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  • Why do some user agents have spam urls in them?

    - by Erx_VB.NExT.Coder
    If you go to (say) the last 100 entries (visits) to the botsvsbrowsers.com website (exact link, feel free to take a look: http://www.botsvsbrowsers.com/recent/listings/index.html ), you'd notice that almost every User Agent that has the keywords "Opera" and "Presto" inside them, will almost certainly have a web link (URL/Web Address) inside it, and it won't just be a normal web address, but a HTML anchor tag/link to that address. Why is this so, I could not even find a single discussion about it on the internet, nowhere, I tried varying my search terms many times. If the user agent contains the words "Opera" and "Presto" it doesnt mean it will have this weblink, but it means there is about an 80% change that it will. A typical anchor tag/link inside a user agent will look like this: Mozilla/4.0 <a href="http://osis-uk.co.uk/disabled-equipment">disability equipment</a> (Windows NT 5.1; U; en) Presto/2.10.229 Version/11.60 If you check it out at the website, http://www.botsvsbrowsers.com/recent/listings/index.html you will notice that the back and forward arrows are in there unescaped format. This isn't just true for botsvsbrowsers, but several other user agent listing sites. I'm really confused and feel line I'm in a room full of 10,000 people and am the only one seeing this ghost :). If I'm doing statistical analysis, should I include or exclude this type of user agent from my listing (ie: are these just normal users who've set their user agents to attempt to drive some traffic to their sites as they browser the web), or is there something else going on? The fact that it is so consistent in terms of its format leads me to believe that it is an automated process (the setting or alteration of the user agent) so I cannot decide or understand the process by which this change is made (I know how to change a user agent), but unsure which program or facility is doing this, especially since it is exclusive to Opera (Presto) user agents that are beyond I think an 8 or 9 point something browser version. I've run some statistical tests, parsing entries from all over the place, writing custom programs, to get a better understanding of this. Keep in mind that I see normal URL's in user agents infrequently, they are just text such as +http://www.someSite.com appended to a user agent normally, especially if its a crawler or bot it provided its service URL, this is normal and isnt done with an embedded link (A HREF=) etc, so I'm not talking about "those".

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  • BizTalk 2009 - SQL Server Job Configuration

    - by StuartBrierley
    Following the installation of Biztalk Server 2009 on my development laptop I used the BizTalk Server Best Practice Analyser which highlighted the fact that two of the SQL Server Agent jobs that BizTalk relies on were not running successfully.  Upon investigation it turned out that these jobs needed to be configured before they would run successfully. To configure these jobs open SQL Server Management Studio, expand SQL Server Agent > Jobs and double click on the appropriate job.  Select Steps and then edit the appropriate entries. Backup BizTalk Server (BizTalkMgmtDb) This job is comprised of three steps BackupFull, MarkAndBackupLog and ClearBackupHistory. BackupFull exec [dbo].[sp_BackupAllFull_Schedule] ‘d’ /* Frequency */,‘BTS’ /* Name */,‘<destination path>’ /* location of backup files */ The frequency here is set/left as daily The name is left as BTS You must provide a full destination path for the backup files to be stored. There are also two optional parameters: A flag that controls if the job forces a full backup if a partial backup fails A parameter to control the time of day to run the full backup; the default is midnight UTC time For example: exec [dbo].[sp_BackupAllFull_Schedule] ‘d’ /* Frequency */,‘BTS’ /* Name */,‘<destination path>’ /* location of backup files */ , 0, 22 MarkAndBackUpLog exec [dbo].[sp_MarkAll] ‘BTS’ /* Log mark name */,’<destination path>’  /*location of backup files */ You must provide a destination path for the log backups. Optionally you can also add an extra parameter that tells the procedure to use local time: exec [dbo].[sp_MarkAll] ‘BTS’ /* Log mark name */,’<destination path>’  /*location of backup files */ ,1 Clear Backup History exec [dbo].[sp_DeleteBackupHistory] @DaysToKeep=7 This will clear out the instances in the MarkLog table older than 7 days.    DTA Purge and Archive (BizTalkDTADb) This job is comprised of a single step. Archive and Purge exec dtasp_BackupAndPurgeTrackingDatabase 0, --@nLiveHours tinyint, 1, --@nLiveDays tinyint = 0, 30, --@nHardDeleteDays tinyint = 0, null, --@nvcFolder nvarchar(1024) = null, null, --@nvcValidatingServer sysname = null, 0 --@fForceBackup int = 0 Any completed instance that is older than the live days plus live hours will be deleted, as will any associated data. Any data older than the HardDeleteDays will be deleted - this means that those long running orchestration instances that would otherwise never be purged will at some point have their data cleared down while allowing the instance to continue, thus preventing the DTA databse from growing indefinitely.  This should always be greater than the soft purge window. The NVC folder is the path for the backup files, if this is null the job will not run failing with the error : DTA Purge and Archive (BizTalkDTADb) Job failed SQL Server Management Studio, job activity monitor, view history The @nvcFolder parameter cannot be null. Archive and Purge step How long you choose to keep instances in the Tracking Database is really up to you. For development I have set this up as: exec dtasp_BackupAndPurgeTrackingDatabase 0, 1, 30, ’<destination path>’, null, 0 On a live server you may want to adjust these figures: exec dtasp_BackupAndPurgeTrackingDatabase 0, 15, 20, ’<destination path>’, null, 0

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  • Play a Webpage Display Prank in Google Chrome

    - by Asian Angel
    Are you looking for a fun but innocent prank to play on someone who loves using Google Chrome? If so then you may want to have a closer look at the Upside Down extension for Chrome. Before Here is our example webpage before starting the prank…looking all “normal like”. Upside Down in Action As soon as the extension has been installed you are ready to go. If you had a webpage open before installing the extension you will only need to refresh the page. As soon as the page has been refreshed or a new one is opened everything is going to look messed up very quickly. With the default setting there are five different “looks” available. To cycle through the five “looks” use the “Windows Key + Semicolon” or “Command + Semicolon” to toggle through them. On the sixth toggle the webpage will revert to normal (toggling afterwards starts the whole process again). Here are the five “looks” available…         Options There are options available for the extension where you can focus on just a specific effect or a group of effects. You can also enable a “Grayscale Effect” and even set a delay timer (a definite “evil touch”)! Think of the fun and surprised looks that await… Conclusion If you have been looking for a fun and unexpected prank for your favorite Google Chrome fan then this just might be what you have been looking for. Get ready to sit back and watch the fun. Links Download the Upside Down extension (Google Chrome Extensions) Similar Articles Productive Geek Tips Take Screenshots of Any Webpage in Google ChromeHow to Make Google Chrome Your Default BrowserSubscribe to RSS Feeds in Chrome with a Single ClickActivate the Redesigned New-Tab Interface in Google ChromeFriday Fun: Play MineSweeper in Google Chrome TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 If Web Browsers Were Modes of Transportation Google Translate (for animals) Out of 100 Tweeters Roadkill’s Scan Port scans for open ports Out of band Security Update for Internet Explorer 7 Cool Looking Screensavers for Windows

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  • How to Deal with a Difficult Boss?

