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• How to integrate Windows Server 2008 R2's NPS with Cisco switches?

  - by Massimo

  I need to evaluate in a lab environment the use of Windows Server 2008 R2's NPS for 802.1x authentication with Cisco Catalyst 3750 switches; the general idea is to only let clients connect to the company network if they can provide valid domain logon credentials, placing them in a restricted VLAN instead if they can't. NAP would also be a bonus, but it can be evaluated later; the main point now is only 802.1x authentication. Although I have very good knowledge of Windows and Active Directory (on the Microsoft side) and quite good knowledge of Catalyst switches (on the Cisco side), I'm totally new to 802.1x; I'd really like some general guidelines and help here, and some sort of implementation guide would also be very useful.

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• I want to install an MSI twice

  - by don.vince

  I have a peculiar wish to install an msi twice on a machine. The purpose of the double install is to first install under the pre-production folder, run the deployment in a safe environment prior to deploying in the production folder. We typically use separate machines to represent these different environments however in this case I need to use the same box. The two scenarios I get are as follows: I've installed pre-production, I'm happy, I want to install production, I run the msi, it asks whether I want to repair or remove the installation I've production installed, I want to install the new version of the msi, it tells me I already have a version of the product installed and I must first un-install the current version The first scenario isn't too bad as we can at that point sensibly un-install and re-install under the production folder, but the second scenario is a pain as we don't want to un-install the live production deployment. Is there a setting I can give to msiexec that will allow this? Is there a more suitable different approach I could use?

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• Is it possible to retrieve lost Windows XP profile information?

  - by Simon Shaw

  I'm running Windows XP Professional on a PC which is less than a year old. About 3 months ago I got an error on boot saying windows could not find my profile. At this point it created a temp one. On this occasion I copied the temp data back into my existing profile and carried on using it. After another month it died again and, once again set me up a temp user. Each time this happens I lose everything related to my profile (desktop, start menu, etc). I ran checks on the hard disk and these suggested nothing was wrong so this seems a software issue not a disk problem. On the advice of my computer manufacturer I am now considering reinstalling Windows but just wanted to check if there's any other ideas for things I might be able to try. Any suggestions for what could be causing the problem would also be gladly appreciated.

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• Recommended Method to Watch Amazon Prime using Ubuntu 14.04 LTS

  - by Kurt Sanger

  I realize that Hal is no longer in the Ubuntu Software Center for Ubuntu 14.04 and it is only available from a third party at this time. But I would like to know what Ubuntu's plans are for integrating DRM into Linux? Especially with Amazon's integration into the search tool, one would hope that they would make it easier for their Amazon Prime customers to watch Instant Videos. Is the repository for getting Hal for 13.10 safe for use? What will that break if I install it onto 14.04? Or do we need to find another OS that has DRM built into it? If Hal is okay to add to the OS using a third party repo, then why doesn't Ubuntu Software Center support it too? I imagine that Amazon's contract with the video copyright holders requires that they have some protection on electronically distributed media. I also imagine that getting Amazon to change is much harder than getting a bunch of software engineers to fix Ubuntu. Unless they don't want too. At which point Ubuntu isn't really a complete OS. Very disappointing. In general the ease of use of Ubuntu, the software center, and the large variety of applications was alluring. But breaking DRM wasn't a great idea. Can't wait to see what fails in our next update. Please tell us that there is a plan that is going to work in our future.

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• Testing domains on intranet/local network?

  - by meder

  This may sound like a very silly question, but how could I setup domains ( eg www.foo.com ) on my local network? I know that all a domain is, is just a name registered to a name server and that nameserver has a zone record, and in the zone record there are several records of which the A Record is the most important in dictating where the lookup goes to, which machine it should point to. I basically want to make it so that I can refer to my other computer/webserver as 'www.foo.com' and make my local sites accessible by that, mess with virtualhost records in Apache and zone records for the domain except locally so I can explore and fiddle around and learn instead of having to rely on the domains I own on a public registrar that I could only access through the internet. Once again I apologize if this is a silly question, or if I'm completely thinking backwards. Background information: My OS is Debian, I'm a novice at Linux. I've done very small edits in zone records on a Bind9 Server but that's the extent of my networking experience.

