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• Premature-Optimization and Performance Anxiety

  - by James Michael Hare

  While writing my post analyzing the new .NET 4 ConcurrentDictionary class (here), I fell into one of the classic blunders that I myself always love to warn about.  After analyzing the differences of time between a Dictionary with locking versus the new ConcurrentDictionary class, I noted that the ConcurrentDictionary was faster with read-heavy multi-threaded operations.  Then, I made the classic blunder of thinking that because the original Dictionary with locking was faster for those write-heavy uses, it was the best choice for those types of tasks.  In short, I fell into the premature-optimization anti-pattern. Basically, the premature-optimization anti-pattern is when a developer is coding very early for a perceived (whether rightly-or-wrongly) performance gain and sacrificing good design and maintainability in the process.  At best, the performance gains are usually negligible and at worst, can either negatively impact performance, or can degrade maintainability so much that time to market suffers or the code becomes very fragile due to the complexity. Keep in mind the distinction above.  I'm not talking about valid performance decisions.  There are decisions one should make when designing and writing an application that are valid performance decisions.  Examples of this are knowing the best data structures for a given situation (Dictionary versus List, for example) and choosing performance algorithms (linear search vs. binary search).  But these in my mind are macro optimizations.  The error is not in deciding to use a better data structure or algorithm, the anti-pattern as stated above is when you attempt to over-optimize early on in such a way that it sacrifices maintainability. In my case, I was actually considering trading the safety and maintainability gains of the ConcurrentDictionary (no locking required) for a slight performance gain by using the Dictionary with locking.  This would have been a mistake as I would be trading maintainability (ConcurrentDictionary requires no locking which helps readability) and safety (ConcurrentDictionary is safe for iteration even while being modified and you don't risk the developer locking incorrectly) -- and I fell for it even when I knew to watch out for it.  I think in my case, and it may be true for others as well, a large part of it was due to the time I was trained as a developer.  I began college in in the 90s when C and C++ was king and hardware speed and memory were still relatively priceless commodities and not to be squandered.  In those days, using a long instead of a short could waste precious resources, and as such, we were taught to try to minimize space and favor performance.  This is why in many cases such early code-bases were very hard to maintain.  I don't know how many times I heard back then to avoid too many function calls because of the overhead -- and in fact just last year I heard a new hire in the company where I work declare that she didn't want to refactor a long method because of function call overhead.  Now back then, that may have been a valid concern, but with today's modern hardware even if you're calling a trivial method in an extremely tight loop (which chances are the JIT compiler would optimize anyway) the results of removing method calls to speed up performance are negligible for the great majority of applications.  Now, obviously, there are those coding applications where speed is absolutely king (for example drivers, computer games, operating systems) where such sacrifices may be made.  But I would strongly advice against such optimization because of it's cost.  Many folks that are performing an optimization think it's always a win-win.  That they're simply adding speed to the application, what could possibly be wrong with that?  What they don't realize is the cost of their choice.  For every piece of straight-forward code that you obfuscate with performance enhancements, you risk the introduction of bugs in the long term technical debt of the application.  It will become so fragile over time that maintenance will become a nightmare.  I've seen such applications in places I have worked.  There are times I've seen applications where the designer was so obsessed with performance that they even designed their own memory management system for their application to try to squeeze out every ounce of performance.  Unfortunately, the application stability often suffers as a result and it is very difficult for anyone other than the original designer to maintain. I've even seen this recently where I heard a C++ developer bemoaning that in VS2010 the iterators are about twice as slow as they used to be because Microsoft added range checking (probably as part of the 0x standard implementation).  To me this was almost a joke.  Twice as slow sounds bad, but it almost never as bad as you think -- especially if you're gaining safety.  The only time twice is really that much slower is when once was too slow to begin with.  Think about it.  2 minutes is slow as a response time because 1 minute is slow.  But if an iterator takes 1 microsecond to move one position and a new, safer iterator takes 2 microseconds, this is trivial!  The only way you'd ever really notice this would be in iterating a collection just for the sake of iterating (i.e. no other operations).  To my mind, the added safety makes the extra time worth it. Always favor safety and maintainability when you can.  I know it can be a hard habit to break, especially if you started out your career early or in a language such as C where they are very performance conscious.  But in reality, these type of micro-optimizations only end up hurting you in the long run. Remember the two laws of optimization.  I'm not sure where I first heard these, but they are so true: For beginners: Do not optimize. For experts: Do not optimize yet. This is so true.  If you're a beginner, resist the urge to optimize at all costs.  And if you are an expert, delay that decision.  As long as you have chosen the right data structures and algorithms for your task, your performance will probably be more than sufficient.  Chances are it will be network, database, or disk hits that will be your slow-down, not your code.  As they say, 98% of your code's bottleneck is in 2% of your code so premature-optimization may add maintenance and safety debt that won't have any measurable impact.  Instead, code for maintainability and safety, and then, and only then, when you find a true bottleneck, then you should go back and optimize further.

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• SQL University: What and why of database refactoring