    - by Anonymous
    I have some problems with my boss, it's quite a long story :) About one year ago, I'm working as team leader of project X. Everything work fine until one of my fellow (staff) flame me that I have problem with ALL member in our team, that guy also flame me to other staff that I report them with a poor performance. My boss call me and blame me without ask a single question. I try to explain everything to my boss but she doesn't listen to me. One month later, we have a meeting. This is only team leader's meeting, my boss talk about this problem with other team leader. There are two person who have worked with this guy, they all say "This guy cannot trust". That guy had do same thing same problem with his former team leader. Finally, everything's clear and I think I gain some trust from her. I can say that I'm the best team leader in her hand, as only project that archive more than 120% profit. Then I move to new project, this is bigger project and I can manage it quite good. But I have a problem again. One of my staff always leave and does not follow our company rule, I call him to talk and tell him that you cannot do this because that's not allow in our company. He also changed working time record file of himself, then I call him to warn again. This time he ask me to move to another project so I go to talk to my boss. She come to my building when I'm not there (other staff call me) and talk with that guy (who have problem with me); I think she still not trust me. And AGAIN, she believe what that guy said and I got blamed. I want to know how can I deal with this kind of boss, or is it better to find a new job, or any other suggestion about this problem? Thank you :) Additional information: Even my job title is "Team Leader" but it's my responsibility to manage staff working time and their behavior. This responsible is my company's rule.

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  • Heightmap in Shader not working

    - by CSharkVisibleBasix
    I'm trying to implement GPU based geometry clipmapping and have problems to apply a simple heightmap to my terrain. For the heightmap I use a simple texture with the surface format "single". I've taken the texture from here. To apply it to my terrain, I use the following shader code: texture Heightmap; sampler2D HeightmapSampler = sampler_state { Texture = <Heightmap>; MinFilter = Point; MagFilter = Point; MipFilter = Point; AddressU = Mirror; AddressV = Mirror; }; Vertex Shader: float4 worldPos = mul(float4(pos.x,0.0f,pos.y, 1.0f), worldMatrix); float elevation = tex2Dlod(HeightmapSampler, float4(worldPos.x, worldPos.z,0,0)); worldPos.y = elevation * 128; The complete vertex shader (also containig clipmapping transforms) looks like this: float4x4 View : View; float4x4 Projection : Projection; float3 CameraPos : CameraPosition; float LODscale; //The LOD ring index 0:highest x:lowest float2 Position; //The position of the part in the world texture Heightmap; sampler2D HeightmapSampler = sampler_state { Texture = <Heightmap>; MinFilter = Point; MagFilter = Point; MipFilter = Point; AddressU = Mirror; AddressV = Mirror; }; //Accept only float2 because we extract 3rd dim out of Heightmap float4 wireframe_VS(float2 pos : POSITION) : POSITION{ float4x4 worldMatrix = float4x4( LODscale, 0, 0, 0, 0, LODscale, 0, 0, 0, 0, LODscale, 0, - Position.x * 64 * LODscale + CameraPos.x, 0, Position.y * 64 * LODscale + CameraPos.z, 1); float4 worldPos = mul(float4(pos.x,0.0f,pos.y, 1.0f), worldMatrix); float elevation = tex2Dlod(HeightmapSampler, float4(worldPos.x, worldPos.z,0,0)); worldPos.y = elevation * 128; float4 viewPos = mul(worldPos, View); float4 projPos = mul(viewPos, Projection); return projPos; }

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  • ATI (fglrx) Dual monitor / laptop hot-plugging

    - by Brendan Piater
    I feel like I've gone back 5 years on my desktop today. I'll try not dump to much frustration here... I been running 12.04 since alpha with the ATI open source drivers and the gnome 3 desktop. I been generally very happy with them with only small issues along the way. Now of course it does not support 3D acceleration 100%, so games like my newly purchased Amnesia from the Humble bundle would not play. OK, no worries, the ATI driver is in the repos so let me have a go I thought. With all this testing that's been done with multi-monitor support, what could go wrong...? How I use my computer: It's laptop, with a HD 3670 card in it. I spend about 50% of the time working directly on the laptop (at home) and about 50% of the time working with an additional display connected (at work), multi desktop environment. What happening now: installed drivers things seemed to working, save some small other bugs (not critical) this morning I take my machine and plug the additional monitor into it, and nothing happens... ok fine. open "displays" try configure dual display, won't work open ati config "thing" (cause it is a thing, a crap thing) and set-up monitors there reboot it says (oh ffs, really.... ok) reboot, login and wow, I got a gnome 2 desktop (presume gnome 3 fall back) and no multi-monitor...great. (screenshot: http://ubuntuone.com/5tFe3QNFsTSIGvUSVLsyL7 ) after getting into a situation where I had to Ctrl + Alt + Del to get out of a frozen display, I eventually manage to set-up a single display desktop on the "main" monitor ok.. time to go home... unplug monitor... nothing happens.. oh boy here we go... try displays again, nothing, just hangs the display.. great. crash all the apps and reboot... So it's been a trying day... What I really hope is that someone else has figured out how to avoid this PAIN. Please help with a solution that: allows me run fglrx (so I can run the games I want) allows me to hot-plug a monitor to my laptop and remove it again allows me to change the display so include the hot-plugged monitor (preferable automatically like it did with the open drivers) Next best if that's not possible: switch between laptop only display and monitor only display easily (i.e. not having to reboot/logout/suspened etc) Really appreciate the time of anyone that has a solution. Thanks in advance. Regards Brendan PS: I guess I should file a bug about this too, so some direction as to the best place to file this would be appreciated too.

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  • Windows Azure Diagnostics: Next to Useless?