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• starting nginx via upstart

  - by Chiggsy

  Background: DISTRIB_ID=Ubuntu DISTRIB_RELEASE=10.04 DISTRIB_CODENAME=lucid DISTRIB_DESCRIPTION="Ubuntu 10.04 LTS" I've built nginx, and I'd like to use upstart to start it: nginx upstart script from the site: description "nginx http daemon" start on runlevel 2 stop on runlevel 0 stop on runlevel 1 stop on runlevel 6 console owner exec /usr/sbin/nginx -c /etc/nginx/nginx.conf -g "daemon off;" respawn I get "unknown job" when i try to use initctl to run it, which I just learned apparently means there is an error, ( what's wrong with "Error" to describe errors?) Can someone point me in the right direction ? I've read the documentation , as it is, and it seems kind of sparse for a SysV init replacement... but whatever just need to add this job to the list, run it, and get on with what's left of my life... Any tips? EDIT: initctl version init (upstart 0.6.5)

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• Java game object pool management

  - by Kenneth Bray

  Currently I am using arrays to handle all of my game objects in the game I am making, and I know how terrible this is for performance. My question is what is the best way to handle game objects and not hurt performance? Here is how I am creating an array and then looping through it to update the objects in the array: public static ArrayList<VboCube> game_objects = new ArrayList<VboCube>(); /* add objects to the game */ while (!Display.isCloseRequested() && !Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) { for (int i = 0; i < game_objects.size(); i++){ // draw the object game_objects.get(i).Draw(); game_objects.get(i).Update(); //world.updatePhysics(); } } I am not looking for someone to write me code for asset or object management, just point me into a better direction to get better performance. I appreciate the help you guys have provided me in the past, and I dont think I would be as far along with my project without the support on stack exchange!

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• To Bit or Not To Bit

  - by Johnm

  'Twas a long day of troubleshooting and firefighting and now, with most of the office vacant, you face a blank scripting window to create a new table in his database. Many questions circle your mind like dirty water gurgling down the bathtub drain: "How normalized should this table be?", "Should I use an identity column?", "NVarchar or Varchar?", "Should this column be NULLABLE?", "I wonder what apple blue cheese bacon cheesecake tastes like?" Well, there are times when the mind goes it's own direction. A Bit About Bit At some point during your table creation efforts you will encounter the decision of whether to use the bit data type for a column. The bit data type is an integer data type that recognizes only the values of 1, 0 and NULL as valid. This data type is often utilized to store yes/no or true/false values. An example of its use would be a column called [IsGasoline] which would be intended to contain the value of 1 if the row's subject (a car) had a gasoline engine and a 0 if the subject did not have a gasoline engine. The bit data type can even be found in some of the system tables of SQL Server. For example, the sysssispackages table in the msdb database which contains SQL Server Integration Services Package information for the packages stored in SQL Server. This table contains a column called [IsEncrypted]. A value of 1 indicates that the package has been encrypted while the value of 0 indicates that it is not. I have learned that the most effective way to disperse the crowd that surrounds the office coffee machine is to engage into SQL Server debates. The bit data type has been one of the most reoccurring, as well as the most enjoyable, of these topics. It contains a practical side and a philosophical side. Practical Consideration This data type certainly has its place and is a valuable option for database design; but it is often used in situations where the answer is really not a pure true/false response. In addition, true/false values are not very informative or scalable. Let's use the previously noted [IsGasoline] column for illustration. While on the surface it appears to be a rather simple question when evaluating a car: "Does the car have a gasoline engine?" If the person entering data is entering a row for a Jeep Liberty, the response would be a 1 since it has a gasoline engine. If the person is entering data is entering a row for a Chevrolet Volt, the response would be a 0 since it is an electric engine. What happens when a person is entering a row for the gasoline/electric hybrid Toyota Prius? Would one person's conclusion be consistent with another person's conclusion? The argument could be made that the current intent for the database is to be used only for pure gasoline and pure electric engines; but this is where the scalability issue comes into play. With the use of a bit data type a database modification and data conversion would be required if the business decided to take on hybrid engines. Whereas, alternatively, if the int data type were used as a foreign key to a reference table containing the engine type options, the change to include the hybrid option would only require an entry into the reference table. Philosophical Consideration Since the bit data type is often used for true/false or yes/no data (also called Boolean) it presents a philosophical conundrum of what to do about the allowance of the NULL value. The inclusion of NULL in a true/false or yes/no response simply violates the logical principle of bivalence which states that "every proposition is either true or false". If NULL is not true, then it must be false. The mathematical laws of Boolean logic support this concept by stating that the only valid values of this scenario are 1 and 0. There is another way to look at this conundrum: NULL is also considered to be the absence of a response. In other words, it is the equivalent to "undecided". Anyone who watches the news can tell you that polls always include an "undecided" option. This could be considered a valid option in the world of yes/no/dunno. Through out all of these considerations I have discovered one absolute certainty: When you have found a person, or group of persons, who are willing to entertain a philosophical debate of the bit data type, you have found some true friends.

