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• How does Sentry aggregate errors?

  - by Hugo Rodger-Brown

  I am using Sentry (in a django project), and I'd like to know how I can get the errors to aggregate properly. I am logging certain user actions as errors, so there is no underlying system exception, and am using the culprit attribute to set a friendly error name. The message is templated, and contains a common message ("User 'x' was unable to perform action because 'y'"), but is never exactly the same (different users, different conditions). Sentry clearly uses some set of attributes under the hood to determine whether to aggregate errors as the same exception, but despite having looked through the code, I can't work out how. Can anyone short-cut my having to dig further into the code and tell me what properties I need to set in order to manage aggregation as I would like? [UPDATE 1: event grouping] This line appears in sentry.models.Group: class Group(MessageBase): """ Aggregated message which summarizes a set of Events. """ ... class Meta: unique_together = (('project', 'logger', 'culprit', 'checksum'),) ... Which makes sense - project, logger and culprit I am setting at the moment - the problem is checksum. I will investigate further, however 'checksum' suggests that binary equivalence, which is never going to work - it must be possible to group instances of the same exception, with differenct attributes? [UPDATE 2: event checksums] The event checksum comes from the sentry.manager.get_checksum_from_event method: def get_checksum_from_event(event): for interface in event.interfaces.itervalues(): result = interface.get_hash() if result: hash = hashlib.md5() for r in result: hash.update(to_string(r)) return hash.hexdigest() return hashlib.md5(to_string(event.message)).hexdigest() Next stop - where do the event interfaces come from? [UPDATE 3: event interfaces] I have worked out that interfaces refer to the standard mechanism for describing data passed into sentry events, and that I am using the standard sentry.interfaces.Message and sentry.interfaces.User interfaces. Both of these will contain different data depending on the exception instance - and so a checksum will never match. Is there any way that I can exclude these from the checksum calculation? (Or at least the User interface value, as that has to be different - the Message interface value I could standardise.) [UPDATE 4: solution] Here are the two get_hash functions for the Message and User interfaces respectively: # sentry.interfaces.Message def get_hash(self): return [self.message] # sentry.interfaces.User def get_hash(self): return [] Looking at these two, only the Message.get_hash interface will return a value that is picked up by the get_checksum_for_event method, and so this is the one that will be returned (hashed etc.) The net effect of this is that the the checksum is evaluated on the message alone - which in theory means that I can standardise the message and keep the user definition unique. I've answered my own question here, but hopefully my investigation is of use to others having the same problem. (As an aside, I've also submitted a pull request against the Sentry documentation as part of this ;-)) (Note to anyone using / extending Sentry with custom interfaces - if you want to avoid your interface being use to group exceptions, return an empty list.)

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• Coping with feelings of technical mediocrity

  - by Karim

  As I've progressed as a programmer, I noticed more nuance and areas I could study in depth. In part, I've come to think of myself from, at one point, a "guru" to now much less, even mediocre or inadequate. Is this normal, or is it a sign of a destructive excessive ambition? Background I started to program when I was still a kid, I had about 10 or 11 years. I really enjoy my work and never get bored from it. It's amazing how somebody could be paid for what he really likes to do and would be doing it anyway even for free. When I first started to program, I was feeling proud of what I was doing, each application I built was for me a success and after 2-3 year I had a feeling that I'm a coding guru. It was a nice feeling. ;-) But the more I was in the field and the more types of software I started to develop, I was starting to have a feeling that I'm completely wrong in thinking I'm a guru. I felt that I'm not even a mediocre developer. Each new field I start to work on is giving me this feeling. Like when I once developed a device driver for a client, I saw how much I need to learn about device drivers. When I developed a video filter for an application, I saw how much do I still need to learn about DirectShow, Color Spaces, and all the theory behind that. The worst thing was when I started to learn algorithms. It was several years ago. I knew then the basic structures and algorithms like the sorting, some types of trees, some hashtables, strings, etc. and when I really wanted to learn a group of structures I learned about 5-6 new types and saw that in fact even this small group has several hundred subtypes of structures. It's depressing how little time people have in their lives to learn all this stuff. I'm now a software developer with about 10 years of experience and I still feel that I'm not a proficient developer when I think about things that others do in the industry.

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• Extend argparse to write set names in the help text for optional argument choices and define those sets once at the end

  - by Kent

  Example of the problem If I have a list of valid option strings which is shared between several arguments, the list is written in multiple places in the help string. Making it harder to read: def main(): elements = ['a', 'b', 'c', 'd', 'e', 'f'] parser = argparse.ArgumentParser() parser.add_argument( '-i', nargs='*', choices=elements, default=elements, help='Space separated list of case sensitive element names.') parser.add_argument( '-e', nargs='*', choices=elements, default=[], help='Space separated list of case sensitive element names to ' 'exclude from processing') parser.parse_args() When running the above function with the command line argument --help it shows: usage: arguments.py [-h] [-i [{a,b,c,d,e,f} [{a,b,c,d,e,f} ...]]] [-e [{a,b,c,d,e,f} [{a,b,c,d,e,f} ...]]] optional arguments: -h, --help show this help message and exit -i [{a,b,c,d,e,f} [{a,b,c,d,e,f} ...]] Space separated list of case sensitive element names. -e [{a,b,c,d,e,f} [{a,b,c,d,e,f} ...]] Space separated list of case sensitive element names to exclude from processing What would be nice It would be nice if one could define an option list name, and in the help output write the option list name in multiple places and define it last of all. In theory it would work like this: def main_optionlist(): elements = ['a', 'b', 'c', 'd', 'e', 'f'] # Two instances of OptionList are equal if and only if they # have the same name (ALFA in this case) ol = OptionList('ALFA', elements) parser = argparse.ArgumentParser() parser.add_argument( '-i', nargs='*', choices=ol, default=ol, help='Space separated list of case sensitive element names.') parser.add_argument( '-e', nargs='*', choices=ol, default=[], help='Space separated list of case sensitive element names to ' 'exclude from processing') parser.parse_args() And when running the above function with the command line argument --help it would show something similar to: usage: arguments.py [-h] [-i [ALFA [ALFA ...]]] [-e [ALFA [ALFA ...]]] optional arguments: -h, --help show this help message and exit -i [ALFA [ALFA ...]] Space separated list of case sensitive element names. -e [ALFA [ALFA ...]] Space separated list of case sensitive element names to exclude from processing sets in optional arguments: ALFA {a,b,c,d,e,f} Question I need to: Replace the {'l', 'i', 's', 't', 's'} shown with the option name, in the optional arguments. At the end of the help text show a section explaining which elements each option name consists of. So I ask: Is this possible using argparse? Which classes would I have to inherit from and which methods would I need to override? I have tried looking at the source for argparse, but as this modification feels pretty advanced I don´t know how to get going.

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• Applying styles to a GridView matching certain criteria

  - by NickK

  Hi everyone. I'm fairly new to ASP.Net so it's probably just me being a bit stupid, but I just can't figure out why this isn't working. Basically, I have a GridView control (GridView1) on a page which is reading from a database. I already have a CSS style applied to the GridView and all I want to do is change the background image applied in the style depending on if a certain cell has data in it or not. The way I'm trying to handle this change is updating the CSS class applied to each row through C#. I have the code below doing this: protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) { GridViewRow row = e.Row; string s = row.Cells[7].Text; if (s.Length > 0) { row.CssClass = "newRowBackground"; } else { row.CssClass = "oldRowBackground"; } } In theory, the data from Cell[7] will either be null or be a string (in this case, likely a person's name). The problem is that when the page loads, every row in the GridView has the new style applied to it, whether it's empty or not. However, when I change it to use hard coded examples, it works fine. So for example, the below would work exactly how I want it to: protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e) { GridViewRow row = e.Row; string s = row.Cells[7].Text; if (s == "Smith") //Matching a name in one of the rows { row.CssClass = "newRowBackground"; } else { row.CssClass = "oldRowBackground"; } } It seems as if the top piece of code is always returning the string with a value greater than 0, but when I check the database the fields are all null (except for my test record of "Smith"). I'm probably doing something very simple that's wrong here, but I can't see what. Like I said, I'm still very new to this. One thing I have tried is changing the argument in the if statement to things like: if (s != null), if (s != "") and if (s == string.empty) all with no luck. Any help is greatly appreciated and don't hesitate to tell me if I'm just being stupid here. :)

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• Insert Registration Data in MySQL using PHP

  - by J M 4

  I may not be asking this in the best way possible but i will try my hardest. Thank you ahead of time for your help: I am creating an enrollment website which allows an individual OR manager to enroll for medical testing services for professional athletes. I will NOT be using the site as a query DB which anybody can view information stored within the database. The information is instead simply stored, and passed along in a CSV format to our network provider so they can use as needed after the fact. There are two possible scenarios: Scenario 1 - Individual Enrollment If an individual athlete chooses to enroll him/herself, they enter their personal information, submit their payment information (credit/bank account) for processing, and their information is stored in an online database as Athlete1. Scenario 2 - Manager Enrollment If a manager chooses to enroll several athletes he manages/ promotes for, he enters his personal information, then enters the personal information for each athlete he wishes to pay for (name, address, ssn, dob, etc), then submits payment information for ALL athletes he is enrolling. This number can range from 1 single athlete, up to 20 athletes per single enrollment (he can return and complete a follow up enrollment for additional athletes). Initially, I was building the database to house ALL information regardless of enrollment type in a single table which housed over 400 columns (think 20 athletes with over 10 fields per athlete such as name, dob, ssn, etc). Now that I think about it more, I believe create multiple tables (manager(s), athlete(s)) may be a better idea here but still not quite sure how to go about it for the following very important reasons: Issue 1 If I list the manager as the parent table, I am afraid the individual enrolling athlete will not show up in the primary table and will not be included in the overall registration file which needs to be sent on to the network providers. Issue 2 All athletes being enrolled by a manager are being stored in SESSION as F1FirstName, F2FirstName where F1 and F2 relate to the id of the fighter. I am not sure technically speaking how to store multiple pieces of information within the same table under separate rows using PHP. For example, all athleteswill have a first name. The very basic theory of what i am trying to do is: If number_of_athletes 1, store F1FirstName in row 1, column 1 of Table "Athletes"; store F1LastName in row 1, column 2 of Table "Athletes"; store F2FirstName in row 2, column 1 of Table "Athletes"; store F2LastName in row 2, column 2 of table "Athletes"; Does this make sense? I know this question is very long and probably difficult so i appreciate the guidance.

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• Directly Jump to another C++ function

  - by maligree

  I'm porting a small academic OS from TriCore to ARM Cortex (Thumb-2 instruction set). For the scheduler to work, I sometimes need to JUMP directly to another function without modifying the stack nor the link register. On TriCore (or, rather, on tricore-g++), this wrapper template (for any three-argument-function) works: template< class A1, class A2, class A3 > inline void __attribute__((always_inline)) JUMP3( void (*func)( A1, A2, A3), A1 a1, A2 a2, A3 a3 ) { typedef void (* __attribute__((interrupt_handler)) Jump3)( A1, A2, A3); ( (Jump3)func )( a1, a2, a3 ); } //example for using the template: JUMP3( superDispatch, this, me, next ); This would generate the assembler instruction J (a.k.a. JUMP) instead of CALL, leaving the stack and CSAs unchanged when jumping to the (otherwise normal) C++ function superDispatch(SchedulerImplementation* obj, Task::Id from, Task::Id to). Now I need an equivalent behaviour on ARM Cortex (or, rather, for arm-none-linux-gnueabi-g++), i.e. generate a B (a.k.a. BRANCH) instruction instead of BLX (a.k.a. BRANCH with link and exchange). But there is no interrupt_handler attribute for arm-g++ and I could not find any equivalent attribute. So I tried to resort to asm volatile and writing the asm code directly: template< class A1, class A2, class A3 > inline void __attribute__((always_inline)) JUMP3( void (*func)( A1, A2, A3), A1 a1, A2 a2, A3 a3 ) { asm volatile ( "mov.w r0, %1;" "mov.w r1, %2;" "mov.w r2, %3;" "b %0;" : : "r"(func), "r"(a1), "r"(a2), "r"(a3) : "r0", "r1", "r2" ); } So far, so good, in my theory, at least. Thumb-2 requires function arguments to be passed in the registers, i.e. r0..r2 in this case, so it should work. But then the linker dies with undefined reference to `r6' on the closing bracket of the asm statement ... and I don't know what to make of it. OK, I'm not the expert in C++, and the asm syntax is not very straightforward... so has anybody got a hint for me? A hint to the correct __attribute__ for arm-g++ would be one way, a hint to fix the asm code would be another. Another way maybe would be to tell the compiler that a1..a3 should already be in the registers r0..r2 when the asm statement is entered (I looked into that a bit, but did not find any hint).

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• Declare Locally or Globally in Delphi?