  - by Mladen Prajdic

  This is a post for a great idea called SQL University started by Jorge Segarra also famously known as SqlChicken on Twitter. It’s a collection of blog posts on different database related topics contributed by several smart people all over the world. So this week is mine and we’ll be talking about database testing and refactoring. In 3 posts we’ll cover: SQLU part 1 - What and why of database testing SQLU part 2 - What and why of database refactoring SQLU part 3 - Tools of the trade This is a second part of the series and in it we’ll take a look at what database refactoring is and why do it. Why refactor a database To know why refactor we first have to know what refactoring actually is. Code refactoring is a process where we change module internals in a way that does not change that module’s input/output behavior. For successful refactoring there is one crucial thing we absolutely must have: Tests. Automated unit tests are the only guarantee we have that we haven’t broken the input/output behavior before refactoring. If you haven’t go back ad read my post on the matter. Then start writing them. Next thing you need is a code module. Those are views, UDFs and stored procedures. By having direct table access we can kiss fast and sweet refactoring good bye. One more point to have a database abstraction layer. And no, ORM’s don’t fall into that category. But also know that refactoring is NOT adding new functionality to your code. Many have fallen into this trap. Don’t be one of them and resist the lure of the dark side. And it’s a strong lure. We developers in general love to add new stuff to our code, but hate fixing our own mistakes or changing existing code for no apparent reason. To be a good refactorer one needs discipline and focus. Now we know that refactoring is all about changing inner workings of existing code. This can be due to performance optimizations, changing internal code workflows or some other reason. This is a typical black box scenario to the outside world. If we upgrade the car engine it still has to drive on the road (preferably faster) and not fly (no matter how cool that would be). Also be aware that white box tests will break when we refactor. What to refactor in a database Refactoring databases doesn’t happen that often but when it does it can include a lot of stuff. Let us look at a few common cases. Adding or removing database schema objects Adding, removing or changing table columns in any way, adding constraints, keys, etc… All of these can be counted as internal changes not visible to the data consumer. But each of these carries a potential input/output behavior change. Dropping a column can result in views not working anymore or stored procedure logic crashing. Adding a unique constraint shows duplicated data that shouldn’t exist. Foreign keys break a truncate table command executed from an application that runs once a month. All these scenarios are very real and can happen. With the proper database abstraction layer fully covered with black box tests we can make sure something like that does not happen (hopefully at all). Changing physical structures Physical structures include heaps, indexes and partitions. We can pretty much add or remove those without changing the data returned by the database. But the performance can be affected. So here we use our performance tests. We do have them, right? Just by adding a single index we can achieve orders of magnitude performance improvement. Won’t that make users happy? But what if that index causes our write operations to crawl to a stop. again we have to test this. There are a lot of things to think about and have tests for. Without tests we can’t do successful refactoring! Fixing bad code We all have some bad code in our systems. We usually refer to that code as code smell as they violate good coding practices. Examples of such code smells are SQL injection, use of SELECT *, scalar UDFs or cursors, etc… Each of those is huge code smell and can result in major code changes. Take SELECT * from example. If we remove a column from a table the client using that SELECT * statement won’t have a clue about that until it runs. Then it will gracefully crash and burn. Not to mention the widely unknown SELECT * view refresh problem that Tomas LaRock (@SQLRockstar on Twitter) and Colin Stasiuk (@BenchmarkIT on Twitter) talk about in detail. Go read about it, it’s informative. Refactoring this includes replacing the * with column names and most likely change to application using the database. Breaking apart huge stored procedures Have you ever seen seen a stored procedure that was 2000 lines long? I have. It’s not pretty. It hurts the eyes and sucks the will to live the next 10 minutes. They are a maintenance nightmare and turn into things no one dares to touch. I’m willing to bet that 100% of time they don’t have a single test on them. Large stored procedures (and functions) are a clear sign that they contain business logic. General opinion on good database coding practices says that business logic has no business in the database. That’s the applications part. Refactoring such behemoths requires writing lots of edge case tests for the stored procedure input/output behavior and then start to refactor it. First we split the logic inside into smaller parts like new stored procedures and UDFs. Those then get called from the master stored procedure. Once we’ve successfully modularized the database code it’s best to transfer that logic into the applications consuming it. This only leaves the stored procedure with common data manipulation logic. Of course this isn’t always possible so having a plethora of performance and behavior unit tests is absolutely necessary to confirm we’ve actually improved the codebase in some way.   Refactoring is not a popular chore amongst developers or managers. The former don’t like fixing old code, the latter can’t see the financial benefit. Remember how we talked about being lousy at estimating future costs in the previous post? But there comes a time when it must be done. Hopefully I’ve given you some ideas how to get started. In the last post of the series we’ll take a look at the tools to use and an example of testing and refactoring.

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• DRY and SRP

  - by Timothy Klenke

  Originally posted on: http://geekswithblogs.net/TimothyK/archive/2014/06/11/dry-and-srp.aspxKent Beck’s XP Simplicity Rules (aka Four Rules of Simple Design) are a prioritized list of rules that when applied to your code generally yield a great design.  As you’ll see from the above link the list has slightly evolved over time.  I find today they are usually listed as: All Tests Pass Don’t Repeat Yourself (DRY) Express Intent Minimalistic These are prioritized.  If your code doesn’t work (rule 1) then everything else is forfeit.  Go back to rule one and get the code working before worrying about anything else. Over the years the community have debated whether the priority of rules 2 and 3 should be reversed.  Some say a little duplication in the code is OK as long as it helps express intent.  I’ve debated it myself.  This recent post got me thinking about this again, hence this post.   I don’t think it is fair to compare “Expressing Intent” against “DRY”.  This is a comparison of apples to oranges.  “Expressing Intent” is a principal of code quality.  “Repeating Yourself” is a code smell.  A code smell is merely an indicator that there might be something wrong with the code.  It takes further investigation to determine if a violation of an underlying principal of code quality has actually occurred. For example “using nouns for method names”, “using verbs for property names”, or “using Booleans for parameters” are all code smells that indicate that code probably isn’t doing a good job at expressing intent.  They are usually very good indicators.  But what principle is the code smell of Duplication pointing to and how good of an indicator is it? Duplication in the code base is bad for a couple reasons.  If you need to make a change and that needs to be made in a number of locations it is difficult to know if you have caught all of them.  This can lead to bugs if/when one of those locations is overlooked.  By refactoring the code to remove all duplication there will be left with only one place to change, thereby eliminating this problem. With most projects the code becomes the single source of truth for a project.  If a production code base is inconsistent with a five year old requirements or design document the production code that people are currently living with is usually declared as the current reality (or truth).  Requirement or design documents at this age in a project life cycle are usually of little value. Although comparing production code to external documentation is usually straight forward, duplication within the code base muddles this declaration of truth.  When code is duplicated small discrepancies will creep in between the two copies over time.  The question then becomes which copy is correct?  As different factions debate how the software should work, trust in the software and the team behind it erodes. The code smell of Duplication points to a violation of the “Single Source of Truth” principle.  Let me define that as: A stakeholder’s requirement for a software change should never cause more than one class to change. Violation of the Single Source of Truth principle will always result in duplication in the code.  However, the inverse is not always true.  Duplication in the code does not necessarily indicate that there is a violation of the Single Source of Truth principle. To illustrate this, let’s look at a retail system where the system will (1) send a transaction to a bank and (2) print a receipt for the customer.  Although these are two separate features of the system, they are closely related.  The reason for printing the receipt is usually to provide an audit trail back to the bank transaction.  Both features use the same data:  amount charged, account number, transaction date, customer name, retail store name, and etcetera.  Because both features use much of the same data, there is likely to be a lot of duplication between them.  This duplication can be removed by making both features use the same data access layer. Then start coming the divergent requirements.  The receipt stakeholder wants a change so that the account number has the last few digits masked out to protect the customer’s privacy.  That can be solve with a small IF statement whilst still eliminating all duplication in the system.  Then the bank wants to take a picture of the customer as well as capture their signature and/or PIN number for enhanced security.  Then the receipt owner wants to pull data from a completely different system to report the customer’s loyalty program point total. After a while you realize that the two stakeholders have somewhat similar, but ultimately different responsibilities.  They have their own reasons for pulling the data access layer in different directions.  Then it dawns on you, the Single Responsibility Principle: There should never be more than one reason for a class to change. In this example we have two stakeholders giving two separate reasons for the data access class to change.  It is clear violation of the Single Responsibility Principle.  That’s a problem because it can often lead the project owner pitting the two stakeholders against each other in a vein attempt to get them to work out a mutual single source of truth.  But that doesn’t exist.  There are two completely valid truths that the developers need to support.  How is this to be supported and honour the Single Responsibility Principle?  The solution is to duplicate the data access layer and let each stakeholder control their own copy. The Single Source of Truth and Single Responsibility Principles are very closely related.  SST tells you when to remove duplication; SRP tells you when to introduce it.  They may seem to be fighting each other, but really they are not.  The key is to clearly identify the different responsibilities (or sources of truth) over a system.  Sometimes there is a single person with that responsibility, other times there are many.  This can be especially difficult if the same person has dual responsibilities.  They might not even realize they are wearing multiple hats. In my opinion Single Source of Truth should be listed as the second rule of simple design with Express Intent at number three.  Investigation of the DRY code smell should yield to the proper application SST, without violating SRP.  When necessary leave duplication in the system and let the class names express the different people that are responsible for controlling them.  Knowing all the people with responsibilities over a system is the higher priority because you’ll need to know this before you can express it.  Although it may be a code smell when there is duplication in the code, it does not necessarily mean that the coder has chosen to be expressive over DRY or that the code is bad.

