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  • Ubuntu 13.10 isn't remembering my passwords anymore, why?

    - by Nik Reiman
    Ubuntu's password management used to be working just fine for me, but around two weeks ago after running apt-get upgrade, I've noticed that now it keeps "forgetting" my passwords. For instance, I need to manually enter passwords to unlock my ssh keys to use git, which previously was done automatically on login. My workplace's 802.11x authentication also no longer works, I need to manually re-auth just to connect to internet. What's going on?

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  • All the posts in LINQ series

    - by vik20000in
    In Last few weeks I have done a few LINQ series Post. Here is a list of all the posts done.Filtering data in LINQ with the help of where clauseUsing Take and skip keyword to filter records in LINQ TakeWhile and SkipWhile method in LINQLINQ and ordering of the result setGrouping data in LINQ with the help of group keywordUsing set operation in LINQLINQ and conversion operatorsRetrieving only the first record or record at a certain index in LINQUsing Generation operator in LINQWorking with Joins in LINQLINQ and Aggregate function Vikram

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  • Windows Azure Use Case: High-Performance Computing (HPC)

    - by BuckWoody
    This is one in a series of posts on when and where to use a distributed architecture design in your organization's computing needs. You can find the main post here: http://blogs.msdn.com/b/buckwoody/archive/2011/01/18/windows-azure-and-sql-azure-use-cases.aspx  Description: High-Performance Computing (also called Technical Computing) at its most simplistic is a layout of computer workloads where a “head node” accepts work requests, and parses them out to “worker nodes'”. This is useful in cases such as scientific simulations, drug research, MatLab work and where other large compute loads are required. It’s not the immediate-result type computing many are used to; instead, a “job” or group of work requests is sent to a cluster of computers and the worker nodes work on individual parts of the calculations and return the work to the scheduler or head node for the requestor in a batch-request fashion. This is typical to the way that many mainframe computing use-cases work. You can use commodity-based computers to create an HPC Cluster, such as the Linux application called Beowulf, and Microsoft has a server product for HPC using standard computers, called the Windows Compute Cluster that you can read more about here. The issue with HPC (from any vendor) that some organization have is the amount of compute nodes they need. Having too many results in excess infrastructure, including computers, buildings, storage, heat and so on. Having too few means that the work is slower, and takes longer to return a result to the calling application. Unless there is a consistent level of work requested, predicting the number of nodes is problematic. Implementation: Recently, Microsoft announced an internal partnership between the HPC group (Now called the Technical Computing Group) and Windows Azure. You now have two options for implementing an HPC environment using Windows. You can extend the current infrastructure you have for HPC by adding in Compute Nodes in Windows Azure, using a “Broker Node”.  You can then purchase time for adding machines, and then stop paying for them when the work is completed. This is a common pattern in groups that have a constant need for HPC, but need to “burst” that load count under certain conditions. The second option is to install only a Head Node and a Broker Node onsite, and host all Compute Nodes in Windows Azure. This is often the pattern for organizations that need HPC on a scheduled and periodic basis, such as financial analysis or actuarial table calculations. References: Blog entry on Hybrid HPC with Windows Azure: http://blogs.msdn.com/b/ignitionshowcase/archive/2010/12/13/high-performance-computing-on-premise-and-in-the-windows-azure-cloud.aspx  Links for further research on HPC, includes Windows Azure information: http://blogs.msdn.com/b/ncdevguy/archive/2011/02/16/handy-links-for-hpc-and-azure.aspx 

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  • XNA Per-Polygon Collision Check

    - by user22985
    I'm working on a project in XNA for WP7 with a low-poly environment, my problem is I need to setup a working per-polygon collision check between 2 or more 3d meshes. I've checked tons of tutorials but all of them use bounding-boxes, bounding-spheres,rays etc., but what I really need is a VERY precise way of checking if the polygons of two distinct models have intersected or not. If you could redirect me to an example or at least give me some pointers I would be grateful.

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  • Site Search Engine for 1,000 page website

    - by Ian
    I manage a website with about 1,000 articles that need to be searchable by my members. The site search engines I've tried all had their own problems: Fluid Dynamics Search Engine Since it's written in perl, it was a bit hacky to integrate with my PHP-based CMS. I basically had to file_get_contents the search results page. However, FDSE had the best search results. Google CSE Ugh, the search results SUCK. It can't find documents even using unique strings. I'm so surprised that a Google search product is this bad. Nor can I get any answers on their 'help' forums, and I am a paying user. Boo, Google. Boo. Sphider Again, bad search results. Unable to locate some phrases used in link text. Better results than Google CSE though. Shame on Google that a free PHP script has better search results than their paid application. IndexTank This one looked really promising. I got all set up with their PHP API client. But it would only randomly add articles that I submitted. Out of 700+ articles I pushed to the index through their API, only 8 made it in. Unable to find any help on this subject. Update for IndexTank -- Got the above issue fixed, so this looks most promising so far. The site itself runs on php/mysql and FreeBSD, though this shouldn't matter for a web crawling indexer. I've looked at Lucene, but I don't know anything about Java or installing Java programs on my web server. I also do not have root access on my web server, if this would be required for installation. I really don't need a lot of fancy features. It just needs to be able to crawl my web site and return great (even decent!) search results. I don't need any crazy search operators. It doesn't need to index off my primary domain. It just needs to work! Thanks, Hive Mind!

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  • Integrating Coherence & Java EE 6 Applications using ActiveCache