  - by lkessler

  I have a procedure my program calls tens of thousands of times that uses a generic structure like this: procedure PrintIndiEntry(JumpID: string); type TPeopleIncluded = record IndiPtr: pointer; Relationship: string; end; var PeopleIncluded: TList<TPeopleIncluded>; PI: TPeopleIncluded; begin { PrintIndiEntry } PeopleIncluded := TList<TPeopleIncluded>.Create; { A loop here that determines a small number (up to 100) people to process } while ... do begin PI.IndiPtr := ...; PI.Relationship := ...; PeopleIncluded.Add(PI); end; DoSomeProcess(PeopleIncluded); PeopleIncluded.Clear; PeopleIncluded.Free; end { PrintIndiEntry } Alternatively, I can declare PeopleIncluded globally rather than locally as follows: unit process; interface type TPeopleIncluded = record IndiPtr: pointer; Relationship: string; end; var PeopleIncluded: TList<TPeopleIncluded>; PI: TPeopleIncluded; procedure PrintIndiEntry(JumpID: string); begin { PrintIndiEntry } { A loop here that determines a small number (up to 100) people to process } while ... do begin PI.IndiPtr := ...; PI.Relationship := ...; PeopleIncluded.Add(PI); end; DoSomeProcess(PeopleIncluded); PeopleIncluded.Clear; end { PrintIndiEntry } procedure InitializeProcessing; begin PeopleIncluded := TList<TPeopleIncluded>.Create; end; procedure FinalizeProcessing; begin PeopleIncluded.Free; end; My question is whether in this situation it is better to declare PeopleIncluded globally rather than locally. I know the theory is to define locally whenever possible, but I would like to know if there are any issues to worry about with regards to doing tens of thousands of of "create"s and "free"s? Making them global will do only one create and one free. What is the recommended method to use in this case? If the recommended method is to still define it locally, then I'm wondering if there are any situations where it is better to define globally when defining locally is still an option.

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• avoiding enums as interface identifiers c++ OOP

  - by AlasdairC

  Hi I'm working on a plugin framework using dynamic loaded shared libraries which is based on Eclipse's (and probally other's) extension-point model. All plugins share similar properties (name, id, version etc) and each plugin could in theory satisfy any extension-point. The actual plugin (ie Dll) handling is managed by another library, all I am doing really is managing collections of interfaces for the application. I started by using an enum PluginType to distinguish the different interfaces, but I have quickly realised that using template functions made the code far cleaner and would leave the grunt work up to the compiler, rather than forcing me to use lots of switch {...} statements. The only issue is where I need to specify like functionality for class members - most obvious example is the default plugin which provides a particular interface. A Settings class handles all settings, including the default plugin for an interface. ie Skin newSkin = settings.GetDefault<ISkin>(); How do I store the default ISkin in a container without resorting to some other means of identifying the interface? As I mentioned above, I currently use a std::map<PluginType, IPlugin> Settings::defaults member to achieve this (where IPlugin is an abstract base class which all plugins derive from. I can then dynamic_cast to the desired interface when required, but this really smells of bad design to me and introduces more harm than good I think. would welcome any tips edit: here's an example of the current use of default plugins typedef boost::shared_ptr<ISkin> Skin; typedef boost::shared_ptr<IPlugin> Plugin; enum PluginType { skin, ..., ... } class Settings { public: void SetDefault(const PluginType type, boost::shared_ptr<IPlugin> plugin) { m_default[type] = plugin; } boost::shared_ptr<IPlugin> GetDefault(const PluginType type) { return m_default[type]; } private: std::map<PluginType, boost::shared_ptr<IPlugin> m_default; }; SkinManager::Initialize() { Plugin thedefault = g_settings.GetDefault(skinplugin); Skin defaultskin = boost::dynamic_pointer_cast<ISkin>(theskin); defaultskin->Initialize(); } I would much rather call the getdefault as the following, with automatic casting to the derived class. However I need to specialize for every class type. template<> Skin Settings::GetDefault<ISkin>() { return boost::dynamic_pointer_cast<ISkin>(m_default(skin)); }

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• SwingWorker exceptions lost even when using wrapper classes

  - by Ti Strga

  I've been struggling with the usability problem of SwingWorker eating any exceptions thrown in the background task, for example, described on this SO thread. That thread gives a nice description of the problem, but doesn't discuss recovering the original exception. The applet I've been handed needs to propagate the exception upwards. But I haven't been able to even catch it. I'm using the SimpleSwingWorker wrapper class from this blog entry specifically to try and address this issue. It's a fairly small class but I'll repost it at the end here just for reference. The calling code looks broadly like try { // lots of code here to prepare data, finishing with SpecialDataHelper helper = new SpecialDataHelper(...stuff...); helper.execute(); } catch (Throwable e) { // used "Throwable" here in desperation to try and get // anything at all to match, including unchecked exceptions // // no luck, this code is never ever used :-( } The wrappers: class SpecialDataHelper extends SimpleSwingWorker { public SpecialDataHelper (SpecialData sd) { this.stuff = etc etc etc; } public Void doInBackground() throws Exception { OurCodeThatThrowsACheckedException(this.stuff); return null; } protected void done() { // called only when successful // never reached if there's an error } } The feature of SimpleSwingWorker is that the actual SwingWorker's done()/get() methods are automatically called. This, in theory, rethrows any exceptions that happened in the background. In practice, nothing is ever caught, and I don't even know why. The SimpleSwingWorker class, for reference, and with nothing elided for brevity: import java.util.concurrent.ExecutionException; import javax.swing.SwingWorker; /** * A drop-in replacement for SwingWorker<Void,Void> but will not silently * swallow exceptions during background execution. * * Taken from http://jonathangiles.net/blog/?p=341 with thanks. */ public abstract class SimpleSwingWorker { private final SwingWorker<Void,Void> worker = new SwingWorker<Void,Void>() { @Override protected Void doInBackground() throws Exception { SimpleSwingWorker.this.doInBackground(); return null; } @Override protected void done() { // Exceptions are lost unless get() is called on the // originating thread. We do so here. try { get(); } catch (final InterruptedException ex) { throw new RuntimeException(ex); } catch (final ExecutionException ex) { throw new RuntimeException(ex.getCause()); } SimpleSwingWorker.this.done(); } }; public SimpleSwingWorker() {} protected abstract Void doInBackground() throws Exception; protected abstract void done(); public void execute() { worker.execute(); } }

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• PHP/MySQL Interview - How would you have answered?

  - by martincarlin87

  I was asked this interview question so thought I would post it here to see how other users would answer: Please write some code which connects to a MySQL database (any host/user/pass), retrieves the current date & time from the database, compares it to the current date & time on the local server (i.e. where the application is running), and reports on the difference. The reporting aspect should be a simple HTML page, so that in theory this script can be put on a web server, set to point to a particular database server, and it would tell us whether the two servers’ times are in sync (or close to being in sync). This is what I put: // Connect to database server $dbhost = 'localhost'; $dbuser = 'xxx'; $dbpass = 'xxx'; $dbname = 'xxx'; $conn = mysql_connect($dbhost, $dbuser, $dbpass) or die (mysql_error()); // Select database mysql_select_db($dbname) or die(mysql_error()); // Retrieve the current time from the database server $sql = 'SELECT NOW() AS db_server_time'; // Execute the query $result = mysql_query($sql) or die(mysql_error()); // Since query has now completed, get the time of the web server $php_server_time = date("Y-m-d h:m:s"); // Store query results in an array $row = mysql_fetch_array($result); // Retrieve time result from the array $db_server_time = $row['db_server_time']; echo $db_server_time . '<br />'; echo $php_server_time; if ($php_server_time != $db_server_time) { // Server times are not identical echo '<p>Database server and web server are not in sync!</p>'; // Convert the time stamps into seconds since 01/01/1970 $php_seconds = strtotime($php_server_time); $sql_seconds = strtotime($db_server_time); // Subtract smaller number from biggest number to avoid getting a negative result if ($php_seconds > $sql_seconds) { $time_difference = $php_seconds - $sql_seconds; } else { $time_difference = $sql_seconds - $php_seconds; } // convert the time difference in seconds to a formatted string displaying hours, minutes and seconds $nice_time_difference = gmdate("H:i:s", $time_difference); echo '<p>Time difference between the servers is ' . $nice_time_difference; } else { // Timestamps are exactly the same echo '<p>Database server and web server are in sync with each other!</p>'; } Yes, I know that I have used the deprecated mysql_* functions but that aside, how would you have answered, i.e. what changes would you make and why? Are there any factors I have omitted which I should take into consideration? The interesting thing is that my results always seem to be an exact number of minutes apart when executed on my hosting account: 2012-12-06 11:47:07 2012-12-06 11:12:07

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• Michael Crump&rsquo;s notes for 70-563 PRO &ndash; Designing and Developing Windows Applications usi

  - by mbcrump

  TIME TO GO PRO! This is my notes for 70-563 PRO – Designing and Developing Windows Applications using .NET Framework 3.5 I created it using several resources (various certification web sites, msdn, official ms 70-548 book). The reason that I created this review is because a) I am taking the exam. b) MS did not create a book for this exam. Use the(MS 70-548)book. c) To make sure I am familiar with each before the exam. I hope that it provides a good start for your own notes. I hope that someone finds this useful. At least, it will give you a starting point of what to expect to know on the PRO exam. Also, for those wondering, the PRO exam does contains very little code. It is basically all theory. 1. Validation Controls – How to prevent users from entering invalid data on forms. (MaskedTextBox control and RegEx) 2. ServiceController – used to start and control the behavior of existing services. 3. User Feedback (know winforms Status Bar, Tool Tips, Color, Error Provider, Context-Sensitive and Accessibility) 4. Specific (derived) exceptions must be handled before general (base class) exceptions. By moving the exception handling for the base type Exception to after exception handling of ArgumentNullException, all ArgumentNullException thrown by the Helper method will be caught and logged correctly. 5. A heartbeat method is a method exposed by a Web service that allows external applications to check on the status of the service. 6. New users must master key tasks quickly. Giving these tasks context and appropriate detail will help. However, advanced users will demand quicker paths. Shortcuts, accelerators, or toolbar buttons will speed things along for the advanced user. 7. MSBuild uses project files to instruct the build engine what to build and how to build it. MSBuild project files are XML files that adhere to the MSBuild XML schema. The MSBuild project files contain complete file, build action, and dependency information for each individual projects. 8. Evaluating whether or not to fix a bug involves a triage process. You must identify the bug's impact, set the priority, categorize it, and assign a developer. Many times the person doing the triage work will assign the bug to a developer for further investigation. In fact, the workflow for the bug work item inside of Team System supports this step. Developers are often asked to assess the impact of a given bug. This assessment helps the person doing the triage make a decision on how to proceed. When assessing the impact of a bug, you should consider time and resources to fix it, bug risk, and impacts of the bug. 9. In large projects it is generally impossible and unfeasible to fix all bugs because of the impact on schedule and budget. 10. Code reviews should be conducted by a technical lead or a technical peer. 11. Testing Applications 12. WCF Services – application state 13. SQL Server 2005 / 2008 Express Edition – reliable storage of data / Microsoft SQL Server 3.5 Compact Database– used for client computers to retrieve and save data from a shared location. 14. SQL Server 2008 Compact Edition – used for minimum possible memory and can synchronize data with a corporate SQL Server 2008 Database. Supports offline user and minimum dependency on external components. 15. MDI and SDI Forms (specifically IsMDIContainer) 16. GUID – in the case of data warehousing, it is important to define unique keys. 17. Encrypting / Security Data 18. Understanding of Isolated Storage/Proper location to store items 19. LINQ to SQL 20. Multithreaded access 21. ADO.NET Entity Framework model 22. Marshal.ReleaseComObject 23. Common User Interface Layout (ComboBox, ListBox, Listview, MaskedTextBox, TextBox, RichTextBox, SplitContainer, TableLayoutPanel, TabControl) 24. DataSets Class - http://msdn.microsoft.com/en-us/library/system.data.dataset%28VS.71%29.aspx 25. SQL Server 2008 Reporting Services (SSRS) 26. SystemIcons.Shield (Vista UAC) 27. Leverging stored procedures to perform data manipulation for a database schema that can change. 28. DataContext 29. Microsoft Windows Installer Packages, ClickOnce(bootstrapping features), XCopy. 30. Client Application Services – will authenticate users by using the same data source as a ASP.NET web application. 31. SQL Server 2008 Caching 32. StringBuilder 33. Accessibility Guidelines for Windows Applications http://msdn.microsoft.com/en-us/library/ms228004.aspx 34. Logging erros 35. Testing performance related issues. 36. Role Based Security, GenericIdentity and GenericPrincipal 37. System.Net.CookieContainer will store session data for webapps (see isolated storage for winforms) 38. .NET CLR Profiler tool will identify objects that cause performance issues. 39. ADO.NET Synchronization (SyncGroup) 40. Globalization - CultureInfo 41. IDisposable Interface- reports on several questions relating to this. 42. Adding timestamps to determine whether data has changed or not. 43. Converting applications to .NET Framework 3.5 44. MicrosoftReportViewer 45. Composite Controls 46. Windows Vista KNOWN folders. 47. Microsoft Sync Framework 48. TypeConverter -Provides a unified way of converting types of values to other types, as well as for accessing standard values and sub properties. http://msdn.microsoft.com/en-us/library/system.componentmodel.typeconverter.aspx 49. Concurrency control mechanisms The main categories of concurrency control mechanisms are: Optimistic - Delay the checking of whether a transaction meets the isolation rules (e.g., serializability and recoverability) until its end, without blocking any of its (read, write) operations, and then abort a transaction, if the desired rules are violated. Pessimistic - Block operations of a transaction, if they may cause violation of the rules. Semi-optimistic - Block operations in some situations, and do not block in other situations, while delaying rules checking to transaction's end, as done with optimistic. 50. AutoResetEvent 51. Microsoft Messaging Queue (MSMQ) 4.0 52. Bulk imports 53. KeyDown event of controls 54. WPF UI components 55. UI process layer 56. GAC (installing, removing and queuing) 57. Use a local database cache to reduce the network bandwidth used by applications. 58. Sound can easily be annoying and distracting to users, so use it judiciously. Always give users the option to turn sound off. Because a user might have sound off, never convey important information through sound alone.

