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  • 3d transformation of game world keeping gameplay 2d - COCOS2D 2.0

    - by samfisher
    Using: COCOS2D + iOS. I want to rotate the game world, may be loading another .tmx file for another dimensions when user want to switch dimension. the effect what I am looking for is something like this:CLICK HERE What I have thought of till now: rotating CCCamera will be mandatory. Question: How will I have the other part of the level in place while the camera rotates/rotating? I can load a CCSprite and rotate it accordingly to the 3rd dimension. phew..!! Question: When the camera and world is rotated, will the player controls work properly.. I think not...? I think a better option would be to checkout with COCOS3D... there I could implement 3d world... right?? Question: Not sure how well 2d dynamics will work there as I want to user Box2d as physics engine.. could anyone provide suggestions? Regards, Sam

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  • Physics engine that can handle multiple attractors?

    - by brice
    I'm putting together a game that will be played mostly with three dimensional gravity. By that I mean multiple planets/stars/moons behaving realistically, and path plotting and path prediction in the gravity field. I have looked at a variety of physics engines, such as Bullet, tokamak or Newton, but none of them seem to be suitable, as I'd essentially have to re-write the gravity engine in their framework. Do you know of a physics engine that is capable of dealing with multiple bodies all attracted to one another? I don't need scenegraph management, or rendering, just core physics. (collision detection would be a bonus, as would rigid body dynamics). My background is in physics, so I would be able to write an engine that uses Verlet integration or RK4 (or even Euler integration, if I had to) but I'd much rather adapt an off the shelf solution. [edit]: There are some great resources for physics simulation of n-body problems online, and on stackoverflow

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  • Common usecases and techniques when integrating a 3rd party application with Oracle Sales Cloud

    - by asantaga
    Over the last year or so I've see a lot of partners migrating and integrate their applications with Oracle Sales Cloud. Interestingly I'd say 60% of the partners use the same set of design patterns over and over again. Most of the time I see that they want to embed their application into Oracle Sales Cloud, within a tab usually, perhaps click on a link to their application (passing some piece of data + credentials) and then within their application update sales cloud again using webservices. Here are some examples of the different use-cases I've seen , and how partners are embedding their applications into Sales Cloud, NB : The following examples use the "Desktop" User Interface rather than the Newer "Simplified User Interface", I'll update the sample application soon but the integration patterns are precisely the same Use Case 1 :  Navigator "Link out" to third party application This is an example of where the developer has added a link to the global navigator and this links out to the 3rd Party Application. Typically one doesn't pass any contextual data with the exception of perhaps user credentials, or better still JWT Token. Techniques Used   Adding Link to Menu Item Using JWT Token in Sales Cloud Use Case 2 : Application Embedded within the Sales Cloud Dashboard Within the Oracle Sales Cloud application there is a tab called "Sales", within this tab its possible to embed a SubTab and embed a iFrame pointing to your application. To do this the developer simply needs to edit the page in customization mode, add the tab and then add the iFrame, simples! The developer can pass credentials/JWT Token and some other pieces of data but not object data (ie the current OpportunityID etc)  Techniques Used Adding a page to the dashboard  Using JWT Token in Sales Cloud  Use Case 3 : Embedding a Tab and Context Linking out from a Sales Cloud object to the 3rd party application In this usecase the developer embeds two components into Oracle Sales Cloud. The first is a SubTab showing summary data to the user (a quote in our case) and then secondly a hyperlink, (although it could be a button) which when clicked navigates the user to the 3rd party application. In this case the developer almost always passes context specific data (i.e. the opportunityId) and a security token (username password combo or JWT Token). The third party application usually takes the data, perhaps queries more data using the Sales Cloud SOAP/WebService interface and then displays the resulting mashup to the user for further processing. When the user has finished their work in the 3rd party application they normally navigate back to Oracle Sales Cloud using what's called a "DeepLink", ie taking them back to the object [opportunity in our case] they came from. This image visually shows a "Happy Path" a user may follow, and combines linking out to an application , webservice calls and deep linking back to Sales Cloud. Techniques Used Extending a SalesCloud application with a custom button Using JWT Token in Sales Cloud Extending Oracle Sales Cloud [Opportnity] with a custom tab exposing External Content Retrieving Data from Oracle Sales cloud using WebServices Coding some groovy script to generate the URLs required (Doc 1571200.1 on MyOracle Support) DeepLinking to specific Oracle Sales Cloud Pages (Doc 1516151.1 on My Oracle Support) Use-Case 4 :  Server Side processing/synchronization This usecase focuses on the Server Side processing of data, in this case synchronizing data. Here the 3rd party application is running on a "timer", e.g. cron or similar, and when triggered it queries data from Oracle Sales Cloud, then it queries data from the 3rd party application, determines the deltas and then inserts the data where required. Specifically here we are calling Oracle Sales Cloud using SOAP/WebServices and the 3rd party application is being communicated to using the REST API, for Oracle Sales Cloud one would use standard JAX-WS WebService calls and for REST one would use the JAX-RS api and perhap the Jackson api for managing JSON objects.. This is a very common use case and one which specifically lends itself to using the Oracle Java Cloud Service as the ideal application server where to host the mediator between the two applications.  Techniques Used Using JWT Token in Sales Cloud Integrating with the Oracle Java Cloud Service Retrieving Data from Oracle Sales cloud using WebServices General Resources The above is just a small set of techniques and use-cases which are used today. There are plenty of other sources of documentation and resources available on the internet but to get you started here are a few of my favourite places  Sales Cloud General Documentation Sales Cloud Customize Tab is useful for general customization of Sales Cloud Sales Cloud Integration Tab focuses on the 3rd party integration techniques  Official Oracle Fusion Developer Relations Blog Official Oracle Fusion Developer Relations YouTube Channel Enjoy integrating! 

