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Private Cloud: Putting some method behind the madness

- by Sudip Datta

Finally, I decided to join the blogging community. And what could be a better time to start than the week after OpenWorld 2012. 50K+ attendees, demonstrations, speaker sessions and a whole lot of buzz on Oracle Cloud..It was raining clouds in this year's Openworld. I am not here to write about Oracle's cloud strategy in general, but on Enterprise Manager's cloud management capabilities. This year's Openworld was the first after we announced the 12c Cloud Control and we were happy to share the stage with quite a few early adopters. Stay tuned for videos from our customers and partners, I will post them as they get published. I met a number of platform administrators in Oracle-DBAs, Middleware Admins, SOA Admins...The cloud has affected them all, at least to the point where it beckoned more than just curiosity..Most IT infrastructure are already heavily virtualized (on VMWare and on others including Oracle VM), and some would claim they are already on “cloud” (at least their Sysadmins told them so). But none of them were confident of the benefits because their pain points continued to grow.. Isn't cloud supposed to ease those? Instead, they were chasing hundreds of databases running on hundreds of VMs, often with as much certainty propounded by Heisenberg. What happened to the age-old IT discipline around administration, compliance, configuration management? VMs are great for what they are. I personally think they have opened the doors to new approaches in which an application stack gets provisioned and updated. In fact, Enterprise Manager 12c is possibly the only tool out there that can provision full-fledged application as VM Assemblies. In this year's Openworld, customers talked on how they provisioned RAC and Siebel assemblies, which as the techies out there know, are not trivial (hearing provisioning time for Siebel down from weeks to hours was gratifying indeed). However, I do have an issue with a "one-size fits all" approach to cloud. In a week's span, I met several personas: Project owners requiring an EC2 like VM instance for their projects Admins needing the same for Sparc-Solaris. DBAs requiring dedicated databases for new projects APEX Developers needing just a ready-to-consume schema as a service Java Developers looking for a runtime platform QA engineers needing a fast clone of their production environment If you drill down further, you will end up peeling more layers of the details. For example, the requirements for Load testing and Functional testing are very different. For Load testing the test environment should ideally be the same as the production. You shouldn't run production on Exadata and load test on a VM; they will just not be good representations of one another. For Functional testing it does not possibly matter. DBAs seem to be at the worst affected of the lot. It seems they have been asked to choose between agile provisioning and faster runtime performance. And in some cases, it is really a Hobson's choice, because their infrastructure provider made no distinction between the OLTP application and the Virtual desktop! Sad indeed. When one looks at the portfolio of services that we already offer (vanilla IaaS, VM Assembly based PaaS, DBaaS) or have announced (Java PaaS, Instant Cloning, Schema-aaS), one can possibly think that we are trying to be the "renaissance man" ! Well I would have possibly digested that had it not been for the various personas that I described above. Getting the use cases right is very important for an application such as cloud management. We iterate and iterate over these over and over again and re-validate them in CABs (Customer Advisory Boards). We consider over the major aspects of tenancy: service placement, resource isolation (can a tenant execute an expensive SQL and run away with all the resources), quota and security. We, in Engineering, keep reminding ourselves that we are dealing with enterprise clouds. We owe it to our customer base ! In the coming posts, I will drill down more into each of the services. In the meanwhile, here are some collateral and demos for starters with EM 12c. http://www.oracle.com/technetwork/oem/cloud-mgmt/index.html Sudip Datta The views expressed here are my own and do not necessarily reflect the views of Oracle. Stay Connected: Twitter | Facebook | YouTube | Linkedin | Newsletter --

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How do I organize a GUI application for passing around events and for setting up reads from a shared resource

- by Savanni D'Gerinel

My tools involved here are GTK and Haskell. My questions are probably pretty trivial for anyone who has done significant GUI work, but I've been off in the equivalent of CGI applications for my whole career. I'm building an application that displays tabular data, displays the same data in a graph form, and has an edit field for both entering new data and for editing existing data. After asking about sharing resources, I decided that all of the data involved will be stored in an MVar so that every component can just read the current state from the MVar. All of that works, but now it is time for me to rearrange the application so that it can be interactive. With that in mind, I have three widgets: a TextView (for editing), a TreeView (for displaying the data), and a DrawingArea (for displaying the data as a graph). I THINK I need to do two things, and the core of my question is, are these the right things, or is there a better way. Thing the first: All event handlers, those functions that will be called any time a redisplay is needed, need to be written at a high level and then passed into the function that actually constructs the widget to begin with. For instance: drawStatData :: DrawingArea -> MVar Core.ST -> (Core.ST -> SetRepWorkout.WorkoutStore) -> IO () createStatView :: (DrawingArea -> IO ()) -> IO VBox createUI :: MVar Core.ST -> (Core.ST -> SetRepWorkout.WorkoutStore) -> IO HBox createUI storeMVar field = do graphs <- createStatView (\area -> drawStatData area storeMVar field) hbox <- hBoxNew False 10 boxPackStart hbox graphs PackNatural 0 return hbox In this case, createStatView builds up a VBox that contains a DrawingArea to graph the data and potentially other widgets. It attaches drawStatData to the realize and exposeEvent events for the DrawingArea. I would do something similar for the TreeView, but I am not completely sure what since I have not yet done it and what I am thinking of would involve replacing the TreeModel every time the TreeView needs to be updated. My alternative to the above would be... drawStatData :: DrawingArea -> MVar Core.ST -> (Core.ST -> SetRepWorkout.WorkoutStore) -> IO () createStatView :: IO (VBox, DrawingArea) ... but in this case, I would arrange createUI like so: createUI :: MVar Core.ST -> (Core.ST -> SetRepWorkout.WorkoutStore) -> IO HBox createUI storeMVar field = do (graphbox, graph) <- createStatView (\area -> drawStatData area storeMVar field) hbox <- hBoxNew False 10 boxPackStart hbox graphs PackNatural 0 on graph realize (drawStatData graph storeMVar field) on graph exposeEvent (do liftIO $ drawStatData graph storeMVar field return ()) return hbox I'm not sure which is better, but that does lead me to... Thing the second: it will be necessary for me to rig up an event system so that various events can send signals all the way to my widgets. I'm going to need a mediator of some kind to pass events around and to translate application-semantic events to the actual events that my widgets respond to. Is it better for me to pass my addressable widgets up the call stack to the level where the mediator lives, or to pass the mediator down the call stack and have the widgets register directly with it? So, in summary, my two questions: 1) pass widgets up the call stack to a global mediator, or pass the global mediator down and have the widgets register themselves to it? 2) pass my redraw functions to the builders and have the builders attach the redraw functions to the constructed widgets, or pass the constructed widgets back and have a higher level attach the redraw functions (and potentially link some widgets together)? Okay, and... 3) Books or wikis about GUI application architecture, preferably coherent architectures where people aren't arguing about minute details? The application in its current form (displays data but does not write data or allow for much interaction) is available at https://bitbucket.org/savannidgerinel/fitness . You can run the application by going to the root directory and typing runhaskell -isrc src/Main.hs data/ or... cabal build dist/build/fitness/fitness data/ You may need to install libraries, but cabal should tell you which ones.

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Managing text-maps in a 2D array on to be painted on HTML5 Canvas

- by weka

So, I'm making a HTML5 RPG just for fun. The map is a <canvas> (512px width, 352px height | 16 tiles across, 11 tiles top to bottom). I want to know if there's a more efficient way to paint the <canvas>. Here's how I have it right now. How tiles are loaded and painted on map The map is being painted by tiles (32x32) using the Image() piece. The image files are loaded through a simple for loop and put into an array called tiles[] to be PAINTED on using drawImage(). First, we load the tiles... and here's how it's being done: // SET UP THE & DRAW THE MAP TILES tiles = []; var loadedImagesCount = 0; for (x = 0; x <= NUM_OF_TILES; x++) { var imageObj = new Image(); // new instance for each image imageObj.src = "js/tiles/t" + x + ".png"; imageObj.onload = function () { console.log("Added tile ... " + loadedImagesCount); loadedImagesCount++; if (loadedImagesCount == NUM_OF_TILES) { // Onces all tiles are loaded ... // We paint the map for (y = 0; y <= 15; y++) { for (x = 0; x <= 10; x++) { theX = x * 32; theY = y * 32; context.drawImage(tiles[5], theY, theX, 32, 32); } } } }; tiles.push(imageObj); } Naturally, when a player starts a game it loads the map they last left off. But for here, it an all-grass map. Right now, the maps use 2D arrays. Here's an example map. [[4, 1, 4, 1, 4, 1, 4, 1, 4, 1, 4, 1, 1, 1, 1, 1], [1, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 1, 1, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 13, 13, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 13, 13, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 13, 13, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 1, 1, 1, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 13, 13, 13, 1, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 13, 13, 11, 11, 11, 13, 13, 13, 13, 13, 13, 13, 1], [13, 13, 13, 1, 1, 1, 1, 1, 1, 1, 13, 13, 13, 13, 13, 1], [1, 1, 1, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 1, 1, 1]]; I get different maps using a simple if structure. Once the 2d array above is return, the corresponding number in each array will be painted according to Image() stored inside tile[]. Then drawImage() will occur and paint according to the x and y and times it by 32 to paint on the correct x-y coordinate. How multiple map switching occurs With my game, maps have five things to keep track of: currentID, leftID, rightID, upID, and bottomID. currentID: The current ID of the map you are on. leftID: What ID of currentID to load when you exit on the left of current map. rightID: What ID of currentID to load when you exit on the right of current map. downID: What ID of currentID to load when you exit on the bottom of current map. upID: What ID of currentID to load when you exit on the top of current map. Something to note: If either leftID, rightID, upID, or bottomID are NOT specific, that means they are a 0. That means they cannot leave that side of the map. It is merely an invisible blockade. So, once a person exits a side of the map, depending on where they exited... for example if they exited on the bottom, bottomID will the number of the map to load and thus be painted on the map. Here's a representational .GIF to help you better visualize: As you can see, sooner or later, with many maps I will be dealing with many IDs. And that can possibly get a little confusing and hectic. The obvious pros is that it load 176 tiles at a time, refresh a small 512x352 canvas, and handles one map at time. The con is that the MAP ids, when dealing with many maps, may get confusing at times. My question Is this an efficient way to store maps (given the usage of tiles), or is there a better way to handle maps? I was thinking along the lines of a giant map. The map-size is big and it's all one 2D array. The viewport, however, is still 512x352 pixels. Here's another .gif I made (for this question) to help visualize: Sorry if you cannot understand my English. Please ask anything you have trouble understanding. Hopefully, I made it clear. Thanks.

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Why bother writing an Windows 8 app?