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• Agile Awakenings and the Rules of Agile

  - by Robert May

  For those that care, you can read my history of management and technology to understand why I think I’m qualified to talk about this at all.  It’s boring, so feel free to skip it. Awakenings I first started to play around with the idea of “agile” in 2004 or 2005.  I found a book on the Rational Unified Process that I thought was good, and attempted to implement parts of it.  I thought I was agile, but really, it wasn’t.   I still didn’t understand the concept of a team.  I still wanted to tell the team what to do and how to get it done.  I still thought I was smarter than the team. After that job, I started work on another project and began helping that team.  The first few months were really rough.  We were implementing Scrum, which was relatively new to everyone on the team, and, quite frankly, I was doing a poor job of it.  I was trying to micro-manage every aspect of the teams work, and we were all miserable. The moment of change came when the senior architect bailed on the project.  His comment to me was: “This isn’t Agile.  Where are the stand-ups?  Where are the stories?”  He was dead on, and I finally woke up.  I finally realized that I was the problem!  I wasn’t trusting the team.  I wasn’t helping the team.  I was being a manager. Like many (most?), I was claiming to be Agile and use Scrum, but I wasn’t in fact following the rules Scrum.  Since then, I’ve done a lot of studying, hands on practice, coaching of many different teams, and other learning around Scrum, and I have discovered that Scrum has some rules that must be followed for success, even though the process is about continuous improvement. I’ve been practicing Scrum right for about 4 years now and have helped multiple teams implement it successfully, so what you’re about to get is based on experience, rather than just theory. The Rules of Scrum In my experience, what I’ve found is that most companies that claim to be doing Scrum or Agile are actually NOT doing either.  This stems largely because they think that they can “adopt the rules of Agile that fit their organization.”  Sadly, many of them think that this means they can adopt iterations (sprints) and not much else.  Either that, or they think they can do whatever they want, or were doing before, and call it Scrum.  This is simply not true. Here are some rules that must be followed for you to really be doing Scrum.  I’ll go into detail on each one of these posts in future blog posts and update links here.  My intent is that this will help other teams implementing scrum to see more success. Agile does not allow you to do whatever you want A Product Owner is required A ScrumMaster is required The team must function as a Team, and QA must be part of the team Support from upper management is required A prioritized product backlog is required A prioritized sprint backlog is required Release planning is required Complete spring planning is required Showcases are required Velocity must be measured Retrospectives are required Daily stand-ups are required Visibility is absolutely required For now, I think that’s enough, although I reserve the right to add more.  If you’re breaking any of these rules, you’re probably not doing Scrum.  There are exceptions to these rules, but until you have practiced Scrum for a while, you don’t know what those exceptions are. Breaking the Rules Many teams break these rules because they are the ones that expose the most pain.  Scrum is not Advil.  It’s not intended to mask the pain, its intended to cure it.  Let me explain that analogy a bit more.  Recently, my 7 year old son broke his arm, quite severely (see the X-Ray to the right).  That caused him a great deal of pain.  We went first to one doctor, and after viewing the X-Ray, they determined that there was no way that they’d cast the arm at their location.  It was simply too bad of a break for them to deal with.  They did, however, give him some Advil for the pain and put a splint on his arm to stabilize the broken bones.  Within minutes, he was feeling much better.  Had we been stupid, we could have gone home and he’d have been just as happy as ever . . . until the pain medication wore off or one of his siblings touched the splint.  Then, all of that pain would come right back to the top.  Sure, he could make it go away by just taking more Advil and moving the splint out of the way, but that wasn’t going to fix the problem permanently. We ended up in an emergency room with a doctor who could fix his arm.  However, we were warned that the fix was going to be VERY painful, and it was.  Even with heavy sedation (Propofol), my son was in enough pain that he squirmed and wiggled trying to get his arm away from the doctor.  He had to endure this pain in order to have a functional arm. But the setting wasn’t the end.  He had to have several casts, had to have it re-broken once, since the first setting didn’t take and finally was given a clean bill of health. Agile implementation is much like this story.  Agile was developed as a result of people recognizing that the development methodologies that were currently in place simply were ineffective.  However, the fix to the broken development that’s been festering for many years is not painless.  Many people start Agile thinking that things will be wonderful.  They won’t!  Agile is about visibility, and often, it brings great pain to surface.  It causes all of the missed deadlines, the cowboy coders, the coasters, the micro-managers, the lazy, and all of the other problems that are really part of your development process now to become painfully visible to EVERYONE.  Many people don’t like this exposure.  Agile will make the pain better, but not if you remove the cast (the rules above) prematurely and start breaking the rules that expose the most pain.  The healing will take time and is not instant (like Advil).  Figuring out what the true source of pain and fixing it is very valuable to you, your team, and your company.  Remember as you’re doing this that Agile isn’t the source of the pain, it’s really just exposing it.  Find the source. My recommendation is that ALL of these rules are followed for a minimum of six months, and preferably for an entire year, before you decide to break any of these rules.  Get a few good releases under your belt.  Figure out what your velocity is and start firing as a team.  Chances are, after you see agile really in action, you won’t want to break the rules because you’ll see their value. More Reading Jean Tabaka recently published a list of 78 Things I Have Learned in 6 Years of Agile Coaching.  Highly recommended. Technorati Tags: Agile,Scrum,Rules

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• SQL SERVER – Interview Questions and Answers – Frequently Asked Questions – Introduction – Day 1 of 31

  - by pinaldave

  List of all the Interview Questions and Answers Series blogs Posts covering interview questions and answers always make for interesting reading.  Some people like the subject for their helpful hints and thought provoking subject, and others dislike these posts because they feel it is nothing more than cheating.  I’d like to discuss the pros and cons of a Question and Answer format here. Interview Questions and Answers are Helpful Just like blog posts, books, and articles, interview Question and Answer discussions are learning material.  The popular Dummy’s books or Idiots Guides are not only for “dummies,” but can help everyone relearn the fundamentals.  Question and Answer discussions can serve the same purpose.  You could call this SQL Server Fundamentals or SQL Server 101. I have administrated hundreds of interviews during my career and I have noticed that sometimes an interviewee with several years of experience lacks an understanding of the fundamentals.  These individuals have been in the industry for so long, usually working on a very specific project, that the ABCs of the business have slipped their mind. Or, when a college graduate is looking to get into the industry, he is not expected to have experience since he is just graduated. However, the new grad is expected to have an understanding of fundamentals and theory.  Sometimes after the stress of final exams and graduation, it can be difficult to remember the correct answers to interview questions, though. An interview Question and Answer discussion can be very helpful to both these individuals.  It is simply a way to go back over the building blocks of a topic.  Many times a simple review like this will help “jog” your memory, and all those previously-memorized facts will come flooding back to you.  It is not a way to re-learn a topic, but a way to remind yourself of what you already know. A Question and Answer discussion can also be a way to go over old topics in a more interesting manner.  Especially if you have been working in the industry, or taking lots of classes on the topic, everything you read can sound like a repeat of what you already know.  Going over a topic in a new format can make the material seem fresh and interesting.  And an interested mind will be more engaged and remember more in the end. Interview Questions and Answers are Harmful A common argument against a Question and Answer discussion is that it will give someone a “cheat sheet.” A new guy with relatively little experience can read the interview questions and answers, and then memorize them. When an interviewer asks him the same questions, he will repeat the answers and get the job. Honestly, is he good hire because he memorized the interview questions? Wouldn’t it be better for the interviewer to hire someone with actual experience?  The answer is not as easy as it seems – there are many different factors to be considered. If the interviewer is asking fundamentals-related questions only, he gets the answers he wants to hear, and then hires this first candidate – there is a good chance that he is hiring based on personality rather than experience.  If the interviewer is smart he will ask deeper questions, have more than one person on the interview team, and interview a variety of candidates.  If one interviewee happens to memorize some answers, it usually doesn’t mean he will automatically get the job at the expense of more qualified candidates. Another argument against interview Question and Answers is that it will give candidates a false sense of confidence, and that they will appear more qualified than they are. Well, if that is true, it will not last after the first interview when the candidate is asked difficult questions and he cannot find the answers in the list of interview Questions and Answers.  Besides, confidence is one of the best things to walk into an interview with! In today’s competitive job market, there are often hundreds of candidates applying for the same position.  With so many applicants to choose from, interviewers must make decisions about who to call back and who to hire based on their gut feeling.  One drawback to reading an interview Question and Answer article is that you might sound very boring in your interview – saying the same thing as every single candidate, and parroting answers that sound like someone else wrote them for you – because they did.  However, it is definitely better to go to an interview prepared, just make sure that you give a lot of thought to your answers to make them sound like your own voice.  Remember that you will be hired based on your skills as well as your personality, so don’t think that having all the right answers will make get you hired.  A good interviewee will be prepared, confident, and know how to stand out. My Opinion A list of interview Questions and Answers is really helpful as a refresher or for beginners. To really ace an interview, one needs to have real-world, hands-on experience with SQL Server as well. Interview questions just serve as a starter or easy read for experienced professionals. When I have to learn new technology, I often search online for interview questions and get an idea about the breadth and depth of the technology. Next Action I am going to write about interview Questions and Answers for next 30 days. I have previously written a series of interview questions and answers; now I have re-written them keeping the latest version of SQL Server and current industry progress in mind. If you have faced interesting interview questions or situations, please write to me and I will publish them as a guest post. If you want me to add few more details, leave a comment and I will make sure that I do my best to accommodate. Tomorrow we will start the interview Questions and Answers series, with a few interesting stories, best practices and guest posts. We will have a prize give-away and other awards when the series ends. List of all the Interview Questions and Answers Series blogs Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Interview Questions and Answers, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Robotic Arm &ndash; Hardware

