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  • How to boot load the kernel using EFI stub (efistub) loader?

    - by Pro Backup
    I have Ubuntu 14.04 running in UEFI mode as only operating system, no dual-boot here. The kernel version is 3.13.0-24-generic. There is an EFI partition. In this case the EFI partition is not at the default /dev/sda1 but at /dev/sda3 because I did actually convert BIOS mode to EFI mode. I have used the grub-efi-amd64 package, though that actually loads GRUB boot menu from UEFI firmware boot menu (UEFI boot loads \EFI\ubuntu\grubx64.efi). I want to skip that double boot menu loading step, and boot faster, directly from UEFI into the kernel. The Ubuntu kernels since 12.10 have "Kernel EFI stub loader" feature. I know I do need to copy the Ubuntu kernel to the EFI partition (possibly rename) and create an entry in UEFI boot menu (for instance using efibootmgr). Which exact terminal commands are necessary to do this?

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  • What the Hekaton?

    - by Tony Davis
    Hekaton, the power behind SQL Server 2014′s In-Memory OLTP technology, is intended to make data operations run orders of magnitude faster on SQL Server. This works its magic partly by serving database workloads entirely from main memory, using memory-optimized table structures. It replaces the relational engine’s standard locking model with an optimistic concurrency model based on time-stamped row versions. Deeper down the Hekaton engine uses new, ‘latch free’ data structures. So far, so good, but performance improvements on this scale require a compromise, and the compromise is that these aren’t tables as we understand them. For the database developer, these differences are painful because they involve sacrificing some very important bits of the relational model. Most importantly, Hekaton tables don’t currently support FOREIGN KEY constraints or CHECK constraints, and you can’t put the checks in triggers because there aren’t any DML triggers either. Constraints allow a relational designer to enforce relational integrity and data integrity. Without them, of course, ‘bad data’ can get into our Hekaton tables. There is no easy way of preventing it. For several classes of database and data, this is a show-stopper. One may regard all these restrictions regretfully, seeing limited opportunity to try out Hekaton with current databases, but perhaps there is also a sudden glow of recognition. Isn’t this how we all originally imagined table variables were going to be, back in SQL 2005? And they have much the same restrictions. Maybe, instead of pretending that a currently-designed database can be ‘Hekatonized’ with a few mouse clicks, we should redesign databases for SQL 2014 to replace table variables with Hekaton tables, exploiting this technology for fast intermediate processing, and for the most part forget, for now, the idea of trying to convert our base relational tables into Hekaton tables. Few database developers would be averse to having their working tables running an order of magnitude faster, as long as it didn’t compromise the integrity of the data in the base tables.

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  • Batch file to Delete Old Virtual Directories.

    - by Michael Freidgeim
    On some servers we have many old Virtual Directories created for previous versions of our application. IIS user interface allows to delete only one in a time. Fortunately we can use IIS scripts as described in How to manage Web sites and Web virtual directories by using command-line scripts in IIS 6.0 I've created batch file DeleteOldVDirs.cmd rem http://support.microsoft.com/kb/816568 rem syntax: iisvdir /delete WebSite [/Virtual Path]Name [/s Computer [/u [Domain\]User /p Password]] REM list all directories and create batch of deletes iisvdir /query "Default Web Site" echo "Enter Ctrl-C  if you want to stop deleting" Pause iisvdir /delete "Default Web Site/VDirName1" iisvdir /delete "Default Web Site/VDirName2" ...   If the name of WebSite or Virtual directory contain spaces(e.g  "Default Web Site"), don't forget to use double quotes. Note that the batch doesn't delete physical directories from flie system.You need to delete them using Windows Explorer, but it does support multiple selection!

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  • Install a Wii Game Loader for Easy Backups and Fast Load Times

    - by Jason Fitzpatrick
    We’ve shown you how to hack your Wii for homebrew software and DVD playback as well as how to safeguard and supercharge your Wii. Now we’re taking a peek at Wii game loaders so you can backup and play your Wii games from an external HDD. Latest Features How-To Geek ETC HTG Projects: How to Create Your Own Custom Papercraft Toy How to Combine Rescue Disks to Create the Ultimate Windows Repair Disk What is Camera Raw, and Why Would a Professional Prefer it to JPG? The How-To Geek Guide to Audio Editing: The Basics How To Boot 10 Different Live CDs From 1 USB Flash Drive The 20 Best How-To Geek Linux Articles of 2010 Lord of the Rings Movie Parody Double Feature [Video] Turn a Webpage into an Asteroids-Styled Shooting Game in Opera Dolphin Browser Mini Leaves Beta; Sports New GUI, Easy Bookmarking, and More Updated Google Goggles Scans Faster; Solves Sudoku Puzzles Snowy Castle Retreat in the Mountains Wallpaper Fix TV Show Sorting Issues on iOS Devices

