Distributed Resource Management System for Business Process Management Systems

I did my final year research on Distributed Resource Management System for Business Process Management Systems. I have shared my research abstract which was published in UCSC researh symposium 2011 here with. For the purpose of research evaluation and demonstration, RESTful Distributed Resource Management System (DRMS) engine has been developed and integrated with one of FOSS BPMS.

Business Process Management (BPM) is a discipline which maps human tasks and non human tasks according to a predefined workflow in a way that technical and non technical people in the organization can administrate, monitor and communicate effectively and efficiently. Considerable amount of BPM software are available to automate business processes. When business becomes more complex and needed to be expanded or out sourced, a single BPM server may not be sufficient to tackle all these processes. This may lead to manage several BPM systems within one organization. However if those servers are not properly connected and configured, even allocating a single resource for a single BPM system can also be difficult due to the lack of information available at a glance. Apparently a mechanism should be established to enforce cooperation among homogeneous BPM systems.

DRMS for YAWL is a distributed resource management system which leverages administrative activities like monitoring, decision making and scheduling for YAWL, an open source Business Process Management System (BPMS) developed by YAWL foundation. When business is needed
to be expanded to cope with internal or external transactions, organizations should have to increase their technical servers from one to several. At this stage when each of these servers is dealing with organizational processes (business processes) instead of writing their own logic to tackle with business, they can use existing BPM engines to get efficient and effective results. While using several BPM systems within same organization, accurate coordination among each is
highly required to place correct decisions and schedules. Placing a new business process tends to be difficult if the administrator cannot deterministically come to a conclusion, in which BPM engine he should place the new process. In fact that is what DRMS is trying to solve.

DRMS uses existing resource patterns and introduces some new patterns to cope with distributed resource management. DRMS is equipped with two major perspectives called snapshot view and rule execution. In snapshot view, global synchronized view and non-synchronized view are considered. Synchronized view is what administrator can get as a real global view of all resources in BPM cluster. Non-synchronized view lets administrator to explicitly decide in which distributed BPM servers’ view he tends to view in a given time independently from other servers. Before making decisions when managing resources distributed across a cluster of servers, it is more important to analyze the current state of the cluster; thus, we came up with this idea of global view. For this, we have extended few resource patterns where more significant and important features of a state of the cluster can be extracted easily. By thoroughly analyzing, we manipulated several key factors of functions which must be available in any view, to speed up the process of making more effective decisions. The idea of granting administrators both synchronized and non-synchronized views can leverage identifying different states of the cluster before executing the correct rule set. There administrators of the organization can analyze independent views by switching among each of BPMS by standing with a single interface of DRMS. This is facilitated in non-synchronized view. Gradually when cluster expands, implicit information gathering from cluster by the system is more efficient and it is facilitated by synchronized global view.

Views help to decide on decisions that are going to be made. In fact to execute those decided decisions, there should be a distributed rule execution mechanism for DRMS which is called rule implementation. At the moment these rules can be evaluated and put in to action in the synchronized view. Distributing resources according to capabilities, roles or positions and assign administrative access levels to employees are two patterns which are implicitly available in DRMS. Distributing newly available work items (processes) among BPM cluster based on how similar kinds of processes were executed in history is an advanced solution. Mutual and union resource extraction and updating the cluster through global flooding with or without a restriction are some sub patterns that are also available in DRMS for YAWL.

DRMS also supports for load balancing up to some extent. Workflows will be deployed according to the selected load balancing algorithm. Four suggested workload routing algorithms namely random, round robin, priority and dynamic help to adjust the load of the BPM cluster as determined. At the moment DRMS has been developed to work with YAWL BPM engine through mainly communicating via its resource engine. However one of the key features of DRMS is that its implementation is completely independent from YAWL’s implementation issues. That is, DRMS calls to YAWL remote functions via RESTful service calls over HTTP and in order to facilitate this DRMS service, it would be more appropriate to have a homogenous BPM cluster. That means each and every BPM engine should be from the same vendor or otherwise must be same open source product. Apparently, in reality, it is very rare that a particular organization may use different kinds of BPM engines within their domain as it adds performance and scalability issues while integrating, controlling flow of events, associating data and handling exceptions due to different architectural implementations of each BPM systems.