  - by Szymon Kobalczyk

  This is first in series of articles about project I've been building  in my spare time since last Summer. Actually it all began when I was researching a topic of modeling human motion kinematics in order to create gesture recognition library for Kinect. This ties heavily into motion theory of robotic manipulators so I also glanced at some designs of robotic arms. Somehow I stumbled upon this cool looking open source robotic arm: It was featured on Thingiverse and published by user jjshortcut (Jan-Jaap). Since for some time I got hooked on toying with microcontrollers, robots and other electronics, I decided to give it a try and build it myself. In this post I will describe the hardware build of the arm and in later posts I will be writing about the software to control it. Another reason to build the arm myself was the cost factor. Even small commercial robotic arms are quite expensive – products from Lynxmotion and Dagu look great but both cost around USD $300 (actually there is one cheap arm available but it looks more like a toy to me). In comparison this design is quite cheap. It uses seven hobby grade servos and even the cheapest ones should work fine. The structure is build from a set of laser cut parts connected with few metal spacers (15mm and 47mm) and lots of M3 screws. Other than that you’d only need a microcontroller board to drive the servos. So in total it comes a lot cheaper to build it yourself than buy an of the shelf robotic arm. Oh, and if you don’t like this one there are few more robotic arm projects at Thingiverse (including one by oomlout). Laser cut parts Some time ago I’ve build another robot using laser cut parts so I knew the process already. You can grab the design files in both DXF and EPS format from Thingiverse, and there are also 3D models of each part in STL. Actually the design is split into a second project for the mini servo gripper (there is also a standard servo version available but it won’t fit this arm).  I wanted to make some small adjustments, layout, and add measurements to the parts before sending it for cutting. I’ve looked at some free 2D CAD programs, and finally did all this work using QCad 3 Beta with worked great for me (I also tried LibreCAD but it didn’t work that well). All parts are cut from 4 mm thick material. Because I was worried that acrylic is too fragile and might break, I also ordered another set cut from plywood. In the end I build it from plywood because it was easier to glue (I was told acrylic requires a special glue). Btw. I found a great laser cutter service in Kraków and highly recommend it (www.ebbox.com.pl). It cost me only USD $26 for both sets ($16 acrylic + $10 plywood). Metal parts I bought all the M3 screws and nuts at local hardware store. Make sure to look for nylon lock (nyloc) nuts for the gripper because otherwise it unscrews and comes apart quickly. I couldn’t find local store with metal spacers and had to order them online (you’d need 11 x 47mm and 3 x 15mm). I think I paid less than USD $10 for all metal parts. Servos This arm uses five standards size servos to drive the arm itself, and two micro servos are used on the gripper. Author of the project used Modelcraft RS-2 Servo and Modelcraft ES-05 HT Servo. I had two Futaba S3001 servos laying around, and ordered additional TowerPro SG-5010 standard size servos and TowerPro SG90 micro servos. However it turned out that the SG90 won’t fit in the gripper so I had to replace it with a slightly smaller E-Sky EK2-0508 micro servo. Later it also turned out that Futaba servos make some strange noise while working so I swapped one with TowerPro SG-5010 which has higher torque (8kg / cm). I’ve also bought three servo extension cables. All servos cost me USD $45. Assembly The build process is not difficult but you need to think carefully about order of assembling it. You can do the base and upper arm first. Because two servos in the base are close together you need to put first with one piece of lower arm already connected before you put the second servo. Then you connect the upper arm and finally put the second piece of lower arm to hold it together. Gripper and base require some gluing so think it through too. Make sure to look closely at all the photos on Thingiverse (also other people copies) and read additional posts on jjshortcust’s blog: My mini servo grippers and completed robotic arm  Multiply the robotic arm and electronics Here is also Rob’s copy cut from aluminum My assembled arm looks like this – I think it turned out really nice: Servo controller board The last piece of hardware I needed was an electronic board that would take command from PC and drive all seven servos. I could probably use Arduino for this task, and in fact there are several Arduino servo shields available (for example from Adafruit or Renbotics).  However one problem is that most support only up to six servos, and second that their accuracy is limited by Arduino’s timer frequency. So instead I looked for dedicated servo controller and found a series of Maestro boards from Pololu. I picked the Pololu Mini Maestro 12-Channel USB Servo Controller. It has many nice features including native USB connection, high resolution pulses (0.25µs) with no jitter, built-in speed and acceleration control, and even scripting capability. Another cool feature is that besides servo control, each channel can be configured as either general input or output. So far I’m using seven channels so I still have five available to connect some sensors (for example distance sensor mounted on gripper might be useful). And last but important factor was that they have SDK in .NET – what more I could wish for! The board itself is very small – half of the size of Tic-Tac box. I picked one for about USD $35 in this store. Perhaps another good alternative would be the Phidgets Advanced Servo 8-Motor – but it is significantly more expensive at USD $87.30. The Maestro Controller Driver and Software package includes Maestro Control Center program with lets you immediately configure the board. For each servo I first figured out their move range and set the min/max limits. I played with setting the speed an acceleration values as well. Big issue for me was that there are two servos that control position of lower arm (shoulder joint), and both have to be moved at the same time. This is where the scripting feature of Pololu board turned out very helpful. I wrote a script that synchronizes position of second servo with first one – so now I only need to move one servo and other will follow automatically. This turned out tricky because I couldn’t find simple offset mapping of the move range for each servo – I had to divide it into several sub-ranges and map each individually. The scripting language is bit assembler-like but gets the job done. And there is even a runtime debugging and stack view available. Altogether I’m very happy with the Pololu Mini Maestro Servo Controller, and with this final piece I completed the build and was able to move my arm from the Meastro Control program.   The total cost of my robotic arm was: $10 laser cut parts $10 metal parts $45 servos $35 servo controller ----------------------- $100 total So here you have all the information about the hardware. In next post I’ll start talking about the software that I wrote in Microsoft Robotics Developer Studio 4. Stay tuned!

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• bluetooth not working on Ubuntu 13.10

  - by iacopo

  I upgrated ubuntu from 13.4 to 13.10 and my bluetooth stopped working. When I open bluetooth I'm able to put it ON but the visibility doesn't show anything and didn't detect any device. when I: dmesg | grep Blue [ 2.046249] usb 3-1: Product: Bluetooth V2.0 Dongle [ 2.046252] usb 3-1: Manufacturer: Bluetooth v2.0 [ 15.255710] Bluetooth: Core ver 2.16 [ 15.255748] Bluetooth: HCI device and connection manager initialized [ 15.255759] Bluetooth: HCI socket layer initialized [ 15.255765] Bluetooth: L2CAP socket layer initialized [ 15.255776] Bluetooth: SCO socket layer initialized [ 20.110379] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 20.110386] Bluetooth: BNEP filters: protocol multicast [ 20.110400] Bluetooth: BNEP socket layer initialized [ 20.120635] Bluetooth: RFCOMM TTY layer initialized [ 20.120656] Bluetooth: RFCOMM socket layer initialized [ 20.120660] Bluetooth: RFCOMM ver 1.11 when I digit: lsusb Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 002: ID 0bc2:2300 Seagate RSS LLC Expansion Portable Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 006 Device 002: ID 0e6a:6001 Megawin Technology Co., Ltd GEMBIRD Flexible keyboard KB-109F-B-DE Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 005 Device 002: ID 13ee:0001 MosArt Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 003 Device 002: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode) Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub when I: hciconfig -a hci0: Type: BR/EDR Bus: USB BD Address: 00:1B:10:00:2A:EC ACL MTU: 1017:8 SCO MTU: 64:0 DOWN RX bytes:457 acl:0 sco:0 events:16 errors:0 TX bytes:68 acl:0 sco:0 commands:16 errors:0 Features: 0xff 0xff 0x8d 0xfe 0x9b 0xf9 0x00 0x80 Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 Link policy: Link mode: SLAVE ACCEPT when I digit: rfkill list 0: phy0: Wireless LAN Soft blocked: yes Hard blocked: no 1: hci0: Bluetooth Soft blocked: no Hard blocked: no when I digit: sudo gedit /etc/bluetooth/main.conf [General] # List of plugins that should not be loaded on bluetoothd startup #DisablePlugins = network,input # Default adaper name # %h - substituted for hostname # %d - substituted for adapter id Name = %h-%d # Default device class. Only the major and minor device class bits are # considered. Class = 0x000100 # How long to stay in discoverable mode before going back to non-discoverable # The value is in seconds. Default is 180, i.e. 3 minutes. # 0 = disable timer, i.e. stay discoverable forever DiscoverableTimeout = 0 # How long to stay in pairable mode before going back to non-discoverable # The value is in seconds. Default is 0. # 0 = disable timer, i.e. stay pairable forever PairableTimeout = 0 # Use some other page timeout than the controller default one # which is 16384 (10 seconds). PageTimeout = 8192 # Automatic connection for bonded devices driven by platform/user events. # If a platform plugin uses this mechanism, automatic connections will be # enabled during the interval defined below. Initially, this feature # intends to be used to establish connections to ATT channels. AutoConnectTimeout = 60 # What value should be assumed for the adapter Powered property when # SetProperty(Powered, ...) hasn't been called yet. Defaults to true InitiallyPowered = true # Remember the previously stored Powered state when initializing adapters RememberPowered = false # Use vendor id source (assigner), vendor, product and version information for # DID profile support. The values are separated by ":" and assigner, VID, PID # and version. # Possible vendor id source values: bluetooth, usb (defaults to usb) #DeviceID = bluetooth:1234:5678:abcd # Do reverse service discovery for previously unknown devices that connect to # us. This option is really only needed for qualification since the BITE tester # doesn't like us doing reverse SDP for some test cases (though there could in # theory be other useful purposes for this too). Defaults to true. ReverseServiceDiscovery = true # Enable name resolving after inquiry. Set it to 'false' if you don't need # remote devices name and want shorter discovery cycle. Defaults to 'true'. NameResolving = true # Enable runtime persistency of debug link keys. Default is false which # makes debug link keys valid only for the duration of the connection # that they were created for. DebugKeys = false # Enable the GATT functionality. Default is false EnableGatt = false when I digit: dmesg | grep Bluetooth [ 2.013041] usb 3-1: Product: Bluetooth V2.0 Dongle [ 2.013049] usb 3-1: Manufacturer: Bluetooth v2.0 [ 13.798293] Bluetooth: Core ver 2.16 [ 13.798338] Bluetooth: HCI device and connection manager initialized [ 13.798352] Bluetooth: HCI socket layer initialized [ 13.798357] Bluetooth: L2CAP socket layer initialized [ 13.798368] Bluetooth: SCO socket layer initialized [ 20.184162] Bluetooth: BNEP (Ethernet Emulation) ver 1.3 [ 20.184173] Bluetooth: BNEP filters: protocol multicast [ 20.184197] Bluetooth: BNEP socket layer initialized [ 20.238947] Bluetooth: RFCOMM TTY layer initialized [ 20.238983] Bluetooth: RFCOMM socket layer initialized [ 20.239018] Bluetooth: RFCOMM ver 1.11 When I digit: uname -a Linux casa-desktop 3.11.0-13-generic #20-Ubuntu SMP Wed Oct 23 07:38:26 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux When I digit: lsmod Module Size Used by parport_pc 32701 0 rfcomm 69070 4 bnep 19564 2 ppdev 17671 0 ip6t_REJECT 12910 1 xt_hl 12521 6 ip6t_rt 13507 3 nf_conntrack_ipv6 18938 9 nf_defrag_ipv6 34616 1 nf_conntrack_ipv6 ipt_REJECT 12541 1 xt_LOG 17718 8 xt_limit 12711 11 xt_tcpudp 12884 32 xt_addrtype 12635 4 nf_conntrack_ipv4 15012 9 nf_defrag_ipv4 12729 1 nf_conntrack_ipv4 xt_conntrack 12760 18 ip6table_filter 12815 1 ip6_tables 27025 1 ip6table_filter nf_conntrack_netbios_ns 12665 0 nf_conntrack_broadcast 12589 1 nf_conntrack_netbios_ns nf_nat_ftp 12741 0 nf_nat 26653 1 nf_nat_ftp kvm_amd 59958 0 nf_conntrack_ftp 18608 1 nf_nat_ftp kvm 431315 1 kvm_amd nf_conntrack 91736 8 nf_nat_ftp,nf_conntrack_netbios_ns,nf_nat,xt_conntrack,nf_conntrack_broadcast,nf_conntrack_ftp,nf_conntrack_ipv4,nf_conntrack_ipv6 iptable_filter 12810 1 crct10dif_pclmul 14289 0 crc32_pclmul 13113 0 ip_tables 27239 1 iptable_filter snd_hda_codec_realtek 55704 1 ghash_clmulni_intel 13259 0 aesni_intel 55624 0 aes_x86_64 17131 1 aesni_intel snd_hda_codec_hdmi 41117 1 x_tables 34059 13 ip6table_filter,xt_hl,ip_tables,xt_tcpudp,xt_limit,xt_conntrack,xt_LOG,iptable_filter,ip6t_rt,ipt_REJECT,ip6_tables,xt_addrtype,ip6t_REJECT lrw 13257 1 aesni_intel snd_hda_intel 48171 5 gf128mul 14951 1 lrw glue_helper 13990 1 aesni_intel ablk_helper 13597 1 aesni_intel joydev 17377 0 cryptd 20329 3 ghash_clmulni_intel,aesni_intel,ablk_helper snd_hda_codec 188738 3 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_intel arc4 12608 2 snd_hwdep 13602 1 snd_hda_codec rt2800pci 18690 0 snd_pcm 102033 3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel radeon 1402449 3 rt2800lib 79963 1 rt2800pci btusb 28267 0 rt2x00pci 13287 1 rt2800pci rt2x00mmio 13603 1 rt2800pci snd_page_alloc 18710 2 snd_pcm,snd_hda_intel rt2x00lib 55238 4 rt2x00pci,rt2800lib,rt2800pci,rt2x00mmio snd_seq_midi 13324 0 mac80211 596969 3 rt2x00lib,rt2x00pci,rt2800lib snd_seq_midi_event 14899 1 snd_seq_midi ttm 83995 1 radeon snd_rawmidi 30095 1 snd_seq_midi cfg80211 479757 2 mac80211,rt2x00lib drm_kms_helper 52651 1 radeon snd_seq 61560 2 snd_seq_midi_event,snd_seq_midi bluetooth 371880 12 bnep,btusb,rfcomm microcode 23518 0 eeprom_93cx6 13344 1 rt2800pci snd_seq_device 14497 3 snd_seq,snd_rawmidi,snd_seq_midi crc_ccitt 12707 1 rt2800lib snd_timer 29433 2 snd_pcm,snd_seq snd 69141 21 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_hda_codec,snd_hda_intel,snd_seq_device,snd_seq_midi psmouse 97626 0 drm 296739 5 ttm,drm_kms_helper,radeon k10temp 13126 0 soundcore 12680 1 snd serio_raw 13413 0 i2c_algo_bit 13413 1 radeon i2c_piix4 22106 0 video 19318 0 mac_hid 13205 0 lp 17759 0 parport 42299 3 lp,ppdev,parport_pc hid_generic 12548 0 usbhid 53014 0 hid 105818 2 hid_generic,usbhid pata_acpi 13038 0 usb_storage 62062 1 r8169 67341 0 sdhci_pci 18985 0 sdhci 42630 1 sdhci_pci mii 13934 1 r8169 pata_atiixp 13242 0 ohci_pci 13561 0 ahci 25819 2 libahci 31898 1 ahci Someone can help me?