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  • kubuntu - what's the best smplayer configuration for best quality in hd movies (mkv)

    - by Frank
    I have ubuntu x64 13.04 with kde 4.11 and smplayer v0.8.6 and the last mplayer version from ppa. I have ATI video card HD6870 MSI with fglrx driver v13.4. My kde settings are: Composition mode: Opengl 3.1 graphic system qt: Raster scaling mode: precise Vsync: auto So what's the best configuration for quality over performace in smplayer according to my system specs? For example what do I have to set for the following options? enable postprocessing by default and postprocessing quality output driver Deinterlacing method software equalizer direct rendering double buffering draw video using slices threads for decoding (MPEG-1/2 and H.264 only loop filter use CoreAVC Thanks

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  • Configuring Application/User Settings in WPF the easy way.

    - by mbcrump
    In this tutorial, we are going to configure the application/user settings in a WPF application the easy way. Most example that I’ve seen on the net involve the ConfigurationManager class and involve creating your own XML file from scratch. I am going to show you a easier way to do it. (in my humble opinion) First, the definitions: User Setting – is designed to be something specific to the user. For example, one user may have a requirement to see certain stocks, news articles or local weather. This can be set at run-time. Application Setting – is designed to store information such as a database connection string. These settings are read-only at run-time. 1) Lets create a new WPF Project and play with a few settings. Once you are inside VS, then paste the following code snippet inside the <Grid> tags. <Grid> <TextBox Height="23" HorizontalAlignment="Left" Margin="12,11,0,0" Name="textBox1" VerticalAlignment="Top" Width="285" Grid.ColumnSpan="2" /> <Button Content="Set Title" Name="button2" Click="button2_Click" Margin="108,40,96,114" /> <TextBlock Height="23" Name="textBlock1" Text="TextBlock" VerticalAlignment="Bottom" Width="377" /> </Grid> Basically, its just a Textbox, Button and TextBlock. The main Window should look like the following:   2) Now we are going to setup our Configuration Settings. Look in the Solution Explorer and double click on the Settings.settings file. Make sure that your settings file looks just like mine included below:   What just happened was the designer created an XML file and created the Settings.Designer.cs file which looks like this: //------------------------------------------------------------------------------ // <auto-generated> // This code was generated by a tool. // Runtime Version:4.0.30319.1 // // Changes to this file may cause incorrect behavior and will be lost if // the code is regenerated. // </auto-generated> //------------------------------------------------------------------------------ namespace WPFExam.Properties { [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()] [global::System.CodeDom.Compiler.GeneratedCodeAttribute("Microsoft.VisualStudio.Editors.SettingsDesigner.SettingsSingleFileGenerator", "10.0.0.0")] internal sealed partial class Settings : global::System.Configuration.ApplicationSettingsBase { private static Settings defaultInstance = ((Settings)(global::System.Configuration.ApplicationSettingsBase.Synchronized(new Settings()))); public static Settings Default { get { return defaultInstance; } } [global::System.Configuration.UserScopedSettingAttribute()] [global::System.Diagnostics.DebuggerNonUserCodeAttribute()] [global::System.Configuration.DefaultSettingValueAttribute("ApplicationName")] public string ApplicationName { get { return ((string)(this["ApplicationName"])); } set { this["ApplicationName"] = value; } } [global::System.Configuration.ApplicationScopedSettingAttribute()] [global::System.Diagnostics.DebuggerNonUserCodeAttribute()] [global::System.Configuration.DefaultSettingValueAttribute("SQL_SRV342")] public string DatabaseServerName { get { return ((string)(this["DatabaseServerName"])); } } } } The XML File is named app.config and looks like this: <?xml version="1.0" encoding="utf-8" ?> <configuration> <configSections> <sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" > <section name="WPFExam.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowExeDefinition="MachineToLocalUser" requirePermission="false" /> </sectionGroup> <sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" > <section name="WPFExam.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" /> </sectionGroup> </configSections> <userSettings> <WPFExam.Properties.Settings> <setting name="ApplicationName" serializeAs="String"> <value>ApplicationName</value> </setting> </WPFExam.Properties.Settings> </userSettings> <applicationSettings> <WPFExam.Properties.Settings> <setting name="DatabaseServerName" serializeAs="String"> <value>SQL_SRV342</value> </setting> </WPFExam.Properties.Settings> </applicationSettings> </configuration> 3) The only left now is the code behind the button. Double click the button and replace the MainWindow() method with the following code snippet. public MainWindow() { InitializeComponent(); this.Title = Properties.Settings.Default.ApplicationName; textBox1.Text = Properties.Settings.Default.ApplicationName; textBlock1.Text = Properties.Settings.Default.DatabaseServerName; } private void button2_Click(object sender, RoutedEventArgs e) { Properties.Settings.Default.ApplicationName = textBox1.Text.ToString(); Properties.Settings.Default.Save(); } Run the application and type something in the textbox and hit the Set Title button. Now, restart the application and you should see the text that you entered earlier.   If you look at the button2 click event, you will see that it was actually 2 lines of codes to save to the configuration file. I hope this helps, for more information consult MSDN.