Main objective of this project is to show that if managing several BPM engines, by using a mechanism which is equipped with view analyzing and rule execution by extending standard resource patterns and introducing some new resource patterns to fit with a BPM cluster, both resource and work item scheduling can be orchestrated more easily and effectively. It adds a central accessibility for all distributed engines. Hence, we suggest by applying our studies to existing BPM systems, both local and global contexts will be implicitly available for customers unlike existing BPM engines support only for resource management within its local context. Therefore, as distributed resource management among homogenous BPM engines via work flow patterns is not yet ported, we hope our research findings will be useful in coping with similar kinds of situations in future emerging extensible Service Oriented Architecture (SOA) based BPM engines.

Inter-Servlet communication among different contexts

Suppose you have Servlet X in Web App A and Servlet Y in Web App B. You want to pass some parameters through your Web App A's JSP to your Servlet X and there that Servlet should pass those parameters again to another Servlet in difference context (i.e Web App B's Servlet Y) and then redirect back to the calling JSP in Web App A. Users may feel that they are dealing with single context but literally it will be tow difference contexts.

I will direct you to experience this by 5 steps.

1. Viewer JSP - index.jsp (User will simply click a button to pass parameters to a Servlet within the same context)

< Ex: input type="button" value="Fetch Info" name="Get_Info" onclick="location.href='ServletX?action=getParticipants&id=user&pwd=yawl'"/>

Here after you clicking the button "Fetch Info" it will call "ServletX" Servlet in the same Web App (same context) along with "getParticipants" and two other parameters.

Scenario discussed here is retrieving some info resides in another context to a jsp by invoking two Servlets.


2. Servlet X will collect parameters in its service method

String action = request.getParameter("action");
String id = request.getParameter("id");
String pwd = request.getParameter("pwd");

Then We can redirect it to another Servlet as below,

request.setAttribute("output", action );
ServletContext cont = getServletContext().getContext("/WebAppB");
RequestDispatcher dis = cont.getRequestDispatcher("/ServletY");
dis.forward( request, response );

//getServletContext().getContext("/WebAppB"); is the important part because in this way you can jump in to other contexts and by invoking the method getRequestDispatcher() you can forward messages to what ever jsp/servlet combinations as wish. But if you use getRequestDispatcher(String path) of the ServletRequest interface it cannot extend outside the current servlet context.

For more info visit the api for ServletContext.

3. Then Servlet Y in Web App B can access the parameters and apply what ever the logic has to be performed.

String action = (String) request.getAttribute("output");

//Business logic goes here

request.setAttribute("output", action);
ServletContext cont = getServletContext().getContext("/WebAppA");
RequestDispatcher dis = cont.getRequestDispatcher("/index.jsp");
dis.forward(request, response);

Here after applying what ever the logic you wants, you can switch back to WebApp A servlet's context by invoking getServletContext().getContext("/WebAppA");. Then you can redirect output variable to index jsp in WebApp A's context to view the results.

4. Therefore to receive and view the results you need to implement a code similar to this in your earlier index.jsp page.

<%--

if (request.getAttribute("output") != null) {

String suc = (String) request.getAttribute("output");
%><--input type="text" name="output" value="<%=suc%>" readonly="readonly" disabled="disabled" --/><%

}


--%>

5. Last step is very important because without setting crossContext parameter to true server will not allow to happen inter-servlet communication in two deference contexts due to security policies.

There are several ways to do this. First one is enabling in each web app's perspective and the second one is enabling in server side which affect globally for all web apps hosted.

1. In this way you have to set crossContext parameter to true in each and every Web App's context.xml file which resides in META-INF folder of your web directory.

2. Without configuring each context.xml files, you can directly enable crossContext parameter to true which resides in context.xml file in server's (Here it is Apache Tomcat) conf directory. Then in deployment time server will create context.xml files for each and every web apps in its host and enable crossContext parameter to true in each. These individual contexts files are located at $CATALINA_HOME/conf/[enginename]/[hostname]/ folder.

For more info regarding Tomcat's context container visit this link.This is just a one scenario. But this can be applied in various ways to achieve communication among deference contexts in same Web Container.

MCrazies : Keep in touch with your favourite movie theaters

MCrazies simply implies the shortened name of Movie Crazies which is a simple sms mobile application can be used to get movie details of your favorite movie theater/s purposely developed for movie crazies :). It was developed as an appzone application of Etizalat. In detailed this application provides information about on going movies in famous theaters. In some urgent situations browsing through the internet to get information on the on going movies in theaters becomes so irritate. But getting those information by sending a simple SMS sounds more easier and simpler. You don't have to spend time surfing the internet or calling friends to get these information anymore! Just type

mcraz SPACE <name of theater 1> SPACE <name of theater 2> and send to 4499 from your Etisalat phone.