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• PeopleSoft Upgrades, Fusion, & BI for Leading European PeopleSoft Applications Customers

  - by Mark Rosenberg

  With so many industry-leading services firms around the globe managing their businesses with PeopleSoft, it’s always an adventure setting up times and meetings for us to keep in touch with them, especially those outside of North America who often do not get to join us at Oracle OpenWorld. Fortunately, during the first two weeks of May, Nigel Woodland (Oracle’s Service Industries Director for the EMEA region) and I successfully blocked off our calendars to visit seven different customers spanning four countries in Western Europe. We met executives and leaders at four Staffing industry firms, two Professional Services firms that engage in consulting and auditing, and a Financial Services firm. As we shared the latest information regarding product capabilities and plans, we also gained valuable insight into the hot technology topics facing these businesses. What we heard was both informative and inspiring, and I suspect other Oracle PeopleSoft applications customers can benefit from one or more of the following observations from our trip. Great IT Plans Get Executed When You Respect the Users Each of our visits followed roughly the same pattern. After introductions, Nigel outlined Oracle’s product and technology strategy, including a discussion of how we at Oracle invest in each layer of the “technology stack” to provide customers with unprecedented business management capabilities and choice. Then, I provided the specifics of the PeopleSoft product line’s investment strategy, detailing the dramatic number of rich usability and functionality enhancements added to release 9.1 since its general availability in 2009 and the game-changing capabilities slated for 9.2. What was most exciting about each of these discussions was that shortly after my talking about what customers can do with release 9.1 right now to drive up user productivity and satisfaction, I saw the wheels turning in the minds of our audiences. Business analyst and end user-configurable tools and technologies, such as WorkCenters and the Related Action Framework, that provide the ability to tailor a “central command center” to the exact needs of each recruiter, biller, and every other role in the organization were exactly what each of our customers had been looking for. Every one of our audiences agreed that these tools which demonstrate a respect for the user would finally help IT pole vault over the wall of resistance that users had often raised in the past. With these new user-focused capabilities, IT is positioned to definitively partner with the business, instead of drag the business along, to unlock the value of their investment in PeopleSoft. This topic of respecting the user emerged during our very first visit, which was at Vital Services Group at their Head Office “The Mill” in Manchester, England. (If you are a student of architecture and are ever in Manchester, you should stop in to see this amazingly renovated old mill building.) I had just finished explaining our PeopleSoft 9.2 roadmap, and Mike Code, PeopleSoft Systems Manager for this innovative staffing company, said, “Mark, the new features you’ve shown us in 9.1/9.2 are very relevant to our business. As we forge ahead with the 9.1 upgrade, the ability to configure a targeted user interface with WorkCenters, Related Actions, Pivot Grids, and Alerts will enable us to satisfy the business that this upgrade is for them and will deliver tangible benefits. In fact, you’ve highlighted that we need to start talking to the business to keep up the momentum to start reviewing the 9.2 upgrade after we get to 9.1, because as much as 9.1 and PeopleTools 8.52 offers, what you’ve shown us for 9.2 is what we’ve envisioned was ultimately possible with our investment in PeopleSoft applications.” We also received valuable feedback about our investment for the Staffing industry when we visited with Hans Wanders, CIO of Randstad (the second largest Staffing company in the world) in the Netherlands. After our visit, Hans noted, “It was very interesting to see how the PeopleSoft applications have developed. I was truly impressed by many of the new developments.” Hans and Mike, sincere thanks for the validation that our team’s hard work and dedication to “respecting the users” is worth the effort! Co-existence of PeopleSoft and Fusion Applications Just Makes Sense As a “product person,” one of the most rewarding things about visiting customers is that they actually want to talk to me. Sometimes, they want to discuss a product area that we need to enhance; other times, they are interested in learning how to extract more value from their applications; and still others, they want to tell me how they are using the applications to drive real value for the business. During this trip, I was very pleased to hear that several of our customers not only thought the co-existence of Fusion applications alongside PeopleSoft applications made sense in theory, but also that they were aggressively looking at how to deploy one or more Fusion applications alongside their PeopleSoft HCM and FSCM applications. The most common deployment plan in the works by three of the organizations is to upgrade to PeopleSoft 9.1 or 9.2, and then adopt one of the new Fusion HCM applications, such as Fusion Performance Management or the full suite of  Fusion Talent Management. For example, during an applications upgrade planning discussion with the staffing company Hays plc., Mark Thomas, who is Hays’ UK IT Director, commented, “We are very excited about where we can go with the latest versions of the PeopleSoft applications in conjunction with Fusion Talent Management.” Needless to say, this news was very encouraging, because it reiterated that our applications investment strategy makes good business sense for our customers. Next Generation Business Intelligence Is the Key to the Future The third, and perhaps most exciting, lesson I learned during this journey is that our audiences already know that the latest generation of Business Intelligence technologies will be the “secret sauce” for organizations to transform business in radical ways. While a number of the organizations we visited on the trip have deployed or are deploying Oracle Business Intelligence Enterprise Edition and the associated analytics applications to provide dashboards of easy-to-understand, user-configurable metrics that help optimize business performance according to current operating procedures, what’s most exciting to them is being able to use Business Intelligence to change the way an organization does business, grows revenue, and makes a profit. In particular, several executives we met asked whether we can help them minimize the need to have perfectly structured data and at the same time generate analytics that improve order fulfillment decision-making. To them, the path to future growth lies in having the ability to analyze unstructured data rapidly and intuitively and leveraging technology’s ability to detect patterns that a human cannot reasonably be expected to see. For illustrative purposes, here is a good example of a business problem where analyzing a combination of structured and unstructured data can produce better results. If you have a resource manager trying to decide which person would be the best fit for an assignment in terms of ensuring (a) client satisfaction, (b) the individual’s satisfaction with the work, (c) least travel distance, and (d) highest margin, you traditionally compare resource qualifications to assignment needs, calculate margins on past work with the client, and measure distances. To perform these comparisons, you are likely to need the organization to have profiles setup, people ranked against profiles, margin targets setup, margins measured, distances setup, distances measured, and more. As you can imagine, this requires organizations to plan and implement data setup, capture, and quality management initiatives to ensure that dependable information is available to support resourcing analysis and decisions. In the fast-paced, tight-budget world in which most organizations operate today, the effort and discipline required to maintain high-quality, structured data like those described in the above example are certainly not desirable and in some cases are not feasible. You can imagine how intrigued our audiences were when I informed them that we are ready to help them analyze volumes of unstructured data, detect trends, and produce recommendations. Our discussions delved into examples of how the firms could leverage Oracle’s Secure Enterprise Search and Endeca technologies to keyword search against, compare, and learn from unstructured resource and assignment data. We also considered examples of how they could employ Oracle Real-Time Decisions to generate statistically significant recommendations based on similar resourcing scenarios that have produced the desired satisfaction and profit margin results. --- Although I had almost no time for sight-seeing during this trip to Europe, I have to say that it may have been one of the most energizing and engaging trips of my career. Showing these dedicated customers how they can give every user a uniquely tailored set of tools and address business problems in ways that have to date been impossible made the journey across the Atlantic more than worth it. If any of these three topics intrigue you, I’d recommend you contact your Oracle applications representative to arrange for more detailed discussions with the appropriate members of our organization.

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• Azure, don't give me multiple VMs, give me one elastic VM

  - by FransBouma

  Yesterday, Microsoft revealed new major features for Windows Azure (see ScottGu's post). It all looks shiny and great, but after reading most of the material describing the new features, I still find the overall idea behind all of it flawed: why should I care on how much VMs my web app runs? Isn't that a problem to solve for the Windows Azure engineers / software? And what if I need the file system, why can't I simply get a virtual filesystem ? To illustrate my point, let's use a real example: a product website with a customer system/database and next to it a support site with accompanying database. Both are written in .NET, using ASP.NET and use a SQL Server database each. The product website offers files to download by customers, very simple. You have a couple of options to host these websites: Buy a server, place it in a rack at an ISP and run the sites on that server Use 'shared hosting' with an ISP, which means your sites' appdomains are running on the same machine, as well as the files stored, and the databases are hosted in the same server as the other shared databases. Hire a VM, install your OS of choice at an ISP, and host the sites on that VM, basically the same as the first option, except you don't have a physical server At some cloud-vendor, either host the sites 'shared' or in a VM. See above. With all of those options, scalability is a problem, even the cloud-based ones, though not due to the same reasons: The physical server solution has the obvious problem that if you need more power, you need to buy a bigger server or more servers which requires you to add replication and other overhead Shared hosting solutions are almost always capped on memory usage / traffic and database size: if your sites get too big, you have to move out of the shared hosting environment and start over with one of the other solutions The VM solution, be it a VM at an ISP or 'in the cloud' at e.g. Windows Azure or Amazon, in theory allows scaling out by simply instantiating more VMs, however that too introduces the same overhead problems as with the physical servers: suddenly more than 1 instance runs your sites. If a cloud vendor offers its services in the form of VMs, you won't gain much over having a VM at some ISP: the main problems you have to work around are still there: when you spin up more than one VM, your application must be completely stateless at any moment, including the DB sub system, because what's in memory in instance 1 might not be in memory in instance 2. This might sounds trivial but it's not. A lot of the websites out there started rather small: they were perfectly runnable on a single machine with normal memory and CPU power. After all, you don't need a big machine to run a website with even thousands of users a day. Moving these sites to a multi-VM environment will cause a problem: all the in-memory state they use, all the multi-page transitions they use while keeping state across the transition, they can't do that anymore like they did that on a single machine: state is something of the past, you have to store every byte of state in either a DB or in a viewstate or in a cookie somewhere so with the next request, all state information is available through the request, as nothing is kept in-memory. Our example uses a bunch of files in a file system. Using multiple VMs will require that these files move to a cloud storage system which is mounted in each VM so we don't have to store the files on each VM. This might require different file paths, but this change should be minor. What's perhaps less minor is the maintenance procedure in place on the new type of cloud storage used: instead of ftp-ing into a VM, you might have to update the files using different ways / tools. All in all this makes moving an existing website which was written for an environment that's based around a VM (namely .NET with its CLR) overly cumbersome and problematic: it forces you to refactor your website system to be able to be used 'in the cloud', which is caused by the limited way how e.g. Windows Azure offers its cloud services: in blocks of VMs. Offer a scalable, flexible VM which extends with my needs Instead, cloud vendors should offer simply one VM to me. On that VM I run the websites, store my DB and my files. As it's a virtual machine, how this machine is actually ran on physical hardware (e.g. partitioned), I don't care, as that's the problem for the cloud vendor to solve. If I need more resources, e.g. I have more traffic to my server, way more visitors per day, the VM stretches, like I bought a bigger box. This frees me from the problem which comes with multiple VMs: I don't have any refactoring to do at all: I can simply build my website as if it runs on my local hardware server, upload it to the VM offered by the cloud vendor, install it on the VM and I'm done. "But that might require changes to windows!" Yes, but Microsoft is Windows. Windows Azure is their service, they can make whatever change to what they offer to make it look like it's windows. Yet, they're stuck, like Amazon, in thinking in VMs, which forces developers to 'think ahead' and gamble whether they would need to migrate to a cloud with multiple VMs in the future or not. Which comes down to: gamble whether they should invest time in code / architecture which they might never need. (YAGNI anyone?) So the VM we're talking about, is that a low-level VM which runs a guest OS, or is that VM a different kind of VM? The flexible VM: .NET's CLR ? My example websites are ASP.NET based, which means they run inside a .NET appdomain, on the .NET CLR, which is a VM. The only physical OS resource the sites need is the file system, however this too is accessed through .NET. In short: all the websites see is what .NET allows the websites to see, the world as the websites know it is what .NET shows them and lets them access. How the .NET appdomain is run physically, that's the concern of .NET, not mine. This begs the question why Windows Azure doesn't offer virtual appdomains? Or better: .NET environments which look like one machine but could be physically multiple machines. In such an environment, no change has to be made to the websites to migrate them from a local machine or own server to the cloud to get proper scaling: the .NET VM will simply scale with the need: more memory needed, more CPU power needed, it stretches. What it offers to the application running inside the appdomain is simply increasing, but not fragmented: all resources are available to the application: this means that the problem of how to scale is back to where it should be: with the cloud vendor. "Yeah, great, but what about the databases?" The .NET application communicates with the database server through a .NET ADO.NET provider. Where the database is located is not a problem of the appdomain: the ADO.NET provider has to solve that. I.o.w.: we can host the databases in an environment which offers itself as a single resource and is accessible through one connection string without replication overhead on the outside, and use that environment inside the .NET VM as if it was a single DB. But what about memory replication and other problems? This environment isn't simple, at least not for the cloud vendor. But it is simple for the customer who wants to run his sites in that cloud: no work needed. No refactoring needed of existing code. Upload it, run it. Perhaps I'm dreaming and what I described above isn't possible. Yet, I think if cloud vendors don't move into that direction, what they're offering isn't interesting: it doesn't solve a problem at all, it simply offers a way to instantiate more VMs with the guest OS of choice at the cost of me needing to refactor my website code so it can run in the straight jacket form factor dictated by the cloud vendor. Let's not kid ourselves here: most of us developers will never build a website which needs a truck load of VMs to run it: almost all websites created by developers can run on just a few VMs at most. Yet, the most expensive change is right at the start: moving from one to two VMs. As soon as you have refactored your website code to run across multiple VMs, adding another one is just as easy as clicking a mouse button. But that first step, that's the problem here and as it's right there at the beginning of scaling the website, it's particularly strange that cloud vendors refuse to solve that problem and leave it to the developers to solve that. Which makes migrating 'to the cloud' particularly expensive.

