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  • Cannot access Domain Controller through VPN

    - by Markus
    In our small network there is a Windows 2008 R2 Domain Controller that also serves as Remote Access Server. For years, we could access this server and the resources in the network over a VPN connection without any problem. Since some time however, I am able to connect to the VPN, but my Windows 8 client (and another one I used for testing purposes) is not able to connect the domain controller afterwards. I can access any other server in the network, but there seems to be a problem regarding the trust between the client(s) and the server. If I connect the client to the network directly over a LAN cable, everything works as expected. Also I can connect to another server over VPN and open a RDP prompt to the DC without a problem. On the client, whenever I try to access the DC, I get an access denied message. I've tried to update the group policies both over VPN and LAN. Also, I've removed the client from the domain and re-added it. The client shows a message that Windows requires valid login information when connected to the VPN - but my credentials are valid. They work when I logon to the client when not connected to the VPN and also when connected to the LAN. Turning off the firewall on the client and the server did not change anything. DNS resolution works both on the server and the client. What else can I do to diagnose and solve the problem?

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  • computer randomly restarting. both in game and out of game

    - by eric
    first my specs are. AMD Phenom II x4 955 processor 3.2ghz 20gb ddr3 ram 4Gb Nvidia Geforce GTX 770 850w Corsair tx850w psu Gigabyte ud3 mobo Windows 7 professional I recently uprgraded my vid card to gtx770 and upgraded my psu to the 850w thats in it now. i did a reformat with the installation of the new gpu and psu and started fresh and only have a couple programs installed (diablo3, nvidia control panel, wow, and steam). all drivers are up to date and everything is hooked up correctly. the problem is it will randomly shut down. no blue screen. just turns itself straight off and reboots after a couple seconds. occasionally i will have to unplug the power cable from the psu for a few minutes then reconnect and it will start up. it seems pretty random. sometimes it does it when my pc is just sitting there on the home screen. and sometimes it does it during games. and sometimes it doesnt do it for days at a time. i noticed the psu felt hot so i put an extra fan blowing straight onto both the psu and gpu and neither feel overly hot after it shuts down now. could it just be that it is a psu problem. the psu was taken from another machine but wasnt having this problem in that machine. i have seen a few articles online about gtx770 doing the same thing. but i havent found any answers or solutions. any help will be appreciated. im sure the 850w is enough to power my machine, im just stumped and ran out of ideas to fix it. i have even returned the video card for another thinking it might have been an issue with that particular card, but still gettin the same problem.

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  • Can I have a single solid state drive and a RAID array on the same machine? [closed]

    - by jaminto
    Hi- To summarize, i'm looking to use a single solid state drive as my primary drive, and two conventional sata drives in a RAID 1 configuration for data. I am trying to install 64-bit Windows 7 onto this configuration. Is this possible? Here are the details: I built a desktop that has been running 64-bit Vista on two 500Gb in a RAID 1 array for a few years. I just purchased an Intel X25-M 80Gb Sata Solid-State Drive, and was planning on using this a my primary drive, and keeping the RAID 1 array as my data drive. I added the SSD drive and in the RAID setup, configured it as a RAID 0 array of only one disk. Then, I tried to do a clean install of windows 7 64-bit, but got stuck in the "Missing driver for CD/DVD drive" black hole of selecting driver files and Windows telling me that i don't have the appropriate driver for my hardware. The missing hardware is NOT a CD/DVD drive, since i'm installing off of my only CD/DVD drive. Plus at one point i was able to point it at a driver for my raid controller, and then my hard drives magically showed up as browsable sources for finding drivers for some other unnamed device that setup couldn't recognize. After a few hours of trying drivers (this was a very slow process) i decided to reboot and look at the BIOS settings. I'm using an ASUS M2A-VM motherboard which has an ATI SB600 RAID controller on board. I switched the "On board SATA Type" setting from "SATA" to "AHCI" thinking that since AHCI is an Intel thing, this would help. Unfortunately, this abandoned my RAID configuration, and my previously mirrored drives are showing up as separate drives when i boot into my current windows installation. Am i trying to do the impossible here? Should i just buy a separate SATA/RAID PCI card and plug the SSD into that? Any help would be greatly appreciated.

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  • Windows 7 Icons, Buttons, and Tabs corrupted...Professional 32-bit

    - by xhyperx
    The other day, about two or three ago, I was simply typing in a Microsoft Word document when my screen froze. After a few moments, it went black...I thought it was my vid hardware (dual nVidia 9800 GTs). Anyway, I did a hard reboot, and chose to Start Normally. The system blue screened telling me there was a failure in the Memory Manager. So then I thought maybe a RAM failure or vid memory failure. I attempted reboot again, this time I got presented with the option to repair windows...so I went with that. The repair app finished and did an auto reboot. This time I got all the way back to my desktop where in a matter of a about 30 seconds, the system blue screened again and pointed to the Memory Manager as the area of cause. Again I rebooted, the repair thingy came up again and I allowed it to do its thing. Deciding if the same failure occured I'd begin pulling hardware to see at what point I may have found the possibly defective party. However, this time it rebooted, I got back to desktop and no crash. All looked well, untill I looked at the baloon messages when hovering over the System Bar icons. Also when I opened any of my browsers, the tabs had no text, and any window that pops up that has regular buttons (OK, Cancel, etc., etc.) looks weird. The buttons are really really long and have no text. So it seems like the system is once again running smoothly, however something has gotten corrupted.. something relating to drawing basic windows user interface objects. Help...all ideas are respected and appreciated. Have a great day everyone!

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  • Can my employer force me to backup my personal machine? [closed]

    - by Eric B
    Here's the background: Approximately 1.25 years ago, the company I work for was acquired by a larger 400 person company. Before acquisition (and today still) we are all remote employees using our own personal hardware for work-related duties (coding, email, etc). We are approximately 15 employees within the larger organization. Some time after acquisition, the now owning company was slapped with a civil lawsuit. Part of this lawsuit (discovery) is requiring them to retrieve & store from us any related information. Because we were a separate company up until acquisition, there is a high probability that our personal machines might contain information about what the lawsuit alleges (email, documents, chat logs?, etc). Obviously, this depends largely on the person's job function (engineer vs. customer support vs. CEO). All employees are being required to comply. Since acquisition (1.25 yrs), the new company has not provided us with company laptops/desktops. We continue to use personal hardware, licenses, etc for work. Email is via POP3s and not hanging around on the mail server - it's on everyone's client. Documents are spread across personal machines. So, now they want us each to backup our complete personal machines. They are allowing us to create a "personal" folder where we can place personal documents. That single folder will be excluded from backup. Of course, that means total re-arrangement of documents, etc. For most of us, 99% of the data on the machine is NOT related to work. So, what's the consensus? Should we comply? What is their recourse if we do not?

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  • windows server 2003 speed issues

    - by farzinSH
    I have a HP server with windows server 2003 and 50 windows XP clients. Since a week and a half the networks speed suddenly drop 2-3 times per day. It gets so slow that none of the clients could work with the HIS program installed on them. We tried so many different things such as replacing the hubs,switches and even some wires. Every time one of these changes solves the problem and the network goes back to its normal state. I checked everything. Even when I disconnected all the clients from the server and connected it to just one computer the problem still remained for 2 hours. I just narrowed down the problem to the couple of likely speculations as follows: viruses? (Updated Kaspersky running on the server shows none) server hardware failure? Physical memory usage on the server? (Because the last time the problem occurred none of the changes above solved the issue so I restarted the server an checked the physical memory usage which was 2 GBs. But I noticed it's increasing over time to over 9 GBs...the server has 16 GBs of RAM.) I surfed the internet and got nothing. Any help would do us a lot....thanks in advance

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  • Debian on HP ProLiant server hangs (disk i/o is my guess)

    - by Martin
    I installed Debian (2.6.32-5-amd64) on my HP ProLiant MicroServer (purchased recently.) I also added 3 2tb hd in zfs. I've experienced several server froze. Sometimes it showed Soft lockup CUP stuck for 61s! Today I experienced a different problem (I think) and the message looked like this [431336.200002] Call Trace: [431336.200002] [<ffffffff812fcc7c>] ? _write_lock+0xe/0xf [431336.200002] [<ffffffff810d7a86>] ? __vmalloc_node+0x99/0xe2 : : and (in different screen) [431354.222318] Node 0 DMA32 free: 2064kB min:5520kB low:69900kB high:8280kB active_anon:181648kB inactive_anon:61728kB active_file:313152kB inactive_file:832456kB unevictable: 0kB isolated(anon): 0kB isolated(file):0kB present:1922596kB mlocked:0kB dirty:72kB writeback:0kB mapped:25620kB shmem:344kB slab_reclaimable:34460kB slab_unreclaimable:31400kB kernel_stack:2288kB pagetables:7556kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no [431354.222431] lowmem_reserve[]: 0 0 0 0 : : Is this a hardware problem? What tools/methods can I find out the source of the problem? I've used Debian for years but never had problem like this.

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  • Windows 7 Icons, Buttons, and Tabs corrupted...Professional 32-bit

    - by xhyperx
    The other day, about two or three ago, I was simply typing in a Microsoft Word document when my screen froze. After a few moments, it went black...I thought it was my vid hardware (dual nVidia 9800 GTs). Anyway, I did a hard reboot, and chose to Start Normally. The system blue screened telling me there was a failure in the Memory Manager. So then I thought maybe a RAM failure or vid memory failure. I attempted reboot again, this time I got presented with the option to repair windows...so I went with that. The repair app finished and did an auto reboot. This time I got all the way back to my desktop where in a matter of a about 30 seconds, the system blue screened again and pointed to the Memory Manager as the area of cause. Again I rebooted, the repair thingy came up again and I allowed it to do its thing. Deciding if the same failure occured I'd begin pulling hardware to see at what point I may have found the possibly defective party. However, this time it rebooted, I got back to desktop and no crash. All looked well, untill I looked at the baloon messages when hovering over the System Bar icons. Also when I opened any of my browsers, the tabs had no text, and any window that pops up that has regular buttons (OK, Cancel, etc., etc.) looks weird. The buttons are really really long and have no text. So it seems like the system is once again running smoothly, however something has gotten corrupted.. something relating to drawing basic windows user interface objects. Help...all ideas are respected and appreciated. Have a great day everyone!