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• Implementing Light Volume Front Faces

  - by cubrman

  I recently read an article about light indexed deferred rendering from here: http://code.google.com/p/lightindexed-deferredrender/ It explains its ideas in a clear way, but there was one point that I failed to understand. It in fact is one of the most interesting ones, as it explains how to implement transparency with this approach: Typically when rendering light volumes in deferred rendering, only surfaces that intersect the light volume are marked and lit. This is generally accomplished by a “shadow volume like” technique of rendering back faces – incrementing stencil where depth is greater than – then rendering front faces and only accepting when depth is less than and stencil is not zero. By only rendering front faces where depth is less than, all future lookups by fragments in the forward rendering pass will get all possible lights that could hit the fragment. Can anyone explain how exactly you need to render only front faces? Another question is why do you need the front faces at all? Why can't we simply render all the lights and store the ones that overlap at this pixel in a texture? Does this approach serves as a cut-off plane to discard lights blocked by opaque geometry?

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• How to fetch only the sprites in the player's range of motion for collision testing? (2D, axis aligned sprites)

  - by Twodordan

  I am working on a 2D sprite game for educational purposes. (In case you want to know, it uses WebGl and Javascript) I've implemented movement using the Euler method (and delta time) to keep things simple. Now I'm trying to tackle collisions. The way I wrote things, my game only has rectangular sprites (axis aligned, never rotated) of various/variable sizes. So I need to figure out what I hit and which side of the target sprite I hit (and I'm probably going to use these intersection tests). The old fashioned method seems to be to use tile based grids, to target only a few tiles at a time, but that sounds silly and impractical for my game. (Splitting the whole level into blocks, having each sprite's bounding box fit multiple blocks I might abide. But if the sprites change size and move around, you have to keep changing which tiles they belong to, every frame, it doesn't sound right.) In Flash you can test collision under one point, but it's not efficient to iterate through all the elements on stage each frame. (hence why people use the tile method). Bottom line is, I'm trying to figure out how to test only the elements within the player's range of motion. (I know how to get the range of motion, I have a good idea of how to write a collisionCheck(playerSprite, targetSprite) function. But how do I know which sprites are currently in the player's vicinity to fetch only them?) Please discuss. Cheers!

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• Deferred rendering with both Clockwise and CounterClockwise culling

  - by user1423893

  I have a deferred rendering system that works well with objects that appear solid and drawn using CounterClockwise culling. I have a problem with Clockwise culled objects that are supposed to represent hollow that display their inside faces only. The image below shows a CounterClockwise culled object (left) Clockwise culled object (right). The Clockwise culled object faces display what would be displayed on the CounterClockwise face. How can I get the lighting to light the inner faces for Clockwise culled objects and continue lighting the outer CounterClockwise faces as normal? My lighting method is below private void DeferredLighting(GameTime gameTime) { // Set the render target for the lights game.GraphicsDevice.SetRenderTarget(lightMap); // Clear the render target to (0, 0, 0, 0) game.GraphicsDevice.Clear(Color.Transparent); // Set the render states game.GraphicsDevice.BlendState = BlendState.Additive; game.GraphicsDevice.DepthStencilState = DepthStencilState.None; game.GraphicsDevice.RasterizerState = RasterizerState.CullCounterClockwise; // Set sampler state to Point as the Surface type requires it in XNA 4.0 game.GraphicsDevice.SamplerStates[0] = SamplerState.PointClamp; // Set the camera properties for all lights BaseLight.SetCameraProperties(game.ActiveCamera); // Draw the lights int numLights = lights.Count; for (int i = 0; i < numLights; ++i) { if (lights[i].Diffuse.W > 0f) { lights[i].Render(gameTime, ref normalMap, ref depthMap, ref sgrMap); } } // Resolve the render target game.GraphicsDevice.SetRenderTarget(null); } I have tried adjusting the render states but no combination works for both objects.