    - by Ricardo Ferreira
    OK, so you are a developer and are starting a new Java EE 6 application using the most wonderful features of the Java EE platform like Enterprise JavaBeans, JavaServer Faces, CDI, JPA e another cool stuff technologies. And your architecture need to hold piece of data into distributed caches to improve application's performance, scalability and reliability? If this is your current facing scenario, maybe you should look closely in the solutions provided by Oracle WebLogic Server. Oracle had integrated WebLogic Server and its champion data caching technology called Oracle Coherence. This seamless integration between this two products provides a comprehensive environment to develop applications without the complexity of extra Java code to manage cache as a dependency, since Oracle provides an DI ("Dependency Injection") mechanism for Coherence, the same DI mechanism available in standard Java EE applications. This feature is called ActiveCache. In this article, I will show you how to configure ActiveCache in WebLogic and at your Java EE application. Configuring WebLogic to manage Coherence Before you start changing your application to use Coherence, you need to configure your Coherence distributed cache. The good news is, you can manage all this stuff without writing a single line of code of XML or even Java. This configuration can be done entirely in the WebLogic administration console. The first thing to do is the setup of a Coherence cluster. A Coherence cluster is a set of Coherence JVMs configured to form one single view of the cache. This means that you can insert or remove members of the cluster without the client application (the application that generates or consume data from the cache) knows about the changes. This concept allows your solution to scale-out without changing the application server JVMs. You can growth your application only in the data grid layer. To start the configuration, you need to configure an machine that points to the server in which you want to execute the Coherence JVMs. WebLogic Server allows you to do this very easily using the Administration Console. In this example, I will call the machine as "coherence-server". Remember that in order to the machine concept works, you need to ensure that the NodeManager are being executed in the target server that the machine points to. The NodeManager executable can be found in <WLS_HOME>/server/bin/startNodeManager.sh. The next thing to do is to configure a Coherence cluster. In the WebLogic administration console, go to Environment > Coherence Clusters and click in "New". Call this Coherence cluster of "my-coherence-cluster". Click in next. Specify a valid cluster address and port. The Coherence members will communicate with each other through this address and port. Our Coherence cluster are now configured. Now it is time to configure the Coherence members and add them to this cluster. In the WebLogic administration console, go to Environment > Coherence Servers and click in "New". In the field "Name" set to "coh-server-1". In the field "Machine", associate this Coherence server to the machine "coherence-server". In the field "Cluster", associate this Coherence server to the cluster named "my-coherence-cluster". Click in "Finish". Start the Coherence server using the "Control" tab of WebLogic administration console. This will instruct WebLogic to start a new JVM of Coherence in the target machine that should join the pre-defined Coherence cluster. Configuring your Java EE Application to Access Coherence Now lets pass to the funny part of the configuration. The first thing to do is to inform your Java EE application which Coherence cluster to join. Oracle had updated WebLogic server deployment descriptors so you will not have to change your code or the containers deployment descriptors like application.xml, ejb-jar.xml or web.xml. In this example, I will show you how to enable DI ("Dependency Injection") to a Coherence cache from a Servlet 3.0 component. In the WEB-INF/weblogic.xml deployment descriptor, put the following metadata information: <?xml version="1.0" encoding="UTF-8"?> <wls:weblogic-web-app xmlns:wls="http://xmlns.oracle.com/weblogic/weblogic-web-app" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd http://xmlns.oracle.com/weblogic/weblogic-web-app http://xmlns.oracle.com/weblogic/weblogic-web-app/1.4/weblogic-web-app.xsd"> <wls:context-root>myWebApp</wls:context-root> <wls:coherence-cluster-ref> <wls:coherence-cluster-name>my-coherence-cluster</wls:coherence-cluster-name> </wls:coherence-cluster-ref> </wls:weblogic-web-app> As you can see, using the "coherence-cluster-name" tag, we are informing our Java EE application that it should join the "my-coherence-cluster" when it loads in the web container. Without this information, the application will not be able to access the predefined Coherence cluster. It will form its own Coherence cluster without any members. So never forget to put this information. Now put the coherence.jar and active-cache-1.0.jar dependencies at your WEB-INF/lib application classpath. You need to deploy this dependencies so ActiveCache can automatically take care of the Coherence cluster join phase. This dependencies can be found in the following locations: - <WLS_HOME>/common/deployable-libraries/active-cache-1.0.jar - <COHERENCE_HOME>/lib/coherence.jar Finally, you need to write down the access code to the Coherence cache at your Servlet. In the following example, we have a Servlet 3.0 component that access a Coherence cache named "transactions" and prints into the browser output the content (the ammount property) of one specific transaction. package com.oracle.coherence.demo.activecache; import java.io.IOException; import javax.annotation.Resource; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.tangosol.net.NamedCache; @WebServlet("/demo/specificTransaction") public class TransactionServletExample extends HttpServlet { @Resource(mappedName = "transactions") NamedCache transactions; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { int transId = Integer.parseInt(request.getParameter("transId")); Transaction transaction = (Transaction) transactions.get(transId); response.getWriter().println("<center>" + transaction.getAmmount() + "</center>"); } } Thats it! No more configuration is necessary and you have all set to start producing and getting data to/from Coherence. As you can see in the example code, the Coherence cache are treated as a normal dependency in the Java EE container. The magic happens behind the scenes when the ActiveCache allows your application to join the defined Coherence cluster. The most interesting thing about this approach is, no matter which type of Coherence cache your are using (Distributed, Partitioned, Replicated, WAN-Remote) for the client application, it is just a simple attribute member of com.tangosol.net.NamedCache type. And its all managed by the Java EE container as an dependency. This means that if you inject the same dependency (the Coherence cache named "transactions") in another Java EE component (JSF managed-bean, Stateless EJB) the cache will be the same. Cool isn't it? Thanks to the CDI technology, we can extend the same support for non-Java EE standards components like simple POJOs. This means that you are not forced to only use Servlets, EJBs or JSF in order to inject Coherence caches. You can do the same approach for regular POJOs created for you and managed by lightweight containers like Spring or Seam.

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  • How to Block a HTTP Website along with Its All Subdomain using IPTABLE

    - by netnovice
    I run a small HTTP web proxy site . We can not modify anything there in Proxy program. Few users mainly use Yahoo Web mail for Spamming and We need to block yahoo web mail access only ( complete yahoo website is also Ok) through our proxy . specially .mail.yahoo.com.. Like - we need to block URL like - http://uk-mg61.mail.yahoo.com http://in-mg61.mail.yahoo.com etc. etc. Note : We generaly open http://mail.yahoo.com in browser - but after loggin in it forwards it to Urls like above but all those are subdomain of mail.yahoo.com My target is if we can get all IP list for all available subdomain of mail.yahoo.com I can block it totally . We can only use IPTABLE ...I know using proxy itself we can check HTTP header and check Host field for .mail.yahoo.com. and block it. Solution : Follwoign what I did using IPtable . I collected IP CIDR block for yahoo mainly for yahoo web mail ( mail.yahoo.com ) as much as possible ( using linux host and whois command ) [ like 66.163.160.0/19 nd 98.136.0.0/14 etc ] and applied follwing command Like iptables -A OUTPUT -p tcp -d 66.163.160.0/19 -m state --state NEW -j DROP etc. Things are working fine. user can not access yahoo mail BUT the problem is I need to be updated with the avaialble CIDR YAHOO IP list ... I am ready to do it every week. I collected many from Net... You know theer are countles subdomain of mail.yahoo.com and seems every week Yahoo adding new IP... But what I observed some time user can bypass our rule and the reason obvously all the avaialble Ips are not entered in IPtable yet. What we need to do is enter all Ips of mail.yahoo.co But where do I find all subdomain for mail.yahoo.com I know we can get it from DNS but I must not be allowed to make DNS axfr query. Also doing reverse DNS will have performance issue. I want to know all subdomain of .mail.yahoo.c Can I get it from yahoo site. I have the list of all YAHOO smtp IP....but I need webmail Ip... ( http://public.yahoo.com/carloc/ymail.html ) Can you please share your Idea. Thank you