    - by Your DisplayName here!
    To quote my good friend Christian: “Tracing is probably one of the most discussed topics in the Windows Azure world. Not because it is freaking cool – but because it can be very tedious and partly massively counter-intuitive.” <rant> The .NET Framework has this wonderful facility called TraceSource. You define a named trace and route that to a configurable listener. This gives you a lot of flexibility – you can create a single trace file – or multiple ones. There is even nice tooling around that. SvcTraceViewer from the SDK let’s you open the XML trace files – you can filter and sort by trace source and event type, aggreate multiple files…blablabla. Just what you would expect from a decent tracing infrastructure. Now comes Windows Azure. I was already were grateful that starting with the SDK 1.2 we finally had a way to do tracing and diagnostics in the cloud (kudos!). But the way the Azure DiagnosticMonitor is currently implemented – could be called flawed. The Azure SDK provides a DiagnosticsMonitorTraceListener – which is the right way to go. The only problem is, that way this works is, that all traces (from all sources) get written to an ETW trace. Then the DiagMon listens to these traces and copies them periodically to your storage account. So far so good. But guess what happens to your nice trace files: the trace source names get “lost”. They appear in your message text at the end. So much for filtering and sorting and aggregating (regex #fail or #win??). Every trace line becomes an entry in a Azure Storage Table – the svclog format is gone. So much for the existing tooling. To solve that problem, one workaround was to write your own trace listener (!) that creates svclog files inside of local storage and use the DiagMon to copy those. Christian has a blog post about that. OK done that. Now it turns out that this mechanism does not work anymore in 1.3 with FullIIS (see here). Quoting: “Some IIS 7.0 logs not collected due to permissions issues...The root cause to both of these issues is the permissions on the log files.” And the workaround: “To read the files yourself, log on to the instance with a remote desktop connection.” Now then have fun with your multi-instance deployments…. </rant>

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  • facebook share and opengraph

    - by hannit cohen
    I'm managing a video blog. The blog contains a main youtube video on the homepage and several thumbnail images of other videos elsewhere. I have a share button for the main page and the single posts pages and have added opengraph to specify the used image. For some reason facebook ignores my opengraph image and uses othe images it finds in the page... the header looks like this: (for the homepage) <!-- Facebook Opengraph --> <meta property="fb:app_id" content="155967927783206" /> <meta property="og:url" content="http://mttv.co.il/2010/12/%d7%9e%d7%a4%d7%92%d7%a9-%d7%a1%d7%99%d7%99%d7%a2%d7%95%d7%aa-%d7%92%d7%a0%d7%a0%d7%95%d7%aa-%d7%9c%d7%93%d7%95%d7%a8%d7%aa%d7%99%d7%94%d7%9d-1959-2010-%d7%91%d7%9e%d7%a2%d7%9c%d7%95%d7%aa/"/> <meta property="og:title" content="???? ?????? ????? ???????? 1959-2010 ??????" /> <meta property="og:description" content="???? ????? ?? ?????? ????? ?????? ????????? ???? ?????? 1959 ??? 2010 ?????? ????? ??????? ???' ??? ??? ????? ???? ??????? ???????? ?????? ?&quot;? ???? ??? ?&quot;? ????? ?????? ????? ???? 08.12.10 " /> <meta property="og:type" content="article" /> <meta property="og:image" content="http://www.mttv.co.il/wp-content/uploads/2010/12/Gvi91UEjCAw_mid-135x77.jpg" /> The website address is: http://mttv.co.il Any help will be appreciated

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  • What is new in Oracle SOA Suite 11g R1 PS6? by Shanny Anoep

    - by JuergenKress
    Oracle has released a new version 11.1.1.7.0 for their Oracle Fusion Middleware product line. This version includes Patch Set #6 (PS6) for Oracle SOA Suite 11g R1, with a big list of improvements and fixes for each component in that suite. In this post we will highlight some of the interesting updates with regards to troubleshooting, performance, reliability and scalability. Infrastructure/Purging scripts Database growth is a common problem for large-scale Oracle SOA Suite deployments. Oracle already provides multiple purging strategies for the SOA Suite runtime database. This patch set includes two new scripts for purging most of the runtime data: Table Recreation Script (TRS): This script can be used to reclaim as much database space as possible, while still retaining the open instances. It can be used as a corrective action for databases that grew excessively, for example when purging was not performed at all. This should be used as a single corrective action only; the script does not replace the normal purging scripts. Truncate script: Remove all records from the SOA Suite runtime tables without dropping the tables. This script can be used for cloning SOA Suite environments without copying the instance data, or for recreating test scenarios by cleaning all the runtime data. The Oracle SOA Suite Administrator's guide contains a table with the available purging strategies. Diagnostic dumps Using WLST you could already dump diagnostic information about various components of the SOA Suite. This version adds support to retrieve more information on BPEL and Adapters from the command-line. Diagnostic dumps for BPEL New diagnostic dumps are available for BPEL to get information on thread pools, average processing time for BPEL components, and average waiting times for asynchronous instances. This information can be very useful for performance analysis or troubleshooting. With WLST this information can be retrieved from the command-line and included for monitoring or reporting. Read the full article here. SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Facebook Wiki Mix Forum Technorati Tags: SOA Suite PS6,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress

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  • Code Analysis Rule Sets in Visual Studio 2010

    - by Anthony Trudeau
    Microsoft Visual Studio 2010 introduces the concept of rule sets when configuring code analysis.  This is a valuable change from Visual Studio 2008 that I didn't even realize I wanted.  Visual Studio 2008 by default selected all rules and then you had to remove rules on an item by item basis. The rule sets fall into logical groups including "Microsoft All Rules", "Microsoft Basic Correctness Rules", "Microsoft Security Rules", et al.  And within the project properties you can select one rule set, multiple rule sets, or you can define your own rule set based upon another. Selecting a single rule set is obviously the easiest option.  The default rule set when you create a new project is the "Microsoft Minimum Recommended Rules".  However, in my opinion the recommended rules are just too permissive.  For that reason you might want to change your rule set to "Microsoft All Rules" until you get around to creating your own rule set; or alternately you can select multiple rule sets which is an option from the rule set combo box.  The Visual Studio documentation has comprehensive help on what is contained within the rule sets. Creating your own rule set is easy if not obvious.  You need to start a rule set from an existing rule set.  To get started select a rule set in the combo box within the Code Analysis tab of the project properties.  I selected the "Microsoft All Rules" for my rule set, but you may find it easier to start with the "Microsoft Minimum Recommended Rules" if your rules are on the more permissive side. Once your rule set is selected click the Open button.  This will display a dialog that is similar in composition to the rules selection from Visual Studio 2008.  Browsing through the tree view you can select or deselect individual rules within their categories; and you can indicate that the rules are flagged as errors instead of the default which is a warning.  A nice touch to the form is that you get a help pane when you select an individual rule.  That helped me considerably when I first configured my rule set. Once you have finished selecting your rules click the Save tool button, specify a location and name, and click the Save button on the Save As dialog.  Once you're back on the Code Analysis tab you'll choose the Browse option within the combo box and open the file you just created.