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• Making an interactive 2D map

  - by Chad

  So recently I have been working on a Legend of Zelda: A Link to the Past clone, and I am wondering how I could handle certain map interactions (like cutting grass, lifting rocks, etc). The way I am currently doing the tilemap is with 2 PNGs. The first is the "tilemap" where each pixel represents a 16x16 tile and the (red, green) values are the (x, y) coords for the tile in the second PNG (the "tileset"). I am then using the blue channel to store collision data. Each tile is split into 4 8x8 tiles and represented by a 2 bit value (0 = empty, 1 = Jumpdown point, 2 = unused right now, 3 = blocking). 4 of these 2 bit values make up the full blue channel (1 byte). So collisions work great, and I am moving on to putting interactive units on the level; but I am not sure what a good way is to do it. I have experimented with spawning an entity for each grass and rock, but there are just WAY to many; FPS just dies even if I confine it to the current "zone" the user is in (for those who remember LTTP it had zones you moved between). It does make a difference that this is a browser-based JavaScript game. tl;dr: What is a good way to have an interactive map without using full blown entities for each interactive item?

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• Can't enable wireless lan on Fujitsu Siemens A1665G with Ubuntu 11.10 installed

  - by Theo

  I saw my old Notebook yesterday and wanted to make that work again. On Windows XP the wireless worked still fine. Then I installed new Ubuntu 11.10 32bit and I'm sadly not able to make the wireless enabled. [I replaced Win XP entirely] lspci lists following network: 08:0a.0 Network controller: Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller (rev 02) So after recommendation from this link I installed the b43 firmware module. iwconfig prints the following: wlan0 IEEE 802.11bg ESSID:off/any Mode:Managed Access Point: Not-Associatd Tx-Power=off Retry long limit:7 RTS thr:off Fragment thr:off Power Management: off As you can see, my wireless lan adapter is not turned on. sudo iwconfig wlan0 txpower auto Doesn't change anything. Then I tried to make it work with rfkill. rfkill list 0: phy0: Wirless LAN Soft blocked: no Hard blocked: yes sudo rfkill unblock all rfkill list 0: phy0: Wireless LAN Soft blocked: no Hard blocked: yes remains the same. The question is now, how I could enable the hard blocked wireless LAN. There is no hardware switch for wlan integrated. However there is a button to change the state. I always thought this would be software sided, but it seems to make some hardware changes as well... The wireless LED is also not blinking (as it did on windows xp) I reset bios and searched for some settings in there, but it has only a few options and nothing to do with wireless settings, nothing works here.. At last I tried to install the acer hotkeys but I was not able to manage that. I installed the acerhkgui package, but in initializing progress, it was not able to compile acer hotkeys for my machine. There was a message that asm/linkage.h was not found while compiling. Do you have any ideas what I could do to make this hard blocked stuff disabled and my wireless card work? PS: I also tried sudo rm /dev/rfkill and a reboot to reinit that stuff... No success :(

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• Why should I -minus flags of eselect profile? [closed]

  - by Xsi

  Why not just disable profile and add + + + , and thats it? Rationale. Could I ask ??? second question: where is there a short YES\NO Questions & Answers service? My questions were a subject to closing and deletion at Unix&Linux (as they were not real - we know perfectly admins can't answer and think to help others), but they were long forming in my head, since I'm a very novice user to Linux. My questions were some of that size and were from my point, all-specific, they were not fault ones, but knowledge q's (not to fault), although some not banned questions of others are as short as a line (U&L).