- by Dennis Vroegop

So you want to know more about development for Window 8. Great! There are lots of reasons you should be excited about this. Since I don’t know why YOU are interested in this, I’ll make a list of reasons people can choose from. (as a side note: whenever I talk about Win8 development I am referring to the Metro Style / WinRt side of things. Apps for the ‘classic’ desktop side of Win8 on Intel are business as usual…) So… Why would you care about making an app for Windows 8? 1. It’s cool. Let’s not beat around the bush: if you like development for a hobby then you’ll love to work on this new platform. You can create apps in a relative short time (short time as in compared to writing a new CRM system) and that makes it great for a hobby product. 2. You’ll stand out. Hey, we all need an ego boost every now and then. We all need to feel special. So if you can manage to be one of the first to have you app in the Store then you’ll likely to be noticed. Just close your eyes for a moment and image you standing in a bar. It’s crowded, and then you casually say “Oh yeah, I just had my app certified and it’s in the Win8 store now”. People will stop talking, will offer you drinks and beautiful women / gorgeous man / furry creatures from Alpha Centauri (whatever your preferences are) will propose. Or maybe not. Anyway…. 3. Make some cash! IDC predicts there will be about 350,000,000 Windows 8 licenses sold in the next year. Think about that number. 350,000,000. And they all have access to the Store. Where you’re app will be. With one little click they can select it, download and somehow magically $1.00 or $2.00 from their bank account is transferred to yours. Now, I am not saying that all of those people will download and buy your app but what if only 1% of them did? Remember: there aren’t that many apps available yet….. 4. Learn. Creating new small apps is a great way to learn new stuff. Yes, you could read about it (on this blog for instance) but the only way to learn something is to do it. So be prepared for the future and learn something new by doing it.Write an app! Now! 5. The biggie (for me at least): it’s fun. Even if you remove the points above it’s still fun to write for these devices and this platform. Now some of you will say : “But why not write a great app for IOS or Android?” I think this is a valid question. Of course the novelty of the platform wears out and points 2 and 3 from above list will not be as relevant as it is today. But still 1 4 and 5 remain. And don’t forget: if you already work on the Microsoft platform it’s not that hard to learn this new Win8 stuff. If you have done some XAML development (be it WPF or Silverlight) you are almost there in becoming a good Win8 developer. So you’ll be more productive much sooner than when you have to learn Objective C or Java. Even if you’re a HTML / Javascript developer (I say developer here, not designer) you’ll be up to speed on Win8 development pretty soon. Yes, you, that funky Web Developer who lives and breathes HTML5, CSS3 and JavaScript / Node.Js / JQuery: you too can be a Win8 developer. A first class Win8 developer! So.. Download the stuff you need from http://dev.windows.com install Windows 8 and Visual Studio 12 and by the time you’re ready I’ll be working on the next article: how to do all this? Happy coding!

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Developing Schema Compare for Oracle (Part 6): 9i Query Performance

- by Simon Cooper

All throughout the EAP and beta versions of Schema Compare for Oracle, our main request was support for Oracle 9i. After releasing version 1.0 with support for 10g and 11g, our next step was then to get version 1.1 of SCfO out with support for 9i. However, there were some significant problems that we had to overcome first. This post will concentrate on query execution time. When we first tested SCfO on a 9i server, after accounting for various changes to the data dictionary, we found that database registration was taking a long time. And I mean a looooooong time. The same database that on 10g or 11g would take a couple of minutes to register would be taking upwards of 30 mins on 9i. Obviously, this is not ideal, so a poke around the query execution plans was required. As an example, let's take the table population query - the one that reads ALL_TABLES and joins it with a few other dictionary views to get us back our list of tables. On 10g, this query takes 5.6 seconds. On 9i, it takes 89.47 seconds. The difference in execution plan is even more dramatic - here's the (edited) execution plan on 10g: -------------------------------------------------------------------------------| Id | Operation | Name | Bytes | Cost |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 108K| 939 || 1 | SORT ORDER BY | | 108K| 939 || 2 | NESTED LOOPS OUTER | | 108K| 938 ||* 3 | HASH JOIN RIGHT OUTER | | 103K| 762 || 4 | VIEW | ALL_EXTERNAL_LOCATIONS | 2058 | 3 ||* 20 | HASH JOIN RIGHT OUTER | | 73472 | 759 || 21 | VIEW | ALL_EXTERNAL_TABLES | 2097 | 3 ||* 34 | HASH JOIN RIGHT OUTER | | 39920 | 755 || 35 | VIEW | ALL_MVIEWS | 51 | 7 || 58 | NESTED LOOPS OUTER | | 39104 | 748 || 59 | VIEW | ALL_TABLES | 6704 | 668 || 89 | VIEW PUSHED PREDICATE | ALL_TAB_COMMENTS | 2025 | 5 || 106 | VIEW | ALL_PART_TABLES | 277 | 11 |------------------------------------------------------------------------------- And the same query on 9i: -------------------------------------------------------------------------------| Id | Operation | Name | Bytes | Cost |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 16P| 55G|| 1 | SORT ORDER BY | | 16P| 55G|| 2 | NESTED LOOPS OUTER | | 16P| 862M|| 3 | NESTED LOOPS OUTER | | 5251G| 992K|| 4 | NESTED LOOPS OUTER | | 4243M| 2578 || 5 | NESTED LOOPS OUTER | | 2669K| 1440 ||* 6 | HASH JOIN OUTER | | 398K| 302 || 7 | VIEW | ALL_TABLES | 342K| 276 || 29 | VIEW | ALL_MVIEWS | 51 | 20 ||* 50 | VIEW PUSHED PREDICATE | ALL_TAB_COMMENTS | 2043 | ||* 66 | VIEW PUSHED PREDICATE | ALL_EXTERNAL_TABLES | 1777K| ||* 80 | VIEW PUSHED PREDICATE | ALL_EXTERNAL_LOCATIONS | 1744K| ||* 96 | VIEW | ALL_PART_TABLES | 852K| |------------------------------------------------------------------------------- Have a look at the cost column. 10g's overall query cost is 939, and 9i is 55,000,000,000 (or more precisely, 55,496,472,769). It's also having to process far more data. What on earth could be causing this huge difference in query cost? After trawling through the '10g New Features' documentation, we found item 1.9.2.21. Before 10g, Oracle advised that you do not collect statistics on data dictionary objects. From 10g, it advised that you do collect statistics on the data dictionary; for our queries, Oracle therefore knows what sort of data is in the dictionary tables, and so can generate an efficient execution plan. On 9i, no statistics are present on the system tables, so Oracle has to use the Rule Based Optimizer, which turns most LEFT JOINs into nested loops. If we force 9i to use hash joins, like 10g, we get a much better plan: -------------------------------------------------------------------------------| Id | Operation | Name | Bytes | Cost |-------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 7587K| 3704 || 1 | SORT ORDER BY | | 7587K| 3704 ||* 2 | HASH JOIN OUTER | | 7587K| 822 ||* 3 | HASH JOIN OUTER | | 5262K| 616 ||* 4 | HASH JOIN OUTER | | 2980K| 465 ||* 5 | HASH JOIN OUTER | | 710K| 432 ||* 6 | HASH JOIN OUTER | | 398K| 302 || 7 | VIEW | ALL_TABLES | 342K| 276 || 29 | VIEW | ALL_MVIEWS | 51 | 20 || 50 | VIEW | ALL_PART_TABLES | 852K| 104 || 78 | VIEW | ALL_TAB_COMMENTS | 2043 | 14 || 93 | VIEW | ALL_EXTERNAL_LOCATIONS | 1744K| 31 || 106 | VIEW | ALL_EXTERNAL_TABLES | 1777K| 28 |------------------------------------------------------------------------------- That's much more like it. This drops the execution time down to 24 seconds. Not as good as 10g, but still an improvement. There are still several problems with this, however. 10g introduced a new join method - a right outer hash join (used in the first execution plan). The 9i query optimizer doesn't have this option available, so forcing a hash join means it has to hash the ALL_TABLES table, and furthermore re-hash it for every hash join in the execution plan; this could be thousands and thousands of rows. And although forcing hash joins somewhat alleviates this problem on our test systems, there's no guarantee that this will improve the execution time on customers' systems; it may even increase the time it takes (say, if all their tables are partitioned, or they've got a lot of materialized views). Ideally, we would want a solution that provides a speedup whatever the input. To try and get some ideas, we asked some oracle performance specialists to see if they had any ideas or tips. Their recommendation was to add a hidden hook into the product that allowed users to specify their own query hints, or even rewrite the queries entirely. However, we would prefer not to take that approach; as well as a lot of new infrastructure & a rewrite of the population code, it would have meant that any users of 9i would have to spend some time optimizing it to get it working on their system before they could use the product. Another approach was needed. All our population queries have a very specific pattern - a base table provides most of the information we need (ALL_TABLES for tables, or ALL_TAB_COLS for columns) and we do a left join to extra subsidiary tables that fill in gaps (for instance, ALL_PART_TABLES for partition information). All the left joins use the same set of columns to join on (typically the object owner & name), so we could re-use the hash information for each join, rather than re-hashing the same columns for every join. To allow us to do this, along with various other performance improvements that could be done for the specific query pattern we were using, we read all the tables individually and do a hash join on the client. Fortunately, this 'pure' algorithmic problem is the kind that can be very well optimized for expected real-world situations; as well as storing row data we're not using in the hash key on disk, we use very specific memory-efficient data structures to store all the information we need. This allows us to achieve a database population time that is as fast as on 10g, and even (in some situations) slightly faster, and a memory overhead of roughly 150 bytes per row of data in the result set (for schemas with 10,000 tables in that means an extra 1.4MB memory being used during population). Next: fun with the 9i dictionary views.

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Orchard shapeshifting

- by Bertrand Le Roy

I've shown in a previous post how to make it easier to change the layout template for specific contents or areas. But what if you want to change another shape template for specific pages, for example the main Content shape on the home page? Here's how. When we changed the layout, we had the problem that layout is created very early, so early that in fact it can't know what content is going to be rendered. For that reason, we had to rely on a filter and on the routing information to determine what layout template alternates to add. This time around, we are dealing with a content shape, a shape that is directly related to a content item. That makes things a little easier as we have access to a lot more information. What I'm going to do here is handle an event that is triggered every time a shape named "Content" is about to be displayed: public class ContentShapeProvider : IShapeTableProvider { public void Discover(ShapeTableBuilder builder) { builder.Describe("Content") .OnDisplaying(displaying => { // do stuff to the shape }); } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This handler is implemented in a shape table provider which is where you do all shape related site-wide operations. The first thing we want to do in this event handler is check that we are on the front-end, displaying the "Detail" version, and not the "Summary" or the admin editor: if (displaying.ShapeMetadata.DisplayType == "Detail") { Now I want to provide the ability for the theme developer to provide an alternative template named "Content-HomePage.cshtml" for the home page. In order to determine if we are indeed on the home page I can look at the current site's home page property, which for the default home page provider contains the home page item's id at the end after a semicolon. Compare that with the content item id for the shape we are looking at and you can know if that's the homepage content item. Please note that if that content is also displayed on another page than the home page it will also get the alternate: we are altering at the shape level and not at the URL/routing level like we did with the layout. ContentItem contentItem = displaying.Shape.ContentItem; if (_workContextAccessor.GetContext().CurrentSite .HomePage.EndsWith(';' + contentItem.Id.ToString())) { _workContextAccessor is an injected instance of IWorkContextAccessor from which we can get the current site and its home page. Finally, once we've determined that we are in the specific conditions that we want to alter, we can add the alternate: displaying.ShapeMetadata.Alternates.Add("Content__HomePage"); And that's it really. Here's the full code for the shape provider that I added to a custom theme (but it could really live in any module or theme): using Orchard; using Orchard.ContentManagement; using Orchard.DisplayManagement.Descriptors; namespace CustomLayoutMachine.ShapeProviders { public class ContentShapeProvider : IShapeTableProvider { private readonly IWorkContextAccessor _workContextAccessor; public ContentShapeProvider( IWorkContextAccessor workContextAccessor) { _workContextAccessor = workContextAccessor; } public void Discover(ShapeTableBuilder builder) { builder.Describe("Content") .OnDisplaying(displaying => { if (displaying.ShapeMetadata.DisplayType == "Detail") { ContentItem contentItem = displaying.Shape.ContentItem; if (_workContextAccessor.GetContext() .CurrentSite.HomePage.EndsWith( ';' + contentItem.Id.ToString())) { displaying.ShapeMetadata.Alternates.Add( "Content__HomePage"); } } }); } } } The code for the custom theme, with layout and content alternates, can be downloaded from the following link: Orchard.Themes.CustomLayoutMachine.1.0.nupkg Note: this code is going to be used in the Contoso theme that should be available soon from the theme gallery.

