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• Rackspace Cloud Sites: Compute Cycles exploding. Very expensive

  - by Jaap

  Since last week my compute cycles (CC) went through the roof (Rackspace Cloud Sites). Normally I stay under the 10,000 cycles per month . Now this month I already have more than 75,000 compute cycles. I don't have more visitors and I did not change anything in the code. I looked in the raw log files, that didn't help either... This explosion of CC already costs me more than 750 USD right now. And still counting. Anyone know what to do? I have contacted Rackspace last week. But still no solution/answer.... Looks like Rackspace is liking the money! Help! Thanks.

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• How reduce size of PPT 2010 Notes Pages PDFs?

  - by KnowItAllWannabe

  I have a PPT presentation of about 400 slides that I periodically update and publish as PDF. The view I publish is the Notes Pages. This worked fine for several years, during which time I was using PPT 2002. I recently upgraded to PPT 2010, and now I find that the PDFs I create are about 25 times bigger than they used to be, and the text in the slides part of the Notes Pages is no longer selectable in Acrobat. According to Why does Powerpoint 2010 print notes pages to PDF as raster images? , the problem is that PPT 2010 is rendering the slides' content as images, which is not what earlier versions of PPT did. The solution offered in that discussion involves Office Automation and VBA, neither of which I know anything about, and it's not clear whether that approach solves the problem of the text in the slides not being selectable in the PDF. Isn't there a simple way to get PPT 2010 to print Notes Pages to PDF the way it did in PPT 2002?

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• One-week release cycle: how do I make this feasible?

  - by Arkaaito

  At my company (3-yr-old web industry startup), we have frequent problems with the product team saying "aaaah this is a crisis patch it now!" (doesn't everybody?) This has an impact on the productivity (and morale) of engineering staff, self included. Management has spent some time thinking about how to reduce the frequency of these same-day requests and has come up with the solution that we are going to have a release every week. (Previously we'd been doing one every two weeks, which usually slipped by a couple of days or so.) There are 13 developers and 6 local / 9 offshore testers; the theory is that only 4 developers (and all testers) will work on even-numbered releases, unless a piece of work comes up that really requires some specific expertise from one of the other devs. Each cycle will contain two days of dev work and two days of QA work (plus 1 day of scoping / triage / ...). My questions are: (a) Does anyone have experience with this length of release cycle? (b) Has anyone heard of this length of release cycle even being attempted? (c) If (a) or (b), how on Earth do you make it work? (Any pitfalls to avoid, etc., are also appreciated.) (d) How can we minimize the damage if this effort fails?

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• Friday Tips #5

  - by Chris Kawalek

  Happy Friday, everyone! Following up on yesterday's post about Oracle VM VirtualBox being selected as the best virtualization solution for 2012 by the readers of Linux Journal, our Friday tip is about that very cool piece of software: Question: How do I move a VM from one machine to another with Oracle VM VirtualBox? Answer by Andy Hall, Product Management Director, Oracle Desktop Virtualization: There are a number of ways to do this, with pros and cons for each. The most reliable approach is to Export and Import virtual machines: From the VirtualBox manager, simply use the File…Export appliance menu and follow the wizard's lead. Move the resulting file(s) to the destination machine; and Import the VM into VirtualBox. This method will take longer and use more disk space than other methods because the configuration files and virtual hard drives are converted into an industry standard format (.ova or .ovf). But an advantage of this approach is that the creator of the virtual appliance can add a license which the importer will see and click-to-accept at import time. This is especially useful for ISVs looking to deliver pre-built, configured and tested appliances to their customers and prospects. Thanks Andy! Remember, if you have a question for us, use Twitter hashtag #AskOracleVirtualization. We'll see you next week! -Chris 

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• Time between AWS Notifying of Scale Down and Terminating instance

  - by SteveEdson

  Here is the scenario, there are multiple EC2 instances behind a load balancer. When traffic dies down, the SCALE_DOWN policy is triggered from a CloudWatch alarm. What I would like, is for the instance that is going to be terminated, or a separate server altogether, to be able to run a quick script that will execute a few commands to ensure all data has been transferred. My initial question was going to be how can I send a notification when an instance is going to be terminated by an auto scale, SCALE_DOWN policy. But then I saw this question Amazon EC2 notifying the instance when the autoscale service terminates it. If the notification is sent, how much time is there before the instance actually gets terminated? Are there any parameters to specify this time? Would it be a better idea to notify an instance that it is no longer needed, and get the instance to terminate itself once it has finished running the final script? Or, am I making this into a bigger problem than it actually is, and theres a far simpler solution?