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• Installing all the bits to demo Entity Framework 4 on the Visual Studio 2010 Release Candidate

  - by Eric Nelson

  Next week (17th March 2010) I am presenting on EF4 at www.devweek.com in London (and Azure on the 18th). Today I wanted to get all the latest bits on my demo machine and also check if there are any cool new resources I can point people at. Whilst most of the new improvements in Entity Framework come with the Visual Studio 2010 RC (and the RTM), there are a couple of separate items you need to install if you want to explore all the features. To demo EF4 you need: Visual Studio 2010 RC Download and install the Visual Studio 2010 Release Candidate. In my case I went from the Ultimate Edition but it will work fine on Premium and Professional. POCO Templates See the team blog post for a detailed explanation. Use the Extension Manager inside Visual Studio 2010: And install the updated POCO templates for either C# or VB (or both if you are so inclined!): Code First Next you will also need to install Code First (formally called Code Only). This is part of the Entity Framework Feature CTP 3. See the team blog post for a detailed explanation. Download the CTP from Microsoft downloads and run the setup. This will give you a new dll for Code First Optionally (but I recommend it) install LINQPad for the RC Download LINQPad Beta for .NET 4.0 Related Links 101 EF4 Resources

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• #altnetseattle &ndash; MEF, What is it?

  - by GeekAgilistMercenary

  I dived into the MEF session with Glenn Block, Sourabh Mathur, Brian Henderson, and others.  Glenn covered the basic architectural ideas of MEF and then dived into a few examples. Is a framework around decoupling components. Built around the idea of discoverable type systems. Traditional extensibility mechanisms have a host and the respective extensions, commonly linking these two aspects with a form of registration. MEF removes the need for the registration part of the architecture and uses a contract. At some point with MEF you get down to parts, which removes even the complexity of a host or extensions, but a truly evolvable architecture based on natural growth of parts. Also referred to as the framework that removes the "new" keyword. The idea is that parts pull together other parts that they need.  Between each part is a contract. Each part has imports or exports for the parts it needs or the things it offers. If one checks out the MEF Codeplex Site you will find a host of additional information.  The framework download also has some decent examples that help one get kick started.

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• Illumination and Shading for computer graphics class

  - by Sam I Am

  I am preparing for my test tomorrow and this is one of the practice questions. I solved it partially but I am confused with the rest. Here is the problem: Consider a gray world with no ambient and specular lighting ( only diffuse lighting). The screen coordinates of a triangle P1,P2,P3, are P1=(100,100), P2= (300,150), P3 = (200, 200). The gray values at P!,P2,P3 are 1/2, 3/4, and 1/4 respectively. The light is at infinity and its direction and gray color are (1,1,1) and 1.0 respectively. The coefficients of diffused reflection is 1/2. The normals of P1,P2,P3 are N1= (0,0,1), N2 = (1,0,0), and N3 = (0,1,0) respectively. Consider the coordinates of three points P1,P2,P3 to be 0. Do not normalize the normals. I have computed that the illumination at the 3 vertices P1,P2,P3 is (1/4,3/8,1/8). Also I computed that interpolation coefficients of a point P inside the triangle whose coordinates are (220, 160) are given by (1/5,2/5,2/5). Now I have 4 more questions regarding this problem. 1) The illumination at P using Gouraud Shading is: i) 1/2 The answer is 1/2, but I have no idea how to compute it.. 2) The interpolated normal at P is given by i) (2/5, 2/5,1/5) ii) (1/2, 1/4, 1/4) iii) (3/5, 1/5, 1/5) 3) The interpolated color at P is given by: i) 1/2 Again, I know the correct answer but no idea how to solve it 4) The illumination at P using Phong Shading is i) 1/4 ii) 9/40 iii) 1/2

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• Talking JavaOne with Rock Star Charles Nutter