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  • How to avoid Hotmail/Live rejections for (legit) large volume eMailing?

    - by vmarquez
    While qualifying eMail for Spam, Hotmail/Live checks the historical records of numbers of eMails sent by a sender (FROM, eMail Server, IP, etc.). Some times, perfectly valid bulk eMails that are not Spam, (i.e. double opt-in list, from a server with proper SPF Record, signed with DKIM, unregister links and contact info, etc.) are rejected and not delivered to destinataries. Not even to their Junk folder. I guess we can avoid this situation by progressivelly "training" Hotmail/Live about the reputation of our sender and sending small quantyties of eMails innitially and increasing the quantity for some amount/percentaje during each delivery. Are there guidelines or do you have any experience on these quantities, strategy, solutions? Thank you in advance. EDIT: This question with a bounty is still unanswered. 8 hours to be automatically awarded! Do you have the answer?

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  • LibreOffice: Open in current program by default?

    - by David Oneill
    I often need to open pipe delimited .txt files in LibreOffice Calc. However, once I have Calc running, if I do File Open and select a spreadsheet with the extension .txt, it opens it in Writer instead. Is there a way to tell the file I'm trying to open using whatever program instead of trying to pick which one to use? Barring that, is there a way I tell it to always use Calc for .txt files (when I open them from the open dialog in Calc)? I still want them to open in GEdit like they currently do if I double click them from Thunar.

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  • Reading train stop display names from a resource bundle

    - by Frank Nimphius
    v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 false false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} In Oracle JDeveloper 11g R1, you set the display name of a train stop of an ADF bounded task flow train model by using the Oracle JDeveloper Structure Window. To do so Double-click onto the bounded task flow configuration file (XML) located in the Application Navigator so the task flow diagram open In the task flow diagram, select the view activity node for which you want to define the display name. In the Structure Window., expand the view activity node and then the train-stop node therein Add the display name element by using the right-click context menu on the train-stop node, selecting Insert inside train-stop > Display Name Edit the Display Name value with the Property Inspector Following the steps outlined above, you can define static display names – like "PF1" for page fragment 1 shown in the image below - for train stops to show at runtime. In the following, I explain how you can change the static display string to a dynamic string that reads the display label from a resource bundle so train stop labels can be internationalized. There are different strategies available for managing message bundles within an Oracle JDeveloper project. In this blog entry, I decided to build and configure the default properties file as indicated by the projects properties. To learn about the suggested file name and location, open the JDeveloper project properties (use a right mouse click on the project node in the Application Navigator and choose Project Properties. Select the Resource Bundle node to see the suggested name and location for the default message bundle. Note that this is the resource bundle that Oracle JDeveloper would automatically create when you assign a text resource to an ADF Faces component in a page. For the train stop display name, we need to create the message bundle manually as there is no context menu help available in Oracle JDeveloper. For this, use a right mouse click on the JDeveloper project and choose New | General | File from the menu and in the opened dialog. Specify the message bundle file name as the name looked up before in the project properties Resource Bundle option. Also, ensure that the file is saved in a directory structure that matches the package structure shown in the Resource Bundle dialog. For example, you would save the properties file in the View Project's src > adf > sample directory if the package structure was "adf.sample" (adf.sample.ViewControllerBundle). Edit the properties file and define key – values pairs for the train stop component. In the sample, such key value pairs are TrainStop1=Train Stop 1 TrainStop2=Train Stop 2 TrainStop3=Train Stop 3 Next, double click the faces-config.xml file and switch the opened editor to the Overview tab. Select the Application category and press the green plus icon next to the Resource Bundle section. Define the resource bundle Base Name as the package and properties file name, for example adf.sample.ViewControllerBundle Finally, define a variable name for the message bundle so the bundle can be accessed from Expression Language. For this blog example, the name is chosen as "messageBundle". <resource-bundle>   <base-name>adf.sample.ViewControllerBundle</base-name>   <var>messageBundle</var> </resource-bundle> Next, select the display-name element in the train stop node (similar to when creating the display name) and use the Property Inspector to change the static display string to an EL expression referencing the message bundle. For example: #{messageBundle.TrainStop1} At runtime, the train stops now show display names read from a message bundle (the properties file).

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  • Unable to access jar. Why?

    - by SystemNetworks
    I was making a game in java and exported it as jar file. Then after that, I opeed jar splice. I added the libaries and exported jar. I added the natives then i made a main class. I created a fat jar and put it on my desktop. I'm using Mac OS X 10.8 Mountain Lion. When I put in the terminal, java -jar System Front.jar it says unable to access System Front.jar Even if i double click on the file, it doesen't show up! Help! I'm using slick. I added slick and lwjgl as libraries for the jar splice at the jars.