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• Best Performing Remote Desktop Software for WAN

  - by Dave

  I've been tasked with connecting a computer in one of our branches in the midlands to one in south wales. We have been using windows remote desktop but find it too slow. The ADSL on the computer were connecting to is about 6Mb Download and 470Kb Upload so not majorly fast. That connection is also shared with about 10 other internet users. I'm trying to find out if the is any remote desktopn connecting software that performs better than the microsoft remote desktop software. Or, would i be better using a KVM over IP? I've looked into connecting the offices through BT's fiber optic but at £21k a year rental were trying to find a cheaper solution! Any help would be great. Thanks, Dave,

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• How to restrict HTTP Methods

  - by hemalshah

  I want to restrict HTTP methods to those required by the MOSS07 application(s) using IIS6. I am not able to find a solution after googling. Can any one help. Update this is what was written in the document IIS6 should be used to restrict HTTP methods to those required by the MOSS07 application(s). I also searched some books and saw something curious in O'Reilly's Sharepoint 2007 by James Pyles and others. There is no real suppported way to use HTTP POST and HTTP GET because of the web.config settings and the static definition of the WSDL. In the web.config <protocols> <remove name="HttpGet"> <remove name="HttpPost"> <remove name="HttpPostLocalHost"> <add name="Documentation"> </protocols> If we do this in the Web.Config file, would it solve the problem?

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• Apache doesn't autostart because vpn isn't up yet.

  - by Col. Shrapnel

  I have a FreeBSD8 server, and VPN connection to my ISP. I use mpd5 and it works fine. A have an Apache server whch works fine, if I start it manually, after VPN is get up. But when I add it to rc.conf autostart, it fail to start, saying (49) can't assign requested address: make_sock could not bind to address I suppose it's because VPN isn't up yet and no IP address assigned to the interface which i set in the Listen directive in the httpd.conf. If i set Listen to the existing 127.0.0.1, it fail to serve wan requests. Is there a solution, either to delay apache autostart or configure it some different?

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• 3 Monitors 2 different graphic cards

  - by Michael

  I am looking to add a third monitor to my workstation. I currently have 2 monitors connected to a geforce gt 120. I am wanting to find the cheapest solution on adding another monitor, I have a old ati x300 laying around and wanting to know if I would be able to use that to power the other monitor and if it would conflict with my other graphic card (I am not a gamer). What I want to do is have the at x300 power 1 monitor via dvi and the gt 120 power 2 monitors via vga and dvi. Thanks edit: im running windows 7 64bit

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• Top tweets SOA Partner Community – November 2012

  - by JuergenKress

  Dear SOA partner community member Too many different product from Oracle, no idea how do they fit together? Get a copy of the Oracle catalog, an excellent overview of the Oracle middleware portfolio. BPM is a key solution to this portfolio. To position BPM to your customers you can find many use case ideas in the paper BPM 11g Patterns and industry specific value propositions for Financial Services & Insurance & Retail. Many more Process Accelerators (11.1.1.6.2) have become available. It is an excellent demo and starting point for BPM projects. Our SOA Suite team published the most important OOW presentation at the OTN website. The Oracle SOA proactive support team is running a series of blog posts about SOA and JMS Introductory. To become an expert in SOA, Bob highlighted the latest list of SOA books. For OSB projects we recommend the EAIESB OSB poster. Thanks to all the experts who contributed and shared their SOA & BPM knowledge this month again. Please feel free to send us the link to your blog post via twitter @soacommunity: Undeploy multiple SOA composites with WLST or ANT by Danilo Schmiedel Fault Handling Slides and Q&A by Vennester Installing Oracle Event Processing 11g by Antoney Reynolds Expanding the Oracle Enterprise Repository with functional documentation by Marc Kuijpers Build Mobile App for E-Business Suite Using SOA Suite and ADF Mobile By Michelle Kimihira A brief note for customers running SOA Suite on AIX platforms By Christian ACM - Adaptive Case Management by Peter Paul BPM 11g - Dynamic Task Assignment with Multi-level Organization Units By Mark Foster Oracle Real User Experience Insight: Oracle's Approach to User Experience Hope to see you at the Middleware Day at UK Oracle User Group Conference 2012 in Birmingham. Jürgen Kress Oracle SOA & BPM Partner Adoption EMEA To read the newsletter please visit http://tinyurl.com/soanewsNovember2012 (OPN Account required) To become a member of the SOA Partner Community please register at http://www.oracle.com/goto/emea/soa (OPN account required) If you need support with your account please contact the Oracle Partner Business Center. Blog Twitter LinkedIn Mix Forum Technorati Tags: SOA Community newsletter,SOA Community,Oracle SOA,Oracle BPM,BPM Community,OPN,Jürgen Kress