  - by Janice J. Heiss

  JavaOne Rock Stars, conceived in 2005, are the top rated speakers from the JavaOne Conference. They are awarded by their peers who through conference surveys recognize them for their outstanding sessions and speaking ability. Over the years many of the world’s leading Java developers have been so recognized.We spoke with distinguished Rock Star, Charles Nutter. A JRuby Update from Charles NutterCharles Nutter of Red Hat is well known as a lead developer of JRuby, a Ruby implementation of Java that is tightly integrated with Java to allow for the embedding of the interpreter into any Java application with full two-way access between the Java and the Ruby code. Nutter is giving the following sessions at this year’s JavaOne: CON7257 – “JVM Bytecode for Dummies (and the Rest of Us Too)” CON7284 – “Implementing Ruby: The Long, Hard Road” CON7263 – “JVM JIT for Dummies” BOF6682 – “I’ve Got 99 Languages, but Java Ain’t One” CON6575 – “Polyglot for Dummies” (Both with Thomas Enebo) I asked Nutter, to give us the latest on JRuby. “JRuby seems to have hit a tipping point this past year,” he explained, “moving from ‘just another Ruby implementation’ to ‘the best Ruby implementation for X,’ where X may be performance, scaling, big data, stability, reliability, security, and a number of other features important for today's applications. We're currently wrapping up JRuby 1.7, which improves support for Ruby 1.9 APIs, solves a number of user issues and concurrency challenges, and utilizes invokedynamic to outperform all other Ruby implementations by a wide margin. JRuby just gets better and better.” When asked what he thought about the rapid growth of alternative languages for the JVM, he replied, “I'm very intrigued by efforts to bring a high-performance JavaScript runtime to the JVM. There's really no reason the JVM couldn't be the fastest platform for running JavaScript with the right implementation, and I'm excited to see that happen.”And what is Nutter working on currently? “Aside from JRuby 1.7 wrap-up,” he explained, “I'm helping the Hotspot developers investigate invokedynamic performance issues and test-driving their new invokedynamic code in Java 8. I'm also starting to explore ways to improve the general state of dynamic languages on the JVM using JRuby as a guide, and to help the JVM become a better platform for all kinds of languages.” Originally published on blogs.oracle.com/javaone.

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• phpmyadmin forbidden after changing config for my IP

  - by Jonathan Kushner

  I followed the phpmyadmin setup and changed the config to require ip my ipaddress and allow from my ipaddress and its still telling me forbidden You don't have permission to access /phpmyadmin on this server. when I try to access the page on my browser (my server is not located on my machine). I installed everything using root. I also chmod 775 the entire phpMyAdmin folder. Im running RHEL 6.1. Any idea what to do at this point? Here is my /etc/httpd/conf.d/phpMyAdmin.conf: <Directory /usr/share/phpMyAdmin/> <IfModule mod_authz_core.c> # Apache 2.4 <RequireAny> Require ip myserveripaddress Require ip ::1 </RequireAny> </IfModule> <IfModule !mod_authz_core.c> # Apache 2.2 Order Deny,Allow Deny from All Allow from myserveripaddress Allow from ::1 </IfModule> </Directory>

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• Client side latency when using prediction

  - by Tips48

  I've implemented Client-Side prediction into my game, where when input is received by the client, it first sends it to the server and then acts upon it just as the server will, to reduce the appearance of lag. The problem is, the server is authoritative, so when the server sends back the position of the Entity to the client, it undo's the effect of the interpolation and creates a rubber-banding effect. For example: Client sends input to server - Client reacts on input - Server receives and reacts on input - Server sends back response - Client reaction is undone due to latency between server and client To solve this, I've decided to store the game state and input every tick in the client, and then when I receive a packet from the server, get the game state from when the packet was sent and simulate the game up to the current point. My questions: Won't this cause lag? If I'm receiving 20/30 EntityPositionPackets a second, that means I have to run 20-30 simulations of the game state. How do I sync the client and server tick? Currently, I'm sending the milli-second the packet was sent by the server, but I think it's adding too much complexity instead of just sending the tick. The problem with converting it to sending the tick is that I have no guarantee that the client and server are ticking at the same rate, for example if the client is an old-end PC.

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• Weighted round robins via TTL - possible?