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  • Samba issue with sharing directories on NTFS/FAT32

    - by Microkernel
    I have some strange problems with Samba server. I am using samba Version 3.5.4 on Ubuntu 10.10. I have two Windows XP machines, one on VirtualBox on Ubuntu and another office laptop. Windows machine on VirtualBox has no issues in accessing the shared folders, but the laptop is not able to access all the shared content. The issue faced on laptop is the following. Shared folders on ext3 drives have no issues in accessing, but the contents shared on NTFS and FAT32 drives (mounted ones) are not accessible. When I try to open the shared folder, it asks for user name and password, but doesn't accept when I provide it. (Even if I provide admin login details). I changed workgroup value to the domain_name in office laptop, but still the problem persists. Here is the smdb.conf I am using: [global] workgroup = XXX.XXX.ORG server string = %h server (Samba, Ubuntu) map to guest = Bad User obey pam restrictions = Yes pam password change = Yes passwd program = /usr/bin/passwd %u passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* . unix password sync = Yes syslog = 0 log file = /var/log/samba/log.%m max log size = 1000 dns proxy = No usershare allow guests = Yes panic action = /usr/share/samba/panic-action %d guest ok = Yes [homes] comment = Home Directories [printers] comment = All Printers path = /var/spool/samba read only = No create mask = 0700 printable = Yes browseable = No [print$] comment = Samba server's CD-ROM path = /cdrom force user = nobody force group = nobody locking = No Workgroup was defined as "HOMENET" before, changed it to domain name on the office laptop thinking it was the problem, but for no avail.

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  • WPF Databinding- Part 2 of 3

    - by Shervin Shakibi
    This is a follow up to my previous post WPF Databinding- Not your fathers databinding Part 1-3 you can download the source code here  http://ssccinc.com/wpfdatabinding.zip Example 04   In this example we demonstrate  the use of default properties and also binding to an instant of an object which is part of a collection bound to its container. this is actually not as complicated as it sounds. First of all, lets take a look at our Employee class notice we have overridden the ToString method, which will return employees First name , last name and employee number in parentheses, public override string ToString()        {            return String.Format("{0} {1} ({2})", FirstName, LastName, EmployeeNumber);        }   in our XAML we have set the itemsource of the list box to just  “Binding” and the Grid that contains it, has its DataContext set to a collection of our Employee objects. DataContext="{StaticResource myEmployeeList}"> ….. <ListBox Name="employeeListBox"  ItemsSource="{Binding }" Grid.Row="0" /> the ToString in the method for each instance will get executed and the following is a result of it. if we did not have a ToString the list box would look  like this: now lets take a look at the grid that will display the details when someone clicks on an Item, the Grid has the following DataContext DataContext="{Binding ElementName=employeeListBox,            Path=SelectedItem}"> Which means its bound to a specific instance of the Employee object. and within the gird we have textboxes that are bound to different Properties of our class. <TextBox Grid.Row="0" Grid.Column="1" Text="{Binding Path=FirstName}" /> <TextBox Grid.Row="1" Grid.Column="1" Text="{Binding Path=LastName}" /> <TextBox Grid.Row="2" Grid.Column="1" Text="{Binding Path=Title}" /> <TextBox Grid.Row="3" Grid.Column="1" Text="{Binding Path=Department}" />   Example 05   This project demonstrates use of the ObservableCollection and INotifyPropertyChanged interface. Lets take a look at Employee.cs first, notice it implements the INotifyPropertyChanged interface now scroll down and notice for each setter there is a call to the OnPropertyChanged method, which basically will will fire up the event notifying to the value of that specific property has been changed. Next EmployeeList.cs notice it is an ObservableCollection . Go ahead and set the start up project to example 05 and then run. Click on Add a new employee and the new employee should appear in the list box.   Example 06   This is a great example of IValueConverter its actuall a two for one deal, like most of my presentation demos I found this by “Binging” ( formerly known as g---ing) unfortunately now I can’t find the original author to give him  the credit he/she deserves. Before we look at the code lets run the app and look at the finished product, put in 0 in Celsius  and you should see Fahrenheit textbox displaying to 32 degrees, I know this is calculating correctly from my elementary school science class , also note the color changed to blue, now put in 100 in Celsius which should give us 212 Fahrenheit but now the color is red indicating it is hot, and finally put in 75 Fahrenheit and you should see 23.88 for Celsius and the color now should be black. Basically IValueConverter allows us different types to be bound, I’m sure you have had problems in the past trying to bind to Date values . First look at FahrenheitToCelciusConverter.cs first notice it implements IValueConverter. IValueConverter has two methods Convert and ConvertBack. In each method we have the code for converting Fahrenheit to Celsius and vice Versa. In our XAML, after we set a reference in our Windows.Resources section. and for txtCelsius we set the path to TxtFahrenheit and the converter to an instance our FahrenheitToCelciusConverter converter. no need to repeat this for TxtFahrenheit since we have a convert and ConvertBack. Text="{Binding  UpdateSourceTrigger=PropertyChanged,            Path=Text,ElementName=txtFahrenheit,            Converter={StaticResource myTemperatureConverter}}" As mentioned earlier this is a twofer Demo, in the second demo, we basically are converting a double datatype to a brush. Lets take a look at TemperatureToColorConverter, notice we in our Covert Method, if the value is less than our cold temperature threshold we return a blue brush and if it is higher than our hot temperature threshold we return a redbrush. since we don’t have to convert a brush to double value in our example the convert back is not being implemented. Take time and go through these three examples and I hope you have a better understanding   of databinding, ObservableCollection  and IValueConverter . Next blog posting we will talk about ValidationRule, DataTemplates and DataTemplate triggers.