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  • Adding a 2008 server to a 2003 Domain with DNS devolution?

    - by mvdwege
    I'm running into a problem adding a 2008 server to our existing 2003 domain, and as I am not a Windows admin, I'm not getting the problem here. Some reading around on Technet seems to indicate that DNS devolution is the issue. Here's the setup: DNS for the entire company is hosted on a Unix server running Bind, including the service records for the Windows domain. Our toplevel is company.local, and functional domains are in subdomains, such as mgt.company.local (our management servers). Our Windows servers live mostly in office.company.local, but some of them live in .mgt.company.local and .customers.company.local. The 2003 servers all succesfully authenticate against company.local as the Windows domain. Their position in the infrastructure is set by setting the primary DNS suffix under the network settings and the computer name dialog. Trying to do the same with a brand new 2008 install throws an error though: "Changing the Primary Domain DNS name of this computer to office.company.local failed [...] The specified server cannot perform the requested operation" I tried googling, but the closest I came was the Technet article on DNS Devolution, and I can't make heads nor tails on how to apply that to my case. Addendum 2012-10-23: The problem is not joining the domain, that works, the problem is that it joins with the wrong name, as .company.local, instead of .office.company.local. So far everything works, but I'm rather afraid to run production like this, because sooner or later something is going to complain about the AD name not matching DNS.

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  • Is there a way to measure wifi traffic on a network from a client?

    - by millimoose
    Is there some way (preferrably one that comes with an existing tool) to measure the traffic going through the whole WiFi network from a computer connected to it? (That is, not from the AP or something between the modem and AP.) My situation is this: a few months back, the internet connection at my parent's place got really sluggish and laggy. (Lag spikes that cause page loads to time out etc, connections plain getting lost and dropping packets forever.) It's impossible to get mom's husband to do anything about this because he brushes this off with something like "just tell your sister to turn off torrents". Unfortunately the WiFi router's firmware doesn't do traffic logging. I'm not going to risk bricking it to put WRT on it; nor am I keen on rewiring the network to add a proxy to analyse the traffic. (I'm one of those people that make computers break just by looking at them, except machines I own.) I'd like to be able to find out roughly how much data is going over the air here while all the LAN wires are out of the router, all the computers accused of torrenting are off, etc. The idea is to either show that: Even if everything but my macbook is turned off, something is congesting the network. The husband is a systems developer and has a whole lot of mysterious hardware that's not to be touched around, one of them might be culprit. There is barely any traffic on the network, but the internet is still sluggish. Meaning this is likely a problem the ISP should solve. (Some hardware of theirs being glitchy, someone on an aggregated line hogging it constantly...) The network is encrypted, but I can temporarily set it to open for the sake of finding this out. So, in conclusion? Can this be done? Or is there some alternative way I could try to diagnose the problem?

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  • What could possibly cause my computer to power down at random times?

    - by geoffreydv
    I have recently bought a new Power Supply and a new graphics card. My PC ran smoothly for a few months now but since a couple of days I'm having a strange problem. I am trying to isolate the problem to a specific piece of hardware (because if it's either the Power Supply or the Graphics card they are still under warranty). The problem started when I was playing a game (diablo 3). My PC suddenly powered down. I was unable to turn it on again by pressing the power button. I unplugged the power cable for a few seconds and plugged it back in. This time the pc powered on but the indication light turned orange instead of white as it normally does. The fans were not spinning and I did not see anything on my screen. After trying a couple of times I gave up. Two days later I tried again and this time the PC did boot up as usual. Everything looked okay until I tested if the problem was resolved by starting Diablo again. After about two minutes it powered down again as it did the first time. If I don't run any games my PC does power down after about 3-5 hours. Another fact that might be relevant: One time the PC did not shut down immediatly, instead first my graphics "powered down" but the music I was playing kept on playing. After about 20 seconds the pc powered down completely as usual. What I also noticed is that when I boot instantly after a power down, the chance of another power down occuring is much higher. Does anyone have an idea what could be causing this kind of behaviour or has a certain tool to diagnose the specific hardware parts? Thanks Specs: Memory: 6GB Processor: Intel i5 OS: Windows 7 64 bit The PC is a Dell Studio XPS 8100 with a replaced PSU and Graphics card: PSU: Corsair CX500 (500 watt) Graphics card: AMD Radeon 6850

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  • Internet keeps connecting and disconnecting

    - by OmerPT
    I have a PC running 32bit Windows 7 Professional. My wireless internet card is Edimax EW-7128G, it is inside my computer case and it is connected to an antenna. My problem is: I have a wireless connection to my router, the signal is fine and it's not slow or anything, but it just keeps disconnecting every 30 seconds or so, then connects back, then it disconnects, then connects back and so on. This is new - it only started about a week ago, everything worked just fine until then. I know it's not a problem with the router because: Other computers can connect to it easily and they work just fine, no disconnections (My phone too). I know it's not a problem with the computer or the wireless card itself because: I have Ubuntu installed side-by-side with my Windows, and when I switch to Ubuntu the internet works great. This caused me to think it's probably a problem with the wireless card drivers installed on windows (Ubuntu auto-installed them, I installed them manually on windows): I tried uninstalling them, and then installing them back again, sadly that didn't help. I'm kind of lost here - can anyone think of anything else I should try? Thanks :)

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  • How do I disable DirectDraw and Direct3D acceleration on Windows 8? [closed]

    - by Favourite Chigozie Onwuemene
    Some old games that i would really like to play run slowly on some graphic drivers when direct3d acceleration is enabled. I have tried many suggestions but none seems to work. The only thing i have not tried is disabling direct3d acceleration. Is it possible to disable DirectDraw and Direct3D acceleration on my Windows 8 pc? There are certain bad versions of GeForce drivers that cause this problem. This is a problem in the drivers themselves and is unfortunately completely outside our control. The recommended way to fix this problem is to update your graphics card drivers (go to NVIDIA's web site for this). Alternatively, there is a workaround that alleviates or solves the slowdown problem altogether. Try this: Right-click on your desktop and select "Properties". Go to the "Settings" tab and click on "Advanced...". Click on the "Troubleshooting" tab and move the slider to the left until it says that all DirectDraw and Direct3D accelerations have been disabled (around the middle of the range). Finally, click on "OK". Note that this workaround might cause other games on your computer to slow down, so you may have to switch back and forth between settings, but it's certainly worth a try if you can't obtain an updated graphics driver. -source: interactionstudios

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  • Strange network issue (ZIP file fails CRC test over VPN)

    - by Joe Schmoe
    We have a server in the office running Windows Server 2003 Our office is connected to our datacenter via hardware VPN (Linksys RV082 router in the office to CISCO router in the datacenter). There is a job that runs on the server in the office that does following: ZIP certain files from the server using 7Zip, copy ZIP file to a network share in the office and verify ZIP integrity, copy ZIP file to a network share in the data center and verify ZIP integrity. Problem is - verifying ZIP integrity for the file in the data center always fails. However, if I run 7Zip on the server in data center that exposes that share ZIP file verifies just fine, so it is not actually corrupted during copy operation. Additionally, I tried running ZIP on other computers in the office to verify ZIP file on datacenter file share and it verifies OK. I tried plugging server to the same network port where my workstation is connected using different cable (my workstation doesn't exhibit this problem) and ZIP verification still fails. So the problem is local to that specific server. On network adapter properties for the server in question there is no "Advanced" tab where one can usually configure a lot of network settings. Network card driver is up to date (Windows Update doesn't find anything newer and Lenovo website doesn't have any drivers for Windows 2003 for this computer model). Is there any other way to configure network setting via command line? What settings could be relevant to this problem?

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  • php mail() function painfully slow on local development machine

    - by Michael B
    Background: If you have set up a local apache server for development purposes you may have run into the problem where sendmail takes a long time (at least one minute) to send emails. This is extremely frustrating if you are trying to debug a problem with an email you have generated. There are several forum posts on the internet that discuss this problem. However, none of theme described what to do in enough detail for my limited knowledge. Here are the steps that worked for me: 1) find your hostname (in case you've forgotten it) using this command: :~$ cat /hosts/hostname myhostname 2) edit the file /etc/hosts and make sure the first line is the following: 127.0.0.1 localhost.localdomain localhost myhostname 3) edit the sendmail configuration file ( /etc/mail/sendmail.cf in Ubuntu) and Uncomment the line #O HostsFile=/etc/hosts 4) Restart the computer. The computer should boot up much faster now and the mail() function should return almost immediately. HOWEVER, the emails won't actually be sent unless you follow step 5. 5) You must new use the sendmail '-f' option whenever using the mail function. For example: mail('[email protected]', 'the subject', 'the message', null, '[email protected]'); My question for my fellow serverfaulters is: What further changes can be made so that I don't have to use the sendmail -f option? Although it's not very hard to add the -f option, it is a problem when your CMS (such as Drupal) does not use the -f option when sending mail. You would need to hack a core module to add this option.

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  • In Windows 7 is there a way to login from any user account and see the same workspace and be able to use the running programs of another user?

    - by WickedMongoose
    Our group has a number of Test Stands with PCs that are currently being accessed with a single group login. It has been sent from on high that this is not the way to do things for security reasons and we all agree. However. Multiple team members from around the world log into these Test Stands and need to be able to access programs that have been run from what would be different user profiles if we were to no longer have a single common login. Is there a way to have a common workspace such that when different users login, they will be able to see and interact with all running applications as if they were using a common login? Applications that we run link to and monopolize hardware resources connected to the PC and it is time consuming to restart and reload settings every time a new user logs in. Even if the program did not monopolize the hardware many of these programs are resource intensive and require a large portion of each machine's RAM to run, so trying to run the application again when it is already running from multiple user accounts would quickly consume all system resources. Simple Example: I open a chrome browser while logged into our pc. I then logout and another team member remotes in and should be able to see my open browser and be able to interact with it as if he were the one who opened it. Any alternative process flows or solutions from someone who has gone through a similar transition would be appreciated. This is not a request for how to give all users access to the ability to run a program, but it is the request for how to allow all users access to interact with running applications that have been started by other users and need to be interacted with as if the new user started and has control of the application.