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Collision Detection problems in Voxel Engine (XNA)

- by Darestium

I am creating a minecraft like terrain engine in XNA and have had some collision problems for quite some time. I have checked and changed my code based on other peoples collision code and I still have the same problem. It always seems to be off by about a block. for instance, if I walk across a bridge which is one block high I fall through it. Also, if you walk towards a "row" of blocks like this: You are able to stand "inside" the left most one, and you collide with nothing in the right most side (where there is no block and is not visible on this image). Here is all my collision code: private void Move(GameTime gameTime, Vector3 direction) { float speed = playermovespeed * (float)gameTime.ElapsedGameTime.TotalSeconds; Matrix rotationMatrix = Matrix.CreateRotationY(player.Camera.LeftRightRotation); Vector3 rotatedVector = Vector3.Transform(direction, rotationMatrix); rotatedVector.Normalize(); Vector3 testVector = rotatedVector; testVector.Normalize(); Vector3 movePosition = player.position + testVector * speed; Vector3 midBodyPoint = movePosition + new Vector3(0, -0.7f, 0); Vector3 headPosition = movePosition + new Vector3(0, 0.1f, 0); if (!world.GetBlock(movePosition).IsSolid && !world.GetBlock(midBodyPoint).IsSolid && !world.GetBlock(headPosition).IsSolid) { player.position += rotatedVector * speed; } //player.position += rotatedVector * speed; } ... public void UpdatePosition(GameTime gameTime) { player.velocity.Y += playergravity * (float)gameTime.ElapsedGameTime.TotalSeconds; Vector3 footPosition = player.Position + new Vector3(0f, -1.5f, 0f); Vector3 headPosition = player.Position + new Vector3(0f, 0.1f, 0f); // If the block below the player is solid the Y velocity should be zero if (world.GetBlock(footPosition).IsSolid || world.GetBlock(headPosition).IsSolid) { player.velocity.Y = 0; } UpdateJump(gameTime); UpdateCounter(gameTime); ProcessInput(gameTime); player.Position = player.Position + player.velocity * (float)gameTime.ElapsedGameTime.TotalSeconds; velocity = Vector3.Zero; } and the one and only function in the camera class: protected void CalculateView() { Matrix rotationMatrix = Matrix.CreateRotationX(upDownRotation) * Matrix.CreateRotationY(leftRightRotation); lookVector = Vector3.Transform(Vector3.Forward, rotationMatrix); cameraFinalTarget = Position + lookVector; Vector3 cameraRotatedUpVector = Vector3.Transform(Vector3.Up, rotationMatrix); viewMatrix = Matrix.CreateLookAt(Position, cameraFinalTarget, cameraRotatedUpVector); } which is called when the rotation variables are changed: public float LeftRightRotation { get { return leftRightRotation; } set { leftRightRotation = value; CalculateView(); } } public float UpDownRotation { get { return upDownRotation; } set { upDownRotation = value; CalculateView(); } } World class: public Block GetBlock(int x, int y, int z) { if (InBounds(x, y, z)) { Vector3i regionalPosition = GetRegionalPosition(x, y, z); Vector3i region = GetRegionPosition(x, y, z); return regions[region.X, region.Y, region.Z].Blocks[regionalPosition.X, regionalPosition.Y, regionalPosition.Z]; } return new Block(BlockType.none); } public Vector3i GetRegionPosition(int x, int y, int z) { int regionx = x == 0 ? 0 : x / Variables.REGION_SIZE_X; int regiony = y == 0 ? 0 : y / Variables.REGION_SIZE_Y; int regionz = z == 0 ? 0 : z / Variables.REGION_SIZE_Z; return new Vector3i(regionx, regiony, regionz); } public Vector3i GetRegionalPosition(int x, int y, int z) { int regionx = x == 0 ? 0 : x / Variables.REGION_SIZE_X; int X = x % Variables.REGION_SIZE_X; int regiony = y == 0 ? 0 : y / Variables.REGION_SIZE_Y; int Y = y % Variables.REGION_SIZE_Y; int regionz = z == 0 ? 0 : z / Variables.REGION_SIZE_Z; int Z = z % Variables.REGION_SIZE_Z; return new Vector3i(X, Y, Z); } Any ideas how to fix this problem? EDIT 1: Graphic of the problem: EDIT 2 GetBlock, Vector3 version: public Block GetBlock(Vector3 position) { int x = (int)Math.Floor(position.X); int y = (int)Math.Floor(position.Y); int z = (int)Math.Ceiling(position.Z); Block block = GetBlock(x, y, z); return block; } Now, the thing is I tested the theroy that the Z is always "off by one" and by ceiling the value it actually works as intended. Altough it still could be greatly more accurate (when you go down holes you can see through the sides, and I doubt it will work with negitive positions). I also does not feel clean Flooring the X and Y values and just Ceiling the Z. I am surely not doing something correctly still.

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Multiple enemy array in LibGDX

- by johnny-b

I am trying to make a multiple enemy array, where every 30 secods a new bullet comes from a random point. And if the bullet is clicked it should disapear and a pop like an explosion should appear. And if the bullet hits the ball then the ball pops. so the bullet should change to a different sprite or texture. same with the ball pop. But all that happens is the bullet if touched pops and nothing else happens. And if modified then the bullet keeps flashing as the update is way too much. I have added COMMENTS in the code to explain more on the issues. below is the code. if more code is needed i will provide. Thank you public class GameRenderer { private GameWorld myWorld; private OrthographicCamera cam; private ShapeRenderer shapeRenderer; private SpriteBatch batcher; // Game Objects private Ball ball; private ScrollHandler scroller; private Background background; private Bullet bullet1; private BulletPop bPop; private Array<Bullet> bullets; // This is for the delay of the bullet coming one by one every 30 seconds. /** The time of the last shot fired, we set it to the current time in nano when the object is first created */ double lastShot = TimeUtils.nanoTime(); /** Convert 30 seconds into nano seconds, so 30,000 milli = 30 seconds */ double shotFreq = TimeUtils.millisToNanos(30000); // Game Assets private TextureRegion bg, bPop; private Animation bulletAnimation, ballAnimation; private Animation ballPopAnimation; public GameRenderer(GameWorld world) { myWorld = world; cam = new OrthographicCamera(); cam.setToOrtho(true, 480, 320); batcher = new SpriteBatch(); // Attach batcher to camera batcher.setProjectionMatrix(cam.combined); shapeRenderer = new ShapeRenderer(); shapeRenderer.setProjectionMatrix(cam.combined); // This is suppose to produce 10 bullets at random places on the background. bullets = new Array<Bullet>(); Bullet bullet = null; float bulletX = 00.0f; float bulletY = 00.0f; for (int i = 0; i < 10; i++) { bulletX = MathUtils.random(-10, 10); bulletY = MathUtils.random(-10, 10); bullet = new Bullet(bulletX, bulletY); AssetLoader.bullet1.flip(true, false); AssetLoader.bullet2.flip(true, false); bullets.add(bullet); } // Call helper methods to initialize instance variables initGameObjects(); initAssets(); } private void initGameObjects() { ball = GameWorld.getBall(); bullet1 = myWorld.getBullet1(); bPop = myWorld.getBulletPop(); scroller = myWorld.getScroller(); } private void initAssets() { bg = AssetLoader.bg; ballAnimation = AssetLoader.ballAnimation; bullet1Animation = AssetLoader.bullet1Animation; ballPopAnimation = AssetLoader.ballPopAnimation; } // This is to take the bullet away when clicked or touched. public void onClick() { for (int i = 0; i < bullets.size; i++) { if (bullets.get(i).getBounds().contains(0, 0)) bullets.removeIndex(i); } } private void drawBackground() { batcher.draw(bg1, background.getX(), background.getY(), background.getWidth(), backgroundMove.getHeight()); } public void render(float runTime) { Gdx.gl.glClearColor(0, 0, 0, 1); Gdx.gl.glClear(GL30.GL_COLOR_BUFFER_BIT); batcher.begin(); // Disable transparency // This is good for performance when drawing images that do not require // transparency. batcher.disableBlending(); drawBackground(); batcher.enableBlending(); // when the bullet hits the ball, it should be disposed or taken away and a ball pop sprite/texture should be put in its place if (bullet1.collides(ball)) { // draws the bPop texture but the bullet does not go just keeps going around, and the bPop texture goes. batcher.draw(AssetLoader.bPop, 195, 273); } batcher.draw(AssetLoader.ballAnimation.getKeyFrame(runTime), ball.getX(), ball.getY(), ball.getWidth(), ball.getHeight()); // this is where i am trying to make the bullets come one by one, and if removed via the onClick() then bPop animation // should play but does not??? if(TimeUtils.nanoTime() - lastShot > shotFreq){ // Create your stuff for (int i = 0; i < bullets.size; i++) { bullets.get(i); batcher.draw(AssetLoader.bullet1Animation.getKeyFrame(runTime), bullet1.getX(), bullet1.getY(), bullet1.getOriginX(), bullet1.getOriginY(), bullet1.getWidth(), bullet1.getHeight(), 1.0f, 1.0f, bullet1.getRotation()); if (bullets.removeValue(bullet1, false)) { batcher.draw(AssetLoader.ballPopAnimation.getKeyFrame(runTime), bPop1.getX(), bPop1.getY(), bPop1.getWidth(), bPop1.getHeight()); } } /* Very important to set the last shot to now, or it will mess up and go full auto */ lastShot = TimeUtils.nanoTime(); } // End SpriteBatch batcher.end(); } } Thank you

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Extending Expression Blend 4 & Blend for Visual Studio 2012