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• Rockmelt, the technology adoption model, and Facebook's spare internet

  - by Roger Hart

  Regardless of how good it is, you'd have to have a heart of stone not to make snide remarks about Rockmelt. After all, on the surface it looks a lot like some people spent two years building a browser instead of just bashing out a Chrome extension over a wet weekend. It probably does some more stuff. I don't know for sure because artificial scarcity is cool, apparently, so the "invitation" is still in the post*. I may in fact never know for sure, because I'm not wild about Facebook sign-in as a prerequisite for anything. From the video, and some initial reviews, my early reaction was: I have a browser, I have a Twitter client; what on earth is this for? The answer, of course, is "not me". Rockmelt is, in a way, quite audacious. Oh, sure, on launch day it's Bay Area bar-chat for the kids with no lenses in their retro specs and trousers that give you deep-vein thrombosis, but it's not really about them. Likewise,  Facebook just launched Google Wave, or something. And all the tech snobbery and scorn packed into describing it that way is irrelevant next to what they're doing with their platform. Here's something I drew in MS Paint** because I don't want to get sued: (see: The technology adoption lifecycle) A while ago in the Guardian, John Lanchester dusted off the idiom that "technology is stuff that doesn't work yet". The rest of the article would be quite interesting if it wasn't largely about MySpace, and he's sort of got a point. If you bolt on the sentiment that risk-averse businessmen like things that work, you've got the essence of Crossing the Chasm. Products for the mainstream market don't look much like technology. Think for  a second about early (1980s ish) hi-fi systems, with all the knobs and fiddly bits, their ostentatious technophile aesthetic. Then consider their sleeker and less (or at least less conspicuously) functional successors in the 1990s. The theory goes that innovators and early adopters like technology, it's a hobby in itself. The rest of the humans seem to like magic boxes with very few buttons that make stuff happen and never trouble them about why. Personally, I consider Apple's maddening insistence that iTunes is an acceptable way to move files around to be more or less morally unacceptable. Most people couldn't care less. Hence Rockmelt, and hence Facebook's continued growth. Rockmelt looks pointless to me, because I aggregate my social gubbins with Digsby, or use TweetDeck. But my use case is different and so are my enthusiasms. If I want to share photos, I'll use Flickr - but Facebook has photo sharing. If I want a short broadcast message, I'll use Twitter - Facebook has status updates. If I want to sell something with relatively little hassle, there's eBay - or Facebook marketplace. YouTube - check, FB Video. Email - messaging. Calendaring apps, yeah there are loads, or FB Events. What if I want to host a simple web page? Sure, they've got pages. Also Notes for blogging, and more games than I can count. This stuff is right there, where millions and millions of users are already, and for what they need it just works. It's not about me, because I'm not in the big juicy area under the curve. It's what 1990s portal sites could never have dreamed of achieving. Facebook is AOL on speed, crack, and some designer drugs it had specially imported from the future. It's a n00b-friendly gateway to the internet that just happens to serve up all the things you want to do online, right where you are. Oh, and everybody else is there too. The price of having all this and the social graph too is that you have all of this, and the social graph too. But plenty of folks have more incisive things to say than me about the whole privacy shebang, and it's not really what I'm talking about. Facebook is maintaining a vast, and fairly fully-featured training-wheels internet. And it makes up a large proportion of the online experience for a lot of people***. It's the entire web (2.0?) experience for the early and late majority. And sure, no individual bit of it is quite as slick or as fully-realised as something like Flickr (which wows me a bit every time I use it. Those guys are good at the web), but it doesn't have to be. It has to be unobtrusively good enough for the regular humans. It has to not feel like technology. This is what Rockmelt sort of is. You're online, you want something nebulously social, and you don't want to faff about with, say, Twitter clients. Wow! There it is on a really distracting sidebar, right in your browser. No effort! Yeah - fish nor fowl, much? It might work, I guess. There may be a demographic who want their social web experience more simply than tech tinkering, and who aren't just getting it from Facebook (or, for that matter, mobile devices). But I'd be surprised. Rockmelt feels like an attempt to grab a slice of Facebook-style "Look! It's right here, where you already are!", but it's still asking the mature market to install a new browser. Presumably this is where that Facebook sign-in predicate comes in handy, though it'll take some potent awareness marketing to make it fly. Meanwhile, Facebook quietly has the entire rest of the internet as a product management resource, and can continue to give most of the people most of what they want. Something that has not gone un-noticed in its potential to look a little sinister. But heck, they might even make Google Wave popular.     *This was true last week when I drafted this post. I got an invite subsequently, hence the screenshot. **MS Paint is no fun any more. It's actually good in Windows 7. Farewell ironically-shonky diagrams. *** It's also behind a single sign-in, lending a veneer of confidence, and partially solving the problem of usernames being crummy unique identifiers. I'll be blogging about that at some point.

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• techniques for an AI for a highly cramped turn-based tactics game

  - by Adam M.

  I'm trying to write an AI for a tactics game in the vein of Final Fantasy Tactics or Vandal Hearts. I can't change the game rules in any way, only upgrade the AI. I have experience programming AI for classic board games (basically minimax and its variants), but I think the branching factor is too great for the approach to be reasonable here. I'll describe the game and some current AI flaws that I'd like to fix. I'd like to hear ideas for applicable techniques. I'm a decent enough programmer, so I only need the ideas, not an implementation (though that's always appreciated). I'd rather not expend effort chasing (too many) dead ends, so although speculation and brainstorming are good and probably helpful, I'd prefer to hear from somebody with actual experience solving this kind of problem. For those who know it, the game is the land battle mini-game in Sid Meier's Pirates! (2004) and you can skim/skip the next two paragraphs. For those who don't, here's briefly how it works. The battle is turn-based and takes place on a 16x16 grid. There are three terrain types: clear (no hindrance), forest (hinders movement, ranged attacks, and sight), and rock (impassible, but does not hinder attacks or sight). The map is randomly generated with roughly equal amounts of each type of terrain. Because there are many rock and forest tiles, movement is typically very cramped. This is tactically important. The terrain is not flat; higher terrain gives minor bonuses. The terrain is known to both sides. The player is always the attacker and the AI is always the defender, so it's perfectly valid for the AI to set up a defensive position and just wait. The player wins by killing all defenders or by getting a unit to the city gates (a tile on the other side of the map). There are very few units on each side, usually 4-8. Because of this, it's crucial not to take damage without gaining some advantage from it. Units can take multiple actions per turn. All units on one side move before any units on the other side. Order of execution is important, and interleaving of actions between units is often useful. Units have melee and ranged attacks. Melee attacks vary widely in strength; ranged attacks have the same strength but vary in range. The main challenges I face are these: Lots of useful move combinations start with a "useless" move that gains no immediate advantage, or even loses advantage, in order to set up a powerful flank attack in the future. And, since the player units are stronger and have longer range, the AI pretty much always has to take some losses before they can start to gain kills. The AI must be able to look ahead to distinguish between sacrificial actions that provide a future benefit and those that don't. Because the terrain is so cramped, most of the tactics come down to achieving good positioning with multiple units that work together to defend an area. For instance, two defenders can often dominate a narrow pass by positioning themselves so an enemy unit attempting to pass must expose itself to a flank attack. But one defender in the same pass would be useless, and three units can defend a slightly larger pass. Etc. The AI should be able to figure out where the player must go to reach the city gates and how to best position its few units to cover the approaches, shifting, splitting, or combining them appropriately as the player moves. Because flank attacks are extremely deadly (and engineering flank attacks is key to the player strategy), the AI should be competent at moving its units so that they cover each other's flanks unless the sacrifice of a unit would give a substantial benefit. They should also be able to force flank attacks on players, for instance by threatening a unit from two different directions such that responding to one threat exposes the flank to the other. The AI should attack if possible, but sometimes there are no good ways to approach the player's position. In that case, the AI should be able to recognize this and set up a defensive position of its own. But the AI shouldn't be vulnerable to a trivial exploit where the player repeatedly opens and closes a hole in his defense and shoots at the AI as it approaches and retreats. That is, the AI should ideally be able to recognize that the player is capable of establishing a solid defense of an area, even if the defense is not currently in place. (I suppose if a good unit allocation algorithm existed, as needed for the second bullet point, the AI could run it on the player units to see where they could defend.) Because it's important to choose a good order of action and interleave actions between units, it's not as simple as just finding the best move for each unit in turn. All of these can be accomplished with a minimax search in theory, but the search space is too large, so specialized techniques are needed. I thought about techniques such as influence mapping, but I don't see how to use the technique to great effect. I thought about assigning goals to the units. This can help them work together in some limited way, and the problem of "how do I accomplish this goal?" is easier to solve than "how do I win this battle?", but assigning good goals is a hard problem in itself, because it requires knowing whether the goal is achievable and whether it's a good use of resources. So, does anyone have specific ideas for techniques that can help cleverize this AI? Update: I found a related question on Stackoverflow: http://stackoverflow.com/questions/3133273/ai-for-a-final-fantasy-tactics-like-game The selected answer gives a decent approach to choosing between alternative actions, but it doesn't seem to have much ability to look into the future and discern beneficial sacrifices from wasteful ones. It also focuses on a single unit at a time and it's not clear how it could be extended to support cooperation between units in defending or attacking.

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• SQL SERVER – Weekly Series – Memory Lane – #048

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Order of Result Set of SELECT Statement on Clustered Indexed Table When ORDER BY is Not Used Above theory is true in most of the cases. However SQL Server does not use that logic when returning the resultset. SQL Server always returns the resultset which it can return fastest.In most of the cases the resultset which can be returned fastest is the resultset which is returned using clustered index. Effect of TRANSACTION on Local Variable – After ROLLBACK and After COMMIT One of the Jr. Developer asked me this question (What will be the Effect of TRANSACTION on Local Variable – After ROLLBACK and After COMMIT?) while I was rushing to an important meeting. I was getting late so I asked him to talk with his Application Tech Lead. When I came back from meeting both of them were looking for me. They said they are confused. I quickly wrote down following example for them. 2008 SQL SERVER – Guidelines and Coding Standards Complete List Download Coding standards and guidelines are very important for any developer on the path of a successful career. A coding standard is a set of guidelines, rules and regulations on how to write code. Coding standards should be flexible enough or should take care of the situation where they should not prevent best practices for coding. They are basically the guidelines that one should follow for better understanding. Download Guidelines and Coding Standards complete List Download Get Answer in Float When Dividing of Two Integer Many times we have requirements of some calculations amongst different fields in Tables. One of the software developers here was trying to calculate some fields having integer values and divide it which gave incorrect results in integer where accurate results including decimals was expected. Puzzle – Computed Columns Datatype Explanation SQL Server automatically does a cast to the data type having the highest precedence. So the result of INT and INT will be INT, but INT and FLOAT will be FLOAT because FLOAT has a higher precedence. If you want a different data type, you need to do an EXPLICIT cast. Renaming SP is Not Good Idea – Renaming Stored Procedure Does Not Update sys.procedures I have written many articles about renaming a tables, columns and procedures SQL SERVER – How to Rename a Column Name or Table Name, here I found something interesting about renaming the stored procedures and felt like sharing it with you all. The interesting fact is that when we rename a stored procedure using SP_Rename command, the Stored Procedure is successfully renamed. But when we try to test the procedure using sp_helptext, the procedure will be having the old name instead of new names. 2009 Insert Values of Stored Procedure in Table – Use Table Valued Function It is clear from the result set that , where I have converted stored procedure logic into the table valued function, is much better in terms of logic as it saves a large number of operations. However, this option should be used carefully. The performance of the stored procedure is “usually” better than that of functions. Interesting Observation – Index on Index View Used in Similar Query Recently, I was working on an optimization project for one of the largest organizations. While working on one of the queries, we came across a very interesting observation. We found that there was a query on the base table and when the query was run, it used the index, which did not exist in the base table. On careful examination, we found that the query was using the index that was on another view. This was very interesting as I have personally never experienced a scenario like this. In simple words, “Query on the base table can use the index created on the indexed view of the same base table.” Interesting Observation – Execution Plan and Results of Aggregate Concatenation Queries Working with SQL Server has never seemed to be monotonous – no matter how long one has worked with it. Quite often, I come across some excellent comments that I feel like acknowledging them as blog posts. Recently, I wrote an article on SQL SERVER – Execution Plan and Results of Aggregate Concatenation Queries Depend Upon Expression Location, which is well received in the community. 2010 I encourage all of you to go through complete series and write your own on the subject. If you write an article and send it to me, I will publish it on this blog with due credit to you. If you write on your own blog, I will update this blog post pointing to your blog post. SQL SERVER – ORDER BY Does Not Work – Limitation of the View 1 SQL SERVER – Adding Column is Expensive by Joining Table Outside View – Limitation of the View 2 SQL SERVER – Index Created on View not Used Often – Limitation of the View 3 SQL SERVER – SELECT * and Adding Column Issue in View – Limitation of the View 4 SQL SERVER – COUNT(*) Not Allowed but COUNT_BIG(*) Allowed – Limitation of the View 5 SQL SERVER – UNION Not Allowed but OR Allowed in Index View – Limitation of the View 6 SQL SERVER – Cross Database Queries Not Allowed in Indexed View – Limitation of the View 7 SQL SERVER – Outer Join Not Allowed in Indexed Views – Limitation of the View 8 SQL SERVER – SELF JOIN Not Allowed in Indexed View – Limitation of the View 9 SQL SERVER – Keywords View Definition Must Not Contain for Indexed View – Limitation of the View 10 SQL SERVER – View Over the View Not Possible with Index View – Limitations of the View 11 2011 Startup Parameters Easy to Configure If you are a regular reader of this blog, you must be aware that I have written about SQL Server Denali recently. Here is the quickest way to reach into the screen where we can change the startup parameters. Go to SQL Server Configuration Manager >> SQL Server Services >> Right Click on the Server >> Properties >> Startup Parameters 2012 Validating Unique Columnname Across Whole Database I sometimes come across very strange requirements and often I do not receive a proper explanation of the same. Here is the one of those examples. For example “Our business requirement is when we add new column we want it unique across current database.” Read the solution to this strange request in this blog post. Excel Losing Decimal Values When Value Pasted from SSMS ResultSet It is very common when users are coping the resultset to Excel, the floating point or decimals are missed. The solution is very much simple and it requires a small adjustment in the Excel. By default Excel is very smart and when it detects the value which is getting pasted is numeric it changes the column format to accommodate that. Basic Calculation and PEMDAS Order of Operation Read this interesting blog post for fantastic conversation about the subject. Copy Column Headers from Resultset – SQL in Sixty Seconds #027 – Video http://www.youtube.com/watch?v=x_-3tLqTRv0 Delete From Multiple Table – Update Multiple Table in Single Statement There are two questions which I get every single day multiple times. In my gmail, I have created standard canned reply for them. Let us see the questions here. I want to delete from multiple table in a single statement how will I do it? I want to update multiple table in a single statement how will I do it? Read the answer in the blog post. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• IntelliSense for Razor Hosting in non-Web Applications