Here, name of theater 2 is optional. If user wants to get details of on going movies in more than one theater, then it is possible to type several theater names by leaving a space in between each theater name (case insensitive). User will get a SMS in return with the corresponding results for his SMS.

At the moment mcraz supports eleven movie theatres including Majestic City - Bambalapitiya, Savoy1 & Savoy2 - Wallawatta, Liberty - Kollupitiya, Sigiri - Katugasthota, Ricky1 - Colombo, Eros - Wallawatta, Arena - Katugastota, Regal - Colombo, Concord - Dehiwala, Cinemax - Ja-Ela and Quinlon - Nugegoda. Here User does not need to type the location of the theater and even the exact name of the theater. Application can tackle with validity of names up to some extent like by typing mc or majestic or majesticcity or majesticsity will be considered as Majestic City and reply to the user accordingly. So do not be hesitate to use MCrazies if you are a person who wants to absorb the real enthusiasm of watching a good movie by sitting in a quality theater as soon as you was asked to or you feel to do so :).

Semantic behavior of Google Search Engine

Semantic Web...? Let's be dirty from the nutshell. Nothing to freak out. Semantic means meaning of what we mean :). Suppose you want to search a country but you can't remember the name. But of course you know some facts of social, economic and geographical backgrounds. What if you type all the information you already know on google's text area. Will it be able to give you the exact country at once or will it search through every possible combinations and grant you thousands of results in which many are useless for you. Yet google is not that much of brave enough to deal with that kind of semantic mapping procedure as a background thread.

But certainly you may have seen if you type a single word and google it, there are suggestions appears bottom of your result page. Suppose the word is "Srilanka" then you may see a result like below.
Here they have treated the word Srilanka not just as a syntax of a web page but an additional added weight to gain its meaning as it is. Search Engine has been able to identify that Srilanka is a country and hence it is suggesting you to do following related searches also if need, like "srilanka map", "srilanka news" etc. Though you see it every day, did you simply ignore it or didn't want to go further with it or thought as this is also a kind of ordinary query searching methodology.

Of course this is some what like alpha version of semantic SE and this will not appear if it is not just a single word. The issue is, google is pretty much considering about their query retrieving performance and so when it comes to several words underline process complexity goes wild and therefore time consumption gets increasingly high.

How ever there are several semantically semantic search engines. "hakia" is a one such and you can make use of it via www.hakia.com. Hopefully there will be an another rat race of semantic era.

Sustainable Development #Energy

Today world is facing several critical problems that even the modern technology has also failed to answer perfectly. Growing population of the earth, water and air pollution, running out of fossil fuel etc. But among those most recently discussed aspects were CO2 emission and effects cause to living beans of the earth because of it. We all know co2 emission to the atmosphere increased so rapidly after the industrialization in early 70s. Since then everybody talks about it. but no one cares to take strict actions without hesitations at all.

When it comes to a country like us, of course we have several fall backs and humps towards to the ward sustainable. If I ask what is the key advantage that we have as Sri Lankan's is our position in Asian ocean. We have learnt of it heard of it since our child hoods. But literally doubts are there whether our leaders know that well when we peer in to the actions they should have decided years a go. Thing I want to focus is that we have ocean all around us. We are a tropical country. We have rain forests covering up considerable sand of our land. Wind & Sun rise is of course there. Our holy land is strength enough to grow bio crops too.

I am addressing these issues because in the sense of sustainability, We should give priority to efficient consumption of energy sources and adapt according to melting of those. That means now world is moving towards various kind of re new able energy sources rather than just staying with fossil fuels. One thing is for sure that if demand for the fossil fuel remains as now, there will be a potential risk of world to be in dark. More than 80% of our energy consumption is depending on fuel and one of the coal power station is developing to add up with it. We cant afford for nuclear power plants too. Scientists have found out and even manufactured vehicles those work on re new able energy sources like solar power, wind and even in bio crops like sugar cane. Some local people also have done researches and found out nature friendly vehicles and electronic devices. These innovative and talented creations should have been applied to development process of the country through good hands practically.

Tips & Tricks to J2ME 3D Gaming...

Here I am going to share some experience that I had to face during my short j2me 3d gaming life. Actually I still do many mistakes while coding and consumes several hours sometimes for to catch them. So It is better for me and those who are new to this field to write down some important points which we all forget to focus or neglect to address.

**important:: you better have some considerable knowledge to understand these points because I am not going to explain them in detail.