- by Chris Skardon

Just getting this off the bat, I presume this will also work for Blend 5, but I can’t confirm it… Anyhews, I imagine you’re here because you want to know how to create an addin for Blend, so let’s jump right in there! First, and foremost, we’re going to need to ensure our development environment has the right setup, so the checklist: Visual Studio 2012 Blend for Visual Studio 2012 OK, let’s create a new project (class library, .NET 4.5): Hello.Extension The ‘.Extension’ bit is very very important. The addin will not work unless it is named in this way. You can put whatever you want at the front, but it has to have the extension bit. OK, so now we have a solution with one project. To this project we need to add references to the following things: Microsoft.Expression.Extensibility (from c:\program files\Microsoft Visual Studio 11.0\Blend\ -- x86 folder if you are on an x64 windows install) Microsoft.Expression.Framework (same location as above) PresentationCore PresentationFramework WindowsBase System.ComponentModel.Composition Got them? ACE. Let’s now add a project to contain our control, so, create a new WPF Application project, cunningly named something like ‘Hello.Control’… (I’m creating a WPF application here, because I’m too lazy to dig up the correct references, and this will add all the ones I need ) Once that is created, delete the App.xaml and MainWindow.xaml files, we won’t be needing them. You will also need to change the properties of the project itself, so it is only a class library. Once that is done, let’s add a new UserControl, which will be this: <UserControl x:Class="Hello.Control.HelloControl" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300"> <Grid> <TextBlock Text="HELLO!!!"/> </Grid> </UserControl> Impressive eh? Now, let’s reference the WPF project from the Extension library. All that’s left now is to code up our extension… So, add a class to the Extension project (name wise doesn’t matter), and make it implement the IPackage interface from the Microsoft.Expression.Extensibility library: public class HelloExtension : IPackage { /**/ } We’ll implement the two methods we need to: public class HelloExtension : IPackage { public void Load(IServices services) { } public void Unload() { } } We’re only really concerned about the Load method in this case, as let’s face it, the extension we have doesn’t need to do a lot to bog off. The interesting thing about the Load method is that it receives an IServices instance. This allows us to get access to all the services that Expression provides, in this case we’re interested in one in particular, the ‘IWindowService’ So, let’s get that bad boy… private IWindowService _windowService; public void Load(IServices services) { _windowService = services.GetService<IWindowService>(); } Nailed it… But why? The WindowService allows us to register our UserControl with Blend, which in turn allows people to activate and see it, which is a big plus point. So, let’s do that… We’ll create an ‘Initialize’ method to create our new control, and add it to the WindowService: private HelloControl _helloControl; public void Initialize() { _helloControl = new HelloControl(); if (_windowService.PaletteRegistry["HelloPanel"] == null) _windowService.RegisterPalette("HelloPanel", _helloControl, "Hello Window"); } First we check that we’re not already registered, and if we’re not we register, the first argument is the identifier used by the service to, well, identify your extension. The second argument is the actual control, the third argument is the name that people will see in the ‘Windows’ menu of Blend itself (so important note here – don’t put anything embarrassing or (need I say it?) sweary…) There are only two things to do now - Call ‘Initialize()’ from our Load method, and Export the class This is easy money – add [Export(typeof(IPackage))] to the top of our class… The full code will (should) look like this: [Export(typeof (IPackage))] public class HelloExtension : IPackage { private HelloControl _helloControl; private IWindowService _windowService; public void Load(IServices services) { _windowService = services.GetService<IWindowService>(); Initialize(); } public void Unload() { } public void Initialize() { _helloControl = new HelloControl(); if (_windowService.PaletteRegistry["HelloControl"] == null) _windowService.RegisterPalette("HelloControl", _helloControl, "Hello Window"); } } If you build this and copy it to your ‘Extensions’ folder in Blend (c:\program files\microsoft visual studio 11.0\blend\) and start Blend, you should see ‘Hello Window’ listed in the Window menu: That as they say is it!

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Are IE9 really good ?

- by anirudha

IE9 started a campaign for kill IE6 from the core because they know that IE6 is a big trouble or problem for them for promote 9 version of IE. so they started a campaign for killing IE6. next time they kill IE 7 , 8,9 whenever they found this old version have a big problem for them to promote next version of IE. Why they not make a update system who automatically update the browser and tell user to restart and update goes installed in the user system. well IE9 should learn from all other that they have very well design auto-update system who never give user in trouble that your browser goes old. Chrome and Firefox both update themselves and say user restart to enjoy another good version. in IE6 a big problem is that updates. no one sure that they installed new version of IE6 without any hassles and update goes install without any problem because they really know or care about “you need this to install this and this for this” so they thing “why I update IE whenever I am unsure that my browser goes update and I have no problem again” so they do nothing because their work done with no problem because common person used high profile application who work even in IE6. so they do nothing. IE6 countdown website have designed a banner for warn or force user to upgrade to next version of IE. well there is no good reason for put the banner on website some of reason are:- Windows 7 comes with pre-installed IE8 and Vista comes with upgrade version them IE6 so that is sure that you force a user who have Windows XP [luna] and if they want to upgrade IE then they can get IE8 not version 9 because IE9 is design for Windows 7 or Vista Service pack 2. so What is the use of update when user still have a outdate version too because IE8 is old version and not have any capability of HTML5 so forcing user by using the banner have no sense. I am not know why they all listed on website put the banner on their own website. it’s good that you offer user what they want instead of giving them a outdate version of IE again. My means to give a user list of browser they can try to enhance their browser experience instead of only IE. IE9 build upon WPF and they spent more time on using WPF in IE instead of making user experience browser. many thing is designed wrongly in IE first thing is tabs. the tabs in chrome are bigger and easily to move and same in Firefox even not have smooth tabbing. IE have same tabbing as chrome have but leak a point that it’s too small. if you really want to move then sometime they create a problem that they going elsewhere from the current instance of IE. Chrome have a big buttons, tabs and menu to enhance browser experience and Firefox have a good feature that you can make them bigger or small. you can put the icon for add-ons on the toolbar for easily use but IE have no relation with customization so we never can thinking about that. When chrome provide lot’s of extensions and a webstore for browser application and same feature in Firefox can be seen then there is no plugin in IE. really you can see their IE addons Website where no plugin listed for web development. even in the category or tag. as a response from many blog there is new for developer that new version of IE9 developer tool. well IE9 have three new tabs a blogger tell on their blog. when I trying them I found many thing but I still unable to edit the Css from the HTML tab and no plugin I found I can get to enhance IE9 web development. something more other provide never IE9 give me like personas , customization , browser extension or any other they used to tell a small thing customization . IE9 still have some problem with JavaScript that when I use Firefox and chrome and logout in both then my cookie is deleted but in IE it’s not done. it’s show me that IE9 still have different from other not for good thing even some bad thing too. When I trying to read a article that is written in Hindi using Unicode font I found that they show many thing misspelled. there is three Sha in Hindi but they all goes wrong in IE. the misprint thing is not that the writing for the articles goes wrong. it’s problem or browser to rendering a font. the Firefox and chrome not give me this problem even opera render the font in italic style by decrease the font-size but all those work perfect. in Pwn2Own the apple’s safari and IE9 both are hacked. this is a awesome news for whose who thing that open-source is lose in Security and close-source is highly-secured software. well this is not a good parameter for talking about software. it’s should depend how much application tested and used. because more testing and more use of application make them better. I appreciate IE to making their new version 9 and good luck for them. there is a another matter that I personally found nothing on them.

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Microsoft Sql Server 2008 R2 System Databases

For a majority of software developers little time is spent understanding the inner workings of the database management systems (DBMS) they use to store data for their applications. I personally place myself in this grouping. In my case, I have used various versions of Microsoft’s SQL Server (2000, 2005, and 2008 R2) and just recently learned how valuable they really are when I was preparing to deliver a lecture on "SQL Server 2008 R2, System Databases". Microsoft Sql Server 2008 R2 System DatabasesSo what are system databases in MS SQL Server, and why should I know them? Microsoft uses system databases to support the SQL Server DBMS, much like a developer uses config files or database tables to support an application. These system databases individually provide specific functionality that allows MS SQL Server to function. Name Database File Log File Master master.mdf mastlog.ldf Resource mssqlsystemresource.mdf mssqlsystemresource.ldf Model model.mdf modellog.ldf MSDB msdbdata.mdf msdblog.ldf Distribution distmdl.mdf distmdl.ldf TempDB tempdb.mdf templog.ldf Master DatabaseIf you have used MS SQL Server then you should recognize the Master database especially if you used the SQL Server Management Studio (SSMS) to connect to a user created database. MS SQL Server requires the Master database in order for DBMS to start due to the information that it stores. Examples of data stored in the Master database User Logins Linked Servers Configuration information Information on User Databases Resource DatabaseHonestly, until recently I never knew this database even existed until I started to research SQL Server system databases. The reason for this is due largely to the fact that the resource database is hidden to users. In fact, the database files are stored within the Binn folder instead of the standard MS SQL Server database folder path. This database contains all system objects that can be accessed by all other databases. In short, this database contains all system views and store procedures that appear in all other user databases regarding system information. One of the many benefits to storing system views and store procedures in a single hidden database is the fact it improves upgrading a SQL Server database; not to mention that maintenance is decreased since only one code base has to be mainlined for all of the system views and procedures. Model DatabaseThe Model database as the name implies is the model for all new databases created by users. This allows for predefining default database objects for all new databases within a MS SQL Server instance. For example, if every database created by a user needs to have an “Audit” table when it is created then defining the “Audit” table in the model will guarantees that the table will be located in every new database create after the model is altered. MSDB DatabaseThe MSDBdatabase is used by SQL Server Agent, SQL Server Database Mail, SQL Server Service Broker, along with SQL Server. The SQL Server Agent uses this database to store job configurations and SQL job schedules along with SQL Alerts, and Operators. In addition, this database also stores all SQL job parameters along with each job’s execution history. Finally, this database is also used to store database backup and maintenance plans as well as details pertaining to SQL Log shipping if it is being used. Distribution DatabaseThe Distribution database is only used during replication and stores meta data and history information pertaining to the act of replication data. Furthermore, when transactional replication is used this database also stores information regarding each transaction. It is important to note that replication is not turned on by default in MS SQL Server and that the distribution database is hidden from SSMS. Tempdb DatabaseThe Tempdb as the name implies is used to store temporary data and data objects. Examples of this include temp tables and temp store procedures. It is important to note that when using this database all data and data objects are cleared from this database when SQL Server restarts. This database is also used by SQL Server when it is performing some internal operations. Typically, SQL Server uses this database for the purpose of large sort and index operations. Finally, this database is used to store row versions if row versioning or snapsot isolation transactions are being used by SQL Server. Additionally, I would love to hear from others about their experiences using system databases, tables, and objects in a real world environments.

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OIM 11g - Multi Valued attribute reconciliation of a child form

- by user604275

This topic gives a brief description on how we can do reconciliation of a child form attribute which is also multi valued from a flat file . The format of the flat file is (an example): ManagementDomain1|Entitlement1|DIRECTORY SERVER,EMAIL ManagementDomain2|Entitlement2|EMAIL PROVIDER INSTANCE - UMS,EMAIL VERIFICATION In OIM there will be a parent form for fields Management domain and Entitlement.Reconciliation will assign Servers ( which are multi valued) to corresponding Management Domain and Entitlement .In the flat file , multi valued fields are seperated by comma(,). In the design console, Create a form with 'Server Name' as a field and make it a child form . Open the corresponding Resource Object and add this field for reconcilitaion.While adding , choose 'Multivalued' check box. (please find attached screen shot on how to add it , Child Table.docx) Open process definiton and add child form fields for recociliation. Please click on the 'Create Reconcilitaion Profile' buttton on the resource object tab. The API methods used for child form reconciliation are : 1. reconEventKey = reconOpsIntf.createReconciliationEvent(resObjName, reconData, false); · ‘False’ here tells that we are creating the recon for a child table . 2. 2. reconOpsIntf.providingAllMultiAttributeData(reconEventKey, RECON_FIELD_IN_RO, true); RECON_FIELD_IN_RO is the field that we added in the Resource Object while adding for reconciliation, please refer the screen shot) 3. reconOpsIntf.addDirectBulkMultiAttributeData(reconEventKey,RECON_FIELD_IN_RO, bulkChildDataMapList); bulkChildDataMapList is coded as below : List<Map> bulkChildDataMapList = new ArrayList<Map>(); for (int i = 0; i < stokens.length; i++) { Map<String, String> attributeMap = new HashMap<String, String>(); String serverName = stokens[i].toUpperCase(); attributeMap.put("Server Name", stokens[i]); bulkChildDataMapList.add(attributeMap); } 4 4. reconOpsIntf.finishReconciliationEvent(reconEventKey); 5. reconOpsIntf.processReconciliationEvent(reconEventKey); Now, we have to register the plug-in, import metadata into MDS and then create a scheduled job to execute which will run the reconciliation.