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• Are IE 9 will have a place in heart of user ?

  - by anirudha

  in a advertisement of IE 9 MSFT compare two product first is their IE9 and second is chrome 6. I know 6 is not currently [9] but no objection because may be they make ads when 6 is currently version and have RC or beta in their hands. on IE 9 test-drive website they show many of people ads to show the user that IE9 is performance better or other chrome or Firefox not. well they not compare with Firefox because last days firefox not still in news and search trends like before RC release many of user googling for them. Well I myself found IE9 perform smoother then chrome. but what MSFT do after IE9 nothing they waiting for IE 10 not for give updates not as well as Google chrome and Firefox. Are IE9 have anything new for Developer even a small or big. well they tell you blah or useless things everytime when they make for next version no matter for you but a matter for them because they add a new thing even useless for developer. I am not have any feeling with IE bad but I like to make reviews as well as I can make. I show you something who I experience with IE and someother browser like Chrome and Firefox. IE 9 still have no plugin as well as other provided like Firefox have Firebug a great utilities who is best option for developer to debug their code. IE9 developer tool is good but still you never customize them or readymade customization available to work as in firefox many of person make customization for firebug like example :- firepicker for picking color in firebug , firebug autocomplete for intellisense like feature when you write JavaScript inside console panel , pixelperfect , firequery , sitepoint reference and many other great example we all love to use. as other things that Firefox give many things customizable like themes , ui and many thing customization means more thing user or developer want to make themselves and more contribution make them better software so Firefox is great because customization is a great thing inside firefox and chrome. if you read some post of developer on MSDN to what’s new in IE 9 developer tool that you feel they are joking whenever you see some other things of Firefox and chrome. in a Firefox a plugin perform many much things but in IE still use IE 9 developer tool no other option like in Firefox use Firebug and many other utilities to make development easier and time saving and best as we can do.if you see Firefox page on mozilla that sublines of firefox is high performance easy customization advanced security well you can say what’s performance but there is no comparison with IE because IE have only performance and nothing else. but Firefox have these three thing to make product love. and third thing I really love that security yeah security. from long time before whenever IE6 is no hackproff and many other easily hack IE6 whenever Firefox is secure. I found myself that many of website install a software on client’s computer and they still not know about them so they track everything. sometime they hijack the homepage and make their website as their homepage. sometime they do something and you trying  to go to  any website then they go to their site first. the problem I telling about not long before it’s time of late in 2008 whenever Firefox is much better then IE6. if someone have bad experience with anyone of these software share with us I like to hear your voice. whenever IE still not for use Firefox is a good option for us even user or developer. I not know why someone make next version of IE. IE still have time to go away from Web. Firefox not rude as IE they still believe in user feedback and chrome is also open the door for feedback on their product gooogle Chrome. but what thing they made in IE on user feedback nothing. they still thing to teach what they maked not thing about what user need. if you spent some hour on firefox and chrome then you found what’s matter. what thing you have whenever you use IE or other browser like google chrome and Firefox :- as a user IE give you nothing even tell you blah blah and more blah but still next version of IE means next IE6 for the web. as in Google chrome you find plugins addons or customization to make experience better but in IE9 you can’t customize anything even the themes they have by default. Firefox already have a great list of plugins or addons to make experience better with Web but IE9 have nothing. this means IE9 not for user and other like chrome and firefox give you much better experience then IE. next thing after user is developer. first thing is that all developer want smooth development who save their time not take too perhaps saving.posts on IE9 show that a list of thing improved in IE 9 developer tool but are one developer tool enough for web development so developer need more utilities to solve different different type of puzzle who IE 9 never give like in Firefox you have utilities to do a task even small or big one. in chrome same experience you have but IE9 never give any plugin or utilities to make our work faster even they are new headache for developer because IE not give update as soon as other because in Firefox and in chrome if a bug is reported then they solve them fast and distribute them in next version of software very soon but in IE wait for a long time like IE 9 and IE 8 have no official release between them as update. As my conclusion there is no reason to use IE and adopt 9 again. it’s really not for Developer or user even newbie or smart people. as a rule I want to beware you with IE because it’s my responsibilities to move the thing in good way as I can make. well are you sure that there is no reason or profit they thing to have with IE9  if not why they forget luna [windows xp] user. because they are old nothing they want to force user to give them some money by purchasing a new version of OS. so this a thing why they marketed their software. if you thing about what firefox and chrome want to make : Mozilla's mission is to promote openness, innovation and opportunity on the web. chrome mission we all see whenever we use them. but IE9 is a trick they promote because they want to add something to next version of windows. if somebody like IE9 [even surprised by ads they see or post they read] then they purchase windows soon as they possible. Well you feel that I am opposition of IE9 and favor of chrome and Firefox yeah you feel right I hate IE from a heart not from a pencil. well you get same thing when you have trying three product major I described here Chrome firefox and IE. well don’t believe on the blogs , posts or article who are provided by the merchant or vender’s website. open the eyes read and thing what they talk and feel are they really true. if you confused that compare with some other. now you know the true because no one telling so badly as a user can described who use them not only one who make their feature. always open the eyes don’t believe use your mind and find the truth. thanks for reading my post good bye and take care

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• IIS 7.0 informational HTTP status codes

