languages are supported) properly check this out.
Forvo’s goal is to collect proper pronunciations of every word in every language on the plant. Sounds bit dotty yeah…? But I think it’s a matter of time. I have already included some words in Sinhalese to the database and will contribute in the future as well.
So if you need to contribute for your language or like to learn how to pronounce a word in another language like French, Spanish or Japanese (as of now 195 languages are supported) properly check this out.
Adaptation categories
Static Vs Dynamic
The static adaptation can be achieved via logics in the program source code. That’s in the design time where a certain predictions are reflected in program source code and the configuration settings. Dynamic adaptation is the adaptation at runtime. The latter is considered to be more difficult to achieve as it is difficult to predict what are the events are and what the actions on them are. Undoubtedly the latter with a higher research interest.
Manual Vs Automatic
The manual adaptation refers to a sort of adaptation where human intervention is involved. In contrary, the automatic adaptation is where there is no such human involvement. By referring to the existing literature we can see that the more effective adaptation strategies are based on semi-automatic, where at a certain point there is a human involvement but mostly it’s the system itself is adapting to changes. (Especially adaptation of non-functional properties)
Proactive Vs Reactive
The difference here is based on the time of the adaptation occurs with respective to a particular event in the environment. If the adaptation is before the event, then it is proactive adaptation. If the adaptation is after the event then it’s known as reactive adaptation.
The static adaptation can be achieved via logics in the program source code. That’s in the design time where a certain predictions are reflected in program source code and the configuration settings. Dynamic adaptation is the adaptation at runtime. The latter is considered to be more difficult to achieve as it is difficult to predict what are the events are and what the actions on them are. Undoubtedly the latter with a higher research interest.
Manual Vs Automatic
The manual adaptation refers to a sort of adaptation where human intervention is involved. In contrary, the automatic adaptation is where there is no such human involvement. By referring to the existing literature we can see that the more effective adaptation strategies are based on semi-automatic, where at a certain point there is a human involvement but mostly it’s the system itself is adapting to changes. (Especially adaptation of non-functional properties)
Proactive Vs Reactive
The difference here is based on the time of the adaptation occurs with respective to a particular event in the environment. If the adaptation is before the event, then it is proactive adaptation. If the adaptation is after the event then it’s known as reactive adaptation.
Sunday, November 09, 2008
Adaptive web processes in a pervasive services oriented environment
Services Oriented Architecture provides different applications to interact in a distributed environment to perform a particular task. The concept of services orientation in software design aimed to achieve the loose coupling of applications from its underlying operating environment. Being a progression of component based software development, Services oriented computing provide interfaces to users (human or software) to utilize a particular resource in a distributed environment.
On the other hand the image of traditional computer is fading away. Mobile /embedded devices claim for a good portion of computing efforts today, with the advancement of electronic technologies. Our car, phone, watch or what ever a device that we can’t picture today, has started to or will become a computing device. This resulted in many researches on Pervasive Computing or Ubiquitous Computing.
The operating conditions in such a pervasive services oriented computing environment are always subjected to change. For example while you are travelling, you mobile phone in your pocket and the car you drive might be doing some message exchanges/queries with applications hosted in nearby restaurants, shops and motels. The operating conditions like the mobile coverage, network bandwidth, types of technologies and even the availability of services can be subjected to frequent changes. The life time of applications is determined by these varying factors of the environment. The survival is always critical. And this calls for self-adaptive software systems.
Studies about adaptable and adaptive software systems have emerged as a major research topic in the past few years. Survival in highly fluctuating environments is a critical requirement for future software systems. Concepts of self-healing, self-configuration, self-optimization and all other self-* buzzwords are popping up in pervasive services oriented software systems. Many frameworks, solutions, techniques are being introduced in the reason past.
It is interesting to study about how business processes adapts to these highly fluctuating environments. Current approaches like BPEL and WS-CDL does not address the adaptation. Although it is possible to identify sort of programmable adaptation, in above approaches, where pre-defined processes are carrying out according to limited "expected" changes, it is not the sort of adaptation that we would be looking for. It is required to define, change choreographies among different business partners at run time in order to ensure smooth continues business processes. Runtime negotiation and establishment/termination of contracts among participating entities are essential part of the adaptation.
My research would be concentrated finding techniques and designs for process adaptation in such a pervasive, services oriented computing environment. Yeah... A diverted lil bit from security:-). Though this is not a really hot topic, I belive that there are more yet to be investigated. Therefore in coming months I'd be concentrating on this.
On the other hand the image of traditional computer is fading away. Mobile /embedded devices claim for a good portion of computing efforts today, with the advancement of electronic technologies. Our car, phone, watch or what ever a device that we can’t picture today, has started to or will become a computing device. This resulted in many researches on Pervasive Computing or Ubiquitous Computing.
The operating conditions in such a pervasive services oriented computing environment are always subjected to change. For example while you are travelling, you mobile phone in your pocket and the car you drive might be doing some message exchanges/queries with applications hosted in nearby restaurants, shops and motels. The operating conditions like the mobile coverage, network bandwidth, types of technologies and even the availability of services can be subjected to frequent changes. The life time of applications is determined by these varying factors of the environment. The survival is always critical. And this calls for self-adaptive software systems.
Studies about adaptable and adaptive software systems have emerged as a major research topic in the past few years. Survival in highly fluctuating environments is a critical requirement for future software systems. Concepts of self-healing, self-configuration, self-optimization and all other self-* buzzwords are popping up in pervasive services oriented software systems. Many frameworks, solutions, techniques are being introduced in the reason past.
It is interesting to study about how business processes adapts to these highly fluctuating environments. Current approaches like BPEL and WS-CDL does not address the adaptation. Although it is possible to identify sort of programmable adaptation, in above approaches, where pre-defined processes are carrying out according to limited "expected" changes, it is not the sort of adaptation that we would be looking for. It is required to define, change choreographies among different business partners at run time in order to ensure smooth continues business processes. Runtime negotiation and establishment/termination of contracts among participating entities are essential part of the adaptation.
My research would be concentrated finding techniques and designs for process adaptation in such a pervasive, services oriented computing environment. Yeah... A diverted lil bit from security:-). Though this is not a really hot topic, I belive that there are more yet to be investigated. Therefore in coming months I'd be concentrating on this.
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