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Storing non-content data in Orchard

- by Bertrand Le Roy

A CMS like Orchard is, by definition, designed to store content. What differentiates content from other kinds of data is rather subtle. The way I would describe it is by saying that if you would put each instance of a kind of data on its own web page, if it would make sense to add comments to it, or tags, or ratings, then it is content and you can store it in Orchard using all the convenient composition options that it offers. Otherwise, it probably isn't and you can store it using somewhat simpler means that I will now describe. In one of the modules I wrote, Vandelay.ThemePicker, there is some configuration data for the module. That data is not content by the definition I gave above. Let's look at how this data is stored and queried. The configuration data in question is a set of records, each of which has a number of properties: public class SettingsRecord { public virtual int Id { get; set;} public virtual string RuleType { get; set; } public virtual string Name { get; set; } public virtual string Criterion { get; set; } public virtual string Theme { get; set; } public virtual int Priority { get; set; } public virtual string Zone { get; set; } public virtual string Position { get; set; } } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Each property has to be virtual for nHibernate to handle it (it creates derived classed that are instrumented in all kinds of ways). We also have an Id property. The way these records will be stored in the database is described from a migration: public int Create() { SchemaBuilder.CreateTable("SettingsRecord", table => table .Column<int>("Id", column => column.PrimaryKey().Identity()) .Column<string>("RuleType", column => column.NotNull().WithDefault("")) .Column<string>("Name", column => column.NotNull().WithDefault("")) .Column<string>("Criterion", column => column.NotNull().WithDefault("")) .Column<string>("Theme", column => column.NotNull().WithDefault("")) .Column<int>("Priority", column => column.NotNull().WithDefault(10)) .Column<string>("Zone", column => column.NotNull().WithDefault("")) .Column<string>("Position", column => column.NotNull().WithDefault("")) ); return 1; } When we enable the feature, the migration will run, which will create the table in the database. Once we've done that, all we have to do in order to use the data is inject an IRepository<SettingsRecord>, which is what I'm doing from the set of helpers I put under the SettingsService class: private readonly IRepository<SettingsRecord> _repository; private readonly ISignals _signals; private readonly ICacheManager _cacheManager; public SettingsService( IRepository<SettingsRecord> repository, ISignals signals, ICacheManager cacheManager) { _repository = repository; _signals = signals; _cacheManager = cacheManager; } The repository has a Table property, which implements IQueryable<SettingsRecord> (enabling all kind of Linq queries) as well as methods such as Delete and Create. Here's for example how I'm getting all the records in the table: _repository.Table.ToList() And here's how I'm deleting a record: _repository.Delete(_repository.Get(r => r.Id == id)); And here's how I'm creating one: _repository.Create(new SettingsRecord { Name = name, RuleType = ruleType, Criterion = criterion, Theme = theme, Priority = priority, Zone = zone, Position = position }); In summary, you create a record class, a migration, and you're in business and can just manipulate the data through the repository that the framework is exposing. You even get ambient transactions from the work context.

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Microsoft Sql Server 2008 R2 System Databases

For a majority of software developers little time is spent understanding the inner workings of the database management systems (DBMS) they use to store data for their applications. I personally place myself in this grouping. In my case, I have used various versions of Microsoft’s SQL Server (2000, 2005, and 2008 R2) and just recently learned how valuable they really are when I was preparing to deliver a lecture on "SQL Server 2008 R2, System Databases". Microsoft Sql Server 2008 R2 System DatabasesSo what are system databases in MS SQL Server, and why should I know them? Microsoft uses system databases to support the SQL Server DBMS, much like a developer uses config files or database tables to support an application. These system databases individually provide specific functionality that allows MS SQL Server to function. Name Database File Log File Master master.mdf mastlog.ldf Resource mssqlsystemresource.mdf mssqlsystemresource.ldf Model model.mdf modellog.ldf MSDB msdbdata.mdf msdblog.ldf Distribution distmdl.mdf distmdl.ldf TempDB tempdb.mdf templog.ldf Master DatabaseIf you have used MS SQL Server then you should recognize the Master database especially if you used the SQL Server Management Studio (SSMS) to connect to a user created database. MS SQL Server requires the Master database in order for DBMS to start due to the information that it stores. Examples of data stored in the Master database User Logins Linked Servers Configuration information Information on User Databases Resource DatabaseHonestly, until recently I never knew this database even existed until I started to research SQL Server system databases. The reason for this is due largely to the fact that the resource database is hidden to users. In fact, the database files are stored within the Binn folder instead of the standard MS SQL Server database folder path. This database contains all system objects that can be accessed by all other databases. In short, this database contains all system views and store procedures that appear in all other user databases regarding system information. One of the many benefits to storing system views and store procedures in a single hidden database is the fact it improves upgrading a SQL Server database; not to mention that maintenance is decreased since only one code base has to be mainlined for all of the system views and procedures. Model DatabaseThe Model database as the name implies is the model for all new databases created by users. This allows for predefining default database objects for all new databases within a MS SQL Server instance. For example, if every database created by a user needs to have an “Audit” table when it is created then defining the “Audit” table in the model will guarantees that the table will be located in every new database create after the model is altered. MSDB DatabaseThe MSDBdatabase is used by SQL Server Agent, SQL Server Database Mail, SQL Server Service Broker, along with SQL Server. The SQL Server Agent uses this database to store job configurations and SQL job schedules along with SQL Alerts, and Operators. In addition, this database also stores all SQL job parameters along with each job’s execution history. Finally, this database is also used to store database backup and maintenance plans as well as details pertaining to SQL Log shipping if it is being used. Distribution DatabaseThe Distribution database is only used during replication and stores meta data and history information pertaining to the act of replication data. Furthermore, when transactional replication is used this database also stores information regarding each transaction. It is important to note that replication is not turned on by default in MS SQL Server and that the distribution database is hidden from SSMS. Tempdb DatabaseThe Tempdb as the name implies is used to store temporary data and data objects. Examples of this include temp tables and temp store procedures. It is important to note that when using this database all data and data objects are cleared from this database when SQL Server restarts. This database is also used by SQL Server when it is performing some internal operations. Typically, SQL Server uses this database for the purpose of large sort and index operations. Finally, this database is used to store row versions if row versioning or snapsot isolation transactions are being used by SQL Server. Additionally, I would love to hear from others about their experiences using system databases, tables, and objects in a real world environments.

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Concurrency Utilities for Java EE Early Draft (JSR 236)

- by arungupta

Concurrency Utilities for Java EE is being worked as JSR 236 and has released an Early Draft. It provides concurrency capabilities to Java EE application components without compromising container integrity. Simple (common) and advanced concurrency patterns are easily supported without sacrificing usability. Using Java SE concurrency utilities such as java.util.concurrent API, java.lang.Thread and java.util.Timer in a Java EE application component such as EJB or Servlet are problematic since the container and server have no knowledge of these resources. JSR 236 enables concurrency largely by extending the Concurrency Utilities API developed under JSR-166. This also allows a consistency between Java SE and Java EE concurrency programming model. There are four main programming interfaces available: ManagedExecutorService ManagedScheduledExecutorService ContextService ManagedThreadFactory ManagedExecutorService is a managed version of java.util.concurrent.ExecutorService. The implementations of this interface are provided by the container and accessible using JNDI reference: <resource-env-ref> <resource-env-ref-name> concurrent/BatchExecutor </resource-env-ref-name> <resource-env-ref-type> javax.enterprise.concurrent.ManagedExecutorService </resource-env-ref-type><resource-env-ref> and available as: @Resource(name="concurrent/BatchExecutor")ManagedExecutorService executor; Its recommended to bind the JNDI references in the java:comp/env/concurrent subcontext. The asynchronous tasks that need to be executed need to implement java.lang.Runnable or java.util.concurrent.Callable interface as: public class MyTask implements Runnable { public void run() { // business logic goes here }} OR public class MyTask2 implements Callable<Date> { public Date call() { // business logic goes here }} The task is then submitted to the executor using one of the submit method that return a Future instance. The Future represents the result of the task and can also be used to check if the task is complete or wait for its completion. Future<String> future = executor.submit(new MyTask(), String.class);. . .String result = future.get(); Another example to submit tasks is: class MyTask implements Callback<Long> { . . . }class MyTask2 implements Callback<Date> { . . . }ArrayList<Callable> tasks = new ArrayList<();tasks.add(new MyTask());tasks.add(new MyTask2());List<Future<Object>> result = executor.invokeAll(tasks); The ManagedExecutorService may be configured for different properties such as: Hung Task Threshold: Time in milliseconds that a task can execute before it is considered hung Pool Info Core Size: Number of threads to keep alive Maximum Size: Maximum number of threads allowed in the pool Keep Alive: Time to allow threads to remain idle when # of threads > Core Size Work Queue Capacity: # of tasks that can be stored in inbound buffer Thread Use: Application intend to run short vs long-running tasks, accordingly pooled or daemon threads are picked ManagedScheduledExecutorService adds delay and periodic task running capabilities to ManagedExecutorService. The implementations of this interface are provided by the container and accessible using JNDI reference: <resource-env-ref> <resource-env-ref-name> concurrent/BatchExecutor </resource-env-ref-name> <resource-env-ref-type> javax.enterprise.concurrent.ManagedExecutorService </resource-env-ref-type><resource-env-ref> and available as: @Resource(name="concurrent/timedExecutor")ManagedExecutorService executor; And then the tasks are submitted using submit, invokeXXX or scheduleXXX methods. ScheduledFuture<?> future = executor.schedule(new MyTask(), 5, TimeUnit.SECONDS); This will create and execute a one-shot action that becomes enabled after 5 seconds of delay. More control is possible using one of the newly added methods: MyTaskListener implements ManagedTaskListener { public void taskStarting(...) { . . . } public void taskSubmitted(...) { . . . } public void taskDone(...) { . . . } public void taskAborted(...) { . . . } }ScheduledFuture<?> future = executor.schedule(new MyTask(), 5, TimeUnit.SECONDS, new MyTaskListener()); Here, ManagedTaskListener is used to monitor the state of a task's future. ManagedThreadFactory provides a method for creating threads for execution in a managed environment. A simple usage is: @Resource(name="concurrent/myThreadFactory")ManagedThreadFactory factory;. . .Thread thread = factory.newThread(new Runnable() { . . . }); concurrent/myThreadFactory is a JNDI resource. There is lot of interesting content in the Early Draft, download it, and read yourself. The implementation will be made available soon and also be integrated in GlassFish 4 as well. Some references for further exploring ... Javadoc Early Draft Specification concurrency-ee-spec.java.net [email protected]

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With Its MySQL Database-as-a-Service CERN Empowers Scientists

- by Bertrand Matthelié

The European Organization for Nuclear Research (CERN) is one of the world’s largest and most respected centers for scientific research. Founded in 1954 and located near Geneva on the Franco-Swiss border, CERN was one of Europe’s first joint ventures. Today, it has 20 member states. The organization uses the world’s largest and most complex scientific instruments to study fundamental particles and the origin of the universe. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} Challenges Better support the scientists associated with a CERN research program who selected MySQL as their database. Empower users, enabling them to be as self-reliant as possible. Minimize complexity and costs for the CERN IT department to support the growing number of MySQL deployments. Solution Delivered a MySQL Database-as-a-Service offering to the CERN employees and the scientists associated with the organization. Allowed researchers selecting MySQL for their project to get access to a database instance hosted by the CERN IT department, either from the start or once their application has become critical. Implemented the service using Oracle’s server virtualization software, Oracle VM, for increased flexibility and reduced costs. Empowered users with a self-service approach, providing them with tools to manage MySQL themselves while handling backups and other basic database administration tasks for them. Enabled scientists to rely on MySQL with increased reliability, security and manageability while reducing complexity and minimizing costs. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin;} "The Cloud model has allowed us to deliver a self-service platform to our MySQL users, empowering them while minimizing costs for CERN." Tony Cass, Database Services Group Leader, IT department, CERN.