  - by Samir R. Bhogayta

  1xx - Informational These HTTP status codes indicate a provisional response. The client computer receives one or more 1xx responses before the client computer receives a regular response. IIS 7.0 uses the following informational HTTP status codes: 100 - Continue. 101 - Switching protocols. 2xx - Success These HTTP status codes indicate that the server successfully accepted the request. IIS 7.0 uses the following success HTTP status codes: 200 - OK. The client request has succeeded. 201 - Created. 202 - Accepted. 203 - Nonauthoritative information. 204 - No content. 205 - Reset content. 206 - Partial content. 3xx - Redirection These HTTP status codes indicate that the client browser must take more action to fulfill the request. For example, the client browser may have to request a different page on the server. Or, the client browser may have to repeat the request by using a proxy server. IIS 7.0 uses the following redirection HTTP status codes: 301 - Moved permanently. 302 - Object moved. 304 - Not modified. 307 - Temporary redirect. 4xx - Client error These HTTP status codes indicate that an error occurred and that the client browser appears to be at fault. For example, the client browser may have requested a page that does not exist. Or, the client browser may not have provided valid authentication information. IIS 7.0 uses the following client error HTTP status codes: 400 - Bad request. The request could not be understood by the server due to malformed syntax. The client should not repeat the request without modifications. IIS 7.0 defines the following HTTP status codes that indicate a more specific cause of a 400 error: 400.1 - Invalid Destination Header. 400.2 - Invalid Depth Header. 400.3 - Invalid If Header. 400.4 - Invalid Overwrite Header. 400.5 - Invalid Translate Header. 400.6 - Invalid Request Body. 400.7 - Invalid Content Length. 400.8 - Invalid Timeout. 400.9 - Invalid Lock Token. 401 - Access denied. IIS 7.0 defines several HTTP status codes that indicate a more specific cause of a 401 error. The following specific HTTP status codes are displayed in the client browser but are not displayed in the IIS log: 401.1 - Logon failed. 401.2 - Logon failed due to server configuration. 401.3 - Unauthorized due to ACL on resource. 401.4 - Authorization failed by filter. 401.5 - Authorization failed by ISAPI/CGI application. 403 - Forbidden. IIS 7.0 defines the following HTTP status codes that indicate a more specific cause of a 403 error: 403.1 - Execute access forbidden. 403.2 - Read access forbidden. 403.3 - Write access forbidden. 403.4 - SSL required. 403.5 - SSL 128 required. 403.6 - IP address rejected. 403.7 - Client certificate required. 403.8 - Site access denied. 403.9 - Forbidden: Too many clients are trying to connect to the Web server. 403.10 - Forbidden: Web server is configured to deny Execute access. 403.11 - Forbidden: Password has been changed. 403.12 - Mapper denied access. 403.13 - Client certificate revoked. 403.14 - Directory listing denied. 403.15 - Forbidden: Client access licenses have exceeded limits on the Web server. 403.16 - Client certificate is untrusted or invalid. 403.17 - Client certificate has expired or is not yet valid. 403.18 - Cannot execute requested URL in the current application pool. 403.19 - Cannot execute CGI applications for the client in this application pool. 403.20 - Forbidden: Passport logon failed. 403.21 - Forbidden: Source access denied. 403.22 - Forbidden: Infinite depth is denied. 404 - Not found. IIS 7.0 defines the following HTTP status codes that indicate a more specific cause of a 404 error: 404.0 - Not found. 404.1 - Site Not Found. 404.2 - ISAPI or CGI restriction. 404.3 - MIME type restriction. 404.4 - No handler configured. 404.5 - Denied by request filtering configuration. 404.6 - Verb denied. 404.7 - File extension denied. 404.8 - Hidden namespace. 404.9 - File attribute hidden. 404.10 - Request header too long. 404.11 - Request contains double escape sequence. 404.12 - Request contains high-bit characters. 404.13 - Content length too large. 404.14 - Request URL too long. 404.15 - Query string too long. 404.16 - DAV request sent to the static file handler. 404.17 - Dynamic content mapped to the static file handler via a wildcard MIME mapping. 404.18 - Querystring sequence denied. 404.19 - Denied by filtering rule. 405 - Method Not Allowed. 406 - Client browser does not accept the MIME type of the requested page. 408 - Request timed out. 412 - Precondition failed. 5xx - Server error These HTTP status codes indicate that the server cannot complete the request because the server encounters an error. IIS 7.0 uses the following server error HTTP status codes: 500 - Internal server error. IIS 7.0 defines the following HTTP status codes that indicate a more specific cause of a 500 error: 500.0 - Module or ISAPI error occurred. 500.11 - Application is shutting down on the Web server. 500.12 - Application is busy restarting on the Web server. 500.13 - Web server is too busy. 500.15 - Direct requests for Global.asax are not allowed. 500.19 - Configuration data is invalid. 500.21 - Module not recognized. 500.22 - An ASP.NET httpModules configuration does not apply in Managed Pipeline mode. 500.23 - An ASP.NET httpHandlers configuration does not apply in Managed Pipeline mode. 500.24 - An ASP.NET impersonation configuration does not apply in Managed Pipeline mode. 500.50 - A rewrite error occurred during RQ_BEGIN_REQUEST notification handling. A configuration or inbound rule execution error occurred. Note Here is where the distributed rules configuration is read for both inbound and outbound rules. 500.51 - A rewrite error occurred during GL_PRE_BEGIN_REQUEST notification handling. A global configuration or global rule execution error occurred. Note Here is where the global rules configuration is read. 500.52 - A rewrite error occurred during RQ_SEND_RESPONSE notification handling. An outbound rule execution occurred. 500.53 - A rewrite error occurred during RQ_RELEASE_REQUEST_STATE notification handling. An outbound rule execution error occurred. The rule is configured to be executed before the output user cache gets updated. 500.100 - Internal ASP error. 501 - Header values specify a configuration that is not implemented. 502 - Web server received an invalid response while acting as a gateway or proxy. IIS 7.0 defines the following HTTP status codes that indicate a more specific cause of a 502 error: 502.1 - CGI application timeout. 502.2 - Bad gateway. 503 - Service unavailable. IIS 7.0 defines the following HTTP status codes that indicate a more specific cause of a 503 error: 503.0 - Application pool unavailable. 503.2 - Concurrent request limit exceeded.

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• How to Identify Which Hardware Component is Failing in Your Computer