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  • 3 Server, is this a cluster scenario?

    - by HornedBeast
    Hello, At the moment I have one Ubuntu server, 9.10, running with a simple Samba share, a mail server, DNS server and DHCP server. Mostly its just there for file sharing and email server. I also have 2 other servers that are exactly the same hardware and spec as the first, which have an rsync set up to retrieve the shared folders and backs them up. However, if the first server goes down, all of our shares disappear along with our mail and the system must be rebuilt. Also I tend to find if people are downloading a large amount from the file server, no-one can access there emails - especially in the morning when everyone is signing in at once. Would it be more beneficial for me to have all 3 servers, all running the same services, doing the same thing with some sort of cluster with load balancing? In short, how can I get the best out of my 3 hardware servers? I'm not really sure where to begin looking, or how to go about such a setup where 3 servers are all identical, but perhaps one acts as the main load balancer?? If someone can point me in the right direction, or if this simply sounds like one of those Enterprise Cloud's that is now a default setup in Ubuntu Server 9.10+, then I'll go down that route. Cheers in advance. Andy

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  • Windows 7 constantly accessing hard drive [duplicate]

    - by Zohar
    Possible Duplicate: Tool which finds which process is causing the heavy hard drive activity? Did you notice that on Windows 7 (I use 64-bit) the hard drive LED is constantly blinking, which means that the OS is constantly wearing the hard drive by accessing it? It's something related to the system process, and it even occurs in safe mode, so I don't think it's a third party software problem. Has anyone experienced this problem as well, and is it a Windows problem, or caused by something else? Edit: My indexing service is reduced to indexing only the Start Menu. Even if it was set for the whole computer, it would eventually stop; that's not it. My friends also suffer from the same problem. Please answer my first question: have any of you have seen a Windows 7 machine whose hard drive LED is at rest? I'm also trying to track down the offending process using procmon and Resource Monitor, and it actually seems like a system process. It could also be svchost.exe, and I'm not sure which file they are accessing since I see a lot of activity which I can't make sense of. It's loading system DLLs, accessing registry keys, and other nonsense.

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  • How to use onSensorChanged sensor data in combination with OpenGL

    - by Sponge
    I have written a TestSuite to find out how to calculate the rotation angles from the data you get in SensorEventListener.onSensorChanged(). I really hope you can complete my solution to help people who will have the same problems like me. Here is the code, i think you will understand it after reading it. Feel free to change it, the main idea was to implement several methods to send the orientation angles to the opengl view or any other target which would need it. method 1 to 4 are working, they are directly sending the rotationMatrix to the OpenGl view. all other methods are not working or buggy and i hope someone knows to get them working. i think the best method would be method 5 if it would work, because it would be the easiest to understand but i'm not sure how efficient it is. the complete code isn't optimized so i recommend to not use it as it is in your project. here it is: import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.nio.FloatBuffer; import javax.microedition.khronos.egl.EGL10; import javax.microedition.khronos.egl.EGLConfig; import javax.microedition.khronos.opengles.GL10; import static javax.microedition.khronos.opengles.GL10.*; import android.app.Activity; import android.content.Context; import android.content.pm.ActivityInfo; import android.hardware.Sensor; import android.hardware.SensorEvent; import android.hardware.SensorEventListener; import android.hardware.SensorManager; import android.opengl.GLSurfaceView; import android.opengl.GLSurfaceView.Renderer; import android.os.Bundle; import android.util.Log; import android.view.WindowManager; /** * This class provides a basic demonstration of how to use the * {@link android.hardware.SensorManager SensorManager} API to draw a 3D * compass. */ public class SensorToOpenGlTests extends Activity implements Renderer, SensorEventListener { private static final boolean TRY_TRANSPOSED_VERSION = false; /* * MODUS overview: * * 1 - unbufferd data directly transfaired from the rotation matrix to the * modelview matrix * * 2 - buffered version of 1 where both acceleration and magnetometer are * buffered * * 3 - buffered version of 1 where only magnetometer is buffered * * 4 - buffered version of 1 where only acceleration is buffered * * 5 - uses the orientation sensor and sets the angles how to rotate the * camera with glrotate() * * 6 - uses the rotation matrix to calculate the angles * * 7 to 12 - every possibility how the rotationMatrix could be constructed * in SensorManager.getRotationMatrix (see * http://www.songho.ca/opengl/gl_anglestoaxes.html#anglestoaxes for all * possibilities) */ private static int MODUS = 2; private GLSurfaceView openglView; private FloatBuffer vertexBuffer; private ByteBuffer indexBuffer; private FloatBuffer colorBuffer; private SensorManager mSensorManager; private float[] rotationMatrix = new float[16]; private float[] accelGData = new float[3]; private float[] bufferedAccelGData = new float[3]; private float[] magnetData = new float[3]; private float[] bufferedMagnetData = new float[3]; private float[] orientationData = new float[3]; // private float[] mI = new float[16]; private float[] resultingAngles = new float[3]; private int mCount; final static float rad2deg = (float) (180.0f / Math.PI); private boolean mirrorOnBlueAxis = false; private boolean landscape; public SensorToOpenGlTests() { } /** Called with the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE); openglView = new GLSurfaceView(this); openglView.setRenderer(this); setContentView(openglView); } @Override protected void onResume() { // Ideally a game should implement onResume() and onPause() // to take appropriate action when the activity looses focus super.onResume(); openglView.onResume(); if (((WindowManager) getSystemService(WINDOW_SERVICE)) .getDefaultDisplay().getOrientation() == 1) { landscape = true; } else { landscape = false; } mSensorManager.registerListener(this, mSensorManager .getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_GAME); mSensorManager.registerListener(this, mSensorManager .getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD), SensorManager.SENSOR_DELAY_GAME); mSensorManager.registerListener(this, mSensorManager .getDefaultSensor(Sensor.TYPE_ORIENTATION), SensorManager.SENSOR_DELAY_GAME); } @Override protected void onPause() { // Ideally a game should implement onResume() and onPause() // to take appropriate action when the activity looses focus super.onPause(); openglView.onPause(); mSensorManager.unregisterListener(this); } public int[] getConfigSpec() { // We want a depth buffer, don't care about the // details of the color buffer. int[] configSpec = { EGL10.EGL_DEPTH_SIZE, 16, EGL10.EGL_NONE }; return configSpec; } public void onDrawFrame(GL10 gl) { // clear screen and color buffer: gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); // set target matrix to modelview matrix: gl.glMatrixMode(GL10.GL_MODELVIEW); // init modelview matrix: gl.glLoadIdentity(); // move camera away a little bit: if ((MODUS == 1) || (MODUS == 2) || (MODUS == 3) || (MODUS == 4)) { if (landscape) { // in landscape mode first remap the rotationMatrix before using // it with glMultMatrixf: float[] result = new float[16]; SensorManager.remapCoordinateSystem(rotationMatrix, SensorManager.AXIS_Y, SensorManager.AXIS_MINUS_X, result); gl.glMultMatrixf(result, 0); } else { gl.glMultMatrixf(rotationMatrix, 0); } } else { //in all other modes do the rotation by hand: gl.glRotatef(resultingAngles[1], 1, 0, 0); gl.glRotatef(resultingAngles[2], 0, 1, 0); gl.glRotatef(resultingAngles[0], 0, 0, 1); if (mirrorOnBlueAxis) { //this is needed for mode 6 to work gl.glScalef(1, 1, -1); } } //move the axis to simulate augmented behaviour: gl.glTranslatef(0, 2, 0); // draw the 3 axis on the screen: gl.glVertexPointer(3, GL_FLOAT, 0, vertexBuffer); gl.glColorPointer(4, GL_FLOAT, 0, colorBuffer); gl.glDrawElements(GL_LINES, 6, GL_UNSIGNED_BYTE, indexBuffer); } public void onSurfaceChanged(GL10 gl, int width, int height) { gl.glViewport(0, 0, width, height); float r = (float) width / height; gl.glMatrixMode(GL10.GL_PROJECTION); gl.glLoadIdentity(); gl.glFrustumf(-r, r, -1, 1, 1, 10); } public void onSurfaceCreated(GL10 gl, EGLConfig config) { gl.glDisable(GL10.GL_DITHER); gl.glClearColor(1, 1, 1, 1); gl.glEnable(GL10.GL_CULL_FACE); gl.glShadeModel(GL10.GL_SMOOTH); gl.glEnable(GL10.GL_DEPTH_TEST); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_COLOR_ARRAY); // load the 3 axis and there colors: float vertices[] = { 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1 }; float colors[] = { 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1 }; byte indices[] = { 0, 1, 0, 2, 0, 3 }; ByteBuffer vbb; vbb = ByteBuffer.allocateDirect(vertices.length * 4); vbb.order(ByteOrder.nativeOrder()); vertexBuffer = vbb.asFloatBuffer(); vertexBuffer.put(vertices); vertexBuffer.position(0); vbb = ByteBuffer.allocateDirect(colors.length * 4); vbb.order(ByteOrder.nativeOrder()); colorBuffer = vbb.asFloatBuffer(); colorBuffer.put(colors); colorBuffer.position(0); indexBuffer = ByteBuffer.allocateDirect(indices.length); indexBuffer.put(indices); indexBuffer.position(0); } public void onAccuracyChanged(Sensor sensor, int accuracy) { } public void onSensorChanged(SensorEvent event) { // load the new values: loadNewSensorData(event); if (MODUS == 1) { SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, magnetData); } if (MODUS == 2) { rootMeanSquareBuffer(bufferedAccelGData, accelGData); rootMeanSquareBuffer(bufferedMagnetData, magnetData); SensorManager.getRotationMatrix(rotationMatrix, null, bufferedAccelGData, bufferedMagnetData); } if (MODUS == 3) { rootMeanSquareBuffer(bufferedMagnetData, magnetData); SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, bufferedMagnetData); } if (MODUS == 4) { rootMeanSquareBuffer(bufferedAccelGData, accelGData); SensorManager.getRotationMatrix(rotationMatrix, null, bufferedAccelGData, magnetData); } if (MODUS == 5) { // this mode uses the sensor data recieved from the orientation // sensor resultingAngles = orientationData.clone(); if ((-90 > resultingAngles[1]) || (resultingAngles[1] > 90)) { resultingAngles[1] = orientationData[0]; resultingAngles[2] = orientationData[1]; resultingAngles[0] = orientationData[2]; } } if (MODUS == 6) { SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, magnetData); final float[] anglesInRadians = new float[3]; SensorManager.getOrientation(rotationMatrix, anglesInRadians); if ((-90 < anglesInRadians[2] * rad2deg) && (anglesInRadians[2] * rad2deg < 90)) { // device camera is looking on the floor // this hemisphere is working fine mirrorOnBlueAxis = false; resultingAngles[0] = anglesInRadians[0] * rad2deg; resultingAngles[1] = anglesInRadians[1] * rad2deg; resultingAngles[2] = anglesInRadians[2] * -rad2deg; } else { mirrorOnBlueAxis = true; // device camera is looking in the sky // this hemisphere is mirrored at the blue axis resultingAngles[0] = (anglesInRadians[0] * rad2deg); resultingAngles[1] = (anglesInRadians[1] * rad2deg); resultingAngles[2] = (anglesInRadians[2] * rad2deg); } } if (MODUS == 7) { SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, magnetData); rotationMatrix = transpose(rotationMatrix); /* * this assumes that the rotation matrices are multiplied in x y z * order Rx*Ry*Rz */ resultingAngles[2] = (float) (Math.asin(rotationMatrix[2])); final float cosB = (float) Math.cos(resultingAngles[2]); resultingAngles[2] = resultingAngles[2] * rad2deg; resultingAngles[0] = -(float) (Math.acos(rotationMatrix[0] / cosB)) * rad2deg; resultingAngles[1] = (float) (Math.acos(rotationMatrix[10] / cosB)) * rad2deg; } if (MODUS == 8) { SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, magnetData); rotationMatrix = transpose(rotationMatrix); /* * this assumes that the rotation matrices are multiplied in z y x */ resultingAngles[2] = (float) (Math.asin(-rotationMatrix[8])); final float cosB = (float) Math.cos(resultingAngles[2]); resultingAngles[2] = resultingAngles[2] * rad2deg; resultingAngles[1] = (float) (Math.acos(rotationMatrix[9] / cosB)) * rad2deg; resultingAngles[0] = (float) (Math.asin(rotationMatrix[4] / cosB)) * rad2deg; } if (MODUS == 9) { SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, magnetData); rotationMatrix = transpose(rotationMatrix); /* * this assumes that the rotation matrices are multiplied in z x y * * note z axis looks good at this one */ resultingAngles[1] = (float) (Math.asin(rotationMatrix[9])); final float minusCosA = -(float) Math.cos(resultingAngles[1]); resultingAngles[1] = resultingAngles[1] * rad2deg; resultingAngles[2] = (float) (Math.asin(rotationMatrix[8] / minusCosA)) * rad2deg; resultingAngles[0] = (float) (Math.asin(rotationMatrix[1] / minusCosA)) * rad2deg; } if (MODUS == 10) { SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, magnetData); rotationMatrix = transpose(rotationMatrix); /* * this assumes that the rotation matrices are multiplied in y x z */ resultingAngles[1] = (float) (Math.asin(-rotationMatrix[6])); final float cosA = (float) Math.cos(resultingAngles[1]); resultingAngles[1] = resultingAngles[1] * rad2deg; resultingAngles[2] = (float) (Math.asin(rotationMatrix[2] / cosA)) * rad2deg; resultingAngles[0] = (float) (Math.acos(rotationMatrix[5] / cosA)) * rad2deg; } if (MODUS == 11) { SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, magnetData); rotationMatrix = transpose(rotationMatrix); /* * this assumes that the rotation matrices are multiplied in y z x */ resultingAngles[0] = (float) (Math.asin(rotationMatrix[4])); final float cosC = (float) Math.cos(resultingAngles[0]); resultingAngles[0] = resultingAngles[0] * rad2deg; resultingAngles[2] = (float) (Math.acos(rotationMatrix[0] / cosC)) * rad2deg; resultingAngles[1] = (float) (Math.acos(rotationMatrix[5] / cosC)) * rad2deg; } if (MODUS == 12) { SensorManager.getRotationMatrix(rotationMatrix, null, accelGData, magnetData); rotationMatrix = transpose(rotationMatrix); /* * this assumes that the rotation matrices are multiplied in x z y */ resultingAngles[0] = (float) (Math.asin(-rotationMatrix[1])); final float cosC = (float) Math.cos(resultingAngles[0]); resultingAngles[0] = resultingAngles[0] * rad2deg; resultingAngles[2] = (float) (Math.acos(rotationMatrix[0] / cosC)) * rad2deg; resultingAngles[1] = (float) (Math.acos(rotationMatrix[5] / cosC)) * rad2deg; } logOutput(); } /** * transposes the matrix because it was transposted (inverted, but here its * the same, because its a rotation matrix) to be used for opengl * * @param source * @return */ private float[] transpose(float[] source) { final float[] result = source.clone(); if (TRY_TRANSPOSED_VERSION) { result[1] = source[4]; result[2] = source[8]; result[4] = source[1]; result[6] = source[9]; result[8] = source[2]; result[9] = source[6]; } // the other values in the matrix are not relevant for rotations return result; } private void rootMeanSquareBuffer(float[] target, float[] values) { final float amplification = 200.0f; float buffer = 20.0f; target[0] += amplification; target[1] += amplification; target[2] += amplification; values[0] += amplification; values[1] += amplification; values[2] += amplification; target[0] = (float) (Math .sqrt((target[0] * target[0] * buffer + values[0] * values[0]) / (1 + buffer))); target[1] = (float) (Math .sqrt((target[1] * target[1] * buffer + values[1] * values[1]) / (1 + buffer))); target[2] = (float) (Math .sqrt((target[2] * target[2] * buffer + values[2] * values[2]) / (1 + buffer))); target[0] -= amplification; target[1] -= amplification; target[2] -= amplification; values[0] -= amplification; values[1] -= amplification; values[2] -= amplification; } private void loadNewSensorData(SensorEvent event) { final int type = event.sensor.getType(); if (type == Sensor.TYPE_ACCELEROMETER) { accelGData = event.values.clone(); } if (type == Sensor.TYPE_MAGNETIC_FIELD) { magnetData = event.values.clone(); } if (type == Sensor.TYPE_ORIENTATION) { orientationData = event.values.clone(); } } private void logOutput() { if (mCount++ > 30) { mCount = 0; Log.d("Compass", "yaw0: " + (int) (resultingAngles[0]) + " pitch1: " + (int) (resultingAngles[1]) + " roll2: " + (int) (resultingAngles[2])); } } }