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  • Change default language settings in Visual Studio 2012

    - by sreejukg
    The first thing you need to do after the installation of Visual Studio 2012 is to choose the IDE preferences. Once you select your preferred collection of settings, the IDE will always choose dialogs and other options according to your selection. Nowadays developer’s needs to work with different programming environments and due to this, developers might need to reset the default settings. In this article, I am going to demonstrate how you can change the default settings in Visual Studio 2012. For the purpose of this demonstration, I have installed Visual Studio 2012 and selected C++ as my default environment settings. So now when I go to file -> new project, it will give me C++ templates by default as follows. If you want to select another language, you need to expand Other Languages section and select C# or VB. Now I am going to change these default settings. I am going to change the default language preference to C#. In Visual Studio 2012, go to tools menu and select Import and Export Settings. Here you have 3 options; one is to export the current settings so that the settings are saved for future use. Also you can import previously saved settings. The last option available is to reset it to default. It is a good Idea to export your settings and import it as you need in later stages. To reset the settings to default select the Reset option and click next. Now Visual Studio will ask you to whether you would like to save the settings, which can be used in future to restore. Select any one option and click next. For the purpose of this demo, I have selected not to save the settings. Click Next button to continue. Now Visual Studio will bring you the similar dialog that appears just after installation to select your IDE settings. Select the required settings from the available list and click Finish button. Click Finish once you are done. If everything OK, you will see the success message as below. Now go to file -> new Project, you will see the selected language appear by default. I selected C# in the previous step and the new project dialog appears as follows. Changing IDE settings in Visual Studio 2012 is very easy and straight forward.

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  • How To Use Regular Expressions for Data Validation and Cleanup

    You need to provide data validation at the server level for complex strings like phone numbers, email addresses, etc. You may also need to do data cleanup / standardization before moving it from source to target. Although SQL Server provides a fair number of string functions, the code developed with these built-in functions can become complex and hard to maintain or reuse. The Future of SQL Server Monitoring "Being web-based, SQL Monitor 2.0 enables you to check on your servers from almost any location" Jonathan Allen.Try SQL Monitor now.

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  • How to pad number with leading zero with C#

    - by Jalpesh P. Vadgama
    Recently I was working with a project where I was in need to format a number in such a way which can apply leading zero for particular format.  So after doing such R and D I have found a great way to apply this leading zero format. I was having need that I need to pad number in 5 digit format. So following is a table in which format I need my leading zero format. 1-> 00001 20->00020 300->00300 4000->04000 50000->5000 So in the above example you can see that 1 will become 00001 and 20 will become 00200 format so on. So to display an integer value in decimal format I have applied interger.Tostring(String) method where I have passed “Dn” as the value of the format parameter, where n represents the minimum length of the string. So if we pass 5 it will have padding up to 5 digits. So let’s create a simple console application and see how its works. Following is a code for that. using System; namespace LeadingZero { class Program { static void Main(string[] args) { int a = 1; int b = 20; int c = 300; int d = 4000; int e = 50000; Console.WriteLine(string.Format("{0}------>{1}",a,a.ToString("D5"))); Console.WriteLine(string.Format("{0}------>{1}", b, b.ToString("D5"))); Console.WriteLine(string.Format("{0}------>{1}", c, c.ToString("D5"))); Console.WriteLine(string.Format("{0}------>{1}", d, d.ToString("D5"))); Console.WriteLine(string.Format("{0}------>{1}", e, e.ToString("D5"))); Console.ReadKey(); } } } As you can see in the above code I have use string.Format function to display value of integer and after using integer value’s  ToString method. Now Let’s run the console application and following is the output as expected. Here you can see the integer number are converted into the exact output that we requires. That’s it you can see it’s very easy. We have written code in nice clean way and without writing any extra code or loop. Hope you liked it. Stay tuned for more.. Till than happy programming.

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  • Running TeamCity from Amazon EC2 - Cloud based scalable build and continuous Integration