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  • How to reduce your CRM migration project's risks?

    - by Richard Lefebvre
    In this 1'38 video, discover how you can dramatically reduce your CRM migration project's risks, costs and budgets with the market leading CRM Data Migration tool that offers turnkey migration platform from Salesforce, Microsoft Dynamics or Oracle CRM OnDemand on to Oracle Sales Cloud. This solution is open to any Oracle CRM & CX implementation partner (e.g. System Integrators) as a mean to complement their own offer. For any additional details or for an introduction to the tool, please contact [email protected]  or visit www.conemis.com

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  • BizTalk Server 2010 Beta available

    - by Rajesh Charagandla
    BizTalk Server 2010 Beta - Click Here to Download Overview: BizTalk Server 2010 offers significant enhancements to help integrate heterogeneous Line-of-business systems with Windows .NET and SharePoint based applications to optimize user productivity, gain business efficiency and increase agility . BizTalk Server 2010 allow .Net developers to take advantage of BizTalk services right out of the box to rapidly build solutions that need to integrate transactions and data from applications like SAP, Mainframes, MS Dynamics and Oracle. Similarly SharePoint developers can seamlessly use BizTalk services directly through the new Business Connectivity Services in SharePoint 2010. BizTalk Server 2010 includes new data mapping & transformation tool to dramatically reduce the development time to mediate data exchange between disparate systems. It also provide a new single dashboard to manage performance parameters and streamline deployments from development to test to production. BizTalk 2010 includes new, scalable Trading Partner Management (TPM) model with a graphical interface for flexible management of business partner relationships and efficient on-boarding process.

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  • Car Modelling for race game

    - by Mert Toka
    I am taking Computer Graphics course this semester and we have a video game competition. I am making racing game with simulated dynamics. Our professor told us that we don't have to do much of a modelling but since we haven't started the gaming part and since I have free time I want to model the car. My question is firstly which software do you recommend to design game components? I know Maya right now. Secondly, if I design the car or any other part, what should its polygon count in order to run game smoothly? I can design pretty much everything but I assume that it is hard to design low-poly models.