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  • SQL SERVER – Enumerations in Relational Database – Best Practice

    - by pinaldave
    Marko Parkkola This article has been submitted by Marko Parkkola, Data systems designer at Saarionen Oy, Finland. Marko is excellent developer and always thinking at next level. You can read his earlier comment which created very interesting discussion here: SQL SERVER- IF EXISTS(Select null from table) vs IF EXISTS(Select 1 from table). I must express my special thanks to Marko for sending this best practice for Enumerations in Relational Database. He has really wrote excellent piece here and welcome comments here. Enumerations in Relational Database This is a subject which is very basic thing in relational databases but often not very well understood and sometimes badly implemented. There are of course many ways to do this but I concentrate only two cases, one which is “the right way” and one which is definitely wrong way. The concept Let’s say we have table Person in our database. Person has properties/fields like Firstname, Lastname, Birthday and so on. Then there’s a field that tells person’s marital status and let’s name it the same way; MaritalStatus. Now MaritalStatus is an enumeration. In C# I would definitely make it an enumeration with values likes Single, InRelationship, Married, Divorced. Now here comes the problem, SQL doesn’t have enumerations. The wrong way This is, in my opinion, absolutely the wrong way to do this. It has one upside though; you’ll see the enumeration’s description instantly when you do simple SELECT query and you don’t have to deal with mysterious values. There’s plenty of downsides too and one would be database fragmentation. Consider this (I’ve left all indexes and constraints out of the query on purpose). CREATE TABLE [dbo].[Person] ( [Firstname] NVARCHAR(100), [Lastname] NVARCHAR(100), [Birthday] datetime, [MaritalStatus] NVARCHAR(10) ) You have nvarchar(20) field in the table that tells the marital status. Obvious problem with this is that what if you create a new value which doesn’t fit into 20 characters? You’ll have to come and alter the table. There are other problems also but I’ll leave those for the reader to think about. The correct way Here’s how I’ve done this in many projects. This model still has one problem but it can be alleviated in the application layer or with CHECK constraints if you like. First I will create a namespace table which tells the name of the enumeration. I will add one row to it too. I’ll write all the indexes and constraints here too. CREATE TABLE [CodeNamespace] ( [Id] INT IDENTITY(1, 1), [Name] NVARCHAR(100) NOT NULL, CONSTRAINT [PK_CodeNamespace] PRIMARY KEY ([Id]), CONSTRAINT [IXQ_CodeNamespace_Name] UNIQUE NONCLUSTERED ([Name]) ) GO INSERT INTO [CodeNamespace] SELECT 'MaritalStatus' GO Then I create a table that holds the actual values and which reference to namespace table in order to group the values under different namespaces. I’ll add couple of rows here too. CREATE TABLE [CodeValue] ( [CodeNamespaceId] INT NOT NULL, [Value] INT NOT NULL, [Description] NVARCHAR(100) NOT NULL, [OrderBy] INT, CONSTRAINT [PK_CodeValue] PRIMARY KEY CLUSTERED ([CodeNamespaceId], [Value]), CONSTRAINT [FK_CodeValue_CodeNamespace] FOREIGN KEY ([CodeNamespaceId]) REFERENCES [CodeNamespace] ([Id]) ) GO -- 1 is the 'MaritalStatus' namespace INSERT INTO [CodeValue] SELECT 1, 1, 'Single', 1 INSERT INTO [CodeValue] SELECT 1, 2, 'In relationship', 2 INSERT INTO [CodeValue] SELECT 1, 3, 'Married', 3 INSERT INTO [CodeValue] SELECT 1, 4, 'Divorced', 4 GO Now there’s four columns in CodeValue table. CodeNamespaceId tells under which namespace values belongs to. Value tells the enumeration value which is used in Person table (I’ll show how this is done below). Description tells what the value means. You can use this, for example, column in UI’s combo box. OrderBy tells if the values needs to be ordered in some way when displayed in the UI. And here’s the Person table again now with correct columns. I’ll add one row here to show how enumerations are to be used. CREATE TABLE [dbo].[Person] ( [Firstname] NVARCHAR(100), [Lastname] NVARCHAR(100), [Birthday] datetime, [MaritalStatus] INT ) GO INSERT INTO [Person] SELECT 'Marko', 'Parkkola', '1977-03-04', 3 GO Now I said earlier that there is one problem with this. MaritalStatus column doesn’t have any database enforced relationship to the CodeValue table so you can enter any value you like into this field. I’ve solved this problem in the application layer by selecting all the values from the CodeValue table and put them into a combobox / dropdownlist (with Value field as value and Description as text) so the end user can’t enter any illegal values; and of course I’ll check the entered value in data access layer also. I said in the “The wrong way” section that there is one benefit to it. In fact, you can have the same benefit here by using a simple view, which I schema bound so you can even index it if you like. CREATE VIEW [dbo].[Person_v] WITH SCHEMABINDING AS SELECT p.[Firstname], p.[Lastname], p.[BirthDay], c.[Description] MaritalStatus FROM [dbo].[Person] p JOIN [dbo].[CodeValue] c ON p.[MaritalStatus] = c.[Value] JOIN [dbo].[CodeNamespace] n ON n.[Id] = c.[CodeNamespaceId] AND n.[Name] = 'MaritalStatus' GO -- Select from View SELECT * FROM [dbo].[Person_v] GO This is excellent write up byMarko Parkkola. Do you have this kind of design setup at your organization? Let us know your opinion. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Database, DBA, Readers Contribution, Software Development, SQL, SQL Authority, SQL Documentation, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • Inheritance Mapping Strategies with Entity Framework Code First CTP5: Part 3 – Table per Concrete Type (TPC) and Choosing Strategy Guidelines

    - by mortezam
    This is the third (and last) post in a series that explains different approaches to map an inheritance hierarchy with EF Code First. I've described these strategies in previous posts: Part 1 – Table per Hierarchy (TPH) Part 2 – Table per Type (TPT)In today’s blog post I am going to discuss Table per Concrete Type (TPC) which completes the inheritance mapping strategies supported by EF Code First. At the end of this post I will provide some guidelines to choose an inheritance strategy mainly based on what we've learned in this series. TPC and Entity Framework in the Past Table per Concrete type is somehow the simplest approach suggested, yet using TPC with EF is one of those concepts that has not been covered very well so far and I've seen in some resources that it was even discouraged. The reason for that is just because Entity Data Model Designer in VS2010 doesn't support TPC (even though the EF runtime does). That basically means if you are following EF's Database-First or Model-First approaches then configuring TPC requires manually writing XML in the EDMX file which is not considered to be a fun practice. Well, no more. You'll see that with Code First, creating TPC is perfectly possible with fluent API just like other strategies and you don't need to avoid TPC due to the lack of designer support as you would probably do in other EF approaches. Table per Concrete Type (TPC)In Table per Concrete type (aka Table per Concrete class) we use exactly one table for each (nonabstract) class. All properties of a class, including inherited properties, can be mapped to columns of this table, as shown in the following figure: As you can see, the SQL schema is not aware of the inheritance; effectively, we’ve mapped two unrelated tables to a more expressive class structure. If the base class was concrete, then an additional table would be needed to hold instances of that class. I have to emphasize that there is no relationship between the database tables, except for the fact that they share some similar columns. TPC Implementation in Code First Just like the TPT implementation, we need to specify a separate table for each of the subclasses. We also need to tell Code First that we want all of the inherited properties to be mapped as part of this table. In CTP5, there is a new helper method on EntityMappingConfiguration class called MapInheritedProperties that exactly does this for us. Here is the complete object model as well as the fluent API to create a TPC mapping: public abstract class BillingDetail {     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } }          public class BankAccount : BillingDetail {     public string BankName { get; set; }     public string Swift { get; set; } }          public class CreditCard : BillingDetail {     public int CardType { get; set; }     public string ExpiryMonth { get; set; }     public string ExpiryYear { get; set; } }      public class InheritanceMappingContext : DbContext {     public DbSet<BillingDetail> BillingDetails { get; set; }              protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<BankAccount>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("BankAccounts");         });         modelBuilder.Entity<CreditCard>().Map(m =>         {             m.MapInheritedProperties();             m.ToTable("CreditCards");         });                 } } The Importance of EntityMappingConfiguration ClassAs a side note, it worth mentioning that EntityMappingConfiguration class turns out to be a key type for inheritance mapping in Code First. Here is an snapshot of this class: namespace System.Data.Entity.ModelConfiguration.Configuration.Mapping {     public class EntityMappingConfiguration<TEntityType> where TEntityType : class     {         public ValueConditionConfiguration Requires(string discriminator);         public void ToTable(string tableName);         public void MapInheritedProperties();     } } As you have seen so far, we used its Requires method to customize TPH. We also used its ToTable method to create a TPT and now we are using its MapInheritedProperties along with ToTable method to create our TPC mapping. TPC Configuration is Not Done Yet!We are not quite done with our TPC configuration and there is more into this story even though the fluent API we saw perfectly created a TPC