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  • Default file permissions for php user www-data

    - by John Isaacks
    I have a php installed on my ubuntu machine. The web root is /var/www I set the permissions for this folder like so: sudo chown -R ftpuser:www-data /var/www ftpuser is the user I set up so I can ftp to /var/www from another machine on the network. www-data is the user php uses. I double checked using whoami from php. Whenever I ftp upload a new file to the machine the group has no permissions to the file. So when I try to access it in my browser via machine-name/new-file.php I am told permission denied and I have to go and chmod the new file. I am wondering if there is a way I can default the www-data user/group to have access permissions to new files so I don't have to keep chmod every new file?

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  • What am I doing wrong in my config for MySql?

    - by Knight Hawk3
    When I load my my.conf with the config at the bottom Mysql fails to start and prints no errors. I am running Arch Linux (Updated) with the latest MySQL (5.5) and the latest nginx (Well latest in the repository, Not sure how to check. Only installed it today) I will give you any info you ask for. Thanks for helping! # The following options will be passed to all MySQL clients [client] #password = your_password port = 3306 socket = /var/run/mysqld/mysqld.sock # Here follows entries for some specific programs # The MySQL server [mysqld] port = 3306 socket = /var/run/mysqld/mysqld.sock skip-locking key_buffer = 16K max_allowed_packet = 1M table_cache = 4 sort_buffer_size = 64K read_buffer_size = 256K read_rnd_buffer_size = 256K net_buffer_length = 2K thread_stack = 64K # Don’t listen on a TCP/IP port at all. This can be a security enhancement, # if all processes that need to connect to mysqld run on the same host. # All interaction with mysqld must be made via Unix sockets or named pipes. # Note that using this option without enabling named pipes on Windows # (using the “enable-named-pipe” option) will render mysqld useless! # #skip-networking server-id = 1 # Uncomment the following if you want to log updates #log-bin=mysql-bin # Uncomment the following if you are NOT using BDB tables skip-bdb # Uncomment the following if you are using InnoDB tables #innodb_data_home_dir = /var/lib/mysql/ #innodb_data_file_path = ibdata1:10M:autoextend #innodb_log_group_home_dir = /var/lib/mysql/ #innodb_log_arch_dir = /var/lib/mysql/ # You can set .._buffer_pool_size up to 50 – 80 % # of RAM but beware of setting memory usage too high #innodb_buffer_pool_size = 16M #innodb_additional_mem_pool_size = 2M # Set .._log_file_size to 25 % of buffer pool size #innodb_log_file_size = 5M #innodb_log_buffer_size = 8M #innodb_flush_log_at_trx_commit = 1 #innodb_lock_wait_timeout = 50 skip-innodb [mysqldump] quick max_allowed_packet = 16M [mysql] no-auto-rehash # Remove the next comment character if you are not familiar with SQL #safe-updates [isamchk] key_buffer = 1M sort_buffer_size = 1M [myisamchk] key_buffer = 1M sort_buffer_size = 1M [mysqlhotcopy] interactive-timeout So what is my silly error?

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  • Why isn't DSM for unstructured memory done today?

    - by sinned
    Ages ago, Djikstra invented IPC through mutexes which then somehow led to shared memory (SHM) in multics (which afaik had the necessary mmap first). Then computer networks came up and DSM (distributed SHM) was invented for IPC between computers. So DSM is basically a not prestructured memory region (like a SHM) that magically get's synchronized between computers without the applications programmer taking action. Implementations include Treadmarks (inofficially dead now) and CRL. But then someone thought this is not the right way to do it and invented Linda & tuplespaces. Current implementations include JavaSpaces and GigaSpaces. Here, you have to structure your data into tuples. Other ways to achieve similar effects may be the use of a relational database or a key-value-store like RIAK. Although someone might argue, I don't consider them as DSM since there is no coherent memory region where you can put data structures in as you like but have to structure your data which can be hard if it is continuous and administration like locking can not be done for hard coded parts (=tuples, ...). Why is there no DSM implementation today or am I just unable to find one?