  - by Joe Hopfgartner

  I currently use DNS round robin for load balancing, which works great. The records look like this (I have a ttl of 120 seconds) ;; ANSWER SECTION: orion.2x.to. 116 IN A 80.237.201.41 orion.2x.to. 116 IN A 87.230.54.12 orion.2x.to. 116 IN A 87.230.100.10 orion.2x.to. 116 IN A 87.230.51.65 I learned that not every ISP / device treats such a response the same way. For example some DNS servers rotate the addresses randomly or always cycle them through. Some just propagate the first entry, others try to determine which is best (regionally near) by looking at the ip address. However if the userbase is big enough (spreads over multiple ISPs etc) it balances pretty well. The discrepancies from highest to lowest loaded server hardly every exceeds 15%. However now I have the problem that I am introducing more servers into the systems, that not all have the same capacities. I currently only have 1gbps servers, but I want to work with 100mbit and also 10gbps servers too. So what I want is I want to introduce a server with 10 GBps with a weight of 100, a 1 gbps server with a weight of 10 and a 100 mbit server with a weight of 1. I used to add servers twice to bring more traffic to them (which worked nice. the bandwidth doubled almost.) But adding a 10gbit server 100 times to DNS is a bit rediculous. So I thought about using the TTL. If I give server A 240 seconds ttl and server B only 120 seconds (which is about about the minimum to use for round robin, as a lot of dns servers set to 120 if a lower ttl is specified.. so i have heard) I think something like this should occour in an ideal scenario: first 120 seconds 50% of requests get server A -> keep it for 240 seconds. 50% of requests get server B -> keep it for 120 seconds second 120 seconds 50% of requests still have server A cached -> keep it for another 120 seconds. 25% of requests get server A -> keep it for 240 seconds 25% of requests get server B -> keep it for 120 seconds third 120 seconds 25% will get server A (from the 50% of Server A that now expired) -> cache 240 sec 25% will get server B (from the 50% of Server A that now expired) -> cache 120 sec 25% will have server A cached for another 120 seconds 12.5% will get server B (from the 25% of server B that now expired) -> cache 120sec 12.5% will get server A (from the 25% of server B that now expired) -> cache 240 sec fourth 120 seconds 25% will have server A cached -> cache for another 120 secs 12.5% will get server A (from the 25% of b that now expired) -> cache 240 secs 12.5% will get server B (from the 25% of b that now expired) -> cache 120 secs 12.5% will get server A (from the 25% of a that now expired) -> cache 240 secs 12.5% will get server B (from the 25% of a that now expired) -> cache 120 secs 6.25% will get server A (from the 12.5% of b that now expired) -> cache 240 secs 6.25% will get server B (from the 12.5% of b that now expired) -> cache 120 secs 12.5% will have server A cached -> cache another 120 secs ... i think i lost something at this point but i think you get the idea.... As you can see this gets pretty complicated to predict and it will for sure not work out like this in practice. But it should definitely have an effect on the distribution! I know that weighted round robin exists and is just controlled by the root server. It just cycles through dns records when responding and returns dns records with a set propability that corresponds to the weighting. My DNS server does not support this, and my requirements are not that precise. If it doesnt weight perfectly its okay, but it should go into the right direction. I think using the TTL field could be a more elegant and easier solution - and it deosnt require a dns server that controls this dynamically, which saves resources - which is in my opinion the whole point of dns load balancing vs hardware load balancers. My question now is... are there any best prectices / methos / rules of thumb to weight round robin distribution using the TTL attribute of DNS records? Edit: The system is a forward proxy server system. The amount of Bandwidth (not requests) exceeds what one single server with ethernet can handle. So I need a balancing solution that distributes the bandwidth to several servers. Are there any alternative methods than using DNS? Of course I can use a load balancer with fibre channel etc, but the costs are rediciulous and it also increases only the width of the bottleneck and does not eliminate it. The only thing i can think of are anycast (is it anycast or multicast?) ip addresses, but I don't have the means to set up such a system.

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• How to handle wildly varying rendering hardware / getting baseline

  - by edA-qa mort-ora-y

  I've recently started with mobile programming (cross-platform, also with desktop) and am encountering wildly differing hardware performance, in particular with OpenGL and the GPU. I know I'll basically have to adjust my rendering code but I'm uncertain of how to detect performance and what reasonable default settings are. I notice that certain shader functions are basically free in a desktop implemenation but can be unusable in a mobile device. The problem is I have no way of knowing what features will cause what performance issues on all the devices. So my first issue is that even if I allow configuring options I'm uncertain of which options I have to make configurable. I'm wondering also wheher one just writes one very configurable pipeline, or whether I should have 2 distinct options (high/low). I'm also unsure of where to set the default. If I set to the poorest performer the graphics will be so minimal that any user with a modern device would dismiss the game. If I set them even at some moderate point, the low end devices will basically become a slide-show. I was thinking perhaps that I just run some benchmarks when the user first installs and randomly guess what works, but I've not see a game do this before.