mapping for us in the database. To see why, let's start working with our object model. For example, the following code creates two new objects of BankAccount and CreditCard types and tries to add them to the database: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount();     CreditCard creditCard = new CreditCard() { CardType = 1 };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Running this code throws an InvalidOperationException with this message: The changes to the database were committed successfully, but an error occurred while updating the object context. The ObjectContext might be in an inconsistent state. Inner exception message: AcceptChanges cannot continue because the object's key values conflict with another object in the ObjectStateManager. Make sure that the key values are unique before calling AcceptChanges. The reason we got this exception is because DbContext.SaveChanges() internally invokes SaveChanges method of its internal ObjectContext. ObjectContext's SaveChanges method on its turn by default calls AcceptAllChanges after it has performed the database modifications. AcceptAllChanges method merely iterates over all entries in ObjectStateManager and invokes AcceptChanges on each of them. Since the entities are in Added state, AcceptChanges method replaces their temporary EntityKey with a regular EntityKey based on the primary key values (i.e. BillingDetailId) that come back from the database and that's where the problem occurs since both the entities have been assigned the same value for their primary key by the database (i.e. on both BillingDetailId = 1) and the problem is that ObjectStateManager cannot track objects of the same type (i.e. BillingDetail) with the same EntityKey value hence it throws. If you take a closer look at the TPC's SQL schema above, you'll see why the database generated the same values for the primary keys: the BillingDetailId column in both BankAccounts and CreditCards table has been marked as identity. How to Solve The Identity Problem in TPC As you saw, using SQL Server’s int identity columns doesn't work very well together with TPC since there will be duplicate entity keys when inserting in subclasses tables with all having the same identity seed. Therefore, to solve this, either a spread seed (where each table has its own initial seed value) will be needed, or a mechanism other than SQL Server’s int identity should be used. Some other RDBMSes have other mechanisms allowing a sequence (identity) to be shared by multiple tables, and something similar can be achieved with GUID keys in SQL Server. While using GUID keys, or int identity keys with different starting seeds will solve the problem but yet another solution would be to completely switch off identity on the primary key property. As a result, we need to take the responsibility of providing unique keys when inserting records to the database. We will go with this solution since it works regardless of which database engine is used. Switching Off Identity in Code First We can switch off identity simply by placing DatabaseGenerated attribute on the primary key property and pass DatabaseGenerationOption.None to its constructor. DatabaseGenerated attribute is a new data annotation which has been added to System.ComponentModel.DataAnnotations namespace in CTP5: public abstract class BillingDetail {     [DatabaseGenerated(DatabaseGenerationOption.None)]     public int BillingDetailId { get; set; }     public string Owner { get; set; }     public string Number { get; set; } } As always, we can achieve the same result by using fluent API, if you prefer that: modelBuilder.Entity<BillingDetail>()             .Property(p => p.BillingDetailId)             .HasDatabaseGenerationOption(DatabaseGenerationOption.None); Working With The Object Model Our TPC mapping is ready and we can try adding new records to the database. But, like I said, now we need to take care of providing unique keys when creating new objects: using (var context = new InheritanceMappingContext()) {     BankAccount bankAccount = new BankAccount()      {          BillingDetailId = 1                          };     CreditCard creditCard = new CreditCard()      {          BillingDetailId = 2,         CardType = 1     };                      context.BillingDetails.Add(bankAccount);     context.BillingDetails.Add(creditCard);     context.SaveChanges(); } Polymorphic Associations with TPC is Problematic The main problem with this approach is that it doesn’t support Polymorphic Associations very well. After all, in the database, associations are represented as foreign key relationships and in TPC, the subclasses are all mapped to different tables so a polymorphic association to their base class (abstract BillingDetail in our example) cannot be represented as a simple foreign key relationship. For example, consider the the domain model we introduced here where User has a polymorphic association with BillingDetail. This would be problematic in our TPC Schema, because if User has a many-to-one relationship with BillingDetail, the Users table would need a single foreign key column, which would have to refer both concrete subclass tables. This isn’t possible with regular foreign key constraints. Schema Evolution with TPC is Complex A further conceptual problem with this mapping strategy is that several different columns, of different tables, share exactly the same semantics. This makes schema evolution more complex. For example, a change to a base class property results in changes to multiple columns. It also makes it much more difficult to implement database integrity constraints that apply to all subclasses. Generated SQLLet's examine SQL output for polymorphic queries in TPC mapping. For example, consider this polymorphic query for all BillingDetails and the resulting SQL statements that being executed in the database: var query = from b in context.BillingDetails select b; Just like the SQL query generated by TPT mapping, the CASE statements that you see in the beginning of the query is merely to ensure columns that are irrelevant for a particular row have NULL values in the returning flattened table. (e.g. BankName for a row that represents a CreditCard type). TPC's SQL Queries are Union Based As you can see in the above screenshot, the first SELECT uses a FROM-clause subquery (which is selected with a red rectangle) to retrieve all instances of BillingDetails from all concrete class tables. The tables are combined with a UNION operator, and a literal (in this case, 0 and 1) is inserted into the intermediate result; (look at the lines highlighted in yellow.) EF reads this to instantiate the correct class given the data from a particular row. A union requires that the queries that are combined, project over the same columns; hence, EF has to pad and fill up nonexistent columns with NULL. This query will really perform well since here we can let the database optimizer find the best execution plan to combine rows from several tables. There is also no Joins involved so it has a better performance than the SQL queries generated by TPT where a Join is required between the base and subclasses tables. Choosing Strategy GuidelinesBefore we get into this discussion, I want to emphasize that there is no one single "best strategy fits all scenarios" exists. As you saw, each of the approaches have their own advantages and drawbacks. Here are some rules of thumb to identify the best strategy in a particular scenario: If you don’t require polymorphic associations or queries, lean toward TPC—in other words, if you never or rarely query for BillingDetails and you have no class that has an association to BillingDetail base class. I recommend TPC (only) for the top level of your class hierarchy, where polymorphism isn’t usually required, and when modification of the base class in the future is unlikely. If you do require polymorphic associations or queries, and subclasses declare relatively few properties (particularly if the main difference between subclasses is in their behavior), lean toward TPH. Your goal is to minimize the number of nullable columns and to convince yourself (and your DBA) that a denormalized schema won’t create problems in the long run. If you do require polymorphic associations or queries, and subclasses declare many properties (subclasses differ mainly by the data they hold), lean toward TPT. Or, depending on the width and depth of your inheritance hierarchy and the possible cost of joins versus unions, use TPC. By default, choose TPH only for simple problems. For more complex cases (or when you’re overruled by a data modeler insisting on the importance of nullability constraints and normalization), you should consider the TPT strategy. But at that point, ask yourself whether it may not be better to remodel inheritance as delegation in the object model (delegation is a way of making composition as powerful for reuse as inheritance). Complex inheritance is often best avoided for all sorts of reasons unrelated to persistence or ORM. EF acts as a buffer between the domain and relational models, but that doesn’t mean you can ignore persistence concerns when designing your classes. SummaryIn this series, we focused on one of the main structural aspect of the object/relational paradigm mismatch which is inheritance and discussed how EF solve this problem as an ORM solution. We learned about the three well-known inheritance mapping strategies and their implementations in EF Code First. Hopefully it gives you a better insight about the mapping of inheritance hierarchies as well as choosing the best strategy for your particular scenario. Happy New Year and Happy Code-Firsting! References ADO.NET team blog Java Persistence with Hibernate book a { color: #5A99FF; } a:visited { color: #5A99FF; } .title { padding-bottom: 5px; font-family: Segoe UI; font-size: 11pt; font-weight: bold; padding-top: 15px; } .code, .typeName { font-family: consolas; } .typeName { color: #2b91af; } .padTop5 { padding-top: 5px; } .padTop10 { padding-top: 10px; } .exception { background-color: #f0f0f0; font-style: italic; padding-bottom: 5px; padding-left: 5px; padding-top: 5px; padding-right: 5px; }