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• SharePoint Unit Testing and Load Testing Finally?

  - by Kit Ong

  It has always been a real pain to incorporate extensive SharePoint Unit Testing and Load Testing in a project, could Visual Studio 2012 finally make this easier? It certaining looks like it, here's a brief overview on SharePoint support in Visual Studio 2012. Load testing – We now support load testing for SharePoint out of the box. This is more involved than you might imagine due to how dynamic SharePoint is. You can’t just record a script and play it back – it won’t work because SharePoint generates and expects dynamic data (like GUIDs). We’ve built the extensions to our load testing solution to parse the dynamic SharePoint data and include it appropriately in subsequent requests. So now you can record a script and play it back and we will dynamically adjust it to match what SharePoint expects.Unit testing – One of the big problems with unit testing SharePoint is that most code requires SharePoint to be running and trying to run tests against a live SharePoint instance is a pain. So we’ve built a SharePoint “emulator” using our new VS 2012 Fakes & Stubs capability. This will make unit testing of SharePoint components WAY easier.Read more in the link belowhttp://blogs.msdn.com/b/bharry/archive/2012/09/12/visual-studio-update-this-fall.aspx

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• Setting jQuery after ASP.net AJAX partial post back

  - by Steve Clements

  OK, so for some reason you have a mega mashup solution with ASP.net AJAX, jQuery and web forms.  Perhaps you are just on the migration from AjaxControlToolkit to the jQuery UI framework – who knows!! Anyway, the problem is that when you post back with something like an UpdatePanel, you will find that your nicely setup jQuery stuff, like the datepicker for example will no longer work. You may have something like this… $(document).ready(function () {     $(".date-edit").datepicker({ dateFormat: "dd/mm/yy", firstDay: 1, showOtherMonths: true, selectOtherMonths: true }); });   When you’re ASP.net UpdatePanel post back, you will find that your datepicker has gone.  Bugger! Well you need to add this little gem to set it back up again once the UpdatePanel comes back to the page. var prm = Sys.WebForms.PageRequestManager.getInstance(); prm.add_endRequest(function () {     $(".date-edit").datepicker({ dateFormat: "dd/mm/yy", firstDay: 1, showOtherMonths: true, selectOtherMonths: true }); });   Or like me, you would have a javascript function, something like InitPage(); do all your work in there and call that on document.ready and endRequest. Your choice…you have the power   Share this post :

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• How can I set a time-limit on a batch file?

  - by drknexus

  I have a batch file that calls an external program that periodically hangs. What I would like to do is set a time limit on the batch file / CMD prompt such that it automatically closes after a certain period of time. One catch is that the external program that hangs may have one or more instances running at a given time, and I only want the batch file hitting its time limit to close the instance of the program triggered by the batch. How can I accomplish this? Ideally a solution would work on Windows XP, Vista, and 7.