1. After loading any image or drawing any object or font do not forget to call flushGraphic(). Otherwise No errors will come but relevant images or objects will not draw on the screen.

2. When using Gaming Canvas there are some restrictions regarding key events of the phone according to the way you call gameCanvas’s super class constructor. That means if you call in your constructor as “super (true) “it tells suppress some key events which calls from your class to it’s super class. If you want to assign events for every key then you have to call as “super (false)”. By default gameCanvas support for gaming keys only.

3. When dealing with sprites, specify their proportions correctly. That means if you are going to specify width and height for the sprite, it should be divided in to equivalent segments.

Ex: Suppose you want 10 by 10 sprites to move and total size of your image is 100 by 10. Then when specifying the width you should give 10 exactly to have 10 equal segments. Otherwise image will not load.

4. Use whatever updating code parts earlier than drawing code parts. Suppose in your game loop you first call draw method which takes care of drawing your stuff on the screen and then you call update method. Update method simply update positions of your objects, handle AI etc. If you call update after the draw function then those updates will apply in the next game loop. Actually it does not add much different to the game. But in some cases like low processing power phones it can be felt if your update method is complicated. So it is just better to use this as a best practice.

5. m3g world that you are going to load in to the phone memory can be a large one. It may contain lot of polygons. So when loading it to the screen and rendering it while in the game play, frames might not be smooth enough or game tends to be slow. So use separate m3g worlds and load them only when need. Try to reduce unwanted polygons in mesh objects as much as you can.

6. If you did load worlds as above you should definitely keep remember to null the unnecessary world objects later. Because you load those worlds and extract their objects and add them to a final one world. After that earlier world objects become use less. Otherwise it adds unwanted weight to the game and in some phones it causes to throw out of memory errors.

7. You load m3g world perfectly according to your code. But when you run it it only displays an empty screen with no errors. This is because some textures of your world might be lost or naming mistakes of images.

8. Reduce far clipping frame of your setPerspective method if you want to add some realistic view to the game such as loading distance objects when you are moving towards them. It also adds a little bit of speed to the game.

9. Use image of alphabet font in which fonts have been packed optimally. Use these fonts for menus, alerts and everything rather than using drawFont method because if you use drawFont, that font size and type may vary according to the phone and may not support as well. But if it is an image of course you can call each font separately and create your own messages.

10. Finally do not apply java’s object oriented concept much more. Because if you have written so many classes for each object then your game loop has to switch back and forth for retrieving objects and calling functions. This leads to consume some performance of the game in limited devices.

Online Adaptive Game Design

For my 3rd year survey report, i have selected the topic "Adaptive Game Design". So I am doing some researches on it. I would like to share what I got familiar with this field so far as an Introduction (Below is an abstraction of my interim report)

When compare a commercial game with a specific commercial software product both in similar capacity, still publishers or rather companies tend to fear for directly involving for just games. That is why yet only a few leading well-known gaming companies are in the market. It is true that most of the games have indeed a real competitive game play. What developers try to do is make a player centered game which can satisfy its players at best while granting a competitiveness plus joy. AI for games has reached to its top today. Game world has been able to behave like in the real world with help of the advance physic and mathematical functions. Throughout the processes like modeling agents, coding, alpha, beta and game play testing, and making development kits for bugs and modifications, developers often concern for a particular limited group of potential users.

Throughout the history there are so many research papers have been written and have been practically applied for small scale games. Adaptation is a major topic not only in games but biological experiments, outer space explorations, nano evolutionary theory and many other engineering aspects. But what it differs from each field is that what technology optimally suits and in what extent it is going to be applied.

In this paper it is going to be demonstrated that still highly aggressive and competitive game play can be achieved with exceptive efficiency, effectively and robustness with help of dynamically adaptive gaming concepts and technologies. This adaptively can be either learning without human interaction (offline) or learning with human interaction during game play (online) [1]. This paper concerns most about online adaptive game development and its feasibility with current gaming life cycle. Adaptation can be defined as “ability to make appropriate responses to changed or changing circumstances” [2] plus learn from its past mistakes and acting like smart.

When it comes to the player’s role, there can be players those who are really smart thinking and play the game with their own logics. But some takes much time for completing a level and some are aggressive. Each of them has different views to the game and of course implementing a game which is capable of satisfying majority of these groups can be really hard to achieve. But throughout the playing life cycle of the game, modeling each player to a default weight and while in the game play, adjusting this weight to fit with player’s performance regarding the knowledge gathers from online statistics and player head up displays (HUDs) updates, adaptive decision making system can established inside the game.