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  • Request Limit Length Limits for IIS&rsquo;s requestFiltering Module

    - by Rick Strahl
    Today I updated my CodePaste.net site to MVC 3 and pushed an update to the site. The update of MVC went pretty smooth as well as most of the update process to the live site. Short of missing a web.config change in the /views folder that caused blank pages on the server, the process was relatively painless. However, one issue that kicked my ass for about an hour – and not foe the first time – was a problem with my OpenId authentication using DotNetOpenAuth. I tested the site operation fairly extensively locally and everything worked no problem, but on the server the OpenId returns resulted in a 404 response from IIS for a nice friendly OpenId return URL like this: http://codepaste.net/Account/OpenIdLogon?dnoa.userSuppliedIdentifier=http%3A%2F%2Frstrahl.myopenid.com%2F&dnoa.return_to_sig_handle=%7B634239223364590000%7D%7BjbHzkg%3D%3D%7D&dnoa.return_to_sig=7%2BcGhp7UUkcV2B8W29ibIDnZuoGoqzyS%2F%2FbF%2FhhYscgWzjg%2BB%2Fj10ZpNdBkUCu86dkTL6f4OK2zY5qHhCnJ2Dw%3D%3D&openid.assoc_handle=%7BHMAC-SHA256%7D%7B4cca49b2%7D%7BMVGByQ%3D%3D%7D&openid.claimed_id=http%3A%2F%2Frstrahl.myopenid.com%2F&openid.identity=http%3A%2F%2Frstrahl.myopenid.com%2F&openid.mode=id_res&openid.ns=http%3A%2F%2Fspecs.openid.net%2Fauth%2F2.0&openid.ns.sreg=http%3A%2F%2Fopenid.net%2Fextensions%2Fsreg%2F1.1&openid.op_endpoint=http%3A%2F%2Fwww.myopenid.com%2Fserver&openid.response_nonce=2010-10-29T04%3A12%3A53Zn5F4r5&openid.return_to=http%3A%2F%2Fcodepaste.net%2FAccount%2FOpenIdLogon%3Fdnoa.userSuppliedIdentifier%3Dhttp%253A%252F%252Frstrahl.myopenid.com%252F%26dnoa.return_to_sig_handle%3D%257B634239223364590000%257D%257BjbHzkg%253D%253D%257D%26dnoa.return_to_sig%3D7%252BcGhp7UUkcV2B8W29ibIDnZuoGoqzyS%252F%252FbF%252FhhYscgWzjg%252BB%252Fj10ZpNdBkUCu86dkTL6f4OK2zY5qHhCnJ2Dw%253D%253D&openid.sig=h1GCSBTDAn1on98sLA6cti%2Bj1M6RffNerdVEI80mnYE%3D&openid.signed=assoc_handle%2Cclaimed_id%2Cidentity%2Cmode%2Cns%2Cns.sreg%2Cop_endpoint%2Cresponse_nonce%2Creturn_to%2Csigned%2Csreg.email%2Csreg.fullname&openid.sreg.email=rstrahl%40host.com&openid.sreg.fullname=Rick+Strahl A 404 of course isn’t terribly helpful – normally a 404 is a resource not found error, but the resource is definitely there. So how the heck do you figure out what’s wrong? If you’re just interested in the solution, here’s the short version: IIS by default allows only for a 1024 byte query string, which is obviously exceeded by the above. The setting is controlled by the RequestFiltering module in IIS 6 and later which can be configured in ApplicationHost.config (in \%windir\system32\inetsvr\config). To set the value configure the requestLimits key like so: <configuration> <security> <requestFiltering> <requestLimits maxQueryString="2048"> </requestLimits> </requestFiltering> </security> </configuration> This fixed me right up and made the requests work. How do you find out about problems like this? Ah yes the troubles of an administrator? Read on and I’ll take you through a quick review of how I tracked this down. Finding the Problem The issue with the error returned is that IIS returns a 404 Resource not found error and doesn’t provide much information about it. If you’re lucky enough to be able to run your site from the localhost IIS is actually very helpful and gives you the right information immediately in a nicely detailed error page. The bottom of the page actually describes exactly what needs to be fixed. One problem with this easy way to find an error: You HAVE TO run localhost. On my server which has about 10 domains running localhost doesn’t point at the particular site I had problems with so I didn’t get the luxury of this nice error page. Using Failed Request Tracing to retrieve Error Info The first place I go with IIS errors is to turn on Failed Request Tracing in IIS to get more error information. If you have access to the server to make a configuration change you can enable Failed Request Tracing like this: Find the Failed Request Tracing Rules in the IIS Service Manager.   Select the option and then Edit Site Tracing to enable tracing. Then add a rule for * (all content) and specify status codes from 100-999 to capture all errors. if you know exactly what error you’re looking for it might help to specify it exactly to keep the number of errors down. Then run your request and let it fail. IIS will throw error log files into a folder like this C:\inetpub\logs\FailedReqLogFiles\W3SVC5 where the last 5 is the instance ID of the site. These files are XML but they include an XSL stylesheet that provides some decent formatting. In this case it pointed me straight at the offending module:   Ok, it’s the RequestFilteringModule. Request Filtering is built into IIS 6-7 and configured in ApplicationHost.config. This module defines a few basic rules about what paths and extensions are allowed in requests and among other things how long a query string is allowed to be. Most of these settings are pretty sensible but the query string value can easily become a problem especially if you’re dealing with OpenId since these return URLs are quite extensive. Debugging failed requests is never fun, but IIS 6 and forward at least provides us the tools that can help us point in the right direction. The error message the FRT report isn’t as nice as the IIS error message but it at least points at the offending module which gave me the clue I needed to look at request restrictions in ApplicationHost.config. This would still be a stretch if you’re not intimately familiar, but I think with some Google searches it would be easy to track this down with a few tries… Hope this was useful to some of you. Useful to me to put this out as a reminder – I’ve run into this issue before myself and totally forgot. Next time I got it, right?© Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  Security  