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• How to install INFORMIX (IDS) 11.50 in CENTOS 5.4

  - by d23

  Getting ERROR: The wizard cannot continue because of the following error: could not load wizard specified in /wizard.inf (104) Solution: Uninstall everything related with java and jre. Then, download the lastest version of jre for linux x86 or x64, rpm.bin one. And follow these instructions http://www.java.com/en/download/help/linux_install.xml "To install the Linux RPM (self-extracting) file". Make a user and group informix (as root), then uncompress the (informix package).tar in /opt/informix that you have created. And tun ./ids_install, and GUI will work ok. Hope it helps.

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• C# vector class - Interpolation design decision

  - by Benjamin

  Currently I'm working on a vector class in C# and now I'm coming to the point, where I've to figure out, how i want to implement the functions for interpolation between two vectors. At first I came up with implementing the functions directly into the vector class... public class Vector3D { public static Vector3D LinearInterpolate(Vector3D vector1, Vector3D vector2, double factor) { ... } public Vector3D LinearInterpolate(Vector3D other, double factor { ... } } (I always offer both: a static method with two vectors as parameters and one non-static, with only one vector as parameter) ...but then I got the idea to use extension methods (defined in a seperate class called "Interpolation" for example), since interpolation isn't really a thing only available for vectors. So this could be another solution: public class Vector3D { ... } public static class Interpolation { public static Vector3D LinearInterpolate(this Vector3D vector, Vector3D other, double factor) { ... } } So here an example how you'd use the different possibilities: { var vec1 = new Vector3D(5, 3, 1); var vec2 = new Vector3D(4, 2, 0); Vector3D vec3; vec3 = vec1.LinearInterpolate(vec2, 0.5); //1 vec3 = Vector3D.LinearInterpolate(vec1, vec2, 0.5); //2 //or with extension-methods vec3 = vec1.LinearInterpolate(vec2, 0.5); //3 (same as 1) vec3 = Interpolation.LinearInterpolation(vec1, vec2, 0.5); //4 } So I really don't know which design is better. Also I don't know if there's an ultimate rule for things like this or if it's just about what someone personally prefers. But I really would like to hear your opinions, what's better (and if possible why ).

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• How could I change the colour of the menu font in Lubuntu?

  - by cipricus

  I use Lubuntu 12.04 and I have become obsessed with the looks of it! There is a type of themes that I especially want to use (flat, light), all related to the Elegant brit theme. On my desktop it looks like: As I want to replace the dominating orange with blue, I would prefer even more the theme Elegant Brit re-Revisited The problem is that both of them have a problem with my system tray, a white background appears: A theme that is almost identical to the orange one, but has no problem with the system tray is called Elegant Blackle. I have tried to use this one and replaced the gtk2 folder in its main folder with the gtk2 folder from Elegant Brit re-Revisited. The result is an improvement for me, as I have eliminated a part of the orange stuff with a decent blue :). The orange now appears only with the gtk3 apps, which is rather amusing. Migrating also the gtk3 folder from the blue to the orange theme would bring the sys tray problem too: it is something related to that gtk3 folder. But this is another matter. Now I have something very close to what I want. But I especially would like to have a feature that was present in the Elegant Blackle theme and now is gone as its gtk2 folder was replaced by that of the blue theme: the black font of the menus, instead of the blueish ones. Could anyone instruct me what is to be changed in the gtk2 folder of the Elegant Brit re-Revisited theme so as to make the menus look like this (like they do in Elegant Blackle with its original gtk2 folder): and not like this? : (on my display this blue is more whitish). An alternative and ideal solution would be knowing how to edit the Elegant Brit re-Revisited theme so as to remove the systray problem or, maybe easier, to edit the orange colour of Elegant Blackle theme to as to be completely replaced by the blue of the other one.

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• How can I compare Excel serial dates WITHOUT converting to mm/dd/yy type dates?