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  • TomEE Integration in NetBeans Next

    - by Geertjan
    At JavaOne 2013, there was a lot of buzz around the TomEE server, e.g., many Tweets, nice party, and a new TomEE consulting company. For those tracking TomEE developments, it is interesting to note that recently the NetBeans IDE development builds have had added to them... TomEE support. Note: The TomEE support described here is not in NetBeans IDE 7.4, but in development builds for the next release of NetBeans IDE.For example, with NetBeans IDE development builds you're able to: register TomEE as a server in the Services window (TomEE has several distributions, e.g., one can use the "with JAX-RS" one, for example) create a Java EE 6 web project (e.g., Maven based) against this server create JPA entities from database create JAX-RS classes from JPA entities create JSF pages from JPA entities the IDE lets you create a new data source for TomEE and deploy it to the server the IDE figures out the components that are already packaged in TomEE, and the fact that (unlike with regular Tomcat), it does not need to package any components such as JSF implementation, persistence provider, or JAX-RS runtime, so that the resulting WAR file is very small the IDE can also do "deploy on save" with TomEE, so that your development cycle is very fast Adam Bien blogged about how he set up TomEE sometime ago, here. The official support in NetBeans IDE will be much more tightly integrated, simplifying the steps Adam describes. For example, the IDE does step 2 from Adam's blog for you, i.e., it sets up TomEE deployment roles. Moreover, it knows about all the technologies included in TomEE so that it can optimize the packaging; it knows about TomEE's persistence setup; it can work with TomEE data sources, etc. Below you see a Maven-based Java EE 6 PrimeFaces application (all entities and JSF pages generated from a database) deployed to TomEE in NetBeans IDE: And here's the management console for configuring and finetuning TomEE in NetBeans IDE: When I tried out the NetBeans IDE development build and TomEE, to see how everything fits together, I was surprised at how fast TomEE started up. Not sure what they did to it, but seems like a server on steroids. And setting it up in NetBeans IDE was trivial. Add the simple set up of TomEE in NetBeans IDE to the many benefits that the widely praised out of the box NetBeans Maven tools make possible, together with the fact that not one single plugin had to be installed to get everything you see described here up and running... and you have a really powerful combination of dev tools, all for free.

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  • How to implement efficient Fog of War?

    - by Cambrano
    I've asked a question how to implement Fog Of War(FOW) with shaders. Well I've got this working. I use the vertex color to identify the alpha of a single vertex. I guess the most of you know what the FOW of Age of Empires was like, anyway I'll shortly explain it: You have a map. Everything is unexplored(solid black / 100% transparency) at the beginning. When your NPC's / other game units explore the world (by moving around mostly) they unshadow the map. That means. Everything in a specific radius (viewrange) around a NPC is visible (0%transparency). Anything that is out of viewrange but already explored is visible but shadowed (50% transparency). So yeah, AoE had relatively huge maps. Requirements was something around 100mhz etc. So it should be relatively easy to implement something to solve this problem - actually. Okay. I'm currently adding planes above my world and set the color per vertex. Why do I use many planes ? Unity has a vertex limit of 65.000 per mesh. According to the size of my tiles and the size of my map I need more than one plane. So I actually need a lot of planes. This is obviously pita for my FPS. Well so my question is, what are simple (in sense of performance) techniques to implement a FOW shader? Okay some simplified code what I'm doin so far: // Setup for (int x = 0; x < (Map.Dimension/planeSize); x++) { for (int z = 0; z < (Map.Dimension/planeSize); z++) { CreateMeshAt(x*planeSize, 3, z*planeSize) } } // Explore (is called from NPCs when walking for example) for (int x = ((int) from.x - radius); x < from.x + radius; x ++) { for (int z = ((int) from.z - radius); z < from.z + radius; z ++) { if (from.Distance(x, 1, z) > radius) continue; _transparency[x/tileSize, z/tileSize] = 0.5f; } } // Update foreach(GameObject plane in planes){ foreach(Vector3 vertex in vertices){ Vector3 worldPos = GetWorldPos(vertex); vertex.Color = new Color(0,0,0, _transparency[worldPos.x/tileSize, worldPos.z/tileSize]); } } My shader just sets the transparency of the vertex now, which comes from the vertex color channel

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  • NFS server generating "invalid extent" on EXT4 system disk?

    - by Stephen Winnall
    I have a server running Xen 4.1 with Oneiric in the dom0 and each of the 4 domUs. The system disks of the domUs are LVM2 volumes built on top of an mdadm RAID1. All the domU system disks are EXT4 and are created using snapshots of the same original template. 3 of them run perfectly, but one (called s-ub-02) keeps on being remounted read-only. A subsequent e2fsck results in a single "invalid extent" diagnosis: e2fsck 1.41.14 (22-Dec-2010) /dev/domu/s-ub-02-root contains a file system with errors, check forced. Pass 1: Checking inodes, blocks, and sizes Inode 525418 has an invalid extent (logical block 8959, invalid physical block 0, len 0) Clear<y>? yes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information /dev/domu/s-ub-02-root: 77757/655360 files (0.3% non-contiguous), 360592/2621440 blocks The console shows typically the following errors for the system disk (xvda2): [101980.903416] EXT4-fs error (device xvda2): ext4_ext_find_extent:732: inode #525418: comm apt-get: bad header/extent: invalid extent entries - magic f30a, entries 12, max 340(340), depth 0(0) [101980.903473] EXT4-fs (xvda2): Remounting filesystem read-only I have created new versions of the system disk. The same thing always happens. This, and the fact that the disk is ultimately on a RAID1, leads me to preclude a hardware disk error. The only obvious distinguishing feature of this domU is the presence of nfs-kernel-server, so I suspect that. Its exports file looks like this: /exports/users 192.168.0.0/255.255.248.0(rw,sync,no_subtree_check) /exports/media/music 192.168.0.0/255.255.248.0(rw,sync,no_subtree_check) /exports/media/pictures 192.168.0.0/255.255.248.0(rw,sync,no_subtree_check) /exports/opt 192.168.0.0/255.255.248.0(rw,sync,no_subtree_check) /exports/users and /exports/opt are LVM2 volumes from the same volume group as the system disk. /exports/media is an EXT2 volume. (There is an issue where clients see /exports/media/pictures as being a read-only volume, which I mention for completeness.) With the exception of the read-only problem, the NFS server appears to work correctly under light load for several hours before the "invalid extent" problem occurs. There are no helpful entries in /var/log. All of a sudden, no more files are written, so you can see when the disk was remounted read-only, but there is no indication of what the cause might be. Can anyone help me with this problem? Steve

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  • Tales of a corrupt SQL log