  - by Rick Strahl

  When I posted my Razor Hosting article a couple of weeks ago I got a number of questions on how to get IntelliSense to work inside of Visual Studio while editing your templates. The answer to this question is mainly dependent on how Visual Studio recognizes assemblies, so a little background is required. If you open a template just on its own as a standalone file by clicking on it say in Explorer, Visual Studio will open up with the template in the editor, but you won’t get any IntelliSense on any of your related assemblies that you might be using by default. It’ll give Intellisense on base System namespace, but not on your imported assembly types. This makes sense: Visual Studio has no idea what the assembly associations for the single file are. There are two options available to you to make IntelliSense work for templates: Add the templates as included files to your non-Web project Add a BIN folder to your template’s folder and add all assemblies required there Including Templates in your Host Project By including templates into your Razor hosting project, Visual Studio will pick up the project’s assembly references and make IntelliSense available for any of the custom types in your project and on your templates. To see this work I moved the \Templates folder from the samples from the Debug\Bin folder into the project root and included the templates in the WinForm sample project. Here’s what this looks like in Visual Studio after the templates have been included:   Notice that I take my original example and type cast the Context object to the specific type that it actually represents – namely CustomContext – by using a simple code block: @{ CustomContext Model = Context as CustomContext; } After that assignment my Model local variable is in scope and IntelliSense works as expected. Note that you also will need to add any namespaces with the using command in this case: @using RazorHostingWinForm which has to be defined at the very top of a Razor document. BTW, while you can only pass in a single Context 'parameter’ to the template with the default template I’ve provided realize that you can also assign a complex object to Context. For example you could have a container object that references a variety of other objects which you can then cast to the appropriate types as needed: @{ ContextContainer container = Context as ContextContainer; CustomContext Model = container.Model; CustomDAO DAO = container.DAO; } and so forth. IntelliSense for your Custom Template Notice also that you can get IntelliSense for the top level template by specifying an inherits tag at the top of the document: @inherits RazorHosting.RazorTemplateFolderHost By specifying the above you can then get IntelliSense on your base template’s properties. For example, in my base template there are Request and Response objects. This is very useful especially if you end up creating custom templates that include your custom business objects as you can get effectively see full IntelliSense from the ‘page’ level down. For Html Help Builder for example, I’d have a Help object on the page and assuming I have the references available I can see all the way into that Help object without even having to do anything fancy. Note that the @inherits key is a GREAT and easy way to override the base template you normally specify as the default template. It allows you to create a custom template and as long as it inherits from the base template it’ll work properly. Since the last post I’ve also made some changes in the base template that allow hooking up some simple initialization logic so it gets much more easy to create custom templates and hook up custom objects with an IntializeTemplate() hook function that gets called with the Context and a Configuration object. These objects are objects you can pass in at runtime from your host application and then assign to custom properties on your template. For example the default implementation for RazorTemplateFolderHost does this: public override void InitializeTemplate(object context, object configurationData) { // Pick up configuration data and stuff into Request object RazorFolderHostTemplateConfiguration config = configurationData as RazorFolderHostTemplateConfiguration; this.Request.TemplatePath = config.TemplatePath; this.Request.TemplateRelativePath = config.TemplateRelativePath; // Just use the entire ConfigData as the model, but in theory // configData could contain many objects or values to set on // template properties this.Model = config.ConfigData as TModel; } to set up a strongly typed Model and the Request object. You can do much more complex hookups here of course and create complex base template pages that contain all the objects that you need in your code with strong typing. Adding a Bin folder to your Template’s Root Path Including templates in your host project works if you own the project and you’re the only one modifying the templates. However, if you are distributing the Razor engine as a templating/scripting solution as part of your application or development tool the original project is likely not available and so that approach is not practical. Another option you have is to add a Bin folder and add all the related assemblies into it. You can also add a Web.Config file with assembly references for any GAC’d assembly references that need to be associated with the templates. Between the web.config and bin folder Visual Studio can figure out how to provide IntelliSense. The Bin folder should contain: The RazorHosting.dll Your host project’s EXE or DLL – renamed to .dll if it’s an .exe Any external (bin folder) dependent assemblies Note that you most likely also want a reference to the host project if it contains references that are going to be used in templates. Visual Studio doesn’t recognize an EXE reference so you have to rename the EXE to DLL to make it work. Apparently the binary signature of EXE and DLL files are identical and it just works – learn something new everyday… For GAC assembly references you can add a web.config file to your template root. The Web.config file then should contain any full assembly references to GAC components: <configuration> <system.web> <compilation debug="true"> <assemblies> <add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> <add assembly="System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" /> <add assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> </assemblies> </compilation> </system.web> </configuration> And with that you should get full IntelliSense. Note that if you add a BIN folder and you also have the templates in your Visual Studio project Visual Studio will complain about reference conflicts as it’s effectively seeing both the project references and the ones in the bin folder. So it’s probably a good idea to use one or the other but not both at the same time :-) Seeing IntelliSense in your Razor templates is a big help for users of your templates. If you’re shipping an application level scripting solution especially it’ll be real useful for your template consumers/users to be able to get some quick help on creating customized templates – after all that’s what templates are all about – easy customization. Making sure that everything is referenced in your bin folder and web.config is a good idea and it’s great to see that Visual Studio (and presumably WebMatrix/Visual Web Developer as well) will be able to pick up your custom IntelliSense in Razor templates.© Rick Strahl, West Wind Technologies, 2005-2011Posted in Razor  

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• Personal Development : Time, Planning , Repairs & Maintenance

  - by Rajesh Pillai

  Personal Development : Time, Planning, Repairs & Maintenance These are just my thoughts, but some you may find something interesting in it. Please think over it. We may know many things, but still we always keeps procrastinating it. I have written this as I have heard many people coming back and saying they don’t have time to do things they like. These are my thoughts buy may be useful to someone else too. Certain things in life needs periodic repairs and maintenance. To cite some examples , your CAR, your HOUSE, your personal laptop/desktop, your health etc. Likewise there are certain other things in professional life that requires repair/ maintenance /or some kind of polishing, so that you always stay on top of it. But they are not always obvious. Some of them are - Improving your communication skills - Increasing your vocabulary - Upgrading your technical skills - Pursuing your hobby - Increasing your knowledge/awareness etc… etc… And then there are certain things that we are always short of…. one is TIME. We all know TIME is one of the most precious things in life and yet we all are very miserable at managing it. Remember you can only manage it and not control it. You can only control which you own or which you create. In theory time is infinite. So, there should be abundant of it. But remember one thing, you know this, it’s not reversible. Once it has elapsed you cannot live it again. Think over it. So, how do find that golden 25th hour every day. To find the 25th hour you need to reflect back on your current daily activities. Analyze them and see where you are spending most of your time and is it really important. Even the 8 hours that you spent in the office, is it spent fruitfully. At the end of the day is the 8 precious hour that you spent was worth it. Just reflect back on your activities. Did you learn something? If yes did you make a point to NOTE IT. If you didn’t NOTED it then was the time you spent really worth it. Just ponder over it. Some calculations of your daily activities where most of the time is spent. Let’s start (in no particular order though) - Sleep (6.5 hours) [Remember you only require 6 good hours of sleep every day]. Some may thing it is 8, but it’s a myth.   o To achive 6 hours of sleep and be in good health you can practice 15 minutes of daily meditation. So effectively you can    round it to 6.5 hours. - Morning chores(2 hours) : Some may need to prepare breakfast and all other things. - Office commuting (avg. to and fro 3 hours) - Office Work (avg 9.5 hours) Total Hours: 21 hours effective time which is spent irrespective of what you do. There may be some variations here and there. Still you have 3 hours EXTRA. Where do these 3 hours go? If you can find it, then you may get that golden 25th hour out of these 3 hours. Let’s discount 2 hours for contingencies, still you have 1 hour with you. If you can’t find it then you are living a direction less life. As you can see, the 25th Hour lies within the 24 hours of the day. It’s upto each one of us to find and make use of it. Now what can you do with that 25th hour i.e. 1 hour extra of your life. Imagine the possibility. Again some calculations 1 hour daily * 30 days = 30 hours every month 30 hours pm * 12 month = 360 hours every year. 360 hours every year seems very promising. Let’s add some contingencies, say, let’s be optimistic and say 50 % contingency. Still you have 180 hours every year. That leaves with 30 minutes every day of extra time. That’s hell a lot of time, if you could manage it. These may sound like a high talk [yes, it is, unless you apply these simple rules and rationalize your everyday living and stop procrastinating]. NOTE: I haven’t taken weekend, holidays and leaves into account. So, that leaves us with a lot of buffer time. You can meet family friends, relatives, other tasks, and yet have these 180 pure hours of joy every year. Do whatever you want to do with it. So, how important is this 180 hours per year to you? Just think over it. You may use it the way you like - 50 hours [pursue your hobby like drawing, crafting, learn dance, learn juggling, learn swimming, travelling hmm.. anything you like doing and you didn’t had time to do it.] - 30 hours you can learn a new programming language or technology (i.e. you can get comfortable with it) - 50 hours [improve existing skills] - 20 hours [improve you communication skill]. Do some light reading. - 30 hours [YOU DECIDE WHAT TO DO]? So, if you had done this for one year you would have learnt a new programming language, upgraded existing skills, improved you communication etc.. If you had done this for two years.. imagine the level of personal development or growth which you may have attained….. If you had done this for three years….. NOW I think I don’t need to mention this… So, you still have TIME, as they say TIME is infinite. So, make judicious use of this precious thing. And never ever comeback saying “I don’t have time”. So, if you are RICH in TIME, everything else will be automatically taken care of, as those things may just be a byproduct of how you spend your time… So, happy TIMING your TIME everyday.