  - by dwwilson66

  I have a table that contains a number of values representing Excel serial dates. After a number of unsuccessful attempts to compare fields, my current approach is to do comparisons between serial dates instead of calendar dates. I am trying to summarize the data--by DAY--with formulae. CONSIDER: 41021 some data 41021.625 some data 41021.63542 some data 41022 some data 41022.26042 some data 41022.91667 some data 41023 some data 41023.375 some data DESIRED RESULT: 41021 sum of 41021, 41021.625 and 41021.63542 data 41022 sum of 41022, 41022.26042 and 41022.91667 data 41023 sum of 41023 and 41023.375 data In essence, for all instances of SerialDate.SerialTime, SUM data values associated with SerialDate.* regardless of the *.SerialTime for that date. While I can see how to do this by creating additional dates column formatted as =TEXT(<DateField>,"mm/dd/yyyy") I'm looking for a solution that will allow me to handle this 'conversion' in the formula, e.g.SUMIF((TEXT(<dateRange>,"yy/mm/dd"),=(TEXT(<dateField,"yy/mm/dd")),<dataRange> Make sense? Anyone have any ideas? Thanks

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• Link mysql with php on apache

  - by Cristy

  THE STORY: I've installed Apache 2.2.17 , PHP 5.2.16 , MySQL 5.5.8 . The PHP woks great, the phpinfo() works on the localhost. THE PROBLEM: The thing is that in phpinfo() there is no mysql mentionened. I've done the following: moved php.ini to C:\windows removed the ";" in front of the mysql extension line ( extension=php_mysql.dll ) copied the libmysql.dll to php folder & windows\system32 checked the extension path in php.ini to be " C:\php\ext" searched the internet for a solution for about 2 hours... ADDITIONAL INFO: In the Apache Enviorment path I have the following: C:\Program Files (x86)\PHP\;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\QuickTime\QTSystem\;C:\OJI\MinGWStudio\work\mingw\bin;C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\DTS\Binn\; I think the Microsoft SQL path should be replaced with the MySQL one, but I don't know where to change that...

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• Robustly disabling specific cron.{hourly,daily,weekly} script

  - by benizi

  On various systems that I administer, there are cron scripts that get run via the commonly-used /etc/cron.{hourly,daily,weekly} layout. What I want to know is whether there's any common 'disable this script' functionality. Obviously, simply deleting something out of a given directory will disable it, but I'm looking for a more permanent solution. Deleting /etc/cron.daily/slocate will work to disable the nightly updatedb on my home machine (where I never use slocate), but next time I upgrade the slocate package, I'm pretty sure it'll reappear. The two distributions I'm most interested in are Gentoo and OpenSUSE, but I'm hoping there's a widely-implemented mechanism. Both distros as I have them use vixie-cron (not sure it matters).

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• Tmux causes Emacs glitch

  - by killy9999

  Recently I started using Tmux, but I noticed that it causes a strange Emacs glitch. When I open source code for elisp or haskell, the comments aren't highlighted. Only the comment sign is (; in case of elisp, -- in case of haskell). The rest of the commented line is in normal colour. When I run Emacs outside of Tmux everything works as expected - the whole commented line is highlighted in a colour denoting a comment. Any ideas why this is happening? SOLUTION: Based on Stefan's comment I added this to my .emacs file: (custom-set-variables (custom-set-faces '(font-lock-comment-face ((((class color) (min-colors 8) (background dark)) (:foreground "red")))))) Now the comments are displayed in red, just like comment delimiters.

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• Nginx Rate Limiting by Referrer?

  - by SteveEdson

  I've successfully set up rate limiting on IP addresses like so, limit_req_zone $binary_remote_addr zone=one:10m rate=1r/s; But I was wondering if its possible to do the same on referrers? For example, if a site gets placed in an iframe on a third party site, which generates too much traffic to handle. I can't find any nginx variables for the referrer anywhere. Is this possible? Or can the solution be achieved in a different way? Thanks.

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• Open World Day 2

  - by Antony Reynolds

  A Day in the Life of an Oracle OpenWorld Attendee Part III My second full day started with me waking up and realising that I was supposed to meet my friend Tejas Joshi (co-author of the Oracle Exalogic Elastic Cloud Handbook) at the station in 20 minutes!  Needless to say I didn’t make it, but then I felt better later when I found out he had caught the wrong shuttle bus and ended up at the airport instead of the BART! The morning was spent in the Authors Seminar arranged to give authors a whirlwind tour of Oracle Product updates and strategy plans.  It was useful to see what was happening in areas I knew little or nothing about.  In the afternoon I wandered around Java One, a very different show to OpenWorld with much more bleeding edge stuff and just plain blue sky thinking.  Of course who couldn’t love a show with a full size Duke wondering around and available for photographs. Attended a presentation on a highly available Weblogic JMS environment wich did a great job of laying out to architect a highly available solution. Dinner with customers and then collapsed exhausted into bed!