    - by guybarrette
    Warning: I’m a simple dev, not an all powerful DBA with godly powers. This morning, one of my sites was down and DNN reported a problem with the database.  A quick series of tests revealed that the culprit was a corrupted log file. Easy fix I said, I have daily backups so it’s just a mater of restoring a good copy of the database and log files.  Well, I found out that’s not exactly true.  You see, for this database, I have daily file backups and these are not database backups created by SQL Server. So I restored a set of files from a couple of days ago, stopped the SQL service, copied the files over the bad ones, restarted the service only to find out that SQL doesn’t like when you do that.  It suspects something fishy and marks the database as suspect.  A database marked as suspect can’t be accessed at all.  So now what? I searched throughout the tubes of the InterWeb and found that you can restore from a corrupted log file by creating a new database with the same name as the defective one, then copy the restored database file (the one with data) over the newly created one.  Sweet!  But you still end up with SQL marking the database as suspect but at least, the newly created log is OK.  Well not true, it’s not corrupted but the lack of data makes it not OK for SQL so you need to rebuild the log.  How can you do that when SQL blocks any action the database?  First, you need to change the database status from suspect to emergency.  Then you need to set the database for single access only.  After that, you need to repair the log with DBCC and do the DBA dance.  If you dance long enough, SQL should repair the log file.  Now you need to set the access back to multi user.  Here’s the T-SQL script: use master GO EXEC sp_resetstatus 'MyDatabase' ALTER DATABASE MyDatabase SET EMERGENCY Alter database MyDatabase set Single_User DBCC checkdb('MyDatabase') ALTER DATABASE MyDatabase SET SINGLE_USER WITH ROLLBACK IMMEDIATE DBCC CheckDB ('MyDatabase', REPAIR_ALLOW_DATA_LOSS) ALTER DATABASE MyDatabase SET MULTI_USER So I guess that I would have been a lot easier to restore a SQL backup.  I can’t really say but the InterWeb seems to say so.  Anyway, lessons learned: Vive la différence: File backups are different then SQL backups. Don’t touch me: SQL doesn’t like when you restore a file over a corrupted one. The more the merrier: You should do both SQL and file backups. WTF?: The InterWeb provides you with dozens of way to deal with the problem but many are SQL 2000 or SQL 2005 only, many are confusing and many are written in strange dialects only DBAs understand. var addthis_pub="guybarrette";

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  • Stop Saying "Multi-Channel!"

    - by David Dorf
    I keep hearing the term "multi-channel" in our industry, but its time to move on. It kinda reminds me of the term "ECR" or electronic cash register. Long ago ECR was a leading-edge term, but nowadays its rarely used because its table-stakes. After all, what cash register today isn't electronic? The same logic applies to multi-channel, at least when we're talking about tier-1 and tier-2 retailers. If you're still talking about multi-channel retailing, you're in big trouble. Some have switched over to the term "cross-channel," and that's a step in the right direction but still falls short. Its kinda like saying, "I upgraded my ECR to accept debit cards!" Yawn. Who hasn't? Today's retailers need to focus on omni-channel, which I first heard from my friends over at RSR but was originally coined at IDC. First retailers added e-commerce to their store and catalog channels yielding multi-channel retailing. Consumers could use the channel that worked best for them. Then some consumers wanted to combine channels with features like buy-on-the-Web, pickup-in-the-store. Thus began the cross-channel initiatives to breakdown the silos and enable the channels to communicate with each other. But the multi-channel architecture is full of duplication that thwarts efforts of providing a consistent experience. Each has its own cart, its own pricing, and often its own CRM. This was an outcrop of trying to bring the independent channels to market quickly. Rather than reusing and rebuilding existing components to meet the new demands, silos were created that continue to exist today. Today's consumers want omni-channel retailing. They want to interact with brands in a consistent manner that is channel transparent, yet optimized for that particular interaction. The diagram below, from the soon-to-be-released NRF Mobile Blueprint v2, shows this progression. For retailers to provide an omni-channel experience, there needs to be one logical representation of products, prices, promotions, and customers across all channels. The only thing that varies is the presentation of the content based on the delivery mechanism (e.g. shelf labels, mobile phone, web site, print, etc.) and often these mechanisms can be combined in various ways. I'm looking forward to the day in which I can use my phone to scan QR-codes in a catalog to create a shopping cart of items. Then do some further research on the retailer's Web site and be told about related items that might interest me. Be able to easily solicit opinions and reviews from social sites, and finally enter the store to pickup my items, knowing that any applicable coupons have been applied. In this scenario, I the consumer are dealing with a single brand that is aware of me and my needs throughout the entire transaction. Nirvana.

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  • Oracle's Integrated Systems Management and Support Experience

    - by Scott McNeil
    With its recent launch, Oracle Enterprise Manager 11g introduced a new approach to integrated systems management and support. What this means is taking both areas of IT management and vendor support and combining them into one integrated comprehensive and centralized platform. Traditional Ways Under the traditional method, IT operational teams would often focus on running their systems using management tools that weren’t connected to their vendor’s support systems. If you needed support with a product, administrators would often contact the vendor by phone or visit the vendor website for support and then log a service request in order to fix the issues. This method was also very time consuming, as administrators would have to collect their software configurations, operating systems and hardware settings, then manually enter them into an online form or recite them to a support analyst on the phone. For the vendor, they had to analyze all the configuration data to recreate the problem in order to solve it. This approach was very manual, uncoordinated and error-prone where duplication between the customer and vendor frequently occurred. A Better Support Experience By removing the boundaries between support, IT management tools and the customer’s IT infrastructure, Oracle paved the way for a better support experience. This was achieved through integration between Oracle Enterprise Manager 11g and My Oracle Support. Administrators can not only manage their IT infrastructure and applications through Oracle Enterprise Manager’s centralized console but can also receive proactive alerts and patch recommendations right within the console they use day-in-day-out. Having one single source of information saves time and potentially prevents unforeseen problems down the road. All for One, and One for All The first step for you is to allow Oracle Enterprise Manager to upload configuration data into Oracle’s secure configuration repository, where it can be analyzed for potential issues or conflicts for all customers. A fix to a problem encountered by one customer may actually be relevant to many more. The integration between My Oracle Support and Oracle Enterprise Manager allows all customers who may be impacted by the problem to receive a notification about the fix. Once the alert appears in Oracle Enterprise Manager’s console, the administrator can take his/her time to do further investigations using automated workflows provided in Oracle Enterprise Manager to analyze potential conflicts. Finally, administrators can schedule a time to test and automatically apply the fix to all the systems that need it. In the end, this helps customers maintain their service levels without compromise and avoid experiencing unplanned downtime that may result from potential issues or conflicts. This new paradigm of integrated systems management and support helps customers keep their systems secure, compliant, and up-to-date, while eliminating the traditional silos between IT management and vendor support. Oracle’s next generation platform also works hand-in-hand to provide higher quality of service to business users while at the same time making life for administrators less complicated. For more information on Oracle’s integrated systems management and support experience, be sure to visit our Oracle Enterprise Manager 11g Resource Center for the latest customer videos, webcast, and white papers.