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  • jQuery modifie ses licences et ne garde que la licence MIT

    jQuery modifie ses licences et ne garde que la licence MIT. La fondation jQuery a décidé de modifier sa gestion de licence. Elle abandonne la licence GNU General Public pour ne garder que la licence MIT. Cela lui permet d'éliminer la confusion qui existait sur la politique de double licence. Du côté des utilisateurs, ça ne change pas grand chose. L'utilisateur reste libre d'utiliser des projets de la fondation, de les modifier et même de les repasser en licence GPL si ça l'enchante. Effectivement, la licence MIT est tout à fait compatible avec licence GNU GPL. Il faut savoir qu'il y a plus de 500 personnes qui ont contribués aux projets jQuery. La fondation souhaite q...

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  • Are these interview questions too complex for entry-level C++ positions?

    - by Banana
    Hi All, I recently had a few interviews for programming jobs within the financial industry. I am looking for entry-level positions as I specify in the cover letter. However I am usually asked questions such as: - all two-letters commands you know in unix - representation of float/double numbers (ieee standard) - segmentation fault memory dump, and related issues - all functions you know to convert string to integer (not just atoi) - how to avoid virtual tables - etc.. Is that the custom? Because I don't think this kind of questions make sense for someone willing to get an entry-level job. Is it totally crazy to think that they should ask more conceptual questions? This is beginning to driving me nuts, honestly. Thanks

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  • How can i get latency when using Game Center?

    - by Freddy
    I'm pretty new to network programming. Basically I'm using game center for making a relatively simple iPhone game using Game-center p2p. However i'm now working on a algorithm to improve the multiplayer performance. But, I need to know how long it took for a package to travel from one device to the another device (latency) for the algorithm to work good. As for now, I have solved the problem by sending a double with time interval since 1970 in the package and then I compare it with the time at the other device. However I have heard that the NSDate methods is connected to the internet, which also will cause latency so the time interval would not be perfectly correct. What is the ideal way to check for how long it take for a package to be sent?

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  • More Tables or More Databases?

    - by BuckWoody
    I got an e-mail from someone that has an interesting situation. He has 15,000 customers, and he asks if he should have a database for their data per customer. Without a LOT more data it’s impossible to say, of course, but there are some general concepts to keep in mind. Whenever you’re segmenting data, it’s all about boundary choices. You have not only boundaries around how big the data will get, but things like how many objects (tables, stored procedures and so on) that will be involved, if there are any cross-sections of data (do they share location or product information) and – very important – what are the security requirements? From the answer to these types of questions, you now have the choice of making multiple tables in a single database, or using multiple databases. A database carries some overhead – it needs a certain amount of memory for locking and so on. But it has a very clean boundary – everything from objects to security can be kept apart. Having multiple users in the same database is possible as well, using things like a Schema. But keeping 15,000 schemas can be challenging as well. My recommendation in complex situations like this is similar to a post on decisions that I did earlier – I lay out the choices on a spreadsheet in rows, and then my requirements at the top in the columns. I  give each choice a number based on how well it meets each requirement. At the end, the highest number wins. And many times it’s a mix – perhaps this person could segment customers into larger regions or districts or products, in a database. Within that database might be multiple schemas for the customers. Of course, he needs to query across all customers, that becomes another requirement. Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • Two Weeks As A Software Estimation Rule of Thumb?

    - by Todd Williamson
    I saw a blog posting that spoke to me: http://james-iry.blogspot.com/2010/10/how-to-estimate-software.html Oddly, this is the kind of estimate that I tend to do on smaller projects. Just about everything is "two weeks" as that is comfortably far enough out. I once had an instructor walk us through how to create a more detailed estimate, wherein we already had the requirements up front, etc. and even after all the careful tabulation and such the final instruction was "Now that you have all this documentation go ahead and double it." Agile practitioners seem to like two weeks also as a sprint length. Is there something magical about two weeks? Is it a hrair number for our psyches or some other kind of crutch? Do you have an immediate default fall-back schedule strategy when you are pressed for an initial delivery date?

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  • What Extends JComponent?

    - by Geertjan
    Let NetBeans IDE tell you what extends JComponent: Thanks to Damian from Gdansk in Poland who left a comment in this blog yesterday that explains how to achieve the above: "Let's say you would like to find all implementations of TreeModel interface. I found today an answer: r-click on class/interface -> chose Navigate->Inspect Hierarchy->select second filter at the bottom of opened window or press Alt+Shift+F12 and then Alt+B." In the list above, double-click an item to open it in the NetBeans Java editor. Handy tip, dziekuje bardzo, Damian.