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  • Strategies for Indexing Custom Fields in RavenDB

    - by Adrian Thompson Phillips
    In the relational database world, if I was developing a CRM system and wanted to have the user add their own custom fields that are searchable, I could have tables that store the name of the new column, the data type and the value, etc. (which would be less inefficient to index) or I could use the less elegant (but more searchable) solution that software like Dynamics and SharePoint use, whereas I create a load of columns on my aggregate root called CustomInt1, CustomInt2, etc. (which looks dirty and has a limit of how many custom fields a user can have, but has indexing advantages). But my questions is this, in NoSQL databases, what would be the best way of achieving the same thing? My priority would be for searchability. So what would be the best way to store this data? If I used a predefined set of properties (i.e. CustomData1, CustomData2, etc.), because these are all stored as JSON (i.e. strings) in the database, does this make it simpler because I don't have to worry about data types?

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  • Microsoft accuse un ancien directeur d'avoir emporté des données confidentielles chez Salesforce

    Microsoft accuse un ancien directeur d'avoir emporté des données confidentielles Chez Saleforces.com et s'inquiète pour Dynamics CRM Online 2011 Microsoft accuse un de ses anciens directeurs, actuellement en fonction chez Saleforces.com, d'avoir emporté avec lui des données confidentielles de l'entreprise. Matt Miszewski, ancien directeur de la division des activités grands comptes de Microsoft, avait quitté Microsoft en Décembre pour rejoindre Salesforce.com quelques semaines après où il doit occupe le poste de vice-président du secteur public. Mais Microsoft pense que celui-ci détient des données précieuses. L'entreprise avait obtenu une injonction temporaire pour bloquer l'emba...

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  • Unexpected advantage of Engineered Systems

    - by user12244672
    It's not surprising that Engineered Systems accelerate the debugging and resolution of customer issues. But what has surprised me is just how much faster issue resolution is with Engineered Systems such as SPARC SuperCluster. These are powerful, complex, systems used by customers wanting extreme database performance, app performance, and cost saving server consolidation. A SPARC SuperCluster consists or 2 or 4 powerful T4-4 compute nodes, 3 or 6 extreme performance Exadata Storage Cells, a ZFS Storage Appliance 7320 for general purpose storage, and ultra fast Infiniband switches.  Each with its own firmware. It runs Solaris 11, Solaris 10, 11gR2, LDoms virtualization, and Zones virtualization on the T4-4 compute nodes, a modified version of Solaris 11 in the ZFS Storage Appliance, a modified and highly tuned version of Oracle Linux running Exadata software on the Storage Cells, another Linux derivative in the Infiniband switches, etc. It has an Infiniband data network between the components, a 10Gb data network to the outside world, and a 1Gb management network. And customers can run whatever middleware and apps they want on it, clustered in whatever way they want. In one word, powerful.  In another, complex. The system is highly Engineered.  But it's designed to run general purpose applications. That is, the physical components, configuration, cabling, virtualization technologies, switches, firmware, Operating System versions, network protocols, tunables, etc. are all preset for optimum performance and robustness. That improves the customer experience as what the customer runs leverages our technical know-how and best practices and is what we've tested intensely within Oracle. It should also make debugging easier by fixing a large number of variables which would otherwise be in play if a customer or Systems Integrator had assembled such a complex system themselves from the constituent components.  For example, there's myriad network protocols which could be used with Infiniband.  Myriad ways the components could be interconnected, myriad tunable settings, etc. But what has really surprised me - and I've been working in this area for 15 years now - is just how much easier and faster Engineered Systems have made debugging and issue resolution. All those error opportunities for sub-optimal cabling, unusual network protocols, sub-optimal deployment of virtualization technologies, issues with 3rd party storage, issues with 3rd party multi-pathing products, etc., are simply taken out of the equation. All those error opportunities for making an issue unique to a particular set-up, the "why aren't we seeing this on any other system ?" type questions, the doubts, just go away when we or a customer discover an issue on an Engineered System. It enables a really honed response, getting to the root cause much, much faster than would otherwise be the case. Here's a couple of examples from the last month, one found in-house by my team, one found by a customer: Example 1: We found a node eviction issue running 11gR2 with Solaris 11 SRU 12 under extreme load on what we call our ExaLego test system (mimics an Exadata / SuperCluster 11gR2 Exadata Storage Cell set-up).  We quickly established that an enhancement in SRU12 enabled an 11gR2 process to query Infiniband's Subnet Manager, replacing a fallback mechanism it had used previously.  Under abnormally heavy load, the query could return results which were misinterpreted resulting in node eviction.  In several daily joint debugging sessions between the Solaris, Infiniband, and 11gR2 teams, the issue was fully root caused, evaluated, and a fix agreed upon.  That fix went back into all Solaris releases the following Monday.  From initial issue discovery to the fix being put back into all Solaris releases was just 10 days. Example 2: A customer reported sporadic performance degradation.  The reasons were unclear and the information sparse.  The SPARC SuperCluster Engineered Systems support teams which comprises both SPARC/Solaris and Database/Exadata experts worked to root cause the issue.  A number of contributing factors were discovered, including tunable parameters.  An intense collaborative investigation between the engineering teams identified the root cause to a CPU bound networking thread which was being starved of CPU cycles under extreme load.  Workarounds were identified.  Modifications have been put back into 11gR2 to alleviate the issue and a development project already underway within Solaris has been sped up to provide the final resolution on the Solaris side.  The fixed SPARC SuperCluster configuration greatly aided issue reproduction and dramatically sped up root cause analysis, allowing the correct workarounds and fixes to be identified, prioritized, and implemented.  The customer is now extremely happy with performance and robustness.  Since the configuration is common to other customers, the lessons learned are being proactively rolled out to other customers and incorporated into the installation procedures for future customers.  This effectively acts as a turbo-boost to performance and reliability for all SPARC SuperCluster customers.  If this had occurred in a "home grown" system of this complexity, I expect it would have taken at least 6 months to get to the bottom of the issue.  But because it was an Engineered System, known, understood, and qualified by both the Solaris and Database teams, we were able to collaborate closely to identify cause and effect and expedite a solution for the customer.  That is a key advantage of Engineered Systems which should not be underestimated.  Indeed, the initial issue mitigation on the Database side followed by final fix on the Solaris side, highlights the high degree of collaboration and excellent teamwork between the Oracle engineering teams.  It's a compelling advantage of the integrated Oracle Red Stack in general and Engineered Systems in particular.