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• racoon-tool doesn't generate full racoon.conf file in /var/lib/racoon/racoon.conf

  - by robthewolf

  I am using ipsec-tools/racoon to create my VPN. I am using racoon-tool to configure racoon.conf but when I run racoon-tool reload it only generates the first section - Global items. When I run racoon-tool I get: # racoon-tool reload Loading SAD and SPD... SAD and SPD loaded. Configuring racoon...done. This is the entire file /var/lib/racoon/racoon.conf # # Racoon configuration for Samuel # Generated on Wed Jan 5 21:31:49 2011 by racoon-tool # # # Global items # path pre_shared_key "/etc/racoon/psk.txt"; path certificate "/etc/racoon/certs"; log debug; I cannot find anywhere a solution as to why this is happening. Please help

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• Make the sound louder in Lubuntu

  - by Andrew

  I have a Toshiba r835 running Lubuntu 11.10. Turning the volume slider up all the way doesn't give very loud sound. I've tried typing alsamixer in a terminal and turning up all the levels there to maximum, but the speakers are still fairly quiet. Is there a simple way to increase maximum volume in software? I understand that there are physical limits to the sound the laptop's speakers can produce, but I suspect my maximum volume is limited by software. EDIT: This is exactly the type of solution I'm looking for. However, it doesn't work for me. What I did: sudo pico /etc/asound.conf This file does not exist, so I create a new one, containing: pcm.!default { type plug slave.pcm "softvol" } pcm.softvol { type softvol slave { pcm "dmix" } control { name "Pre-Amp" card 0 } min_dB -5.0 max_dB 20.0 resolution 6 } I reboot the machine, and type alsamixer. I use my left/right arrow keys to inspect the various volume options. I expect to see a new option, called Pre-Amp, but I don't see one. This fix seems to work for other people. Why doesn't this fix work for me?

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• Code Behaviour via Unit Tests