    - by RoyOsherove
    I’ve been having fun playing with the amazon EC2 cloud service. I set up a server running TeamCity, and an image of a server that just runs a TeamCity agent. I also setup TeamCity  to automatically instantiate agents on EC2 and shut them down based upon availability of free agents. Here’s how I did it: The first step was setting up the teamcity server. Create an account on amazon EC2 (BTW, amazon’s sites works better in IE than it does in chrome.. who knew!?) Open the EC2 dashboard, and click “Launch Instance” . From the “Quick Start” tab I selected from the list: “Getting Started on Microsoft Windows Server 2008 (AMI Id: ami-c5e40dac)” .  it’s good enough to just run teamcity. In the instance details, I used the default (Small instance, 1.7 GB mem). You might want to choose a close availability zone based on where you are. We want to “Launch instances” so click continue. Select the default kernel, RAM disk and all. No need to enable monitoring for now (you can do that later). click continue. If you don’t have a key pair, you will be prompted to create one. Once you do, select it in the list. Now you’ll be prompted to create a security group. I named mine “TC” as in “TeamCity”. each group is a bunch of settings on which ports can be let through into and out of a hosted machine.  keep it as the default settings. We will change them later. Click continue,  review and then click “Launch”. Now you’ll be able to see the new instance in the running instances list on your site. Now, you need to install stuff on that instance (TeamCity!) . To do that, you’ll need to Remote desktop into that instance. To do that, we’ll get the admin password for that instance: Check it on the list, and click “Instance Actions” - “Get Windows Admin Password”. You might have to wait about 10 minutes or so for the password to be generated for you. Once you have the password, you will remote desktop (start-run-‘mstsc’) into the instance. It’s address is a dns address shown below the list under “Public DNS”. it looks something like: ec2-256-226-194-91.compute-1.amazonaws.com Once you’re inside the instance – you’ll need to open IE (it is in hardened mode so you’ll have to relax its security settings to download stuff). I first downloaded chrome and using chrome I downloaded TeamCity. Note that the download speed is FAST. several MBs per second. To be able to see TeamCity from the outside, you will need to open the advanced firewall settings inside the remote machine, and add incoming and outgoing rules for port 80 (HTTP). Once you do that, you should be able to see the machine from the outside. If you still can’t, see the next step. I also enabled ports 9090 since I will use this machine to create an agent image later as well. Now configure the security group (TC) to enable talking to agents: IN the EC2 dashboard click on “Security Groups” and select your group. To add a rule, click on the empty list under the ‘protocol’ header. select TCP. from and ‘to’ ports are 9090. source ip is 0.0.0.0/0 (every ip is allowed). click “Save.  Also make sure you can see “HTTP” tcp 80 in that list. if you can’t see it, add it or you won’t be able to browse to the machine’s teamcity server home page. I also set an elastic IP for the machine: so I always have the same IP for the machine instance. Allocate and set one through the”Elastic IP” link on the EC2 dashboard.   you should now have a working instance of teamcity.   Now let’s create an agent image. Repeat steps 1-9, but this time, make sure you select a machine that fits what an agent might do. I selected Instance type – Hihg-CPU medium machine,  that is much faster. On that machine, I installed what I needed (VS 2010, PostSharp etc..). downloading VS 2010 from MSDN (2 GB took less than 10 min!) Now, instead of installing teamcity, browse using the browser to the teamcity homepage (from within the remote machine). go to the Administration page, and click the upper right link “Install agents”. Install the agent on he local machine – set it to the IP or DNS of the running TeamCity server. That way you’ll be able to check their connectivity live before making this machine your official agent image to reuse. Once the agent is installed, see that the TC server can see it and use it. see steps 13-14 above if they can’t. Once it works, you can take steps to make this image your agent image to be reused. next, here is a copy-paste of several steps to take from http://confluence.jetbrains.net/display/TCD5/Setting+Up+TeamCity+for+Amazon+EC2 Configure system so that agent it is started on machine boot (and make sure TeamCity server is accessible on machine boot). Test the setup by rebooting machine and checking that the agent connects normally to the server. Prepare the Image for bundling: Remove any temporary/history information in the system. Stop the agent (under Windows stop the service but leave it in Automatic startup type) Delete content agent logs and temp directories (not necessary) Delete "<Agent Home>/conf/amazon-*" file (not necessary) Change config/buildAgent.properties to remove properties: name, serverAddress, authToken (not necessary)   Now, we need to: Make AMI from the running instance. Configure TeamCity EC2 support on TeamCity server. Making an AMI: Check the instance of the agent in the EC2 dashboard instance list, and select instance actions->Create Image (EBS AMI) you’ll see the image pending in the APIs list in the EC2 dashboard. this could take 30 minutes or more. meanwhile we can configure the could support in the teamcity server. COPY THE AMI ID to the clipboard (looks like ami-a88aa4ce) Configuring TeamCity for Cloud: In TeamCity, click on “Agents” and then on “Cloud” tab. this is where you will control your cloud agents. to configure new cloud agents based on APIs, click on the right link to the “configuration page” Create a new profile and select AMazon EC2 as cloud type. Use your AMI ID that you copied to the clipboard into the “Images” field. Select an availability zone that is the same as the one your instance is running on for best communication perf between them make sure you select the ‘TC’ security group hopefully, that should be it, and teamcity will try to instantiate new instances on demand. Note that it may take around 10 minutes for an agent to become available to teamcity from the time it’s started.

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  • How can i use JIRA for project management with Green Hopper

    - by user22
    I am thinking of using JIRA + GreenHopper for my project management. I have seen that Green Hopper is for making User stories , sprints. I am not able to find how do i need to add tasks , or how to break user stories in to sub stoires. DO i first need to create project in JIRA and then use Green Hopper or i can use use Green Hopper as stand alone for project management. I am thinking of JIRA as issue tracker not project management.

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  • What installation size should i use?

    - by Patrick
    I am installing Ubuntu with the Windows installer, however I am using Windows 8. I need to know if there will be problems with installing it using Windows 8, and I need to know which installation size I should use........4gb....18gb....etc. Also, is it possible to actually install it on a usb drive? the option was available in the installation, but i was not sure if it was safe or not. I would really appreciate some answers.

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  • What "pieces" are needed in order to set up a cluster of physical servers?

    - by Chris Dutrow
    Background: Currently, we use Rackspace cloud servers. We have no intention to stop using them, but would like to look into setting up a cluster of physical servers (probably desktop computers in the $400 range with 8gb memory each) to offset some of our load and work as a secondary, more powerful, less reliable system. To put things in perspective, we can buy comparable desktop computers for the same price as we pay in one month to rent them on Rackspace Cloud. I understand that this is generally a dumb idea. However, in this particular instance, the server cluster is needed for its computation power. It is not mission-critical, it does not host a consumer-facing website, and if it goes down for a day or two, its not really a problem. Currently, we have access to business class verizon fios. If I understand correctly, we can get at least 25 dedicated IP addresses with this service, this should be enough. Requirements: Each server runs Linux Centos 6.3 Some of the servers run Python and execute processes from a task queue (Redis or RabbitMQ) Some of the servers are capable of serving static files and Python driven REST APIs Some of the servers host a Cassandra database cluster One or more of the servers are a Redis database servers One or more of the servers are PostgreSQL servers Questions: What kind of router or switch is needed? We would like the computers to be able to communicate effectively with each other via internal IP addresses. This is especially important for communicating with servers hosting Redis that need to be able to respond to requests very quickly. Are there special switches or routers that need to be used to connect the servers together? Are Desktop computers ok for this? We have found that we are mostly RAM-bottle necked, I understand that some servers have highly superior CPUs, but I'm not sure we need CPU power as much as we need RAM, which is cheap in Desktop computers. Will we have problems with the WIFI cards in the desktops or any other unexpected hardware limitation? What tools should be used to "image" the servers. For example, when we get an installation right for a Redis server or Cassandra node, are there tools that come with Linux Centos 6.3 to image the server to a USB drive or something like that? Or do we need to use some other software for this? What other things are we missing that we should be concerned about? Thanks so much!