  - by Chris Hoffman

  Concluding that your computer has a hardware problem is just the first step. If you’re dealing with a hardware issue and not a software issue, the next step is determining what hardware problem you’re actually dealing with. If you purchased a laptop or pre-built desktop PC and it’s still under warranty, you don’t need to care about this. Have the manufacturer fix the PC for you — figuring it out is their problem. If you’ve built your own PC or you want to fix a computer that’s out of warranty, this is something you’ll need to do on your own. Blue Screen 101: Search for the Error Message This may seem like obvious advice, but searching for information about a blue screen’s error message can help immensely. Most blue screens of death you’ll encounter on modern versions of Windows will likely be caused by hardware failures. The blue screen of death often displays information about the driver that crashed or the type of error it encountered. For example, let’s say you encounter a blue screen that identified “NV4_disp.dll” as the driver that caused the blue screen. A quick Google search will reveal that this is the driver for NVIDIA graphics cards, so you now have somewhere to start. It’s possible that your graphics card is failing if you encounter such an error message. Check Hard Drive SMART Status Hard drives have a built in S.M.A.R.T. (Self-Monitoring, Analysis, and Reporting Technology) feature. The idea is that the hard drive monitors itself and will notice if it starts to fail, providing you with some advance notice before the drive fails completely. This isn’t perfect, so your hard drive may fail even if SMART says everything is okay. If you see any sort of “SMART error” message, your hard drive is failing. You can use SMART analysis tools to view the SMART health status information your hard drives are reporting. Test Your RAM RAM failure can result in a variety of problems. If the computer writes data to RAM and the RAM returns different data because it’s malfunctioning, you may see application crashes, blue screens, and file system corruption. To test your memory and see if it’s working properly, use Windows’ built-in Memory Diagnostic tool. The Memory Diagnostic tool will write data to every sector of your RAM and read it back afterwards, ensuring that all your RAM is working properly. Check Heat Levels How hot is is inside your computer? Overheating can rsult in blue screens, crashes, and abrupt shut downs. Your computer may be overheating because you’re in a very hot location, it’s ventilated poorly, a fan has stopped inside your computer, or it’s full of dust. Your computer monitors its own internal temperatures and you can access this information. It’s generally available in your computer’s BIOS, but you can also view it with system information utilities such as SpeedFan or Speccy. Check your computer’s recommended temperature level and ensure it’s within the appropriate range. If your computer is overheating, you may see problems only when you’re doing something demanding, such as playing a game that stresses your CPU and graphics card. Be sure to keep an eye on how hot your computer gets when it performs these demanding tasks, not only when it’s idle. Stress Test Your CPU You can use a utility like Prime95 to stress test your CPU. Such a utility will fore your computer’s CPU to perform calculations without allowing it to rest, working it hard and generating heat. If your CPU is becoming too hot, you’ll start to see errors or system crashes. Overclockers use Prime95 to stress test their overclock settings — if Prime95 experiences errors, they throttle back on their overclocks to ensure the CPU runs cooler and more stable. It’s a good way to check if your CPU is stable under load. Stress Test Your Graphics Card Your graphics card can also be stress tested. For example, if your graphics driver crashes while playing games, the games themselves crash, or you see odd graphical corruption, you can run a graphics benchmark utility like 3DMark. The benchmark will stress your graphics card and, if it’s overheating or failing under load, you’ll see graphical problems, crashes, or blue screens while running the benchmark. If the benchmark seems to work fine but you have issues playing a certain game, it may just be a problem with that game. Swap it Out Not every hardware problem is easy to diagnose. If you have a bad motherboard or power supply, their problems may only manifest through occasional odd issues with other components. It’s hard to tell if these components are causing problems unless you replace them completely. Ultimately, the best way to determine whether a component is faulty is to swap it out. For example, if you think your graphics card may be causing your computer to blue screen, pull the graphics card out of your computer and swap in a new graphics card. If everything is working well, it’s likely that your previous graphics card was bad. This isn’t easy for people who don’t have boxes of components sitting around, but it’s the ideal way to troubleshoot. Troubleshooting is all about trial and error, and swapping components out allows you to pin down which component is actually causing the problem through a process of elimination. This isn’t a complete guide to everything that could likely go wrong and how to identify it — someone could write a full textbook on identifying failing components and still not cover everything. But the tips above should give you some places to start dealing with the more common problems. Image Credit: Justin Marty on Flickr     

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• CodePlex Daily Summary for Thursday, November 01, 2012