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  • Of transactions and Mongo

    - by Nuri Halperin
    Originally posted on: http://geekswithblogs.net/nuri/archive/2014/05/20/of-transactions-and-mongo-again.aspxWhat's the first thing you hear about NoSQL databases? That they lose your data? That there's no transactions? No joins? No hope for "real" applications? Well, you *should* be wondering whether a certain of database is the right one for your job. But if you do so, you should be wondering that about "traditional" databases as well! In the spirit of exploration let's take a look at a common challenge: You are a bank. You have customers with accounts. Customer A wants to pay B. You want to allow that only if A can cover the amount being transferred. Let's looks at the problem without any context of any database engine in mind. What would you do? How would you ensure that the amount transfer is done "properly"? Would you prevent a "transaction" from taking place unless A can cover the amount? There are several options: Prevent any change to A's account while the transfer is taking place. That boils down to locking. Apply the change, and allow A's balance to go below zero. Charge person A some interest on the negative balance. Not friendly, but certainly a choice. Don't do either. Options 1 and 2 are difficult to attain in the NoSQL world. Mongo won't save you headaches here either. Option 3 looks a bit harsh. But here's where this can go: ledger. See, and account doesn't need to be represented by a single row in a table of all accounts with only the current balance on it. More often than not, accounting systems use ledgers. And entries in ledgers - as it turns out – don't actually get updated. Once a ledger entry is written, it is not removed or altered. A transaction is represented by an entry in the ledger stating and amount withdrawn from A's account and an entry in the ledger stating an addition of said amount to B's account. For sake of space-saving, that entry in the ledger can happen using one entry. Think {Timestamp, FromAccountId, ToAccountId, Amount}. The implication of the original question – "how do you enforce non-negative balance rule" then boils down to: Insert entry in ledger Run validation of recent entries Insert reverse entry to roll back transaction if validation failed. What is validation? Sum up the transactions that A's account has (all deposits and debits), and ensure the balance is positive. For sake of efficiency, one can roll up transactions and "close the book" on transactions with a pseudo entry stating balance as of midnight or something. This lets you avoid doing math on the fly on too many transactions. You simply run from the latest "approved balance" marker to date. But that's an optimization, and premature optimizations are the root of (some? most?) evil.. Back to some nagging questions though: "But mongo is only eventually consistent!" Well, yes, kind of. It's not actually true that Mongo has not transactions. It would be more descriptive to say that Mongo's transaction scope is a single document in a single collection. A write to a Mongo document happens completely or not at all. So although it is true that you can't update more than one documents "at the same time" under a "transaction" umbrella as an atomic update, it is NOT true that there' is no isolation. So a competition between two concurrent updates is completely coherent and the writes will be serialized. They will not scribble on the same document at the same time. In our case - in choosing a ledger approach - we're not even trying to "update" a document, we're simply adding a document to a collection. So there goes the "no transaction" issue. Now let's turn our attention to consistency. What you should know about mongo is that at any given moment, only on member of a replica set is writable. This means that the writable instance in a set of replicated instances always has "the truth". There could be a replication lag such that a reader going to one of the replicas still sees "old" state of a collection or document. But in our ledger case, things fall nicely into place: Run your validation against the writable instance. It is guaranteed to have a ledger either with (after) or without (before) the ledger entry got written. No funky states. Again, the ledger writing *adds* a document, so there's no inconsistent document state to be had either way. Next, we might worry about data loss. Here, mongo offers several write-concerns. Write-concern in Mongo is a mode that marshals how uptight you want the db engine to be about actually persisting a document write to disk before it reports to the application that it is "done". The most volatile, is to say you don't care. In that case, mongo would just accept your write command and say back "thanks" with no guarantee of persistence. If the server loses power at the wrong moment, it may have said "ok" but actually no written the data to disk. That's kind of bad. Don't do that with data you care about. It may be good for votes on a pole regarding how cute a furry animal is, but not so good for business. There are several other write-concerns varying from flushing the write to the disk of the writable instance, flushing to disk on several members of the replica set, a majority of the replica set or all of the members of a replica set. The former choice is the quickest, as no network coordination is required besides the main writable instance. The others impose extra network and time cost. Depending on your tolerance for latency and read-lag, you will face a choice of what works for you. It's really important to understand that no data loss occurs once a document is flushed to an instance. The record is on disk at that point. From that point on, backup strategies and disaster recovery are your worry, not loss of power to the writable machine. This scenario is not different from a relational database at that point. Where does this leave us? Oh, yes. Eventual consistency. By now, we ensured that the "source of truth" instance has the correct data, persisted and coherent. But because of lag, the app may have gone to the writable instance, performed the update and then gone to a replica and looked at the ledger there before the transaction replicated. Here are 2 options to deal with this. Similar to write concerns, mongo support read preferences. An app may choose to read only from the writable instance. This is not an awesome choice to make for every ready, because it just burdens the one instance, and doesn't make use of the other read-only servers. But this choice can be made on a query by query basis. So for the app that our person A is using, we can have person A issue the transfer command to B, and then if that same app is going to immediately as "are we there yet?" we'll query that same writable instance. But B and anyone else in the world can just chill and read from the read-only instance. They have no basis to expect that the ledger has just been written to. So as far as they know, the transaction hasn't happened until they see it appear later. We can further relax the demand by creating application UI that reacts to a write command with "thank you, we will post it shortly" instead of "thank you, we just did everything and here's the new balance". This is a very powerful thing. UI design for highly scalable systems can't insist that the all databases be locked just to paint an "all done" on screen. People understand. They were trained by many online businesses already that your placing of an order does not mean that your product is already outside your door waiting (yes, I know, large retailers are working on it... but were' not there yet). The second thing we can do, is add some artificial delay to a transaction's visibility on the ledger. The way that works is simply adding some logic such that the query against the ledger never nets a transaction for customers newer than say 15 minutes and who's validation flag is not set. This buys us time 2 ways: Replication can catch up to all instances by then, and validation rules can run and determine if this transaction should be "negated" with a compensating transaction. In case we do need to "roll back" the transaction, the backend system can place the timestamp of the compensating transaction at the exact same time or 1ms after the original one. Effectively, once A or B visits their ledger, both transactions would be visible and the overall balance "as of now" would reflect no change.  The 2 transactions (attempted/ reverted) would be visible , since we do actually account for the attempt. Hold on a second. There's a hole in the story: what if several transfers from A to some accounts are registered, and 2 independent validators attempt to compute the balance concurrently? Is there a chance that both would conclude non-sufficient-funds even though rolling back transaction 100 would free up enough for transaction 117 (some random later transaction)? Yes. there is that chance. But the integrity of the business rule is not compromised, since the prime rule is don't dispense money you don't have. To minimize or eliminate this scenario, we can also assign a single validation process per origin account. This may seem non-scalable, but it can easily be done as a "sharded" distribution. Say we have 11 validation threads (or processing nodes etc.). We divide the account number space such that each validator is exclusively responsible for a certain range of account numbers. Sounds cunningly similar to Mongo's sharding strategy, doesn't it? Each validator then works in isolation. More capacity needed? Chop the account space into more chunks. So where  are we now with the nagging questions? "No joins": Huh? What are those for? "No transactions": You mean no cross-collection and no cross-document transactions? Granted - but don't always need them either. "No hope for real applications": well... There are more issues and edge cases to slog through, I'm sure. But hopefully this gives you some ideas of how to solve common problems without distributed locking and relational databases. But then again, you can choose relational databases if they suit your problem.