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  • Install Everpad on Ubuntu 13.10

    - by Muhammad Ahmad Zafar
    I just installed a fresh copy of Ubuntu 13.10 and wanted to install Everpad but there is some issue as the PPA for it is missing it. These were the commands which I execute (took help from http://www.webupd8.org/2012/09/everpad-integrates-evernote-with-ubuntu.html and everywhere its the same): sudo add-apt-repository ppa:nvbn-rm/ppa sudo apt-get update sudo apt-get install everpad The following which what I get when the last command is executed: Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package everpad Please help

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  • The Shift: how Orchard painlessly shifted to document storage, and how it’ll affect you

    - by Bertrand Le Roy
    We’ve known it all along. The storage for Orchard content items would be much more efficient using a document database than a relational one. Orchard content items are composed of parts that serialize naturally into infoset kinds of documents. Storing them as relational data like we’ve done so far was unnatural and requires the data for a single item to span multiple tables, related through 1-1 relationships. This means lots of joins in queries, and a great potential for Select N+1 problems. Document databases, unfortunately, are still a tough sell in many places that prefer the more familiar relational model. Being able to x-copy Orchard to hosters has also been a basic constraint in the design of Orchard. Combine those with the necessity at the time to run in medium trust, and with license compatibility issues, and you’ll find yourself with very few reasonable choices. So we went, a little reluctantly, for relational SQL stores, with the dream of one day transitioning to document storage. We have played for a while with the idea of building our own document storage on top of SQL databases, and Sébastien implemented something more than decent along those lines, but we had a better way all along that we didn’t notice until recently… In Orchard, there are fields, which are named properties that you can add dynamically to a content part. Because they are so dynamic, we have been storing them as XML into a column on the main content item table. This infoset storage and its associated API are fairly generic, but were only used for fields. The breakthrough was when Sébastien realized how this existing storage could give us the advantages of document storage with minimal changes, while continuing to use relational databases as the substrate. public bool CommercialPrices { get { return this.Retrieve(p => p.CommercialPrices); } set { this.Store(p => p.CommercialPrices, value); } } This code is very compact and efficient because the API can infer from the expression what the type and name of the property are. It is then able to do the proper conversions for you. For this code to work in a content part, there is no need for a record at all. This is particularly nice for site settings: one query on one table and you get everything you need. This shows how the existing infoset solves the data storage problem, but you still need to query. Well, for those properties that need to be filtered and sorted on, you can still use the current record-based relational system. This of course continues to work. We do however provide APIs that make it trivial to store into both record properties and the infoset storage in one operation: public double Price { get { return Retrieve(r => r.Price); } set { Store(r => r.Price, value); } } This code looks strikingly similar to the non-record case above. The difference is that it will manage both the infoset and the record-based storages. The call to the Store method will send the data in both places, keeping them in sync. The call to the Retrieve method does something even cooler: if the property you’re looking for exists in the infoset, it will return it, but if it doesn’t, it will automatically look into the record for it. And if that wasn’t cool enough, it will take that value from the record and store it into the infoset for the next time it’s required. This means that your data will start automagically migrating to infoset storage just by virtue of using the code above instead of the usual: public double Price { get { return Record.Price; } set { Record.Price = value; } } As your users browse the site, it will get faster and faster as Select N+1 issues will optimize themselves away. If you preferred, you could still have explicit migration code, but it really shouldn’t be necessary most of the time. If you do already have code using QueryHints to mitigate Select N+1 issues, you might want to reconsider those, as with the new system, you’ll want to avoid joins that you don’t need for filtering or sorting, further optimizing your queries. There are some rare cases where the storage of the property must be handled differently. Check out this string[] property on SearchSettingsPart for example: public string[] SearchedFields { get { return (Retrieve<string>("SearchedFields") ?? "") .Split(new[] {',', ' '}, StringSplitOptions.RemoveEmptyEntries); } set { Store("SearchedFields", String.Join(", ", value)); } } The array of strings is transformed by the property accessors into and from a comma-separated list stored in a string. The Retrieve and Store overloads used in this case are lower-level versions that explicitly specify the type and name of the attribute to retrieve or store. You may be wondering what this means for code or operations that look directly at the database tables instead of going through the new infoset APIs. Even if there is a record, the infoset version of the property will win if it exists, so it is necessary to keep the infoset up-to-date. It’s not very complicated, but definitely something to keep in mind. Here is what a product record looks like in Nwazet.Commerce for example: And here is the same data in the infoset: The infoset is stored in Orchard_Framework_ContentItemRecord or Orchard_Framework_ContentItemVersionRecord, depending on whether the content type is versionable or not. A good way to find what you’re looking for is to inspect the record table first, as it’s usually easier to read, and then get the item record of the same id. Here is the detailed XML document for this product: <Data> <ProductPart Inventory="40" Price="18" Sku="pi-camera-box" OutOfStockMessage="" AllowBackOrder="false" Weight="0.2" Size="" ShippingCost="null" IsDigital="false" /> <ProductAttributesPart Attributes="" /> <AutoroutePart DisplayAlias="camera-box" /> <TitlePart Title="Nwazet Pi Camera Box" /> <BodyPart Text="[...]" /> <CommonPart CreatedUtc="2013-09-10T00:39:00Z" PublishedUtc="2013-09-14T01:07:47Z" /> </Data> The data is neatly organized under each part. It is easy to see how that document is all you need to know about that content item, all in one table. If you want to modify that data directly in the database, you should be careful to do it in both the record table and the infoset in the content item record. In this configuration, the record is now nothing more than an index, and will only be used for sorting and filtering. Of course, it’s perfectly fine to mix record-backed properties and record-less properties on the same part. It really depends what you think must be sorted and filtered on. In turn, this potentially simplifies migrations considerably. So here it is, the great shift of Orchard to document storage, something that Orchard has been designed for all along, and that we were able to implement with a satisfying and surprising economy of resources. Expect this code to make its way into the 1.8 version of Orchard when that’s available.