  CodePlex Daily Summary for Thursday, November 01, 2012Popular ReleasesAccess 2010 Application Platform - Build Your Own Database: Application Platform - 0.0.1: Initial Release This is the first version of the database. At the moment is all contained in one file to make development easier, but the obvious idea would be to split it into Front and Back End for a production version of the tool. The features it contains at the moment are the "Core" features.Python Tools for Visual Studio: Python Tools for Visual Studio 1.5: We’re pleased to announce the release of Python Tools for Visual Studio 1.5 RTM. Python Tools for Visual Studio (PTVS) is an open-source plug-in for Visual Studio which supports programming with the Python language. PTVS supports a broad range of features including CPython/IronPython, Edit/Intellisense/Debug/Profile, Cloud, HPC, IPython, etc. support. For a quick overview of the general IDE experience, please watch this video There are a number of exciting improvement in this release comp...Devpad: 4.25: Whats new for Devpad 4.25: New Theme support New Export Wordpress Minor Bug Fix's, improvements and speed upsAssaultCube Reloaded: 2.5.5: Linux has Ubuntu 11.10 32-bit precompiled binaries and Ubuntu 10.10 64-bit precompiled binaries, but you can compile your own as it also contains the source. If you are using Mac or other operating systems, please wait while we try to package for those OSes. Try to compile it. If it fails, download a virtual machine. The server pack is ready for both Windows and Linux, but you might need to compile your own for Linux (source included) Changelog: Fixed potential bot bugs: Map change, OpenAL...Edi: Edi 1.0 with DarkExpression: Added DarkExpression theme (dialogs and message boxes are not completely themed, yet)MCEBuddy 2.x: MCEBuddy 2.3.6: Changelog for 2.3.6 (32bit and 64bit) 1. Fixed a bug in multichannel audio conversion failure. AAC does not support 6 channel audio, MCEBuddy now checks for it and force the output to 2 channel if AAC codec is specified 2. Fixed a bug in Original Broadcast Date and Time. Original Broadcast Date and Time is reported in UTC timezone in WTV metadata. TVDB and MovieDB dates are reported in network timezone. It is assumed the video is recorded and converted on the same machine, i.e. local timezone...MVVM Light Toolkit: MVVM Light Toolkit V4.1 for Visual Studio 2012: This version only supports Visual Studio 2012 (and all Express editions too). If you use Visual Studio 2010, please stay tuned, we will publish an update in a few days with support for VS10. V4.1 supports: Windows Phone 8 Windows 8 (Windows RT) Silverlight 5 Silverlight 4 WPF 4.5 WPF 4 WPF 3.5 And the following development environments: Visual Studio 2012 (Pro, Premium, Ultimate) Visual Studio 2012 Express for Windows 8 Visual Studio 2012 Express for Windows Phone 8 Visual...Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.73: Fix issue in Discussion #401101 (unreferenced var in a for-in statement was getting removed). add the grouping operator to the parsed output so that unminified parsed code is closer to the original. Will still strip unneeded parens later, if minifying. more cleaning of references as they are minified out of the code.Liberty: v3.4.0.1 Release 28th October 2012: Change Log -Fixed -H4 Fixed the save verification screen showing incorrect mission and difficulty information for some saves -H4 Hopefully fixed the issue where progress did not save between missions and saves would not revert correctly -H3 Fixed crashes that occurred when trying to load player information -Proper exception dialogs will now show in place of crashesPlayer Framework by Microsoft: Player Framework for Windows 8 (Preview 7): This release is compatible with the version of the Smooth Streaming SDK released today (10/26). Release 1 of the player framework is expected to be available next week. IMPROVEMENTS & FIXESIMPORTANT: List of breaking changes from preview 6 Support for the latest smooth streaming SDK. Xaml only: Support for moving any of the UI elements outside the MediaPlayer (e.g. into the appbar). Note: Equivelent changes to the JS version due in coming week. Support for localizing all text used in t...Send multiple SMS via Way2SMS C#: SMS 1.1: Added support for 160by2Quick Launch: Quick Launch 1.0: A Lightweight and Fast Way to Manage and Launch Thousands of Tools and ApplicationsPress Win+Q and start to search and run. http://www.codeplex.com/Download?ProjectName=quicklaunch&DownloadId=523536Orchard Project: Orchard 1.6: Please read our release notes for Orchard 1.6: http://docs.orchardproject.net/Documentation/Orchard-1-6-Release-Notes Please do not post questions as reviews. Questions should be posted in the Discussions tab, where they will usually get promptly responded to. If you post a question as a review, you will pollute the rating, and you won't get an answer.Media Companion: Media Companion 3.507b: Once again, it has been some time since our release, and there have been a number changes since then. It is hoped that these changes will address some of the issues users have been experiencing, and of course, work continues! New Features: Added support for adding Home Movies. Option to sort Movies by votes. Added 'selectedBrowser' preference used when opening links in an external browser. Added option to fallback to getting runtime from the movie file if not available on IMDB. Added new Big...MSBuild Extension Pack: October 2012: Release Blog Post The MSBuild Extension Pack October 2012 release provides a collection of over 475 MSBuild tasks. A high level summary of what the tasks currently cover includes the following: System Items: Active Directory, Certificates, COM+, Console, Date and Time, Drives, Environment Variables, Event Logs, Files and Folders, FTP, GAC, Network, Performance Counters, Registry, Services, Sound Code: Assemblies, AsyncExec, CAB Files, Code Signing, DynamicExecute, File Detokenisation, GUI...NAudio: NAudio 1.6: Release notes at http://mark-dot-net.blogspot.co.uk/2012/10/naudio-16-release-notes-10th.htmlPowerShell Community Extensions: 2.1 Production: PowerShell Community Extensions 2.1 Release NotesOct 25, 2012 This version of PSCX supports both Windows PowerShell 2.0 and 3.0. See the ReleaseNotes.txt download above for more information.Umbraco CMS: Umbraco 4.9.1: Umbraco 4.9.1 is a bugfix release to fix major issues in 4.9.0 BugfixesThe full list of fixes can be found in the issue tracker's filtered results. A summary: Split buttons work again, you can now also scroll easier when the list is too long for the screen Media and Content pickers have information of the full path of the picked item Fixed: Publish status may not be accurate on nodes with large doctypes Fixed: 2 media folders and recycle bins after upgrade to 4.9 The template/code ...AcDown????? - AcDown Downloader Framework: AcDown????? v4.2.2: ??●AcDown??????????、??、??、???????。????，????，?????????????????????????。???????????Acfun、????(Bilibili)、??、??、YouTube、??、???、??????、SF????、????????????。 ●??????AcPlay?????，??????、????????????????。 ● AcDown??????????????????，????????????????????????????。 ● AcDown???????C#??，????.NET Framework 2.0??。?????"Acfun?????"。 ????32??64? Windows XP/Vista/7/8 ???? 32??64? ???Linux ????(1)????????Windows XP???，????????.NET Framework 2.0???(x86)，?????"?????????"??? (2)???????????Linux???，????????Mono?? ??2...Rawr: Rawr 5.0.2: This is the Downloadable WPF version of Rawr!For web-based version see http://elitistjerks.com/rawr.php You can find the version notes at: http://rawr.codeplex.com/wikipage?title=VersionNotes Rawr Addon (NOT UPDATED YET FOR MOP)We now have a Rawr Official Addon for in-game exporting and importing of character data hosted on Curse. The Addon does not perform calculations like Rawr, it simply shows your exported Rawr data in wow tooltips and lets you export your character to Rawr (including ba...New ProjectsAsbesto: Proyecto grupo: "2ravas" para Laboratorio de Computación IV de la carrera TSP de la UTN-FRGP Realizado en C# y ASP.NET en Visual Studio 2012 y SQL Server 2012C++ Diamond printer on console without if statement: prints just a diamond with stars(*). only one important and funny feature is that it's not using 'if' statement. C++ used.CloudTest: Test cloud computing projectEnumeration of objects Class Library C#: At core level in Java I like extension of traditional enum type permiting use as the elements instances of a class. The project implements the same idea by C# with some more advanced features like a set type with boolean operators extending idea of FlagsAttributeEquation Inversion: Visual Studion 2008 Add-in for equation inversions.ESENT Serialization Class Library: ESENT Serialization class library is built above Managed ESENT. It allows you to store your objects in the underlying extensible storage engine database.ForceHttps: Very simple httpModule to ensure that all http requests are https. 1. Drop the dll into your website's bin directory 2. Update httpModules section of your web.config to reference the dll 3. Make sure your Web Server can handle SSL requests for the URL ALL http requests will be redirected as https.forrajeriaPAV2: tp pav2 asd as asd as fasfjaijiasjifoa as asf asf as afs fas asf afs fsaGoogle Analytics for WinRT: A Windows Store (WinRT) class library for tracking Google Analytics page views, events, and custom variables for your Metro style desktop and tablet apps.huanglitest10312: mvc projectiMan: iMan will be your own port manager, which help to provide the information about all the ports open in your PC It's completely developed in .NET C#InjectionCop: Facilitates secure coding through static code analysis and contract annotations in the Common Language Infrastructure.Master of Olympus: Remake of Master of Olympus : Zeus, a game developed by Impressions Games in 2000.MediaScribe: MediaScribe is a note app for your media.MouseNestDotNet: A small personal website application.Project Estimator ???????? ?? ?????????????? ?? ???????: Project Estimator ? ???????? ??????????? ? ??????????? ?? ????? ? ???????? ????.Projekt grupowy 1: Project created only for school purpose.SecondHandApp: Warenwirtschaftsprogramm für denn SecondHand LädenSimple .NET XML Serialization: .NET's XML serialization using Linq XObject classes EG: XElement in an IXmlSerializable base classStrip Converter: A Very Handy Converter for 2D Games Developers Developer Website: http://www.bluebulk.infoSwitch JS Control (Client Side): Switch JS control is a very light client side library to create switch(es) on web applications or mobile applications.VisaSys: Visa System????????: TODO::????