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  • Knowing your user is key--Part 1: Motivation

    - by erikanollwebb
    I was thinking where the best place to start in this blog would be and finally came back to a theme that I think is pretty critical--successful gamification in the enterprise comes down to knowing your user.  Lots of folks will say that gamification is about understanding that everyone is a gamer.  But at least in my org, that argument won't play for a lot of people.  Pun intentional.  It's not that I don't see the attraction to the idea--really, very few people play no games at all.  If they don't play video games, they might play solitaire on their computer.  They may play card games, or some type of sport.  Mario Herger has some great facts on how much game playing there is going on at his Enterprise-Gamification.com website. But at the end of the day, I can't sell that into my organization well.  We are Oracle.  We make big, serious software designed run your whole business.  We don't make Angry Birds out of your financial reporting tools.  So I stick with the argument that works better.  Gamification techniques are really just good principals of user experience packaged a little differently.  Feedback?  We already know feedback is important when using software.  Progress indicators?  Got that too.  Game mechanics may package things in a more explicit way but it's not really "new".  To know how to use game mechanics, and what a user experience team is important for, is totally understanding who our users are and what they are motivated by. For several years, I taught college psychology courses, including Motivation.  Motivation is generally broken down into intrinsic and extrinsic motivation.  There's intrinsic, which comes from within the individual.  And there's extrinsic, which comes from outside the individual.  Intrinsic motivation is that motivation that comes from just a general sense of pleasure in the doing of something.  For example, I like to cook.  I like to cook a lot.  The kind of cooking I think is just fun makes other people--people who don't like to cook--cringe.  Like the cake I made this week--the star-spangled rhapsody from The Cake Bible: two layers of meringue, two layers of genoise flavored with a raspberry eau de vie syrup, whipped cream with berries and a mousseline buttercream, also flavored with raspberry liqueur and topped with fresh raspberries and blueberries. I love cooking--I ask for cooking tools for my birthday and Christmas, I take classes like sushi making and knife skills for fun.  I like reading about you can make an emulsion of egg yolks, melted butter and lemon, cook slowly and transform them into a sauce hollandaise (my use of all the egg yolks that didn't go into the aforementioned cake).  And while it's nice when people like what I cook, I don't do it for that.  I do it because I think it's fun.  My former boss, Ultan Ó Broin, loves to fish in the sea off the coast of Ireland.  Not because he gets prizes for it, or awards, but because it's fun.  To quote a note he sent me today when I asked if having been recently ill kept him from the beginning of mackerel season, he told me he had already been out and said "I can fish when on a deathbed" (read more of Ultan's work, see his blogs on User Assistance and Translation.). That's not the kind of intensity you get about something you don't like to do.  I'm sure you can think of something you do just because you like it. So how does that relate to gamification?  Gamification in the enterprise space is about uncovering the game within work.  Gamification is about tapping into things people already find motivating.  But to do that, you need to know what that user is motivated by. Customer Relationship Management (CRM) is one of those areas where over-the-top gamification seems to work (not to plug a competitor in this space, but you can search on what Bunchball* has done with a company just a little north of us on 101 for the CRM crowd).  Sales people are naturally competitive and thrive on that plus recognition of their sales work.  You can use lots of game mechanics like leaderboards and challenges and scorecards with this type of user and they love it.  Show my whole org I'm leading in sales for the quarter?  Bring it on!  However, take the average accountant and show how much general ledger activity they have done in the last week and expose it to their whole org on a leaderboard and I think you'd see a lot of people looking for a new job.  Why?  Because in general, accountants aren't extraverts who thrive on competition in their work.  That doesn't mean there aren't game mechanics that would work for them, but they won't be the same game mechanics that work for sales people.  It's a different type of user and they are motivated by different things. To break this up, I'll stop here and post now.  I'll pick this thread up in the next post. Thoughts? Questions? *Disclosure: To my knowledge, Oracle has no relationship with Bunchball at this point in time.