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  • SSIS: Deploying OLAP cubes using C# script tasks and AMO

    - by DrJohn
    As part of the continuing series on Building dynamic OLAP data marts on-the-fly, this blog entry will focus on how to automate the deployment of OLAP cubes using SQL Server Integration Services (SSIS) and Analysis Services Management Objects (AMO). OLAP cube deployment is usually done using the Analysis Services Deployment Wizard. However, this option was dismissed for a variety of reasons. Firstly, invoking external processes from SSIS is fraught with problems as (a) it is not always possible to ensure SSIS waits for the external program to terminate; (b) we cannot log the outcome properly and (c) it is not always possible to control the server's configuration to ensure the executable works correctly. Another reason for rejecting the Deployment Wizard is that it requires the 'answers' to be written into four XML files. These XML files record the three things we need to change: the name of the server, the name of the OLAP database and the connection string to the data mart. Although it would be reasonably straight forward to change the content of the XML files programmatically, this adds another set of complication and level of obscurity to the overall process. When I first investigated the possibility of using C# to deploy a cube, I was surprised to find that there are no other blog entries about the topic. I can only assume everyone else is happy with the Deployment Wizard! SSIS "forgets" assembly references If you build your script task from scratch, you will have to remember how to overcome one of the major annoyances of working with SSIS script tasks: the forgetful nature of SSIS when it comes to assembly references. Basically, you can go through the process of adding an assembly reference using the Add Reference dialog, but when you close the script window, SSIS "forgets" the assembly reference so the script will not compile. After repeating the operation several times, you will find that SSIS only remembers the assembly reference when you specifically press the Save All icon in the script window. This problem is not unique to the AMO assembly and has certainly been a "feature" since SQL Server 2005, so I am not amazed it is still present in SQL Server 2008 R2! Sample Package So let's take a look at the sample SSIS package I have provided which can be downloaded from here: DeployOlapCubeExample.zip  Below is a screenshot after a successful run. Connection Managers The package has three connection managers: AsDatabaseDefinitionFile is a file connection manager pointing to the .asdatabase file you wish to deploy. Note that this can be found in the bin directory of you OLAP database project once you have clicked the "Build" button in Visual Studio TargetOlapServerCS is an Analysis Services connection manager which identifies both the deployment server and the target database name. SourceDataMart is an OLEDB connection manager pointing to the data mart which is to act as the source of data for your cube. This will be used to replace the connection string found in your .asdatabase file Once you have configured the connection managers, the sample should run and deploy your OLAP database in a few seconds. Of course, in a production environment, these connection managers would be associated with package configurations or set at runtime. When you run the sample, you should see that the script logs its activity to the output screen (see screenshot above). If you configure logging for the package, then these messages will also appear in your SSIS logging. Sample Code Walkthrough Next let's walk through the code. The first step is to parse the connection string provided by the TargetOlapServerCS connection manager and obtain the name of both the target OLAP server and also the name of the OLAP database. Note that the target database does not have to exist to be referenced in an AS connection manager, so I am using this as a convenient way to define both properties. We now connect to the server and check for the existence of the OLAP database. If it exists, we drop the database so we can re-deploy. svr.Connect(olapServerName); if (svr.Connected) { // Drop the OLAP database if it already exists Database db = svr.Databases.FindByName(olapDatabaseName); if (db != null) { db.Drop(); } // rest of script } Next we start building the XMLA command that will actually perform the deployment. Basically this is a small chuck of XML which we need to wrap around the large .asdatabase file generated by the Visual Studio build process. // Start generating the main part of the XMLA command XmlDocument xmlaCommand = new XmlDocument(); xmlaCommand.LoadXml(string.Format("<Batch Transaction='false' xmlns='http://schemas.microsoft.com/analysisservices/2003/engine'><Alter AllowCreate='true' ObjectExpansion='ExpandFull'><Object><DatabaseID>{0}</DatabaseID></Object><ObjectDefinition/></Alter></Batch>", olapDatabaseName));  Next we need to merge two XML files which we can do by simply using setting the InnerXml property of the ObjectDefinition node as follows: // load OLAP Database definition from .asdatabase file identified by connection manager XmlDocument olapCubeDef = new XmlDocument(); olapCubeDef.Load(Dts.Connections["AsDatabaseDefinitionFile"].ConnectionString); // merge the two XML files by obtain a reference to the ObjectDefinition node oaRootNode.InnerXml = olapCubeDef.InnerXml;   One hurdle I had to overcome was removing detritus from the .asdabase file left by the Visual Studio build. Through an iterative process, I found I needed to remove several nodes as they caused the deployment to fail. The XMLA error message read "Cannot set read-only node: CreatedTimestamp" or similar. In comparing the XMLA generated with by the Deployment Wizard with that generated by my code, these read-only nodes were missing, so clearly I just needed to strip them out. This was easily achieved using XPath to find the relevant XML nodes, of which I show one example below: foreach (XmlNode node in rootNode.SelectNodes("//ns1:CreatedTimestamp", nsManager)) { node.ParentNode.RemoveChild(node); } Now we need to change the database name in both the ID and Name nodes using code such as: XmlNode databaseID = xmlaCommand.SelectSingleNode("//ns1:Database/ns1:ID", nsManager); if (databaseID != null) databaseID.InnerText = olapDatabaseName; Finally we need to change the connection string to point at the relevant data mart. Again this is easily achieved using XPath to search for the relevant nodes and then replace the content of the node with the new name or connection string. XmlNode connectionStringNode = xmlaCommand.SelectSingleNode("//ns1:DataSources/ns1:DataSource/ns1:ConnectionString", nsManager); if (connectionStringNode != null) { connectionStringNode.InnerText = Dts.Connections["SourceDataMart"].ConnectionString; } Finally we need to perform the deployment using the Execute XMLA command and check the returned XmlaResultCollection for errors before setting the Dts.TaskResult. XmlaResultCollection oResults = svr.Execute(xmlaCommand.InnerXml);  // check for errors during deployment foreach (Microsoft.AnalysisServices.XmlaResult oResult in oResults) { foreach (Microsoft.AnalysisServices.XmlaMessage oMessage in oResult.Messages) { if ((oMessage.GetType().Name == "XmlaError")) { FireError(oMessage.Description); HadError = true; } } } If you are not familiar with XML programming, all this may all seem a bit daunting, but perceiver as the sample code is pretty short. If you would like the script to process the OLAP database, simply uncomment the lines in the vicinity of Process method. Of course, you can extend the script to perform your own custom processing and to even synchronize the database to a front-end server. Personally, I like to keep the deployment and processing separate as the code can become overly complex for support staff.If you want to know more, come see my session at the forthcoming SQLBits conference.