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  • Aamir Khan’s Satyamev Jayate stirs a movement

    - by Gopinath
    Bollywood actor Aamir Khan is known for his dedication and hard work in inspiring millions of viewers though movies by discussing social problems and motivating people to solve them. His movie Rang De Basanthi seeded Indian anti-corruption movement, Tare Zameen Par touched the problems faced by few challenged kids and the latest movie 3 idiots exposed how education institutions in India are producing lakhs of Donkeys out of colleges every year. He extended his dedication of serving the society to small screen with the launch of reality TV show Satyamev Jayate. Before you start misjudging it as one of those non sense drama / entertaining reality shows, let me tell you that it is not a typical music, games, fight or dance reality show. Satyamev Jayate is all about the real people of India, their problems and how to tackle them.  This is not just a reality show, its movement to educate people about the social evils. Its been many years since I spent couple of hours  in front of TV as most of the programs are too cynical or does not add much value.  In my childhood I use to anxiously wait for Mahabarath or He-Man TV shows to start but after a two decades I waited anxiously for the start of Satyamev Jayate. The wait was worth and the 1 hours 30 minutes spent watching it meaningful. When was the last time you were so satisfied after watching a TV show and inspired to do something? I don’t remember. Today, the show focused on female foeticide and its impact. It showed women who were tortured and forced to abort female foetuses. On the show few brave women shared their experiences of giving birth to girl babies and rough times they are going through with their in-laws & husbands. The show not only focused on the problem but also on the root cause of the evil,  inspiring people working to tackle it and what every individual can do his part to solve it.  The best part of the show is,  its not a blame game. When there is a problem most of the people quickly get into identifying who is wrong and start blaming them instead of solve the actual problem.  Aamir did not blame anyone for female foeticide – neither the government who don’t impose strict rules, nor the doctors who abort girl babies to make money or the mother-in-laws & husbands who torcher girl baby mothers are blamed. He careful highlighted the problem, showed horrifying statistics and their impact on the future society and few inspiring people working to tackle the problem.  He touched heart and stirred a movement against the issue. First time ever I voted for a reality show through SMS and it’s for Satyamev Jayate. I’m proud to do so. Here are the few reactions of popular people, activists & media about the program @aamir_khan absolutely the best program I have seen on TV in recent past. Thanku for converting an idiot box into an inspirationsl medium — Kiran Bedi (@thekiranbedi) May 6, 2012 Satyamev Jayate proves tht TV 2 can b a tool of social change. — Shekhar Kapur (@shekharkapur) May 6, 2012 i absolutely loved #satyamevjayate. at least aamir is doing what all of us only talk about. — Harsha Bhogle (@bhogleharsha) May 6, 2012 Now Television will no longer be called an idiot box,the VISION of Television broadens up with#SatyamevJayate !!! — Madhur Bhandarkar (@mbhandarkar268) May 6, 2012 The Sunday 11am slot seems to have come back with a bang… #SatyamevJayate — atul kasbekar (@atulkasbekar) May 6, 2012   I was spellbound, says Prasoon Joshi – It’s a unique show. I was completely bowled over by it. It’s a never-done before concept Aamir Khan strikes the right chord with Satyamev Jayate – The format is quite crisp. Talking about the emotional connect, there are moments when your eyes well up with tears, but the various segments ensure there’s more content than emotional drama ‘Satyamev Jayate’ gutsy, sensible show: Viewers – From filmmakers to clinical psychologists to professors – everyone has given the thumbs up to Aamir Khan’s television show ‘Satyamev Jayate’, saying it is a gutsy, hard-hitting and sensible programme that strikes an emotional chord with the audiences. Aamir Khan’s TV debut ‘Satyamev Jayate’ takes Twitter by storm – The roads of the capital sported a deserted look around 11 am on Sunday morning, as everyone was hooked on to their TV sets. Did you watch the program? What is your opinion? I’m waiting for next 11 AM of next Sunday. Are you?

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  • Understanding each other in web development

    - by Pete Hotchkin
    During my career I have been lucky enough to work in several different roles within web development with many extremely talented people, from incredible designers who were passionate about the placement of every pixel right through to server administrators and DBAs who were always measuring the improvements they were making to their queries in the smallest possible unit. The problem I always faced was that more often than not I was stuck in the middle trying to mediate between these different functions and enable each side to understand the other’s point of view. The main areas of contention that there have always been between these functional groups in my experience have been at 2 key points: during the build phase and then when there is a problem post-build. During both of these times it is often easier for someone to pass the buck onto someone else than spend the time to understand the other person’s perspective. Below is a quick look at two upcoming tools that will not only speed up the build phase for each function, but  also help when it comes to the issues faced once a site has been pushed live. In my experience a web project goes through several phases of development. The first of these is design, generally handled as Photoshop files which are then passed onto a front-end developer. This is the first point at which heated discussions can arise. One problem I’ve seen several times is that the designer doesn’t fully understand the platform constraints that need to be considered, and as a result has designed something that does not translate very well or is simply not possible. Working at Red Gate, I am lucky enough to be able to meet some amazing people and this happened just the other day when I was introduced to Neil Kinnish and Pete Nelson, the creators of what I believe could be a great asset in this designer-developer relationship, Mixture. Mixture allows the front end developer to quickly prototype a web page with built-in frameworks such as bootstrap. It’s not an IDE however, it just sits there in the background and monitors the project files in the background so every time you save a file from your favorite IDE, it will compile things like LESS, compact your JavaScript and the automatically refresh your test browser so you can see the changes instantly. I think one of the best parts of this however is a single button that pushes the changed files up to the web so the designer can instantly see how far the developer has got and the problem that he is facing at that time without the need to spend time setting up a remote server. I can see this being a real asset to remote teams where there needs to be a compromise between the designer and the front-end developer, or just to allow the designer to see how the build is progressing and suggest small alterations. Once the design has been built into the front end the designer’s job is generally done and there are no other points of contention between the designer and the other functions involved in building these web projects. As the project moves into the stage of integrating it into the back end and deploying it to the production server other functions start to be pulled in and other issues arise such as the back-end developer understanding the frameworks that they are using such as the routes that are in place in an MVC application or the number of database calls that the ORM layer is actually making. There are many tools out there that can actually help with these problems such as mini profiler that gives you a quick snapshot of what is going on directly in the browser. For a slightly more in-depth look at what is happening and to gain a deeper understanding of an application you may be working on though, you may want to consider Glimpse. Created by Nik and Anthony, it is an application that sits at the bottom of your browser (installed via NuGet) which can show you information about how your application is pieced together and how the information on screen is being delivered as it happens. With a wealth of community-built plugins such as one for nHibernate and linq2SQL (full list of plugins on NuGet). It can be customized directly to your own setup to truly delve into the code to see what is happening, and can help to reduce the number of confusing moments about whether it is your code that is going wrong or whether there is something more sinister happening directly on the server. All the tools that I have mentioned in this post help to do one thing above all, and that is to ease the barrier of understanding between the different functions that are involved in building and maintaining a web application. In my experience it is very easy to say “Well, that’s not my problem”, simply because the two functions involved don’t truly understand the other’s point of view. Software should not only be seen as a way to streamline our own working process or as a debugging tool but also a communication aid to improve the entire lifecycle of a web project. Glimpse is actually the project that I am the designer on and I would love to get your feedback if you do decide to try it out or if you would like to share your own experiences of working on web projects please fill in your details at https://www.surveymk.com/s/joinGlimpse  or add a comment below and I will get in touch with you.