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  • CAPTCHA blocking for my scraping script?

    - by Surabhil Sergy
    I am working on a scraping project which involves getting web data and parsing them for further use. I have been working using PHP and CURL to make scraping scripts which crawls web data and I make use of either PHP Dom or Simple HTML DOM Parser library for these kinds of projects. On a recent project I encountered some challenges; initially I found the target website blocked my server IP such that the server could not make any successful requests to the site. Understanding these issues as common I bought a set of private proxies and tried to make request calls using them. Though this could get successful response, I noticed the script is getting some kind of blocks after 2-3 continuous requests. On printing and checking the response I could see a pop-up asking for CAPTCHA validation. I could not see any captcha characters to be entered and it also shows an error “input error: invalid referrer”. On examining the source I could see some Google recaptcha scripts within. I’m stuck at this point and I m not able to execute my script. My script is used for gathering data and it needs to go through a large number of pages periodically over the site. But in the current scenario I am not able to proceed with my script. I could see there are some options to overcome these captcha issues and scraping these kinds of sites too are common. I have been checking my script performance and responses over last two months. I could see during first month I was able to execute very large number of requests from a single IP and I was able to get results. Later I get an IP block and used private proxies which could get me some results. Later I am facing now with the captcha trouble. I would appreciate any help or suggestions in this regard. (Often in this kind of questions I used to get a first comment as, ‘Have you asked for prior permission from the target?’ .I haven’t ,but I know there are many sites doing so to get the details out of sites and target sites may not often give access to them. I respect the legality and scraping etiquettes but I would like to know at what point I stuck and how could I overcome that! ) I could provide any supporting information if needed.

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  • Why Healthcare Today Needs BPM and SOA by Avio

    - by JuergenKress
    Within the past couple years, the Patient Protection and Affordable Care Act has led to significant changes in the healthcare industry. A highly-complex supply chain between patients, providers, buyers and insurance companies has led to a lack of overall collaboration when it comes to processes. The first open enrollment deadline for products on the Health Insurance Exchange has passed. So what now? Let’s take a brief look at how things have changed and what organizations can do to stay in (and ahead of) the game. New requirements, new processes Organizations that have not adapted processes to meet new regulatory requirements will fall further behind. New regulatory requirements effectively make some legacy applications obsolete, require batch process to move to real-time, and more. Business Process Management (BPM) can help organizations bring data processes in line while helping IT redesign processes rather than change code or replace existing applications. BPM fills in application gaps and links critical information systems for a more visible, efficient and auditable organization. Social and mobile solutions BPM technology also facilitates social and mobile solutions that can help meet new needs. Patients are dependent on a network of doctors, pharmacists, families and others. Social solutions can connect members of the patient’s community in ways never seen before - enabling real-time, relevant communication. Likewise, mobile technology supports social solutions, and BPM is the most efficient way to make processes simple and role-based. It unties medical professionals from their offices by enabling them to access timely information and alerts anywhere. Why SOA is also needed Integrating BPM with Service-Oriented Architecture (SOA) also plays a critical role in the development of healthcare solutions that work. SOA can create a single end-to-end process, integrate applications and move them into a common workflow. While SOA enables the reutilization of existing IT infrastructure, BPM supports the process optimization, monitoring and social aspects. SOA and BPM applications support business analysts as they model, create and monitor processes - providing real-time insight and a unified workflow of process activities. Read “New” Solutions for a New Healthcare Landscape on our blog to learn more. SOA & BPM Partner Community For regular information on Oracle SOA Suite become a member in the SOA & BPM Partner Community for registration please visit www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Facebook Wiki Technorati Tags: Avio,Healthcare,SOA Community,Oracle SOA,Oracle BPM,Community,OPN,Jürgen Kress

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  • Picture rendered from above and below using an Orthographic camera do not match

    - by Roy T.
    I'm using an orthographic camera to render slices of a model (in order to voxelize it). I render each slice both from above and below in order to determine what is inside each slice. I am using an orthographic camera The model I render is a simple 'T' shape constructed from two cubes. The cubes have the same dimensions and have the same Y (height) coordinate. See figure 1 for a render of it in Blender. I render this model once directly from above and once directly from below. My expectation was that I would get exactly the same image (except for mirroring over the y-axis). However when I render using a very low resolution render target (25x25) the position (in pixels) of the 'T' is different when rendered from above as opposed to rendered from below. See figure 2 and 3. The pink blocks are not part of the original rendering but I've added them so you can easily count/see the differences. Figure 2: the T rendered from above Figure 3: the T rendered from below This is probably due to what I've read about pixel and texel coordinates which might be biased to the top-left as seen from the camera. Since I'm using the same 'up' vector for both of my camera's my bias only shows on the x-axis. I've tried to change the position of the camera and it's look-at by, what I thought, should be half a pixel. I've tried both shifting a single camera and shifting both cameras and while I see some effect I am not able to get a pixel-by-pixel perfect copy from both camera's. Here I initialize the camera and compute, what I believe to be, half pixel. boundsDimX and boundsDimZ is a slightly enlarged bounding box around the model which I also use as the width and height of the view volume of the orthographic camera. Matrix projection = Matrix.CreateOrthographic(boundsDimX, boundsDimZ, 0.5f, sliceHeight + 0.5f); Vector3 halfPixel = new Vector3(boundsDimX / (float)renderTarget.Width, 0, boundsDimY / (float)renderTarget.Height) * 0.5f; This is the code where I set the camera position and camera look ats // Position camera if (downwards) { float cameraHeight = bounds.Max.Y + 0.501f - (sliceHeight * i); Vector3 cameraPosition = new Vector3 ( boundsCentre.X, // possibly adjust by half a pixel? cameraHeight, boundsCentre.Z ); camera.Position = cameraPosition; camera.LookAt = new Vector3(cameraPosition.X, cameraHeight - 1.0f, cameraPosition.Z); } else { float cameraHeight = bounds.Max.Y - 0.501f - (sliceHeight * i); Vector3 cameraPosition = new Vector3 ( boundsCentre.X, cameraHeight, boundsCentre.Z ); camera.Position = cameraPosition; camera.LookAt = new Vector3(cameraPosition.X, cameraHeight + 1.0f, cameraPosition.Z); } Main Question Now you've seen all the problems and code you can guess it. My main question is. How do I align both camera's so that they each render exactly the same image (mirrored along the Y axis)? Figure 1 the original model rendered in blender