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  • Using set operation in LINQ

    - by vik20000in
    There are many set operation that are required to be performed while working with any kind of data. This can be done very easily with the help of LINQ methods available for this functionality. Below are some of the examples of the set operation with LINQ. Finding distinct values in the set of data. We can use the distinct method to find out distinct values in a given list.     int[] factorsOf300 = { 2, 2, 3, 5, 5 };     var uniqueFactors = factorsOf300.Distinct(); We can also use the set operation of UNION with the help of UNION method in the LINQ. The Union method takes another collection as a parameter and returns the distinct union values in  both the list. Below is an example.     int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };    int[] numbersB = { 1, 3, 5, 7, 8 };    var uniqueNumbers = numbersA.Union(numbersB); We can also get the set operation of INTERSECT with the help of the INTERSECT method. Below is an example.     int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };     int[] numbersB = { 1, 3, 5, 7, 8 };         var commonNumbers = numbersA.Intersect(numbersB);  We can also find the difference between the 2 sets of data with the help of except method.      int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };     int[] numbersB = { 1, 3, 5, 7, 8 };         IEnumerable<int> aOnlyNumbers = numbersA.Except(numbersB);  Vikram

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  • SQL SERVER – Data Sources and Data Sets in Reporting Services SSRS

    - by Pinal Dave
    This example is from the Beginning SSRS by Kathi Kellenberger. Supporting files are available with a free download from the www.Joes2Pros.com web site. This example is from the Beginning SSRS. Supporting files are available with a free download from the www.Joes2Pros.com web site. Connecting to Your Data? When I was a child, the telephone book was an important part of my life. Maybe I was just a nerd, but I enjoyed getting a new book every year to page through to learn about the businesses in my small town or to discover where some of my school acquaintances lived. It was also the source of maps to my town’s neighborhoods and the towns that surrounded me. To make a phone call, I would need a telephone number. In order to find a telephone number, I had to know how to use the telephone book. That seems pretty simple, but it resembles connecting to any data. You have to know where the data is and how to interact with it. A data source is the connection information that the report uses to connect to the database. You have two choices when creating a data source, whether to embed it in the report or to make it a shared resource usable by many reports. Data Sources and Data Sets A few basic terms will make the upcoming choses make more sense. What database on what server do you want to connect to? It would be better to just ask… “what is your data source?” The connection you need to make to get your reports data is called a data source. If you connected to a data source (like the JProCo database) there may be hundreds of tables. You probably only want data from just a few tables. This means you want to write a specific query against this data source. A query on a data source to get just the records you need for an SSRS report is called a Data Set. Creating a local Data Source You can connect embed a connection from your report directly to your JProCo database which (let’s say) is installed on a server named Reno. If you move JProCo to a new server named Tampa then you need to update the Data Set. If you have 10 reports in one project that were all pointing to the JProCo database on the Reno server then they would all need to be updated at once. It’s possible to make a project level Data Source and have each report use that. This means one change can fix all 10 reports at once. This would be called a Shared Data Source. Creating a Shared Data Source The best advice I can give you is to create shared data sources. The reason I recommend this is that if a database moves to a new server you will have just one place in Report Manager to make the server name change. That one change will update the connection information in all the reports that use that data source. To get started, you will start with a fresh project. Go to Start > All Programs > SQL Server 2012 > Microsoft SQL Server Data Tools to launch SSDT. Once SSDT is running, click New Project to create a new project. Once the New Project dialog box appears, fill in the form, as shown in. Be sure to select Report Server Project this time – not the wizard. Click OK to dismiss the New Project dialog box. You should now have an empty project, as shown in the Solution Explorer. A report is meant to show you data. Where is the data? The first task is to create a Shared Data Source. Right-click on the Shared Data Sources folder and choose Add New Data Source. The Shared Data Source Properties dialog box will launch where you can fill in a name for the data source. By default, it is named DataSource1. The best practice is to give the data source a more meaningful name. It is possible that you will have projects with more than one data source and, by naming them, you can tell one from another. Type the name JProCo for the data source name and click the Edit button to configure the database connection properties. If you take a look at the types of data sources you can choose, you will see that SSRS works with many data platforms including Oracle, XML, and Teradata. Make sure SQL Server is selected before continuing. For this post, I am assuming that you are using a local SQL Server and that you can use your Windows account to log in to the SQL Server. If, for some reason you must use SQL Server Authentication, choose that option and fill in your SQL Server account credentials. Otherwise, just accept Windows Authentication. If your database server was installed locally and with the default instance, just type in Localhost for the Server name. Select the JProCo database from the database list. At this point, the connection properties should look like. If you have installed a named instance of SQL Server, you will have to specify the server name like this: Localhost\InstanceName, replacing the InstanceName with whatever your instance name is. If you are not sure about the named instance, launch the SQL Server Configuration Manager found at Start > All Programs > Microsoft SQL Server 2012 > Configuration Tools. If you have a named instance, the name will be shown in parentheses. A default instance of SQL Server will display MSSQLSERVER; a named instance will display the name chosen during installation. Once you get the connection properties filled in, click OK to dismiss the Connection Properties dialog box and OK again to dismiss the Shared Data Source properties. You now have a data source in the Solution Explorer. What’s next I really need to thank Kathi Kellenberger and Rick Morelan for sharing this material for this 5 day series of posts on SSRS. To get really comfortable with SSRS you will get to know the different SSDT windows, Build reports on your own (without the wizards),  Add report headers and footers, Accept user input,  create levels, charts, or even maps for visual appeal. You might be surprise to know a small 230 page book starts from the very beginning and covers the steps to do all these items. Beginning SSRS 2012 is a small easy to follow book so you can learn SSRS for less than $20. See Joes2Pros.com for more on this and other books. If you want to learn SSRS in easy to simple words – I strongly recommend you to get Beginning SSRS book from Joes 2 Pros. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Reporting Services, SSRS

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  • Microsoft MVP Award Nomination

    - by Mark A. Wilson
    I am extremely honored to announce that I have been nominated to receive the Microsoft MVP Award for my contributions in C#! Hold on; I have not won the award yet. But to be nominated is really humbling. Thank you very much! For those of you who may not know, here is a high-level summary of the MVP award: The Microsoft Most Valuable Professional (MVP) Program recognizes and thanks outstanding members of technical communities for their community participation and willingness to help others. The program celebrates the most active community members from around the world who provide invaluable online and offline expertise that enriches the community experience and makes a difference in technical communities featuring Microsoft products. MVPs are credible, technology experts from around the world who inspire others to learn and grow through active technical community participation. While MVPs come from many backgrounds and a wide range of technical communities, they share a passion for technology and a demonstrated willingness to help others. MVPs do this through the books and articles they author, the Web sites they manage, the blogs they maintain, the user groups they participate in, the chats they host or contribute to, the events and training sessions where they present, as well as through the questions they answer in technical newsgroups or message boards. - Microsoft MVP Award Nomination Email I guess I should start my nomination acceptance speech by profusely thanking Microsoft as well as everyone who nominated me. Unfortunately, I’m not completely certain who those people are. While I could guess (in no particular order: Bill J., Brian H., Glen G., and/or Rob Z.), I would much rather update this post accordingly after I know for certain who to properly thank. I certainly don’t want to leave anyone out! Please Help My next task is to provide the MVP Award committee with information and descriptions of my contributions during the past 12 months. For someone who has difficulty remembering what they did just last week, trying to remember something that I did 12 months ago is going to be a real challenge. (Yes, I should do a better job blogging about my activities. I’m just so busy!) Since this is an award about community, I invite and encourage you to participate. Please leave a comment below or send me an email. Help jog my memory by listing anything and everything that you can think of that would apply and/or be important to include in my reply back to the committee. I welcome advice on what to say and how to say it from previous award winners. Again, I greatly appreciate the nomination and welcome any assistance you can provide. Thanks for visiting and till next time, Mark A. Wilson      Mark's Geekswithblogs Blog Enterprise Developers Guild Technorati Tags: Community,Way Off Topic