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  • Pain Comes Instantly

    - by user701213
    When I look back at recent blog entries – many of which are not all that current (more on where my available writing time is going later) – I am struck by how many of them focus on public policy or legislative issues instead of, say, the latest nefarious cyberattack or exploit (or everyone’s favorite new pastime: coining terms for the Coming Cyberpocalypse: “digital Pearl Harbor” is so 1941). Speaking of which, I personally hope evil hackers from Malefactoria will someday hack into my bathroom scale – which in a future time will be connected to the Internet because, gosh, wouldn’t it be great to have absolutely everything in your life Internet-enabled? – and recalibrate it so I’m 10 pounds thinner. The horror. In part, my focus on public policy is due to an admitted limitation of my skill set. I enjoy reading technical articles about exploits and cybersecurity trends, but writing a blog entry on those topics would take more research than I have time for and, quite honestly, doesn’t play to my strengths. The first rule of writing is “write what you know.” The bigger contributing factor to my recent paucity of blog entries is that more and more of my waking hours are spent engaging in “thrust and parry” activity involving emerging regulations of some sort or other. I’ve opined in earlier blogs about what constitutes good and reasonable public policy so nobody can accuse me of being reflexively anti-regulation. That said, you have so many cycles in the day, and most of us would rather spend it slaying actual dragons than participating in focus groups on whether dragons are really a problem, whether lassoing them (with organic, sustainable and recyclable lassos) is preferable to slaying them – after all, dragons are people, too - and whether we need lasso compliance auditors to make sure lassos are being used correctly and humanely. (A point that seems to evade many rule makers: slaying dragons actually accomplishes something, whereas talking about “approved dragon slaying procedures and requirements” wastes the time of those who are competent to dispatch actual dragons and who were doing so very well without the input of “dragon-slaying theorists.”) Unfortunately for so many of us who would just get on with doing our day jobs, cybersecurity is rapidly devolving into the “focus groups on dragon dispatching” realm, which actual dragons slayers have little choice but to participate in. The general trend in cybersecurity is that powers-that-be – which encompasses groups other than just legislators – are often increasingly concerned and therefore feel they need to Do Something About Cybersecurity. Many seem to believe that if only we had the right amount of regulation and oversight, there would be no data breaches: a breach simply must mean Someone Is At Fault and Needs Supervision. (Leaving aside the fact that we have lots of home invasions despite a) guard dogs b) liberal carry permits c) alarm systems d) etc.) Also note that many well-managed and security-aware organizations, like the US Department of Defense, still get hacked. More specifically, many powers-that-be feel they must direct industry in a multiplicity of ways, up to and including how we actually build and deploy information technology systems. The more prescriptive the requirement, the more regulators or overseers a) can be seen to be doing something b) feel as if they are doing something regardless of whether they are actually doing something useful or cost effective. Note: an unfortunate concomitant of Doing Something is that often the cure is worse than the ailment. That is, doing what overseers want creates unfortunate byproducts that they either didn’t foresee or worse, don’t care about. After all, the logic goes, we Did Something. Prescriptive practice in the IT industry is problematic for a number of reasons. For a start, prescriptive guidance is really only appropriate if: • It is cost effective• It is “current” (meaning, the guidance doesn’t require the use of the technical equivalent of buggy whips long after horse-drawn transportation has become passé)*• It is practical (that is, pragmatic, proven and effective in the real world, not theoretical and unproven)• It solves the right problem With the above in mind, heading up the list of “you must be joking” regulations are recent disturbing developments in the Payment Card Industry (PCI) world. I’d like to give PCI kahunas the benefit of the doubt about their intentions, except that efforts by Oracle among others to make them aware of “unfortunate side effects of your requirements” – which is as tactful I can be for reasons that I believe will become obvious below - have gone, to-date, unanswered and more importantly, unchanged. A little background on PCI before I get too wound up. In 2008, the Payment Card Industry (PCI) Security Standards Council (SSC) introduced the Payment Application Data Security Standard (PA-DSS). That standard requires vendors of payment applications to ensure that their products implement specific requirements and undergo security assessment procedures. In order to have an application listed as a Validated Payment Application (VPA) and available for use by merchants, software vendors are required to execute the PCI Payment Application Vendor Release Agreement (VRA). (Are you still with me through all the acronyms?) Beginning in August 2010, the VRA imposed new obligations on vendors that are extraordinary and extraordinarily bad, short-sighted and unworkable. Specifically, PCI requires vendors to disclose (dare we say “tell all?”) to PCI any known security vulnerabilities and associated security breaches involving VPAs. ASAP. Think about the impact of that. PCI is asking a vendor to disclose to them: • Specific details of security vulnerabilities • Including exploit information or technical details of the vulnerability • Whether or not there is any mitigation available (as in a patch) PCI, in turn, has the right to blab about any and all of the above – specifically, to distribute all the gory details of what is disclosed - to the PCI SSC, qualified security assessors (QSAs), and any affiliate or agent or adviser of those entities, who are in turn permitted to share it with their respective affiliates, agents, employees, contractors, merchants, processors, service providers and other business partners. This assorted crew can’t be more than, oh, hundreds of thousands of entities. Does anybody believe that several hundred thousand people can keep a secret? Or that several hundred thousand people are all equally trustworthy? Or that not one of the people getting all that information would blab vulnerability details to a bad guy, even by accident? Or be a bad guy who uses the information to break into systems? (Wait, was that the Easter Bunny that just hopped by? Bringing world peace, no doubt.) Sarcasm aside, common sense tells us that telling lots of people a secret is guaranteed to “unsecret” the secret. Notably, being provided details of a vulnerability (without a patch) is of little or no use to companies running the affected application. Few users have the technological sophistication to create a workaround, and even if they do, most workarounds break some other functionality in the application or surrounding environment. Also, given the differences among corporate implementations of any application, it is highly unlikely that a single workaround is going to work for all corporate users. So until a patch is developed by the vendor, users remain at risk of exploit: even more so if the details of vulnerability have been widely shared. Sharing that information widely before a patch is available therefore does not help users, and instead helps only those wanting to exploit known security bugs. There’s a shocker for you. Furthermore, we already know that insider information about security vulnerabilities inevitably leaks, which is why most vendors closely hold such information and limit dissemination until a patch is available (and frequently limit dissemination of technical details even with the release of a patch). That’s the industry norm, not that PCI seems to realize or acknowledge that. Why would anybody release a bunch of highly technical exploit information to a cast of thousands, whose only “vetting” is that they are members of a PCI consortium? Oracle has had personal experience with this problem, which is one reason why information on security vulnerabilities at Oracle is “need to know” (we use our own row level access control to limit access to security bugs in our bug database, and thus less than 1% of development has access to this information), and we don’t provide some customers with more information than others or with vulnerability information and/or patches earlier than others. Failure to remember “insider information always leaks” creates problems in the general case, and has created problems for us specifically. A number of years ago, one of the UK intelligence agencies had information about a non-public security vulnerability in an Oracle product that they circulated among other UK and Commonwealth defense and intelligence entities. Nobody, it should be pointed out, bothered to report the problem to Oracle, even though only Oracle could produce a patch. The vulnerability was finally reported to Oracle by (drum roll) a US-based commercial company, to whom the information had leaked. (Note: every time I tell this story, the MI-whatever agency that created the problem gets a bit shirty with us. I know they meant well and have improved their vulnerability handling/sharing processes but, dudes, next time you find an Oracle vulnerability, try reporting it to us first before blabbing to lots of people who can’t actually fix the problem. Thank you!) Getting back to PCI: clearly, these new disclosure obligations increase the risk of exploitation of a vulnerability in a VPA and thus, of misappropriation of payment card data and customer information that a VPA processes, stores or transmits. It stands to reason that VRA’s current requirement for the widespread distribution of security vulnerability exploit details -- at any time, but particularly before a vendor can issue a patch or a workaround -- is very poor public policy. It effectively publicizes information of great value to potential attackers while not providing compensating benefits - actually, any benefits - to payment card merchants or consumers. In fact, it magnifies the risk to payment card merchants and consumers. The risk is most prominent in the time before a patch has been released, since customers often have little option but to continue using an application or system despite the risks. However, the risk is not limited to the time before a patch is issued: customers often need days, or weeks, to apply patches to systems, based upon the complexity of the issue and dependence on surrounding programs. Rather than decreasing the available window of exploit, this requirement increases the available window of exploit, both as to time available to exploit a vulnerability and the ease with which it can be exploited. Also, why would hackers focus on finding new vulnerabilities to exploit if they can get “EZHack” handed to them in such a manner: a) a vulnerability b) in a payment application c) with exploit code: the “Hacking Trifecta!“ It’s fair to say that this is probably the exact opposite of what PCI – or any of us – would want. Established industry practice concerning vulnerability handling avoids the risks created by the VRA’s vulnerability disclosure requirements. Specifically, the norm is not to release information about a security bug until the associated patch (or a pretty darn good workaround) has been issued. Once a patch is available, the notice to the user community is a high-level communication discussing the product at issue, the level of risk associated with the vulnerability, and how to apply the patch. The notices do not include either the specific customers affected by the vulnerability or forensic reports with maps of the exploit (both of which are required by the current VRA). In this way, customers have the tools they need to prioritize patching and to help prevent an attack, and the information released does not increase the risk of exploit. Furthermore, many vendors already use industry standards for vulnerability description: Common Vulnerability Enumeration (CVE) and Common Vulnerability Scoring System (CVSS). CVE helps ensure that customers know which particular issues a patch addresses and CVSS helps customers determine how severe a vulnerability is on a relative scale. Industry already provides the tools customers need to know what the patch contains and how bad the problem is that the patch remediates. So, what’s a poor vendor to do? Oracle is reaching out to other vendors subject to PCI and attempting to enlist then in a broad effort to engage PCI in rethinking (that is, eradicating) these requirements. I would therefore urge all who care about this issue, but especially those in the vendor community whose applications are subject to PCI and who may not have know they were being asked to tell-all to PCI and put their customers at risk, to do one of the following: • Contact PCI with your concerns• Contact Oracle (we are looking for vendors to sign our statement of concern)• And make sure you tell your customers that you have to rat them out to PCI if there is a breach involving the payment application I like to be charitable and say “PCI meant well” but in as important a public policy issue as what you disclose about vulnerabilities, to whom and when, meaning well isn’t enough. We need to do well. PCI, as regards this particular issue, has not done well, and has compounded the error by thus far being nonresponsive to those of us who have labored mightily to try to explain why they might want to rethink telling the entire planet about security problems with no solutions. By Way of Explanation… Non-related to PCI whatsoever, and the explanation for why I have not been blogging a lot recently, I have been working on Other Writing Venues with my sister Diane (who has also worked in the tech sector, inflicting upgrades on unsuspecting and largely ungrateful end users). I am pleased to note that we have recently (self-)published the first in the Miss Information Technology Murder Mystery series, Outsourcing Murder. The genre might best be described as “chick lit meets geek scene.” Our sisterly nom de plume is Maddi Davidson and (shameless plug follows): you can order the paper version of the book on Amazon, or the Kindle or Nook versions on www.amazon.com or www.bn.com, respectively. From our book jacket: Emma Jones, a 20-something IT consultant, is working on an outsourcing project at Tahiti Tacos, a restaurant chain offering Polynexican cuisine: refried poi, anyone? Emma despises her boss Padmanabh, a brilliant but arrogant partner in GD Consulting. When Emma discovers His-Royal-Padness’s body (verdict: death by cricket bat), she becomes a suspect.With her overprotective family and her best friend Stacey providing endless support and advice, Emma stumbles her way through an investigation of Padmanabh’s murder, bolstered by fusion food feeding frenzies, endless cups of frou-frou coffee and serious surfing sessions. While Stacey knows a PI who owes her a favor, landlady Magda urges Emma to tart up her underwear drawer before the next cute cop with a search warrant arrives. Emma’s mother offers to fix her up with a PhD student at Berkeley and showers her with self-defense gizmos while her old lover Keoni beckons from Hawai’i. And everyone, even Shaun the barista, knows a good lawyer. Book 2, Denial of Service, is coming out this summer. * Given the rate of change in technology, today’s “thou shalts” are easily next year’s “buggy whip guidance.”

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