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• Nvidia drivers don't work with mainline kernel

  - by dutchie

  I want to try some of the new features in the btrfs filesystem, and to do that I need to use a newer kernel than is included in Ubuntu 12.04. To do that, I have installed linux-headers-3.4.0-030400_3.4.0-030400.201205210521_all.deb, linux-headers-3.4.0-030400-generic_3.4.0-030400.201205210521_amd64.deb, and linux-image-3.4.0-030400-generic_3.4.0-030400.201205210521_amd64.deb from the mainline kernel download here. However, on rebooting into the 3.4 kernel, my desktop is stuck at a very low resolution and I cannot increase it to the full. This did happen when I first installed, but a simple install of the nvidia-current package got everything working nicely with my GTX570 card. There were appear to be some DKMS errors when I installed the kernel, and they indicated I should look at /var/lib/dkms/nvidia-current/295.40/build/make.log: josh@sirius:~/Downloads$ sudo dpkg -i linux-*.deb Selecting previously unselected package linux-headers-3.4.0-030400. (Reading database ... 309400 files and directories currently installed.) Unpacking linux-headers-3.4.0-030400 (from linux-headers-3.4.0-030400_3.4.0-030400.201205210521_all.deb) ... Selecting previously unselected package linux-headers-3.4.0-030400-generic. Unpacking linux-headers-3.4.0-030400-generic (from linux-headers-3.4.0-030400-generic_3.4.0-030400.201205210521_amd64.deb) ... Selecting previously unselected package linux-image-3.4.0-030400-generic. Unpacking linux-image-3.4.0-030400-generic (from linux-image-3.4.0-030400-generic_3.4.0-030400.201205210521_amd64.deb) ... Done. Setting up linux-headers-3.4.0-030400 (3.4.0-030400.201205210521) ... Setting up linux-headers-3.4.0-030400-generic (3.4.0-030400.201205210521) ... Examining /etc/kernel/header_postinst.d. run-parts: executing /etc/kernel/header_postinst.d/dkms 3.4.0-030400-generic /boot/vmlinuz-3.4.0-030400-generic ERROR (dkms apport): kernel package linux-headers-3.4.0-030400-generic is not supported Error! Bad return status for module build on kernel: 3.4.0-030400-generic (x86_64) Consult /var/lib/dkms/nvidia-current/295.40/build/make.log for more information. Setting up linux-image-3.4.0-030400-generic (3.4.0-030400.201205210521) ... Running depmod. update-initramfs: deferring update (hook will be called later) Examining /etc/kernel/postinst.d. run-parts: executing /etc/kernel/postinst.d/dkms 3.4.0-030400-generic /boot/vmlinuz-3.4.0-030400-generic ERROR (dkms apport): kernel package linux-headers-3.4.0-030400-generic is not supported Error! Bad return status for module build on kernel: 3.4.0-030400-generic (x86_64) Consult /var/lib/dkms/nvidia-current/295.40/build/make.log for more information. run-parts: executing /etc/kernel/postinst.d/initramfs-tools 3.4.0-030400-generic /boot/vmlinuz-3.4.0-030400-generic update-initramfs: Generating /boot/initrd.img-3.4.0-030400-generic run-parts: executing /etc/kernel/postinst.d/pm-utils 3.4.0-030400-generic /boot/vmlinuz-3.4.0-030400-generic run-parts: executing /etc/kernel/postinst.d/update-notifier 3.4.0-030400-generic /boot/vmlinuz-3.4.0-030400-generic run-parts: executing /etc/kernel/postinst.d/zz-update-grub 3.4.0-030400-generic /boot/vmlinuz-3.4.0-030400-generic Generating grub.cfg ... Found linux image: /boot/vmlinuz-3.4.0-030400-generic Found initrd image: /boot/initrd.img-3.4.0-030400-generic Found linux image: /boot/vmlinuz-3.2.0-24-generic Found initrd image: /boot/initrd.img-3.2.0-24-generic Found memtest86+ image: /memtest86+.bin Found Ubuntu 12.04 LTS (12.04) on /dev/sda1 Found Windows 7 (loader) on /dev/sda2 Found Windows 7 (loader) on /dev/sda3 done /var/lib/dkms/nvidia-current/295.40/build/make.log: DKMS make.log for nvidia-current-295.40 for kernel 3.4.0-030400-generic (x86_64) Thu Jun 7 00:58:39 BST 2012 NVIDIA: calling KBUILD... test -e include/generated/autoconf.h -a -e include/config/auto.conf || ( \ echo; \ echo " ERROR: Kernel configuration is invalid."; \ echo " include/generated/autoconf.h or include/config/auto.conf are missing.";\ echo " Run 'make oldconfig && make prepare' on kernel src to fix it."; \ echo; \ /bin/false) mkdir -p /var/lib/dkms/nvidia-current/295.40/build/.tmp_versions ; rm -f /var/lib/dkms/nvidia-current/295.40/build/.tmp_versions/* make -f scripts/Makefile.build obj=/var/lib/dkms/nvidia-current/295.40/build cc -Wp,-MD,/var/lib/dkms/nvidia-current/295.40/build/.nv.o.d -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/4.6/include -I/usr/src/linux-headers-3.4.0-030400-generic/arch/x86/include -Iarch/x86/include/generated -Iinclude -include /usr/src/linux-headers-3.4.0-030400-generic/include/linux/kconfig.h -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Wno-format-security -fno-delete-null-pointer-checks -O2 -m64 -mtune=generic -mno-red-zone -mcmodel=kernel -funit-at-a-time -maccumulate-outgoing-args -fstack-protector -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -DCONFIG_AS_FXSAVEQ=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -Wframe-larger-than=1024 -Wno-unused-but-set-variable -fno-omit-frame-pointer -fno-optimize-sibling-calls -pg -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow -fconserve-stack -DCC_HAVE_ASM_GOTO -I/var/lib/dkms/nvidia-current/295.40/build -Wall -MD -Wsign-compare -Wno-cast-qual -Wno-error -D__KERNEL__ -DMODULE -DNVRM -DNV_VERSION_STRING=\"295.40\" -Wno-unused-function -Wuninitialized -mno-red-zone -mcmodel=kernel -UDEBUG -U_DEBUG -DNDEBUG -DMODULE -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(nv)" -D"KBUILD_MODNAME=KBUILD_STR(nvidia)" -c -o /var/lib/dkms/nvidia-current/295.40/build/.tmp_nv.o /var/lib/dkms/nvidia-current/295.40/build/nv.c In file included from include/linux/kernel.h:19:0, from include/linux/sched.h:55, from include/linux/utsname.h:35, from /var/lib/dkms/nvidia-current/295.40/build/nv-linux.h:38, from /var/lib/dkms/nvidia-current/295.40/build/nv.c:13: include/linux/bitops.h: In function ‘hweight_long’: include/linux/bitops.h:66:41: warning: signed and unsigned type in conditional expression [-Wsign-compare] In file included from /usr/src/linux-headers-3.4.0-030400-generic/arch/x86/include/asm/uaccess.h:577:0, from include/linux/poll.h:14, from /var/lib/dkms/nvidia-current/295.40/build/nv-linux.h:97, from /var/lib/dkms/nvidia-current/295.40/build/nv.c:13: /usr/src/linux-headers-3.4.0-030400-generic/arch/x86/include/asm/uaccess_64.h: In function ‘copy_from_user’: /usr/src/linux-headers-3.4.0-030400-generic/arch/x86/include/asm/uaccess_64.h:53:6: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] In file included from /var/lib/dkms/nvidia-current/295.40/build/nv.c:13:0: /var/lib/dkms/nvidia-current/295.40/build/nv-linux.h: At top level: /var/lib/dkms/nvidia-current/295.40/build/nv-linux.h:114:75: fatal error: asm/system.h: No such file or directory compilation terminated. make[3]: *** [/var/lib/dkms/nvidia-current/295.40/build/nv.o] Error 1 make[2]: *** [_module_/var/lib/dkms/nvidia-current/295.40/build] Error 2 NVIDIA: left KBUILD. nvidia.ko failed to build! make[1]: *** [module] Error 1 make: *** [module] Error 2