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• Windows 2008 File Share

  - by user36540

  Hi, I have 3 Windows 2008 Standard servers in my system with no domain controller. Two of the servers are running a NLB cluster and the third server is a file server that the web servers connect to. I want to store my source code on the file server and point the IIS config to the network file share. The web sites also need access to a file share on the file server. I was able to share the network drive and access while logged into either of the web servers but my web apps are unable to access the file share - I assume due to permissions. Does anybody know the correct way to do this? Thanks, Chris

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• how to link a c++ object to a local variable in Lua

  - by MahanGM

  I'm completing my scripting interface with Lua, but recently I've stuck at some point. I have several functions for my Entitiy events like Update(). I have a function called create_entitiy() which instantiate a new entity from a given entity index: function Update() local bullet = create_entity(0, 0, "obj_bullet") end create_entity returns a table which is the properties of the created entity. Now how can I make a connection between bullet variable and my newly created object? Right now for previously added objects to the scene, I simply set a global table for each of them and then after every call to Update(), I go through registered names to find object tables and perform new changes. Like the one below: function Update() if keyboard_key_press(vk_right) then obj_player.x += 3 end I can get obj_player table because I know its name from C++, plus I can get it as a global table and simply reach for the first instance named obj_player. Is there any solution for me to make bullet variable act like this? I was thinking to get all local variables in Update() function and check for every one to see if is it table and it has an unique field attached to it like id, this way I can determine that this is an object table and do the rest of the process. By the way, is this interface going to work easier with luaBind if I implement it? Bottom line: How can I make a local variable in Lua that receives a table from create_entity function and track that local variable to capture it from C++. e. g. function Update() local bullet = create_entity(0, 0, "obj_bullet") bullet.x = 10 <== Commit a change in table end Now I want to get variable bullet from C++. And it's not just this variable, there might be a ton of these local variables with different names.

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• Steam on 64-bit 14.04: need some help, missing a few 32-bit libs

  - by YellowShark

  Steam says I'm missing the following libs, I'm hoping someone can help me get things in better shape: xyz@abc:~$ STEAM_RUNTIME=0 steam Running Steam on ubuntu 14.04 64-bit STEAM_RUNTIME is disabled by the user Error: You are missing the following 32-bit libraries, and Steam may not run: libpangoft2-1.0.so.0 libpango-1.0.so.0 libgtk-x11-2.0.so.0 libgdk_pixbuf-2.0.so.0 Installing breakpad exception handler for appid(steam)/version(1401381906_client) Installing breakpad exception handler for appid(steam)/version(1401381906_client) [2014-06-11 20:45:39] Startup - updater built May 29 2014 09:19:23 [2014-06-11 20:45:39] Verifying installation... [2014-06-11 20:45:39] Verification complete [2014-06-11 20:45:42] Shutdown I tried installing the following i386 packages: libpango-1.0-0:i386, libpangoft2-1.0-0:i386, and libgdk-pixbuf2.0-0:i386, and symlinking the .so files (from usr/lib/i386whatever../) into the ~/.local/share/Steam/ubuntu12_32/ folder, but wasn't able to find the right match for the gtk-x11 lib, and ultimately would up with a different, but still non-working situation. So I've back-tracked to this point, and have removed those i386 packages for now. It's worth noting thatSteam runs if I don't use STEAM_RUNTIME=0. Also, Steam seemed to "recognize" the i386 version of the libpango & libpangoft2 libs after I symlinked them into place, during the course of my troubleshooting; when I would rerun STEAM_RUNTIME=0 steam, it wouldn't list those two items as missing anymore. Instead though, I had a bunch of gtk-related issues, something about overlay-scrollbar not available, as well as warnings that it can't find the murrine engine... a whole bunch of stuff that sounded like I'd gone too far down the wrong path. Anyhow, any help sorting this out would be appreciated, and thanks!

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