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  • Diagram to show code responsibility

    - by Mike Samuel
    Does anyone know how to visually diagram the ways in which the flow of control in code passes between code produced by different groups and how that affects the amount of code that needs to be carefully written/reviewed/tested for system properties to hold? What I am trying to help people visualize are arguments of the form: For property P to hold, nd developers have to write application code, Ca, without certain kinds of errors, and nm maintainers have to make sure that the code continues to not have these kinds of errors over the project lifetime. We could reduce the error rate by educating nd developers and nm maintainers. For us to be confident that the property holds, ns specialists still need to test or check |Ca| lines of code and continue to test/check the changes by nm maintainers. Alternatively, we could be confident that P holds if all code paths that could violate P went through tool code, Ct, written by our specialists. In our case, test suites alone cannot give confidence that P holdsnd » nsnm ns|Ca| » |Ct| so writing and maintaining Ct is economical, frees up our developers to worry about other things, and reduces the ongoing education commitment by our specialists. or those conditions do not hold, so focusing on education and testing is preferable. Example 1 As a concrete example, suppose we want to ensure that our web-service only produces valid JSON output. Our web-service provides several query and mutation operators that can be composed in interesting ways. We could try to educate everyone who maintains those operations about the JSON syntax, the importance of conformance, and libraries available so that when they write to an output buffer, every possible sequence of appends results in syntactically valid JSON. Alternatively, we don't expose an output stream handle to application code, and instead expose a JSON sink so that every code path that writes a response is channeled through a JSON sink that is written and maintained by a specialist who knows JSON syntax and can use well-written libraries to produce only valid output. Example 2 We need to make sure that a service that receives a URL from an untrusted source and tries to fetch its content does not end up revealing sensitive files from the file-system, like file:///etc/passwd. If there is a single standard way that any developer familiar with the application language's libraries would use to fetch URLs, which has file-system access turned off by default, then simply educating developers about the standard mechanism, and testing that file probing fails for some inputs, will probably be sufficient.

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  • Failing report subscriptions

    - by DavidWimbush
    We had an interesting problem while I was on holiday. (Why doesn't this stuff ever happen when I'm there?) The sysadmin upgraded our Exchange server to Exchange 2010 and everone's subscriptions stopped. My Subscriptions showed an error message saying that the email address of one of the recipients is invalid. When you create a subscription, Reporting puts your Windows user name into the To field and most users have no permissions to edit it. By default, Reporting leaves it up to exchange to resolve that into an email address. This only works if Exchange is set up to translate aliases or 'short names' into email addresses. It turns out this leaves Exchange open to being used as a relay so it is disabled out of the box. You now have three options: Open up Exchange. That would be bad. Give all Reporting users the ability to edit the To field in a subscription. a) They shouldn't have to, it should just work. b) They don't really have any business subscribing anyone but themselves. Fix the report server to add the domain. This looks like the right choice and it works for us. See below for details. Pre-requisites: A single email domain name. A clear relationship between the Windows user name and the email address. eg. If the user name is joebloggs, then joebloggs@domainname needs to be the email address or an alias of it. Warning: Saving changes to the rsreportserver.config file will restart the Report Server service which effectively takes Reporting down for around 30 seconds. Time your action accordingly. Edit the file rsreportserver.config (most probably in the folder ..\Program Files[ (x86)]\Microsoft SQL Server\MSRS10_50[.instancename]\Reporting Services\ReportServer). There's a setting called DefaultHostName which is empty by default. Enter your email domain name without the leading '@'. Save the file. This domain name will be appended to any destination addresses that don't have a domain name of their own.

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  • WebLogic Server Weekly for March 26th, 2012: WLS 1211 Update, Java 7 Certification, Galleria, WebLogic for DBAs, REST and Enterprise Architecture, Singleton Services

    - by Steve Button
    WebLogic Server 12c Certified with Java 7 for Production Use WebLogic Server 12c (12.1.1) has been certified with JDK 7 for development usage since December and we have now completed JDK 7 certification for use with production systems. In doing so, we have updated the WebLogic Server 12c (12.1.1) distributions incorporating fixes associated with JDK 7 support as well as some bundled patches that address several issues that have been discovered since the initial release. These updated distributions are available for download from OTN and will be beneficial for all WebLogic Server 12c (12.1.1) users in general. What's New Release Notes Download Here! Updated Oracle WebLogic Server 12.1.1.0 distribution Never one to miss a trick, Markus Eisele was one of the first to notice the WebLogic Server 12c update and post a blog about it. Sources told me that as of Friday last week you have an updated version of WebLogic Server 12c on OTN. http://blog.eisele.net/2012/03/updated-oracle-weblogic-server-12110.html Using WebLogic Server 12c with Java 7 - Video To illustrate the use of Java 7 with WebLogic Server 12c, I put together a screen cam showing the creation of a domain using Java 7 and then build and deploy a simple web application that uses Java 7 syntax to show it working. Ireland OUG Presentation: WebLogic for DBAs Simon Haslam posted his slides from a presentation he gave Dublin on 21/3/12 at the OUG Ireland conference. In this presentation, he explains the core concepts and ideas behind WebLogic Server, walks through an installation and offers some tips and common gotcha's to avoid. Simon also covers some aspects of installing and use Enterprise Manager 12c. Note: I usually install the JVM and use the generic .jar installer rather than using an installer bundled with a JVM. http://www.slideshare.net/Veriton/weblogic-for-dbas-10h Slightly Retro: Jeff West on Enterprise Architecure and REST In this weeks flashback, we look at Jeff West's blog from early 2011 where he provides some thoughtful opinions on enterprise architecture and innovation, then jumps into his views on REST. After I progressed in my career and did more team-leading and architecture type roles I was ‘educated’ on what it meant to have Asynchronous and Long-Running processes as part of your Enterprise Application architecture. If I had a synchronous process then I needed a thread available to service the request and then provide the response. https://blogs.oracle.com/jeffwest/entry/weblogic_integration_wli_web_services_and_soap_and_rest_part_1 Starting Managed Servers without an Administration Server using Node Manager and WLST Blogger weblogic-tips shows how to start a managed server without going through the Administration Server, using the Node Manager and WLST. Connect WLST to a Node Manager by entering the nmConnect command. http://www.weblogic-tips.com/2012/02/18/starting-managed-servers-without-an-administration-server-using-node-manager-and-wlst/ Using WebLogic Server Singleton Services WebLogic Server has supported the notion of a Singleton Service for a number of releases, in which WebLogic Server will maintain a single instance of a configured singleton service on one managed server within a cluster. This blog demonstrates how the singleton service can be accessed and used from applications deployed on the cluster. http://buttso.blogspot.com.au/2012/03/weblogic-server-singleton-services.html