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  • Security in Software

    The term security has many meanings based on the context and perspective in which it is used. Security from the perspective of software/system development is the continuous process of maintaining confidentiality, integrity, and availability of a system, sub-system, and system data. This definition at a very high level can be restated as the following: Computer security is a continuous process dealing with confidentiality, integrity, and availability on multiple layers of a system. Key Aspects of Software Security Integrity Confidentiality Availability Integrity within a system is the concept of ensuring only authorized users can only manipulate information through authorized methods and procedures. An example of this can be seen in a simple lead management application.  If the business decided to allow each sales member to only update their own leads in the system and sales managers can update all leads in the system then an integrity violation would occur if a sales member attempted to update someone else’s leads. An integrity violation occurs when a team member attempts to update someone else’s lead because it was not entered by the sales member.  This violates the business rule that leads can only be update by the originating sales member. Confidentiality within a system is the concept of preventing unauthorized access to specific information or tools.  In a perfect world the knowledge of the existence of confidential information/tools would be unknown to all those who do not have access. When this this concept is applied within the context of an application only the authorized information/tools will be available. If we look at the sales lead management system again, leads can only be updated by originating sales members. If we look at this rule then we can say that all sales leads are confidential between the system and the sales person who entered the lead in to the system. The other sales team members would not need to know about the leads let alone need to access it. Availability within a system is the concept of authorized users being able to access the system. A real world example can be seen again from the lead management system. If that system was hosted on a web server then IP restriction can be put in place to limit access to the system based on the requesting IP address. If in this example all of the sales members where accessing the system from the 192.168.1.23 IP address then removing access from all other IPs would be need to ensure that improper access to the system is prevented while approved users can access the system from an authorized location. In essence if the requesting user is not coming from an authorized IP address then the system will appear unavailable to them. This is one way of controlling where a system is accessed. Through the years several design principles have been identified as being beneficial when integrating security aspects into a system. These principles in various combinations allow for a system to achieve the previously defined aspects of security based on generic architectural models. Security Design Principles Least Privilege Fail-Safe Defaults Economy of Mechanism Complete Mediation Open Design Separation Privilege Least Common Mechanism Psychological Acceptability Defense in Depth Least Privilege Design PrincipleThe Least Privilege design principle requires a minimalistic approach to granting user access rights to specific information and tools. Additionally, access rights should be time based as to limit resources access bound to the time needed to complete necessary tasks. The implications of granting access beyond this scope will allow for unnecessary access and the potential for data to be updated out of the approved context. The assigning of access rights will limit system damaging attacks from users whether they are intentional or not. This principle attempts to limit data changes and prevents potential damage from occurring by accident or error by reducing the amount of potential interactions with a resource. Fail-Safe Defaults Design PrincipleThe Fail-Safe Defaults design principle pertains to allowing access to resources based on granted access over access exclusion. This principle is a methodology for allowing resources to be accessed only if explicit access is granted to a user. By default users do not have access to any resources until access has been granted. This approach prevents unauthorized users from gaining access to resource until access is given. Economy of Mechanism Design PrincipleThe Economy of mechanism design principle requires that systems should be designed as simple and small as possible. Design and implementation errors result in unauthorized access to resources that would not be noticed during normal use. Complete Mediation Design PrincipleThe Complete Mediation design principle states that every access to every resource must be validated for authorization. Open Design Design PrincipleThe Open Design Design Principle is a concept that the security of a system and its algorithms should not be dependent on secrecy of its design or implementation Separation Privilege Design PrincipleThe separation privilege design principle requires that all resource approved resource access attempts be granted based on more than a single condition. For example a user should be validated for active status and has access to the specific resource. Least Common Mechanism Design PrincipleThe Least Common Mechanism design principle declares that mechanisms used to access resources should not be shared. Psychological Acceptability Design PrincipleThe Psychological Acceptability design principle refers to security mechanisms not make resources more difficult to access than if the security mechanisms were not present Defense in Depth Design PrincipleThe Defense in Depth design principle is a concept of layering resource access authorization verification in a system reduces the chance of a successful attack. This layered approach to resource authorization requires unauthorized users to circumvent each authorization attempt to gain access to a resource. When designing a system that requires meeting a security quality attribute architects need consider the scope of security needs and the minimum required security qualities. Not every system will need to use all of the basic security design principles but will use one or more in combination based on a company’s and architect’s threshold for system security because the existence of security in an application adds an additional layer to the overall system and can affect performance. That is why the definition of minimum security acceptably is need when a system is design because this quality attributes needs to be factored in with the other system quality attributes so that the system in question adheres to all qualities based on the priorities of the qualities. Resources: Barnum, Sean. Gegick, Michael. (2005). Least Privilege. Retrieved on August 28, 2011 from https://buildsecurityin.us-cert.gov/bsi/articles/knowledge/principles/351-BSI.html Saltzer, Jerry. (2011). BASIC PRINCIPLES OF INFORMATION PROTECTION. Retrieved on August 28, 2011 from  http://web.mit.edu/Saltzer/www/publications/protection/Basic.html Barnum, Sean. Gegick, Michael. (2005). Defense in Depth. Retrieved on August 28, 2011 from  https://buildsecurityin.us-cert.gov/bsi/articles/knowledge/principles/347-BSI.html Bertino, Elisa. (2005). Design Principles for Security. Retrieved on August 28, 2011 from  http://homes.cerias.purdue.edu/~bhargav/cs526/security-9.pdf

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