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  • First Windows Phone 7 &ndash; Mobile LOB App.

    - by Richard Jones
    So I spent a couple of hours yesterday building my first Windows 7 Phone Series. application.   I still can’t get used to saying Windows 7 Phone Series.   So I think I’ll just go with WP7.   I must say I’m really impressed.    Calling web-services a breeze laying out User Interface a very straight forward.   I had made called into Dynamics NAV using web-services in under 10 minutes. Working in XAML takes a bit of getting used to,  I’m not trying to-do anything too clever yet. One thing I will point out to transition from one XAML page to the next use this.NavigationService.Navigate(new Uri("/Primary.xaml", UriKind.Relative)); Going from Compact Framework this is equivalent of a Window.Show Its so nice to be able to talk nicely again, about Windows Based Mobile Development!

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  • 2D Car Simulation with Throttle Linear Physics

    - by James
    I'm trying to make a simulation game for an automatic cruise control system. The system simulates a car on varying inclinations and throttle speeds. I've coded up to the car physics but these do note make sense. The dynamics of the simulation are specified as follows: a = V' - V T = (k1)V + ?(k2) + ma V' = (1 - (k1 / m) V) + T - ( k2 / m) * ? Where T = throttle position k1 = viscous friction V = speed V' = next speed ? = angle of incline k2 = m g sin ? a = acceleration m = mass Notice that the angle of incline in the equation is not chopped up by sin or cos. Even the equation for acceleration isn't right. Can anyone correct them or am I misinterpreting the physics?

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  • What are the common character animation techniques used in tile based hack&slash games?

    - by Gorky
    I wonder what kind of animation techniques are used for creature and character animation in modern hack&slash type tile based games? Keyframing for different actions may be one option. Skeletal framing may be another. But how about the physics? Or do they use a totally hybrid system of inverse kinematics supported with a skeleton,physics and mixed with interpolated keyframing for more realistic animations? If so, how and for what reasons? I can think of many different solutions for the issues below but I wonder what's used and best suited for issues like: Walking or moving on an uneven terrain Combat interaction, combat physics and collisions Attaching rigid items to character and their iteractions ih physics world Soft body dynamics like hair, vegetation, clothes and fabric in line with animations and iteractions.