  - by Dewald Galjaard

  Normal 0 false false false EN-ZA X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Some four months ago my car started acting up. Symptoms included a sputtering as my car’s computer switched between gears intermittently. Imagine building up speed, then when you reach 80km/h the car magically and mysteriously decide to switch back to third or even second gear. Clearly it was confused! I managed to track down a technician, an expert in his field to help me out. As he fitted his handheld computer to some hidden port under the dash, he started to explain “These cars are quite intelligent, you know. When they sense something is wrong they run in a restrictive program which probably account for how you managed to drive here in the first place...”  I was surprised and thought this was certainly going to be an interesting test drive. The car ran smoothly down the first couple of stretches as the technician ran through routine checks. Then he said “Ok, all looking good. We need to start testing aspects of the gearbox. Inside the gearbox there are a couple of sensors. One of them is a speed sensor which talks to the computer, which in turn will decide which gear to switch to. The restrictive program avoid these sensors altogether and allow the computer to obtain its input from other [non-affected] sources”. Then, as soon as he forced the speed sensor to come back online the symptoms and ill behaviour re-emerged... What an incredible analogy for getting into a discussion on unit testing software? Besides I should probably put my ill fortune to some good use, right? This example provide a lot of insight into how and why we should conduct unit tests when writing code. More importantly, it captures what is easily and unfortunately often the most overlooked goal of writing unit tests by those new to the art and those who oppose it alike - The goal of writing unit tests is to test the behaviour of our code under predefined conditions. Although it is very possible to test the intrinsic workings of each and every component in your code, writing several tests for each method in practise will soon prove to be an exhausting and ultimately fruitless exercise given the certain and ever changing nature of business requirements. Consequently it is true and quite possible whilst conducting proper unit tests, to call any single method several times as you examine and contemplate different scenarios. Let’s write some code to demonstrate what I mean. In my example I make use of the Moq framework and NUnit to create my tests. Truly you can use whatever you’re comfortable with. First we’ll create an ISpeedSensor interface. This is to represent the speed sensor located in the gearbox.  Then we’ll create a Gearbox class which we’ll pass to a constructor when we instantiate an object of type Computer. All three are described below.   ISpeedSensor.cs namespace AutomaticVehicle {     public interface ISpeedSensor     {         int ReportCurrentSpeed();     } }   Gearbox.cs namespace AutomaticVehicle {      public class Gearbox     {         private ISpeedSensor _speedSensor;           public Gearbox( ISpeedSensor gearboxSpeedSensor )         {             _speedSensor = gearboxSpeedSensor;         }         /// <summary>         /// This method obtain it's reading from the speed sensor.         /// </summary>         /// <returns></returns>         public int ReportCurrentSpeed()         {             return _speedSensor.ReportCurrentSpeed();         }     } } Computer.cs namespace AutomaticVehicle {     public class Computer     {         private Gearbox _gearbox;         public Computer( Gearbox gearbox )         {                     }          public int GetCurrentSpeed()         {             return _gearbox.ReportCurrentSpeed( );         }     } } Since this post is about Unit testing, that is exactly what we’ll create next. Create a second project in your solution. I called mine AutomaticVehicleTests and I immediately referenced the respective nunit, moq and AutomaticVehicle dll’s. We’re going to write a test to examine what happens inside the Computer class. ComputerTests.cs namespace AutomaticVehicleTests {     [TestFixture]     public class ComputerTests     {         [Test]         public void Computer_Gearbox_SpeedSensor_DoesThrow()         {             // Mock ISpeedSensor in gearbox             Mock< ISpeedSensor > speedSensor = new Mock< ISpeedSensor >( );             speedSensor.Setup( n => n.ReportCurrentSpeed() ).Throws<Exception>();             Gearbox gearbox = new Gearbox( speedSensor.Object );               // Create Computer instance to test it's behaviour  towards an exception in gearbox             Computer carComputer = new Computer( gearbox );             // For simplicity let’s assume for now the car only travels at 60 km/h.             Assert.AreEqual( 60, carComputer.GetCurrentSpeed( ) );          }     } }   What is happening in this test? We have created a mocked object using the ISpeedsensor interface which we've passed to our Gearbox object. Notice that I created the mocked object using an interface, not the implementation. I’ll talk more about this in future posts but in short I do this to accentuate the fact that I'm not not really concerned with how SpeedSensor work internally at this particular point in time. Next I’ve gone ahead and created a scenario where I’ve declared the speed sensor in Gearbox to be faulty by forcing it to throw an exception should we ask Gearbox to report on its current speed. Sneaky, sneaky. This test is a simulation of how things may behave in the real world. Inevitability things break, whether it’s caused by mechanical failure, some logical error on your part or a fellow developer which didn’t consult the documentation (or the lack thereof ) - whether you’re calling a speed sensor, making a call to a database, calling a web service or just trying to write a file to disk. It’s a scenario I’ve created and this test is about how the code within the Computer instance will behave towards any such error as I’ve depicted. Now, if you’ve followed closely in my final assert method you would have noticed I did something quite unexpected. I might be getting ahead of myself now but I’m testing to see if the value returned is equal to what I expect it to be under perfect conditions – I’m not testing to see if an error has been thrown! Why is that? Well, in short this is TDD. Test Driven Development is about first writing your test to define the result we want, then to go back and change the implementation within your class to obtain the desired output (I need to make sure I can drive back to the repair shop. Remember? ) So let’s go ahead and run our test as is. It’s fails miserably... Good! Let’s go back to our Computer class and make a small change to the GetCurrentSpeed method.   Computer.cs public int GetCurrentSpeed() {   try   {     return _gearbox.ReportCurrentSpeed( );   }   catch   {     RunRestrictiveProgram( );   } }     This is a simple solution, I know, but it does provide a way to allow for different behaviour. You’re more than welcome to provide an implementation for RunRestrictiveProgram should you feel the need to. It's not within the scope of this post or related to the point I'm trying to make. What is important is to notice how the focus has shifted in our approach from how things can break - to how things behave when broken.   Happy coding!

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