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Solaris 11.1 changes building of code past the point of __NORETURN

- by alanc

While Solaris 11.1 was under development, we started seeing some errors in the builds of the upstream X.Org git master sources, such as: "Display.c", line 65: Function has no return statement : x_io_error_handler "hostx.c", line 341: Function has no return statement : x_io_error_handler from functions that were defined to match a specific callback definition that declared them as returning an int if they did return, but these were calling exit() instead of returning so hadn't listed a return value. These had been generating warnings for years which we'd been ignoring, but X.Org has made enough progress in cleaning up code for compiler warnings and static analysis issues lately, that the community turned up the default error levels, including the gcc flag -Werror=return-type and the equivalent Solaris Studio cc flags -v -errwarn=E_FUNC_HAS_NO_RETURN_STMT, so now these became errors that stopped the build. Yet on Solaris, gcc built this code fine, while Studio errored out. Investigation showed this was due to the Solaris headers, which during Solaris 10 development added a number of annotations to the headers when gcc was being used for the amd64 kernel bringup before the Studio amd64 port was ready. Since Studio did not support the inline form of these annotations at the time, but instead used #pragma for them, the definitions were only present for gcc. To resolve this, I fixed both sides of the problem, so that it would work for building new X.Org sources on older Solaris releases or with older Studio compilers, as well as fixing the general problem before it broke more software building on Solaris. To the X.Org sources, I added the traditional Studio #pragma does_not_return to recognize that functions like exit() don't ever return, in patches such as this Xserver patch. Adding a dummy return statement was ruled out as that introduced unreachable code errors from compilers and analyzers that correctly realized you couldn't reach that code after a return statement. And on the Solaris 11.1 side, I updated the annotation definitions in <sys/ccompile.h> to enable for Studio 12.0 and later compilers the annotations already existing in a number of system headers for functions like exit() and abort(). If you look in that file you'll see the annotations we currently use, though the forms there haven't gone through review to become a Committed interface, so may change in the future. Actually getting this integrated into Solaris though took a bit more work than just editing one header file. Our ELF binary build comparison tool, wsdiff, actually showed a large number of differences in the resulting binaries due to the compiler using this information for branch prediction, code path analysis, and other possible optimizations, so after comparing enough of the disassembly output to be comfortable with the changes, we also made sure to get this in early enough in the release cycle so that it would get plenty of test exposure before the release. It also required updating quite a bit of code to avoid introducing new lint or compiler warnings or errors, and people building applications on top of Solaris 11.1 and later may need to make similar changes if they want to keep their build logs similarly clean. Previously, if you had a function that was declared with a non-void return type, lint and cc would warn if you didn't return a value, even if you called a function like exit() or panic() that ended execution. For instance: #include <stdlib.h> int callback(int status) { if (status == 0) return status; exit(status); } would previously require a never executed return 0; after the exit() to avoid lint warning "function falls off bottom without returning value". Now the compiler & lint will both issue "statement not reached" warnings for a return 0; after the final exit(), allowing (or in some cases, requiring) it to be removed. However, if there is no return statement anywhere in the function, lint will warn that you've declared a function returning a value that never does so, suggesting you can declare it as void. Unfortunately, if your function signature is required to match a certain form, such as in a callback, you not be able to do so, and will need to add a /* LINTED */ to the end of the function. If you need your code to build on both a newer and an older release, then you will either need to #ifdef these unreachable statements, or, to keep your sources common across releases, add to your sources the corresponding #pragma recognized by both current and older compiler versions, such as: #pragma does_not_return(exit) #pragma does_not_return(panic) Hopefully this little extra work is paid for by the compilers & code analyzers being able to better understand your code paths, giving you better optimizations and more accurate errors & warning messages.

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Is it feasible and useful to auto-generate some code of unit tests?

- by skiwi

Earlier today I have come up with an idea, based upon a particular real use case, which I would want to have checked for feasability and usefulness. This question will feature a fair chunk of Java code, but can be applied to all languages running inside a VM, and maybe even outside. While there is real code, it uses nothing language-specific, so please read it mostly as pseudo code. The idea Make unit testing less cumbersome by adding in some ways to autogenerate code based on human interaction with the codebase. I understand this goes against the principle of TDD, but I don't think anyone ever proved that doing TDD is better over first creating code and then immediatly therafter the tests. This may even be adapted to be fit into TDD, but that is not my current goal. To show how it is intended to be used, I'll copy one of my classes here, for which I need to make unit tests. public class PutMonsterOnFieldAction implements PlayerAction { private final int handCardIndex; private final int fieldMonsterIndex; public PutMonsterOnFieldAction(final int handCardIndex, final int fieldMonsterIndex) { this.handCardIndex = Arguments.requirePositiveOrZero(handCardIndex, "handCardIndex"); this.fieldMonsterIndex = Arguments.requirePositiveOrZero(fieldMonsterIndex, "fieldCardIndex"); } @Override public boolean isActionAllowed(final Player player) { Objects.requireNonNull(player, "player"); Hand hand = player.getHand(); Field field = player.getField(); if (handCardIndex >= hand.getCapacity()) { return false; } if (fieldMonsterIndex >= field.getMonsterCapacity()) { return false; } if (field.hasMonster(fieldMonsterIndex)) { return false; } if (!(hand.get(handCardIndex) instanceof MonsterCard)) { return false; } return true; } @Override public void performAction(final Player player) { Objects.requireNonNull(player); if (!isActionAllowed(player)) { throw new PlayerActionNotAllowedException(); } Hand hand = player.getHand(); Field field = player.getField(); field.setMonster(fieldMonsterIndex, (MonsterCard)hand.play(handCardIndex)); } } We can observe the need for the following tests: Constructor test with valid input Constructor test with invalid inputs isActionAllowed test with valid input isActionAllowed test with invalid inputs performAction test with valid input performAction test with invalid inputs My idea mainly focuses on the isActionAllowed test with invalid inputs. Writing these tests is not fun, you need to ensure a number of conditions and you check whether it really returns false, this can be extended to performAction, where an exception needs to be thrown in that case. The goal of my idea is to generate those tests, by indicating (through GUI of IDE hopefully) that you want to generate tests based on a specific branch. The implementation by example User clicks on "Generate code for branch if (handCardIndex >= hand.getCapacity())". Now the tool needs to find a case where that holds. (I haven't added the relevant code as that may clutter the post ultimately) To invalidate the branch, the tool needs to find a handCardIndex and hand.getCapacity() such that the condition >= holds. It needs to construct a Player with a Hand that has a capacity of at least 1. It notices that the capacity private int of Hand needs to be at least 1. It searches for ways to set it to 1. Fortunately it finds a constructor that takes the capacity as an argument. It uses 1 for this. Some more work needs to be done to succesfully construct a Player instance, involving the creation of objects that have constraints that can be seen by inspecting the source code. It has found the hand with the least capacity possible and is able to construct it. Now to invalidate the test it will need to set handCardIndex = 1. It constructs the test and asserts it to be false (the returned value of the branch) What does the tool need to work? In order to function properly, it will need the ability to scan through all source code (including JDK code) to figure out all constraints. Optionally this could be done through the javadoc, but that is not always used to indicate all constraints. It could also do some trial and error, but it pretty much stops if you cannot attach source code to compiled classes. Then it needs some basic knowledge of what the primitive types are, including arrays. And it needs to be able to construct some form of "modification trees". The tool knows that it needs to change a certain variable to a different value in order to get the correct testcase. Hence it will need to list all possible ways to change it, without using reflection obviously. What this tool will not replace is the need to create tailored unit tests that tests all kinds of conditions when a certain method actually works. It is purely to be used to test methods when they invalidate constraints. My questions: Is creating such a tool feasible? Would it ever work, or are there some obvious problems? Would such a tool be useful? Is it even useful to automatically generate these testcases at all? Could it be extended to do even more useful things? Does, by chance, such a project already exist and would I be reinventing the wheel? If not proven useful, but still possible to make such thing, I will still consider it for fun. If it's considered useful, then I might make an open source project for it depending on the time. For people searching more background information about the used Player and Hand classes in my example, please refer to this repository. At the time of writing the PutMonsterOnFieldAction has not been uploaded to the repo yet, but this will be done once I'm done with the unit tests.

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Data Source Security Part 2

- by Steve Felts

In Part 1, I introduced the default security behavior and listed the various options available to change that behavior. One of the key topics to understand is the difference between directly using database user and password values versus mapping from WLS user and password to the associated database values. The direct use of database credentials is relatively new to WLS, based on customer feedback. Some of the trade-offs are covered in this article. Credential Mapping vs. Database Credentials Each WLS data source has a credential map that is a mechanism used to map a key, in this case a WLS user, to security credentials (user and password). By default, when a user and password are specified when getting a connection, they are treated as credentials for a WLS user, validated, and are converted to a database user and password using a credential map associated with the data source. If a matching entry is not found in the credential map for the data source, then the user and password associated with the data source definition are used. Because of this defaulting mechanism, you should be careful what permissions are granted to the default user. Alternatively, you can define an invalid default user to ensure that no one can accidentally get through (in this case, you would need to set the initial capacity for the pool to zero so that the pool is populated only by valid users). To create an entry in the credential map: 1) First create a WLS user. In the administration console, go to Security realms, select your realm (e.g., myrealm), select Users, and select New. 2) Second, create the mapping. In the administration console, go to Services, select Data sources, select your data source name, select Security, select Credentials, and select New. See http://docs.oracle.com/cd/E24329_01/apirefs.1211/e24401/taskhelp/jdbc/jdbc_datasources/ConfigureCredentialMappingForADataSource.html for more information. The advantages of using the credential mapping are that: 1) You don’t hard-code the database user/password into a program or need to prompt for it in addition to the WLS user/password and 2) It provides a layer of abstraction between WLS security and database settings such that many WLS identities can be mapped to a smaller set of DB identities, thereby only requiring middle-tier configuration updates when WLS users are added/removed. You can cut down the number of users that have access to a data source to reduce the user maintenance overhead. For example, suppose that a servlet has the one pre-defined, special WLS user/password for data source access, hard-wired in its code in a getConnection(user, password) call. Every WebLogic user can reap the specific DBMS access coded into the servlet, but none has to have general access to the data source. For instance, there may be a ‘Sales’ DBMS which needs to be protected from unauthorized eyes, but it contains some day-to-day data that everyone needs. The Sales data source is configured with restricted access and a servlet is built that hard-wires the specific data source access credentials in its connection request. It uses that connection to deliver only the generally needed day-to-day information to any caller. The servlet cannot reveal any other data, and no WebLogic user can get any other access to the data source. This is the approach that many large applications take and is the reasoning behind the default mapping behavior in WLS. The disadvantages of using the credential map are that: 1) It is difficult to manage (create, update, delete) with a large number of users; it is possible to use WLST scripts or a custom JMX client utility to manage credential map entries. 2) You can’t share a credential map between data sources so they must be duplicated. Some applications prefer not to use the credential map. Instead, the credentials passed to getConnection(user, password) should be treated as database credentials and used to authenticate with the database for the connection, avoiding going through the credential map. This is enabled by setting the “use-database-credentials” to true. See http://docs.oracle.com/cd/E24329_01/apirefs.1211/e24401/taskhelp/jdbc/jdbc_datasources/ConfigureOracleParameters.html "Configure Oracle parameters" in Oracle WebLogic Server Administration Console Help. Use Database Credentials is not currently supported for Multi Data Source configurations. When enabled, it turns off credential mapping on Generic and Active GridLink data sources for the following attributes: 1. identity-based-connection-pooling-enabled (this interaction is available by patch in 10.3.6.0). 2. oracle-proxy-session (this interaction is first available in 10.3.6.0). 3. set client identifier (this interaction is available by patch in 10.3.6.0). Note that in the data source schema, the set client identifier feature is poorly named “credential-mapping-enabled”. The documentation and the console refer to it as Set Client Identifier. To review the behavior of credential mapping and using database credentials: - If using the credential map, there needs to be a mapping for each WLS user to database user for those users that will have access to the database; otherwise the default user for the data source will be used. If you always specify a user/password when getting a connection, you only need credential map entries for those specific users. - If using database credentials without specifying a user/password, the default user and password in the data source descriptor are always used. If you specify a user/password when getting a connection, that user will be used for the credentials. WLS users are not involved at all in the data source connection process.