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  • BizTalk 2010 - BAM Portal - No Views to Display

    - by Stuart Brierley
    Our latest BizTalk Server 2010 development project is utilising BizTalk as the integration ring around a new and sizable implementaion of Dynamics AX 2012. With this project we have decided to use BAM to monitor the processes within our various new applications.Although I have been specialising in BizTalk for around 9 years, this is my first time using BAM so it is an interesting process to be going through.Recently when deploying a solution I was attempting to check the BAM Portal to see that the View that I had created was properly deployed and that the Activity I was populating was being surfaced in the Portal as expected. Initially I was presented with the message "No view to display" in the "My Views" area of the BAM Portal landing page.This was because you need to set the permissions on the views that you want to see from the command line using the bm.exe tool:bm.exe add-account -AccountName:YourServerOrDomain\YourUsername -View:YourViewThis tool can be found in the BAM folder at the BizTalk installation location:C:\Program Files (x86)\Microsoft BizTalk Server 2010\Tracking

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  • Clean SOAP Calls from iOS - SudzC

    - by Richard Jones
    This is worth another mention. If you need to call SOAP web-services from iOS or Javascript, and lets face who doesn't. http://SudzC.com really delivers. You give it the URL to you're WSDL file (or upload a file) and it just spits out a ready to go Xcode project. I would point out that to get it to work 100% I changed line 204, in Soap.m (commented out line is old version, mine is below) //if([child respondsToSelector:@selector(name)] && [[child name] isEqual: name]) { if([child respondsToSelector:@selector(name)] && [[child name] hasSuffix: name]) { I consumed a Microsoft Dynamics NAV set of web-service pages no problem (and they tend to be fairly complex WSDL definitions).

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  • TFS 2010 and Expanding Possibilities

    - by ssmantha
    My organization is migrating to the new Team Foundation Server 2010, and we all are busy experimenting with ALM features. I find it very exciting and I foresee quite a lot of possibilities for TFS 2010 getting integrated with the Dynamics product line. I hope most of us know about the Version Control capabilities. However, I see a strong possibilities of having Team Builds and other automations, thanks to the technologies like workflow foundation in .net which is now being actively used in various TFS scenarios.   Lots of experiments so there is more to come!!

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  • How is Basic Physics applied in CS/SE?

    - by Wulf
    What basic physics principles do software engineers and/or computer scientists use to help solve specific or common problems? The first one that came to my head was creating a Physics engine for a game; physics is involved, as it requires knowledge of: Forces and Motion: Kinematics, Dynamics, Circular Motion However, I need another example, but haven't come across one that involves basic physics. Please consider the following basic physics (grade 12 level) concepts: Energy and Momentum: Work and Energy, Momentum and Collisions, Gravitational and Celestial Mechanics Electric, Gravitational & Magnetic Field: Electric Charges and Electric Field, Magnetic Fields and Electomagnetism The Wave Nature of Light: Waves and Light, Wave Effects of Light Matter-Energy Interface: Einstein’s Special Theory of Relativity, Waves, Photons and Matter, Radioactivity and Elementary Particles I will be happy with any response; Keywords for google, names of methods like raycasting, etc.

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  • Implementing a Custom Coherence PartitionAssignmentStrategy