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  • Organizing Git repositories with common nested sub-modules

    - by André Caron
    I'm a big fan of Git sub-modules. I like to be able to track a dependency along with its version, so that you can roll-back to a previous version of your project and have the corresponding version of the dependency to build safely and cleanly. Moreover, it's easier to release our libraries as open source projects as the history for libraries is separate from that of the applications that depend on them (and which are not going to be open sourced). I'm setting up workflow for multiple projects at work, and I was wondering how it would be if we took this approach a bit of an extreme instead of having a single monolithic project. I quickly realized there is a potential can of worms in really using sub-modules. Supposing a pair of applications: studio and player, and dependent libraries core, graph and network, where dependencies are as follows: core is standalone graph depends on core (sub-module at ./libs/core) network depdends on core (sub-module at ./libs/core) studio depends on graph and network (sub-modules at ./libs/graph and ./libs/network) player depends on graph and network (sub-modules at ./libs/graph and ./libs/network) Suppose that we're using CMake and that each of these projects has unit tests and all the works. Each project (including studio and player) must be able to be compiled standalone to perform code metrics, unit testing, etc. The thing is, a recursive git submodule fetch, then you get the following directory structure: studio/ studio/libs/ (sub-module depth: 1) studio/libs/graph/ studio/libs/graph/libs/ (sub-module depth: 2) studio/libs/graph/libs/core/ studio/libs/network/ studio/libs/network/libs/ (sub-module depth: 2) studio/libs/network/libs/core/ Notice that core is cloned twice in the studio project. Aside from this wasting disk space, I have a build system problem because I'm building core twice and I potentially get two different versions of core. Question How do I organize sub-modules so that I get the versioned dependency and standalone build without getting multiple copies of common nested sub-modules? Possible solution If the the library dependency is somewhat of a suggestion (i.e. in a "known to work with version X" or "only version X is officially supported" fashion) and potential dependent applications or libraries are responsible for building with whatever version they like, then I could imagine the following scenario: Have the build system for graph and network tell them where to find core (e.g. via a compiler include path). Define two build targets, "standalone" and "dependency", where "standalone" is based on "dependency" and adds the include path to point to the local core sub-module. Introduce an extra dependency: studio on core. Then, studio builds core, sets the include path to its own copy of the core sub-module, then builds graph and network in "dependency" mode. The resulting folder structure looks like: studio/ studio/libs/ (sub-module depth: 1) studio/libs/core/ studio/libs/graph/ studio/libs/graph/libs/ (empty folder, sub-modules not fetched) studio/libs/network/ studio/libs/network/libs/ (empty folder, sub-modules not fetched) However, this requires some build system magic (I'm pretty confident this can be done with CMake) and a bit of manual work on the part of version updates (updating graph might also require updating core and network to get a compatible version of core in all projects). Any thoughts on this?

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  • Card deck and sparse matrix interview questions

    - by MrDatabase
    I just had a technical phone screen w/ a start-up. Here's the technical questions I was asked ... and my answers. What do think of these answers? Feel free to post better answers :-) Question 1: how would you represent a standard 52 card deck in (basically any language)? How would you shuffle the deck? Answer: use an array containing a "Card" struct or class. Each instance of card has some unique identifier... either it's position in the array or a unique integer member variable in the range [0, 51]. Shuffle the cards by traversing the array once from index zero to index 51. Randomly swap ith card with "another card" (I didn't remember how this shuffle algorithm works exactly). Watch out for using the same probability for each card... that's a gotcha in this algorithm. I mentioned the algorithm is from Programming Pearls. Question 2: how to represent a large sparse matrix? the matrix can be very large... like 1000x1000... but only a relatively small number (~20) of the entries are non-zero. Answer: condense the array into a list of the non-zero entries. for a given entry (i,j) in the array... "map" (i,j) to a single integer k... then use k as a key into a dictionary or hashtable. For the 1000x1000 sparse array map (i,j) to k using something like f(i, j) = i + j * 1001. 1001 is just one plus the maximum of all i and j. I didn't recall exactly how this mapping worked... but the interviewer got the idea (I think). Are these good answers? I'm wondering because after I finished the second question the interviewer said the dreaded "well that's all the questions I have for now." Cheers!

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  • Virtual Lab part 2&ndash;Templates, Patterns, Baselines

    - by Geoff N. Hiten
    Once you have a good virtualization platform chosen, whether it is a desktop, server or laptop environment, the temptation is to build “X”.  “X” may be a SharePoint lab, a Virtual Cluster, an AD test environment or some other cool project that you really need RIGHT NOW.  That would be doing it wrong. My grandfather taught woodworking and cabinetmaking for twenty-seven years at a trade school in Alabama.  He was the first instructor hired at that school and the only teacher for the first two years.  His students built tables, chairs, and workbenches so the school could start its HVAC courses.   Visiting as a child, I also noticed many extra “helper” stands, benches, holders, and gadgets all built from wood.  What does that have to do with a virtual lab, you ask?  Well, that is the same approach you should take.  Build stuff that you will use.  Not for solving a particular problem, but to let the Virtual Lab be part of your normal troubleshooting toolkit. Start with basic copies of various Operating Systems.  Load and patch server and desktop OS environments.  This also helps build your collection of ISO files, another essential element of a virtual Lab.  Once you have these “baseline” images, you can use your Virtualization software’s snapshot capability to freeze the image.  Clone the snapshot and you have a brand new fully patched machine in mere moments.  You may have to sysprep some of the Microsoft OS environments if you are going to create a domain environment or experiment with clustering.  That is still much faster than loading and patching from scratch. So once you have a stock of raw materials (baseline images in this case) where should you start.  Again, my grandfather’s workshop gives us the answer.  In the shop it was workbenches and tables to hold large workpieces that made the equipment more useful.  In a Windows environment the same role falls to the fundamental network services:  DHCP, DNS, Active Directory, Routing, File Services, and Storage services.  Plan your internal network setup.  Build out an AD controller with all the features listed.  Make the actual domain an isolated domain so it will not care about where you take it.  Add the Microsoft iSCSI target.  Once you have this single system, you can leverage it for almost any network environment beyond a simple stand-alone system. Having these templates and fundamental infrastructure elements ready to run means I can build a quick lab in minutes instead of hours.  My solutions are well-tested, my processes fully documented with screenshots, and my plans validated well before I have to make any changes to client systems.  the work I put in is easily returned in increased value and client satisfaction.

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