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R12.0 Cash Management Consolidated Patch Collection (CPC) And R12.1 Cash Management Recommended Patch Collection (RPC)

- by user793553

If you have Oracle E-Business Suite's Cash Management (CE) application installed, you'll want to be sure to install the latest CPC (Consolidated Patch Collection) if you are using a R12.0 version of the apps, or the latest RPC (Recommended Patch Collection) for the R12.1 version of the apps. These collections give you all the fixes currently available for known issues in the specified versions of the application, including all of the latest Root Cause Analysis Fixes (RCAs)! What is an "RPC" (for R12.1 users)? Since the release of 12.1, a number of recommended patches for Oracle Cash Management have been made available as standalone patches to help address important business process issues. Adoption of these patches was highly recommended at the time, but not always implemented, so to further facilitate adoption of these patches, Oracle consolidated them into product-specific Recommended Patch Collections (RPCs) - a collection of recommended patches. They were created by Oracle Development with the following goals in mind: Stability: To address data integrity issues that have been identified by Oracle Development and Oracle Software Support as having the potential to interfere with the normal completion of important business processes (such as, period close, etc.). Root Cause Fixes (RCAs): To make available root cause fixes for known data integrity issues. Compact: To keep the file footprint as small as possible to help facilitate the install process and minimize testing. Granular: To compile the collection of patches based on functional areas, allowing a customer to apply multiple RPCs at once, or in phases (based on individual needs and goals). Where to start ALL R12 Cash Management users (R12.0 and R12.1 users) should start with the following Note on My Oracle Support (MOS): Doc ID 1367845.1: R12: Cash Management Recommended Patch Collections It's a great place for important implementation information about both sets of critical patch collections! For R12.1x users R12.1 users should also take a look at the documents below for even more information about the RPC for the R12.1.x versions of the Cash Management application, and other related available RPCs: Note Number Title 1489997.1 Master Troubleshooting Guide for CE: Reconciliation & Clearing [VIDEO] 954704.1 EBS: R12.1 Oracle Financials Recommended Patch Collections (RPCs) 1316506.1 R12: Oracle CE: Upgrading from R11i to R12.1: Latest Recommended Patches Patch Wizard Utility While a patch may contain several hundred files, the impact on your system may actually be minimal. Patches contain hard prerequisites that are intended to make a patch work on a very low code baseline. The Patch Wizard Utility will give you a detailed analysis of the patch’s impact on your instance BEFORE it’s applied, so you’ll know exactly what to expect from the application. Please refer to Doc ID 976188.1 for more information on this important utility

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Using Subjects to Deploy Queries Dynamically

- by Roman Schindlauer

In the previous blog posting, we showed how to construct and deploy query fragments to a StreamInsight server, and how to re-use them later. In today’s posting we’ll integrate this pattern into a method of dynamically composing a new query with an existing one. The construct that enables this scenario in StreamInsight V2.1 is a Subject. A Subject lets me create a junction element in an existing query that I can tap into while the query is running. To set this up as an end-to-end example, let’s first define a stream simulator as our data source: var generator = myApp.DefineObservable( (TimeSpan t) => Observable.Interval(t).Select(_ => new SourcePayload())); This ‘generator’ produces a new instance of SourcePayload with a period of t (system time) as an IObservable. SourcePayload happens to have a property of type double as its payload data. Let’s also define a sink for our example—an IObserver of double values that writes to the console: var console = myApp.DefineObserver( (string label) => Observer.Create<double>(e => Console.WriteLine("{0}: {1}", label, e))) .Deploy("ConsoleSink"); The observer takes a string as parameter which is used as a label on the console, so that we can distinguish the output of different sink instances. Note that we also deploy this observer, so that we can retrieve it later from the server from a different process. Remember how we defined the aggregation as an IQStreamable function in the previous article? We will use that as well: var avg = myApp .DefineStreamable((IQStreamable<SourcePayload> s, TimeSpan w) => from win in s.TumblingWindow(w) select win.Avg(e => e.Value)) .Deploy("AverageQuery"); Then we define the Subject, which acts as an observable sequence as well as an observer. Thus, we can feed a single source into the Subject and have multiple consumers—that can come and go at runtime—on the other side: var subject = myApp.CreateSubject("Subject", () => new Subject<SourcePayload>()); Subject are always deployed automatically. Their name is used to retrieve them from a (potentially) different process (see below). Note that the Subject as we defined it here doesn’t know anything about temporal streams. It is merely a sequence of SourcePayloads, without any notion of StreamInsight point events or CTIs. So in order to compose a temporal query on top of the Subject, we need to 'promote' the sequence of SourcePayloads into an IQStreamable of point events, including CTIs: var stream = subject.ToPointStreamable( e => PointEvent.CreateInsert<SourcePayload>(e.Timestamp, e), AdvanceTimeSettings.StrictlyIncreasingStartTime); In a later posting we will show how to use Subjects that have more awareness of time and can be used as a junction between QStreamables instead of IQbservables. Having turned the Subject into a temporal stream, we can now define the aggregate on this stream. We will use the IQStreamable entity avg that we defined above: var longAverages = avg(stream, TimeSpan.FromSeconds(5)); In order to run the query, we need to bind it to a sink, and bind the subject to the source: var standardQuery = longAverages .Bind(console("5sec average")) .With(generator(TimeSpan.FromMilliseconds(300)).Bind(subject)); Lastly, we start the process: standardQuery.Run("StandardProcess"); Now we have a simple query running end-to-end, producing results. What follows next is the crucial part of tapping into the Subject and adding another query that runs in parallel, using the same query definition (the “AverageQuery”) but with a different window length. We are assuming that we connected to the same StreamInsight server from a different process or even client, and thus have to retrieve the previously deployed entities through their names: // simulate the addition of a 'fast' query from a separate server connection, // by retrieving the aggregation query fragment // (instead of simply using the 'avg' object) var averageQuery = myApp .GetStreamable<IQStreamable<SourcePayload>, TimeSpan, double>("AverageQuery"); // retrieve the input sequence as a subject var inputSequence = myApp .GetSubject<SourcePayload, SourcePayload>("Subject"); // retrieve the registered sink var sink = myApp.GetObserver<string, double>("ConsoleSink"); // turn the sequence into a temporal stream var stream2 = inputSequence.ToPointStreamable( e => PointEvent.CreateInsert<SourcePayload>(e.Timestamp, e), AdvanceTimeSettings.StrictlyIncreasingStartTime); // apply the query, now with a different window length var shortAverages = averageQuery(stream2, TimeSpan.FromSeconds(1)); // bind new sink to query and run it var fastQuery = shortAverages .Bind(sink("1sec average")) .Run("FastProcess"); The attached solution demonstrates the sample end-to-end. Regards, The StreamInsight Team

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Adaptive Connections For ADFBC

- by Duncan Mills

Some time ago I wrote an article on Adaptive Bindings showing how the pageDef for a an ADF UI does not have to be wedded to a fixed data control or collection / View Object. This article has proved pretty popular, so as a follow up I wanted to cover another "Adaptive" feature of your ADF applications, the ability to make multiple different connections from an Application Module, at runtime. Now, I'm sure you'll be aware that if you define your application to use a data-source rather than a hard-coded JDBC connection string, then you have the ability to change the target of that data-source after deployment to point to a different database. So that's great, but the reality of that is that this single connection is effectively fixed within the application right? Well no, this it turns out is a common misconception. To be clear, yes a single instance of an ADF Application Module is associated with a single connection but there is nothing to stop you from creating multiple instances of the same Application Module within the application, all pointing at different connections. If fact this has been possible for a long time using a custom extension point with code that which extends oracle.jbo.http.HttpSessionCookieFactory. This approach, however, involves writing code and no-one likes to write any more code than they need to, so, is there an easier way? Yes indeed. It is in fact a little publicized feature that's available in all versions of 11g, the ELEnvInfoProvider. What Does it Do? The ELEnvInfoProvider is a pre-existing class (the full path is oracle.jbo.client.ELEnvInfoProvider) which you can plug into your ApplicationModule configuration using the jbo.envinfoprovider property. Visuallty you can set this in the editor, or you can also set it directly in the bc4j.xcfg (see below for an example) . Once you have plugged in this envinfoprovider, here's the fun bit, rather than defining the hard-coded name of a datasource instead you can plug in a EL expression for the connection to use. So what's the benefit of that? Well it allows you to defer the selection of a connection until the point in time that you instantiate the AM. To define the expression itself you'll need to do a couple of things: First of all you'll need a managed bean of some sort – e.g. a sessionScoped bean defined in your ViewController project. This will need a getter method that returns the name of the connection. Now this connection itself needs to be defined in your Application Server, and can be managed through Enterprise Manager, WLST or through MBeans. (You may need to read the documentation [http://docs.oracle.com/cd/E28280_01/web.1111/b31974/deployment_topics.htm#CHDJGBDD] here on how to configure connections at runtime if you're not familiar with this) The EL expression (e.g. ${connectionManager.connection} is then defined in the configuration by editing the bc4j.xcfg file (there is a hyperlink directly to this file on the configuration editing screen in the Application Module editor). You simply replace the hardcoded JDBCName value with the expression. So your cfg file would end up looking something like this (notice the reference to the ELEnvInfoProvider that I talked about earlier) <BC4JConfig version="11.1" xmlns="http://xmlns.oracle.com/bc4j/configuration"> <AppModuleConfigBag ApplicationName="oracle.demo.model.TargetAppModule"> <AppModuleConfig DeployPlatform="LOCAL" JDBCName="${connectionManager.connection}" jbo.project="oracle.demo.model.Model" name="TargetAppModuleLocal" ApplicationName="oracle.demo.model.TargetAppModule"> <AM-Pooling jbo.doconnectionpooling="true"/> <Database jbo.locking.mode="optimistic"> <Security AppModuleJndiName="oracle.demo.model.TargetAppModule"/> <Custom jbo.envinfoprovider="oracle.jbo.client.ELEnvInfoProvider"/> </AppModuleConfig> </AppModuleConfigBag> </BC4JConfig> Still Don't Quite Get It? So far you might be thinking, well that's fine but what difference does it make if the connection is resolved "just in time" rather than up front and changed as required through Enterprise Manager? Well a trivial example would be where you have a single application deployed to your application server, but for different users you want to connect to different databases. Because, the evaluation of the connection is deferred until you first reference the AM you have a decision point that can take the user identity into account. However, think about it for a second. Under what circumstances does a new AM get instantiated? Well at the first reference of the AM within the application yes, but also whenever a Task Flow is entered - if the data control scope for the Task Flow is ISOLATED. So the reality is, that on a single screen you can embed multiple Task Flows, all of which are pointing at different database connections concurrently. Hopefully you'll find this feature useful, let me know...