    - by jpurdy
    A recent A-Team engagement required the development of a custom PartitionAssignmentStrategy (PAS). By way of background, a PAS is an implementation of a Java interface that controls how a Coherence partitioned cache service assigns partitions (primary and backup copies) across the available set of storage-enabled members. While seemingly straightforward, this is actually a very difficult problem to solve. Traditionally, Coherence used a distributed algorithm spread across the cache servers (and as of Coherence 3.7, this is still the default implementation). With the introduction of the PAS interface, the model of operation was changed so that the logic would run solely in the cache service senior member. Obviously, this makes the development of a custom PAS vastly less complex, and in practice does not introduce a significant single point of failure/bottleneck. Note that Coherence ships with a default PAS implementation but it is not used by default. Further, custom PAS implementations are uncommon (this engagement was the first custom implementation that we know of). The particular implementation mentioned above also faced challenges related to managing multiple backup copies but that won't be discussed here. There were a few challenges that arose during design and implementation: Naive algorithms had an unreasonable upper bound of computational cost. There was significant complexity associated with configurations where the member count varied significantly between physical machines. Most of the complexity of a PAS is related to rebalancing, not initial assignment (which is usually fairly simple). A custom PAS may need to solve several problems simultaneously, such as: Ensuring that each member has a similar number of primary and backup partitions (e.g. each member has the same number of primary and backup partitions) Ensuring that each member carries similar responsibility (e.g. the most heavily loaded member has no more than one partition more than the least loaded). Ensuring that each partition is on the same member as a corresponding local resource (e.g. for applications that use partitioning across message queues, to ensure that each partition is collocated with its corresponding message queue). Ensuring that a given member holds no more than a given number of partitions (e.g. no member has more than 10 partitions) Ensuring that backups are placed far enough away from the primaries (e.g. on a different physical machine or a different blade enclosure) Achieving the above goals while ensuring that partition movement is minimized. These objectives can be even more complicated when the topology of the cluster is irregular. For example, if multiple cluster members may exist on each physical machine, then clearly the possibility exists that at certain points (e.g. following a member failure), the number of members on each machine may vary, in certain cases significantly so. Consider the case where there are three physical machines, with 3, 3 and 9 members each (respectively). This introduces complexity since the backups for the 9 members on the the largest machine must be spread across the other 6 members (to ensure placement on different physical machines), preventing an even distribution. For any given problem like this, there are usually reasonable compromises available, but the key point is that objectives may conflict under extreme (but not at all unlikely) circumstances. The most obvious general purpose partition assignment algorithm (possibly the only general purpose one) is to define a scoring function for a given mapping of partitions to members, and then apply that function to each possible permutation, selecting the most optimal permutation. This would result in N! (factorial) evaluations of the scoring function. This is clearly impractical for all but the smallest values of N (e.g. a partition count in the single digits). It's difficult to prove that more efficient general purpose algorithms don't exist, but the key take away from this is that algorithms will tend to either have exorbitant worst case performance or may fail to find optimal solutions (or both) -- it is very important to be able to show that worst case performance is acceptable. This quickly leads to the conclusion that the problem must be further constrained, perhaps by limiting functionality or by using domain-specific optimizations. Unfortunately, it can be very difficult to design these more focused algorithms. In the specific case mentioned, we constrained the solution space to very small clusters (in terms of machine count) with small partition counts and supported exactly two backup copies, and accepted the fact that partition movement could potentially be significant (preferring to solve that issue through brute force). We then used the out-of-the-box PAS implementation as a fallback, delegating to it for configurations that were not supported by our algorithm. Our experience was that the PAS interface is quite usable, but there are intrinsic challenges to designing PAS implementations that should be very carefully evaluated before committing to that approach.

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  • How should I choose quadtree depth?

    - by Evpok
    I'm using a quadtree to prune collision detection pairs in a 2d world. How should I choose to what depth said quadtree is calculated? The world is made mostly of moving objects1, so the cost of dispatching the objects between the quadtree cells matters. What is the relationship between the gain from less collision checking and the loss from more dispatching? How can I strike a balance that performs optimally? 1 To be completely explicit, they are autonomous self-replicating cells competing for food sources. This is an attempt to show my pupils predator-prey dynamics and genetic evolution at work.

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  • WCF, Rampart, ADFS2 and SAML Interop issue