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  • Why can I only put some items in the launcher?

    - by HaskellElephant
    Whenever I search for an item using dash it knows the default way of opening it. However if I drag a file into the launcher it can't be added, even if it is executable. For example if you would like minecraft to show up you will have to add a custom launcher, or if you use dash to find a pdf file, you can double click it and it opens evince however you cannot drag it into the launcher. The animation surrounding this behavior suggests that this was done by design. Why is this useful or necessary? Is it a bug?

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  • How to install packages which apt-get can't find?

    - by newcomer
    Hi, I need these packages to build Android source. But I am getting this error: $ sudo apt-get install git-core gnupg flex bison gperf build-essential zip curl zlib1g-dev gcc-multilib g++-multilib libc6-dev-i386 lib32ncurses5-dev ia32-libs x11proto-core-dev libx11-dev lib32readline5-dev lib32z-dev [sudo] password for asdf: Reading package lists... Done Building dependency tree Reading state information... Done E: Unable to locate package libc6-dev-i386 E: Unable to locate package lib32ncurses5-dev E: Unable to locate package ia32-libs E: Unable to locate package lib32readline5-dev E: Unable to locate package lib32z-dev I tried to download & install say libc6-dev-i386 debian package form here. But when I double click on the .deb file Ubuntu Software Manager says wrong architecture 'amd64'. (My OS: Ubuntu 10.10 (updated), Processor: AMD phenom II.)

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  • How to completely integrate Nemo with Ubuntu?

    - by user74660
    I have installed Nemo (a fork of Nautilus created by the Linux Mint Team) in my Ubuntu 12.04.1 LTS with Gnome Shell 3.4.2. I followed the instructions here (https://help.ubuntu.com/community/DefaultFileManager), changing the "inode" and "x-directory" in the file "defaults.list", to make Nemo my default file manager. Now everything works perfectly, except for one thing: opening folders from desktop. I have set the option "Have file manager handle the desktop" on. Cool. The problem is that the desktop seems to be handled by Nautilus only, even if I have set another file manager as default. Every time I double click a folder on the desktop, it is opened by Nautilus, not Nemo. Please, does anybody know how to fix this? Thanks for your time. :)

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