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• Optimizing AES modes on Solaris for Intel Westmere

  - by danx

  Optimizing AES modes on Solaris for Intel Westmere Review AES is a strong method of symmetric (secret-key) encryption. It is a U.S. FIPS-approved cryptographic algorithm (FIPS 197) that operates on 16-byte blocks. AES has been available since 2001 and is widely used. However, AES by itself has a weakness. AES encryption isn't usually used by itself because identical blocks of plaintext are always encrypted into identical blocks of ciphertext. This encryption can be easily attacked with "dictionaries" of common blocks of text and allows one to more-easily discern the content of the unknown cryptotext. This mode of encryption is called "Electronic Code Book" (ECB), because one in theory can keep a "code book" of all known cryptotext and plaintext results to cipher and decipher AES. In practice, a complete "code book" is not practical, even in electronic form, but large dictionaries of common plaintext blocks is still possible. Here's a diagram of encrypting input data using AES ECB mode: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ AESKey-->(AES Encryption) AESKey-->(AES Encryption) | | | | \/ \/ CipherTextOutput CipherTextOutput Block 1 Block 2 What's the solution to the same cleartext input producing the same ciphertext output? The solution is to further process the encrypted or decrypted text in such a way that the same text produces different output. This usually involves an Initialization Vector (IV) and XORing the decrypted or encrypted text. As an example, I'll illustrate CBC mode encryption: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ IV >----->(XOR) +------------->(XOR) +---> . . . . | | | | | | | | \/ | \/ | AESKey-->(AES Encryption) | AESKey-->(AES Encryption) | | | | | | | | | \/ | \/ | CipherTextOutput ------+ CipherTextOutput -------+ Block 1 Block 2 The steps for CBC encryption are: Start with a 16-byte Initialization Vector (IV), choosen randomly. XOR the IV with the first block of input plaintext Encrypt the result with AES using a user-provided key. The result is the first 16-bytes of output cryptotext. Use the cryptotext (instead of the IV) of the previous block to XOR with the next input block of plaintext Another mode besides CBC is Counter Mode (CTR). As with CBC mode, it also starts with a 16-byte IV. However, for subsequent blocks, the IV is just incremented by one. Also, the IV ix XORed with the AES encryption result (not the plain text input). Here's an illustration: Block 1 Block 2 PlainTextInput PlainTextInput | | | | \/ \/ AESKey-->(AES Encryption) AESKey-->(AES Encryption) | | | | \/ \/ IV >----->(XOR) IV + 1 >---->(XOR) IV + 2 ---> . . . . | | | | \/ \/ CipherTextOutput CipherTextOutput Block 1 Block 2 Optimization Which of these modes can be parallelized? ECB encryption/decryption can be parallelized because it does more than plain AES encryption and decryption, as mentioned above. CBC encryption can't be parallelized because it depends on the output of the previous block. However, CBC decryption can be parallelized because all the encrypted blocks are known at the beginning. CTR encryption and decryption can be parallelized because the input to each block is known--it's just the IV incremented by one for each subsequent block. So, in summary, for ECB, CBC, and CTR modes, encryption and decryption can be parallelized with the exception of CBC encryption. How do we parallelize encryption? By interleaving. Usually when reading and writing data there are pipeline "stalls" (idle processor cycles) that result from waiting for memory to be loaded or stored to or from CPU registers. Since the software is written to encrypt/decrypt the next data block where pipeline stalls usually occurs, we can avoid stalls and crypt with fewer cycles. This software processes 4 blocks at a time, which ensures virtually no waiting ("stalling") for reading or writing data in memory. Other Optimizations Besides interleaving, other optimizations performed are Loading the entire key schedule into the 128-bit %xmm registers. This is done once for per 4-block of data (since 4 blocks of data is processed, when present). The following is loaded: the entire "key schedule" (user input key preprocessed for encryption and decryption). This takes 11, 13, or 15 registers, for AES-128, AES-192, and AES-256, respectively The input data is loaded into another %xmm register The same register contains the output result after encrypting/decrypting Using SSSE 4 instructions (AESNI). Besides the aesenc, aesenclast, aesdec, aesdeclast, aeskeygenassist, and aesimc AESNI instructions, Intel has several other instructions that operate on the 128-bit %xmm registers. Some common instructions for encryption are: pxor exclusive or (very useful), movdqu load/store a %xmm register from/to memory, pshufb shuffle bytes for byte swapping, pclmulqdq carry-less multiply for GCM mode Combining AES encryption/decryption with CBC or CTR modes processing. Instead of loading input data twice (once for AES encryption/decryption, and again for modes (CTR or CBC, for example) processing, the input data is loaded once as both AES and modes operations occur at in the same function Performance Everyone likes pretty color charts, so here they are. I ran these on Solaris 11 running on a Piketon Platform system with a 4-core Intel Clarkdale processor @3.20GHz. Clarkdale which is part of the Westmere processor architecture family. The "before" case is Solaris 11, unmodified. Keep in mind that the "before" case already has been optimized with hand-coded Intel AESNI assembly. The "after" case has combined AES-NI and mode instructions, interleaved 4 blocks at-a-time. « For the first table, lower is better (milliseconds). The first table shows the performance improvement using the Solaris encrypt(1) and decrypt(1) CLI commands. I encrypted and decrypted a 1/2 GByte file on /tmp (swap tmpfs). Encryption improved by about 40% and decryption improved by about 80%. AES-128 is slighty faster than AES-256, as expected. The second table shows more detail timings for CBC, CTR, and ECB modes for the 3 AES key sizes and different data lengths. » The results shown are the percentage improvement as shown by an internal PKCS#11 microbenchmark. And keep in mind the previous baseline code already had optimized AESNI assembly! The keysize (AES-128, 192, or 256) makes little difference in relative percentage improvement (although, of course, AES-128 is faster than AES-256). Larger data sizes show better improvement than 128-byte data. Availability This software is in Solaris 11 FCS. It is available in the 64-bit libcrypto library and the "aes" Solaris kernel module. You must be running hardware that supports AESNI (for example, Intel Westmere and Sandy Bridge, microprocessor architectures). The easiest way to determine if AES-NI is available is with the isainfo(1) command. For example, $ isainfo -v 64-bit amd64 applications pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov amd_sysc cx8 tsc fpu 32-bit i386 applications pclmulqdq aes sse4.2 sse4.1 ssse3 popcnt tscp ahf cx16 sse3 sse2 sse fxsr mmx cmov sep cx8 tsc fpu No special configuration or setup is needed to take advantage of this software. Solaris libraries and kernel automatically determine if it's running on AESNI-capable machines and execute the correctly-tuned software for the current microprocessor. Summary Maximum throughput of AES cipher modes can be achieved by combining AES encryption with modes processing, interleaving encryption of 4 blocks at a time, and using Intel's wide 128-bit %xmm registers and instructions. References "Block cipher modes of operation", Wikipedia Good overview of AES modes (ECB, CBC, CTR, etc.) "Advanced Encryption Standard", Wikipedia "Current Modes" describes NIST-approved block cipher modes (ECB,CBC, CFB, OFB, CCM, GCM)

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• Summit Time!

  - by Ajarn Mark Caldwell

  Boy, how time flies!  I can hardly believe that the 2011 PASS Summit is just one week away.  Maybe it snuck up on me because it’s a few weeks earlier than last year.  Whatever the cause, I am really looking forward to next week.  The PASS Summit is the largest SQL Server conference in the world and a fantastic networking opportunity thrown in for no additional charge.  Here are a few thoughts to help you maximize the week. Networking As Karen Lopez (blog | @DataChick) mentioned in her presentation for the Professional Development Virtual Chapter just a couple of weeks ago, “Don’t wait until you need a new job to start networking.”  You should always be working on your professional network.  Some people, especially technical-minded people, get confused by the term networking.  The first image that used to pop into my head was the image of some guy standing, awkwardly, off to the side of a cocktail party, trying to shmooze those around him.  That’s not what I’m talking about.  If you’re good at that sort of thing, and you can strike up a conversation with some stranger and learn all about them in 5 minutes, and walk away with your next business deal all but approved by the lawyers, then congratulations.  But if you’re not, and most of us are not, I have two suggestions for you.  First, register for Don Gabor’s 2-hour session on Tuesday at the Summit called Networking to Build Business Contacts.  Don is a master at small talk, and at teaching others, and in just those two short hours will help you with important tips about breaking the ice, remembering names, and smooth transitions into and out of conversations.  Then go put that great training to work right away at the Tuesday night Welcome Reception and meet some new people; which is really my second suggestion…just meet a few new people.  You see, “networking” is about meeting new people and being friendly without trying to “work it” to get something out of the relationship at this point.  In fact, Don will tell you that a better way to build the connection with someone is to look for some way that you can help them, not how they can help you. There are a ton of opportunities as long as you follow this one key point: Don’t stay in your hotel!  At the least, get out and go to the free events such as the Tuesday night Welcome Reception, the Wednesday night Exhibitor Reception, and the Thursday night Community Appreciation Party.  All three of these are perfect opportunities to meet other professionals with a similar job or interest as you, and you never know how that may help you out in the future.  Maybe you just meet someone to say HI to at breakfast the next day instead of eating alone.  Or maybe you cross paths several times throughout the Summit and compare notes on different sessions you attended.  And you just might make new friends that you look forward to seeing year after year at the Summit.  Who knows, it might even turn out that you have some specific experience that will help out that other person a few months’ from now when they run into the same challenge that you just overcame, or vice-versa.  But the point is, if you don’t get out and meet people, you’ll never have the chance for anything else to happen in the future. One more tip for shy attendees of the Summit…if you can’t bring yourself to strike up conversation with strangers at these events, then at the least, after you sit through a good session that helps you out, go up to the speaker and introduce yourself and thank them for taking the time and effort to put together their presentation.  Ideally, when you do this, tell them WHY it was beneficial to you (e.g. “Now I have a new idea of how to tackle a problem back at the office.”)  I know you think the speakers are all full of confidence and are always receiving a ton of accolades and applause, but you’re wrong.  Most of them will be very happy to hear first-hand that all the work they put into getting ready for their presentation is paying off for somebody. Training With over 170 technical sessions at the Summit, training is what it’s all about, and the training is fantastic!  Of course there are the big-name trainers like Paul Randall, Kimberly Tripp, Kalen Delaney, Itzik Ben-Gan and several others, but I am always impressed by the quality of the training put on by so many other “regular” members of the SQL Server community.  It is amazing how you don’t have to be a published author or otherwise recognized as an “expert” in an area in order to make a big impact on others just by sharing your personal experience and lessons learned.  I would rather hear the story of, and lessons learned from, “some guy or gal” who has actually been through an issue and came out the other side, than I would a trained professor who is speaking just from theory or an intellectual understanding of a topic. In addition to the three full days of regular sessions, there are also two days of pre-conference intensive training available.  There is an extra cost to this, but it is a fantastic opportunity.  Think about it…you’re already coming to this area for training, so why not extend your stay a little bit and get some in-depth training on a particular topic or two?  I did this for the first time last year.  I attended one day of extra training and it was well worth the time and money.  One of the best reasons for it is that I am extremely busy at home with my regular job and family, that it was hard to carve out the time to learn about the topic on my own.  It worked out so well last year that I am doubling up and doing two days or “pre-cons” this year. And then there are the DVDs.  I think these are another great option.  I used the online schedule builder to get ready and have an idea of which sessions I want to attend and when they are (much better than trying to figure this out at the last minute every day).  But the problem that I have run into (seems this happens every year) is that nearly every session block has two different sessions that I would like to attend.  And some of them have three!  ACK!  That won’t work!  What is a guy supposed to do?  Well, one option is to purchase the DVDs which are recordings of the audio and projected images from each session so you can continue to attend sessions long after the Summit is officially over.  Yes, many (possibly all) of these also get posted online and attendees can access those for no extra charge, but those are not necessarily all available as quickly as the DVD recording are, and the DVDs are often more convenient than downloading, especially if you want to share the training with someone who was not able to attend in person. Remember, I don’t make any money or get any other benefit if you buy the DVDs or from anything else that I have recommended here.  These are just my own thoughts, trying to help out based on my experiences from the 8 or so Summits I have attended.  There is nothing like the Summit.  It is an awesome experience, fantastic training, and a whole lot of fun which is just compounded if you’ll take advantage of the first part of this article and make some new friends along the way.

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• Does this prove a network bandwidth bottleneck?

  - by Yuji Tomita

  I've incorrectly assumed that my internal AB testing means my server can handle 1k concurrency @3k hits per second. My theory at at the moment is that the network is the bottleneck. The server can't send enough data fast enough. External testing from blitz.io at 1k concurrency shows my hits/s capping off at 180, with pages taking longer and longer to respond as the server is only able to return 180 per second. I've served a blank file from nginx and benched it: it scales 1:1 with concurrency. Now to rule out IO / memcached bottlenecks (nginx normally pulls from memcached), I serve up a static version of the cached page from the filesystem. The results are very similar to my original test; I'm capped at around 180 RPS. Splitting the HTML page in half gives me double the RPS, so it's definitely limited by the size of the page. If I internally ApacheBench from the local server, I get consistent results of around 4k RPS on both the Full Page and the Half Page, at high transfer rates. Transfer rate: 62586.14 [Kbytes/sec] received If I AB from an external server, I get around 180RPS - same as the blitz.io results. How do I know it's not intentional throttling? If I benchmark from multiple external servers, all results become poor which leads me to believe the problem is in MY servers outbound traffic, not a download speed issue with my benchmarking servers / blitz.io. So I'm back to my conclusion that my server can't send data fast enough. Am I right? Are there other ways to interpret this data? Is the solution/optimization to set up multiple servers + load balancing that can each serve 180 hits per second? I'm quite new to server optimization, so I'd appreciate any confirmation interpreting this data. Outbound traffic Here's more information about the outbound bandwidth: The network graph shows a maximum output of 16 Mb/s: 16 megabits per second. Doesn't sound like much at all. Due to a suggestion about throttling, I looked into this and found that linode has a 50mbps cap (which I'm not even close to hitting, apparently). I had it raised to 100mbps. Since linode caps my traffic, and I'm not even hitting it, does this mean that my server should indeed be capable of outputting up to 100mbps but is limited by some other internal bottleneck? I just don't understand how networks at this large of a scale work; can they literally send data as fast as they can read from the HDD? Is the network pipe that big? In conclusion 1: Based on the above, I'm thinking I can definitely raise my 180RPS by adding an nginx load balancer on top of a multi nginx server setup at exactly 180RPS per server behind the LB. 2: If linode has a 50/100mbit limit that I'm not hitting at all, there must be something I can do to hit that limit with my single server setup. If I can read / transmit data fast enough locally, and linode even bothers to have a 50mbit/100mbit cap, there must be an internal bottleneck that's not allowing me to hit those caps that I'm not sure how to detect. Correct? I realize the question is huge and vague now, but I'm not sure how to condense it. Any input is appreciated on any conclusion I've made.

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