    - by user317647
    Hi, I'm working on establishing interoperability between .NET WCF 3.5 and Axis2/Rampart using ADFS2 as the STS and using SAML authentication. Initially I used Axis 1.4.1/Rampart 1.4 but in an attempt to rule out issues relating to WS-* standards compatbility have also created a duplicate environment running Axis 1.5.1/Rampart 1.5. Both envionment use Eclipse 3.5.1 (Galileo)/Tomcat 5.5 for the Java service side. My objective is: WCF-ADFS2-SAML token-Axis2/Rampart Using Kerberos authentication to obtain a SAML token from ADFS2 and propagating this to Rampart. Much progress has been made so far, but the error I'm now getting on Rampart is as follows (on both versions 1.4 & 1.5): [ERROR] General security error (SAML token security failure) org.apache.axis2.AxisFault: General security error (SAML token security failure) Caused by: org.apache.ws.security.WSSecurityException: General security error (SAML token security failure) at org.apache.ws.security.saml.SAMLUtil.getSAMLKeyInfo(SAMLUtil.java:169) at org.apache.ws.security.saml.SAMLUtil.getSAMLKeyInfo(SAMLUtil.java:73) at org.apache.ws.security.processor.DerivedKeyTokenProcessor.extractSecret(DerivedKeyTokenProcessor.java:170) at org.apache.ws.security.processor.DerivedKeyTokenProcessor.handleToken(DerivedKeyTokenProcessor.java:74) at org.apache.ws.security.WSSecurityEngine.processSecurityHeader(WSSecurityEngine.java:326) at org.apache.ws.security.WSSecurityEngine.processSecurityHeader(WSSecurityEngine.java:243) at org.apache.rampart.RampartEngine.process(RampartEngine.java:144) After building source versions for Rampart (just 1.4 so far) I've traced this problem to the following source code: SAMUtil.java Element e = samlSubj.getKeyInfo(); X509Certificate[] certs = null; try { KeyInfo ki = new KeyInfo(e, null); if (ki.containsX509Data()) { X509Data data = ki.itemX509Data(0); XMLX509Certificate certElem = null; if (data != null && data.containsCertificate()) { certElem = data.itemCertificate(0); } if (certElem != null) { X509Certificate cert = certElem.getX509Certificate(); certs = new X509Certificate[1]; certs[0] = cert; return new SAMLKeyInfo(assertion, certs); } } The line ki.containsX509Data() above return false and fails. The value from the Element e is as follows: CN=Root Agency -147027885241304943914470421251724308948 JMYzUkmrT13JoYj2pGN5o/vxpGq8bKFXI1m18iEFu+5rF0wA4MYURGIEWE9/zg1apgjElQHus5qb4ZRCzg7IHyENCGq7um2w1SXxPzstoMsZ7oZ83Uq08lDdNV51QGzCCOdCi+YizKT7AJ1B6gaplxMnFEJ8TlnzFBCavMxSCho= The attempt to obtain the X509 data above is failing even when it appears in the message? (IssuerSerial). All references I've seen so far indicate that the style of X509 reference is supported by Rampart and WSS4J (default?!). This key reference is the certificate that ADFS2 has used to encrypt the message. Any help at all would be greatly appreciated! Thanks Jason

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  • Chaining multiple MapReduce jobs in Hadoop.

    - by Niels Basjes
    In many real-life situations where you apply MapReduce, the final algorithms end up being several MapReduce steps. I.e. Map1 , Reduce1 , Map2 , Reduce2 , etc. So you have the output from the last reduce that is needed as the input for the next map. The intermediate data is something you (in general) do not want to keep once the pipeline has been successfully completed. Also because this intermediate data is in general some data structure (like a 'map' or a 'set') you don't want to put too much effort in writing and reading these key-value pairs. What is the recommended way of doing that in Hadoop? Is there a (simple) example that shows how to handle this intermediate data in the correct way, including the cleanup afterward? Thanks.

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  • Design workflows for WF4 in Silverlight

    - by avi1234
    Hi, My system is based on activities and I want to give the analysts users the opportunity to create dynamics flows (at runtime). The designer UI based on SL 4.0 . It looks like WorkflowFoundation is the most valuable solution but we didn`t find any WF version that fits to SL (to create the xaml in SL). Any ideas? any other capable engines? Thanks, Hec

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  • C# 4: Real-World Example of Dynamic Types

    - by routeNpingme
    I think I have my brain halfway wrapped around the Dynamic Types concept in C# 4, but can't for the life of me figure out a scenario where I'd actually want to use it. I'm sure there are many, but I'm just having trouble making the connection as to how I could engineer a solution that is better solved with dynamics as opposed to interfaces, dependency injection, etc. So, what's a real-world application scenario where dynamic type usage is appropriate?

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