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Tweaking Hudson memory usage

- by rovarghe

Hudson 3.1 has some performance optimizations that greatly reduces its memory footprint. Prior to this Hudson used to always hold the entire data model (all jobs and all builds) in memory which affected scalability. Some installations configured heap sizes in excess of 1GB to counteract this. Hudson 3.1.x maintains an MRU cache and only loads jobs and builds as they are required. Because of the inability to change existing APIs and be backward compatible with plugins, there were limits to how far we could go with this approach. Memory optimizations almost always come with a related cost, in this case its additional I/O that has to be performed to load data on request. On a small site that has frequent traffic, this is usually not noticeable since the MRU cache will usually hold on to all the data. A large site with infrequent traffic might experience some delays when the first request hits the server after a long gap. If you have a large heap and are able to allocate more memory, the cache settings can be adjusted to take advantage of this and even go back to pre-3.1 behavior. All the cache settings can be passed as options to the JVM container (Tomcat or the default Jetty container) using the -D option. There are two caches, independant of each other, one for Jobs and the other for Builds. For the jobs cache: hudson.jobs.cache.evict_in_seconds ( default=60 ) Seconds from last access (could be because of a servlet request or a background cron thread) a job should be purged from the cache. Set this to 0 to never purge based on time. hudson.jobs.cache.initial_capacity ( default=1024 ) Initial number of jobs the cache can accomodate. Setting this to the number of jobs you typically display on your Hudson landing page or home page will speed up consecutive access to that page. If the default is too large you may consider downsizing and using that memory for the Builds cache instead. hudson.jobs.cache.max_entries ( default=1024) Maximum number of jobs in the cache. The default is large enough for most installations, but if you find I/O activity when always accessing the hudson home page you might consider increasing this, but first verify if the I/O is caused by frequent eviction (see above), rather than by the cache not being large enough. For the builds cache: The builds cache is used to store Build objects as they are read from storage. Typically this happens when a user drills down into the details of a particular Job from the hudson hom epage. The cache is shared among builds for different jobs since in most installations all jobs are not accessed with the same frequency, so a per-job builds cache would be a waste of memory. hudson.job.builds.cache.evict_in_seconds ( default=60 ) Same as the equivalent Job cache, applied to Build. hudson.job.builds.cache.initial_capacity" ( default=512 ) Same as equivalent Job cache setting. Note the smaller initial size. If your site stores a large number of builds and has frequent access to more builds you might consider bumping this up. hudson.job.builds.cache.max_entries ( default=10240 ) The default max is large enough for most installations, the builds cache has bigger sized objects, so be careful about increasing the upper limit on this. See section on monitoring below. Sample usage: java -jar hudson-war-3.1.2-SNAPSHOT.war -Dhudson.jobs.cache.evict_in_seconds=300 \ -Dhudson.job.builds.cache.evict_in_seconds=300 Monitoring cache usage The 'jmap' tool that comes with the JDK can be used to monitor cache performance in an indirect way by looking at the number of Job and Build objects in each cache. Find the PID of the hudson instance and run $ jmap -histo:live <pid | grep 'hudson.model.*Lazy.*Key$' Here's a sample output: num #instances #bytes class name 523: 28 896 hudson.model.RunMap$LazyRunValue$Key 1200: 3 96 hudson.model.LazyTopLevelItem$Key These are the keys to the Jobs (LazyTopLevelItem$Key) and Builds (RunMap$LazyRunValue$Key) in the caches, so counting the number of keys is a good indicator of the number of items in the cache at any given moment. The size in bytes can be ignored, they are just the size of the keys, not the actual sizes of the objects they hold. Those sizes can only be obtained with a profiler. With the output above we can conclude that there are 3 jobs and 28 builds in memory. The 28 builds can all be from 1 job or all 3 jobs. Over time on an idle system, these should get evicted and memory cache should be empty. In practice, because of background cron threads and triggers, jobs rarely fall down to zero. Access of a job or a build by a cron thread resets the eviction timer.

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Why is my animation getting aborted?

- by Homer_Simpson

I have a class named Animation which handles my animations. The animation class can be called from multiple other classes. For example, the class Player.cs can call the animation class like this: Animation Playeranimation; Playeranimation = new Animation(TimeSpan.FromSeconds(2.5f), 80, 40, Animation.Sequences.forwards, 0, 5, false, true); //updating the animation public void Update(GameTime gametime) { Playeranimation.Update(gametime); } //drawing the animation public void Draw(SpriteBatch batch) { playeranimation.Draw(batch, PlayerAnimationSpritesheet, PosX, PosY, 0, SpriteEffects.None); } The class Lion.cs can call the animation class with the same code, only the animation parameters are changing because it's another animation that should be played: Animation Lionanimation; Lionanimation = new Animation(TimeSpan.FromSeconds(2.5f), 100, 60, Animation.Sequences.forwards, 0, 8, false, true); Other classes can call the animation class with the same code like the Player class. But sometimes I have some trouble with the animations. If an animation is running and then shortly afterwards another class calls the animation class too, the second animation starts but the first animation is getting aborted. In this case, the first animation couldn't run until it's end because another class started a new instance of the animation class. Why is an animation sometimes getting aborted when another animation starts? How can I solve this problem? My animation class: public class Animation { private int _animIndex, framewidth, frameheight, start, end; private TimeSpan PassedTime; private List<Rectangle> SourceRects = new List<Rectangle>(); private TimeSpan Duration; private Sequences Sequence; public bool Remove; private bool DeleteAfterOneIteration; public enum Sequences { forwards, backwards, forwards_backwards, backwards_forwards } private void forwards() { for (int i = start; i < end; i++) SourceRects.Add(new Rectangle(i * framewidth, 0, framewidth, frameheight)); } private void backwards() { for (int i = start; i < end; i++) SourceRects.Add(new Rectangle((end - 1 - i) * framewidth, 0, framewidth, frameheight)); } private void forwards_backwards() { for (int i = start; i < end - 1; i++) SourceRects.Add(new Rectangle(i * framewidth, 0, framewidth, frameheight)); for (int i = start; i < end; i++) SourceRects.Add(new Rectangle((end - 1 - i) * framewidth, 0, framewidth, frameheight)); } private void backwards_forwards() { for (int i = start; i < end - 1; i++) SourceRects.Add(new Rectangle((end - 1 - i) * framewidth, 0, framewidth, frameheight)); for (int i = start; i < end; i++) SourceRects.Add(new Rectangle(i * framewidth, 0, framewidth, frameheight)); } public Animation(TimeSpan duration, int frame_width, int frame_height, Sequences sequences, int start_interval, int end_interval, bool remove, bool deleteafteroneiteration) { Remove = remove; DeleteAfterOneIteration = deleteafteroneiteration; framewidth = frame_width; frameheight = frame_height; start = start_interval; end = end_interval; switch (sequences) { case Sequences.forwards: { forwards(); break; } case Sequences.backwards: { backwards(); break; } case Sequences.forwards_backwards: { forwards_backwards(); break; } case Sequences.backwards_forwards: { backwards_forwards(); break; } } Duration = duration; Sequence = sequences; } public void Update(GameTime dt) { PassedTime += dt.ElapsedGameTime; if (PassedTime > Duration) { PassedTime -= Duration; } var percent = PassedTime.TotalSeconds / Duration.TotalSeconds; if (DeleteAfterOneIteration == true) { if (_animIndex >= SourceRects.Count) Remove = true; _animIndex = (int)Math.Round(percent * (SourceRects.Count)); } else { _animIndex = (int)Math.Round(percent * (SourceRects.Count - 1)); } } public void Draw(SpriteBatch batch, Texture2D Textures, float PositionX, float PositionY, float Rotation, SpriteEffects Flip) { if (DeleteAfterOneIteration == true) { if (_animIndex >= SourceRects.Count) return; } batch.Draw(Textures, new Rectangle((int)PositionX, (int)PositionY, framewidth, frameheight), SourceRects[_animIndex], Color.White, Rotation, new Vector2(framewidth / 2.0f, frameheight / 2.0f), Flip, 0f); } }

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Plagued by multithreaded bugs

- by koncurrency

On my new team that I manage, the majority of our code is platform, TCP socket, and http networking code. All C++. Most of it originated from other developers that have left the team. The current developers on the team are very smart, but mostly junior in terms of experience. Our biggest problem: multi-threaded concurrency bugs. Most of our class libraries are written to be asynchronous by use of some thread pool classes. Methods on the class libraries often enqueue long running taks onto the thread pool from one thread and then the callback methods of that class get invoked on a different thread. As a result, we have a lot of edge case bugs involving incorrect threading assumptions. This results in subtle bugs that go beyond just having critical sections and locks to guard against concurrency issues. What makes these problems even harder is that the attempts to fix are often incorrect. Some mistakes I've observed the team attempting (or within the legacy code itself) includes something like the following: Common mistake #1 - Fixing concurrency issue by just put a lock around the shared data, but forgetting about what happens when methods don't get called in an expected order. Here's a very simple example: void Foo::OnHttpRequestComplete(statuscode status) { m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } So now we have a bug in which Shutdown could get called while OnHttpNetworkRequestComplete is occuring on. A tester finds the bug, captures the crash dump, and assigns the bug to a developer. He in turn fixes the bug like this. void Foo::OnHttpRequestComplete(statuscode status) { AutoLock lock(m_cs); m_pBar->DoSomethingImportant(status); } void Foo::Shutdown() { AutoLock lock(m_cs); m_pBar->Cleanup(); delete m_pBar; m_pBar=nullptr; } The above fix looks good until you realize there's an even more subtle edge case. What happens if Shutdown gets called before OnHttpRequestComplete gets called back? The real world examples my team has are even more complex, and the edge cases are even harder to spot during the code review process. Common Mistake #2 - fixing deadlock issues by blindly exiting the lock, wait for the other thread to finish, then re-enter the lock - but without handling the case that the object just got updated by the other thread! Common Mistake #3 - Even though the objects are reference counted, the shutdown sequence "releases" it's pointer. But forgets to wait for the thread that is still running to release it's instance. As such, components are shutdown cleanly, then spurious or late callbacks are invoked on an object in an state not expecting any more calls. There are other edge cases, but the bottom line is this: Multithreaded programming is just plain hard, even for smart people. As I catch these mistakes, I spend time discussing the errors with each developer on developing a more appropriate fix. But I suspect they are often confused on how to solve each issue because of the enormous amount of legacy code that the "right" fix will involve touching. We're going to be shipping soon, and I'm sure the patches we're applying will hold for the upcoming release. Afterwards, we're going to have some time to improve the code base and refactor where needed. We won't have time to just re-write everything. And the majority of the code isn't all that bad. But I'm looking to refactor code such that threading issues can be avoided altogether. One approach I am considering is this. For each significant platform feature, have a dedicated single thread where all events and network callbacks get marshalled onto. Similar to COM apartment threading in Windows with use of a message loop. Long blocking operations could still get dispatched to a work pool thread, but the completion callback is invoked on on the component's thread. Components could possibly even share the same thread. Then all the class libraries running inside the thread can be written under the assumption of a single threaded world. Before I go down that path, I am also very interested if there are other standard techniques or design patterns for dealing with multithreaded issues. And I have to emphasize - something beyond a book that describes the basics of mutexes and semaphores. What do you think? I am also interested in any other approaches to take towards a refactoring process. Including any of the following: Literature or papers on design patterns around threads. Something beyond an introduction to mutexes and semaphores. We don't need massive parallelism either, just ways to design an object model so as to handle asynchronous events from other threads correctly. Ways to diagram the threading of various components, so that it will be easy to study and evolve solutions for. (That is, a UML equivalent for discussing threads across objects and classes) Educating your development team on the issues with multithreaded code. What would you do?

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