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• Exception Handling And Other Contentious Political Topics

  - by Justin Jones

  So about three years ago, around the time of my last blog post, I promised a friend I would write this post. Keeping promises is a good thing, and this is my first step towards easing back into regular blogging. I fully expect him to return from Pennsylvania to buy me a beer over this. However, it’s been an… ahem… eventful three years or so, and blogging, unfortunately, got pushed to the back burner on my priority list, along with a few other career minded activities. Now that the personal drama of the past three years is more or less resolved, it’s time to put a few things back on the front burner. What I consider to be proper exception handling practices is relatively well known these days. There are plenty of blog posts out there already on this topic which more or less echo my opinions on this topic. I’ll try to include a few links at the bottom of the post. Several years ago I had an argument with a co-worker who posited that exceptions should be caught at every level and logged. This might seem like sanity on the surface, but the resulting error log looked something like this: Error: System.SomeException Followed by small stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace. Error: System.SomeException Followed by slightly bigger stack trace.   These were all the same exception. The problem with this approach is that the error log, if you run any kind of analytics on in, becomes skewed depending on how far up the stack trace your exception was thrown. To mitigate this problem, we came up with the concept of the “PreLoggedException”. Basically, we would log the exception at the very top level and subsequently throw the exception back up the stack encapsulated in this pre-logged type, which our logging system knew to ignore. Now the error log looked like this: Error: System.SomeException Followed by small stack trace. Much cleaner, right? Well, there’s still a problem. When your exception happens in production and you go about trying to figure out what happened, you’ve lost more or less all context for where and how this exception was thrown, because all you really know is what method it was thrown in, but really nothing about who was calling the method or why. What gives you this clue is the entire stack trace, which we’re losing here. I believe that was further mitigated by having the logging system pull a system stack trace and add it to the log entry, but what you’re actually getting is the stack for how you got to the logging code. You’re still losing context about the actual error. Not to mention you’re executing a whole slew of catch blocks which are sloooooooowwwww……… In other words, we started with a bad idea and kept band-aiding it until it didn’t suck quite so bad. When I argued for not catching exceptions at every level but rather catching them following a certain set of rules, my co-worker warned me “do yourself a favor, never express that view in any future interviews.” I suppose this is my ultimate dismissal of that advice, but I’m not too worried. My approach for exception handling follows three basic rules: Only catch an exception if 1. You can do something about it. 2. You can add useful information to it. 3. You’re at an application boundary. Here’s what that means: 1. Only catch an exception if you can do something about it. We’ll start with a trivial example of a login system that uses a file. Please, never actually do this in production code, it’s just concocted example. So if our code goes to open a file and the file isn’t there, we get a FileNotFound exception. If the calling code doesn’t know what to do with this, it should bubble up. However, if we know how to create the file from scratch we can create the file and continue on our merry way. When you run into situations like this though, What should really run through your head is “How can I avoid handling an exception at all?” In this case, it’s a trivial matter to simply check for the existence of the file before trying to open it. If we detect that the file isn’t there, we can accomplish the same thing without having to handle in in a catch block. 2. Only catch an exception if you can do something about it. Continuing with the poorly thought out file based login system we contrived in part 1, if the code calls a Login(…) method and the FileNotFound exception is thrown higher up the stack, the code that calls Login must account for a FileNotFound exception. This is kind of counterintuitive because the calling code should not need to know the internals of the Login method, and the data file is an implementation detail. What makes more sense, assuming that we didn’t implement any of the good advice from step 1, is for Login to catch the FileNotFound exception and wrap it in a new exception. For argument’s sake we’ll say LoginSystemFailureException. (Sorry, couldn’t think of anything better at the moment.) This gives us two stack traces, preserving the original stack trace in the inner exception, and also is much more informative to the calling code. 3. Only catch an exception if you’re at an application boundary. At some point we have to catch all the exceptions, even the ones we don’t know what to do with. WinForms, ASP.Net, and most other UI technologies have some kind of built in mechanism for catching unhandled exceptions without fatally terminating the application. It’s still a good idea to somehow gracefully exit the application in this case if possible though, because you can no longer be sure what state your application is in, but nothing annoys a user more than an application just exploding. These unhandled exceptions need to be logged, and this is a good place to catch them. Ideally you never want this option to be exercised, but code as though it will be. When you log these exceptions, give them a “Fatal” status (e.g. Log4Net) and make sure these bugs get handled in your next release. That’s it in a nutshell. If you do it right each exception will only get logged once and with the largest stack trace possible which will make those 2am emergency severity 1 debugging sessions much shorter and less frustrating. Here’s a few people who also have interesting things to say on this topic:  http://blogs.msdn.com/b/ericlippert/archive/2008/09/10/vexing-exceptions.aspx http://www.codeproject.com/Articles/9538/Exception-Handling-Best-Practices-in-NET I know there’s more but I can’t find them at the moment.

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• Disaster, or Migration?

  - by Rob Farley

  This post is in two parts – technical and personal. And I should point out that it’s prompted in part by this month’s T-SQL Tuesday, hosted by Allen Kinsel. First, the technical: I’ve had a few conversations with people recently about migration – moving a SQL Server database from one box to another (sometimes, but not primarily, involving an upgrade). One question that tends to come up is that of downtime. Obviously there will be some period of time between the old server being available and the new one. The way that most people seem to think of migration is this: Build a new server. Stop people from using the old server. Take a backup of the old server Restore it on the new server. Reconfigure the client applications (or alternatively, configure the new server to use the same address as the old) Make the new server online. There are other things involved, such as testing, of course. But this is essentially the process that people tell me they’re planning to follow. The bit that I want to look at today (as you’ve probably guessed from my title) is the “backup and restore” section. If a SQL database is using the Simple Recovery Model, then the only restore option is the last database backup. This backup could be full or differential. The transaction log never gets backed up in the Simple Recovery Model. Instead, it truncates regularly to stay small. One that’s using the Full Recovery Model (or Bulk-Logged) won’t truncate its log – the log must be backed up regularly. This provides the benefit of having a lot more option available for restores. It’s a requirement for most systems of High Availability, because if you’re making sure that a spare box is up-and-running, ready to take over, then you have to be interested in the logs that are happening on the current box, rather than truncating them all the time. A High Availability system such as Mirroring, Replication or Log Shipping will initialise the spare machine by restoring a full database backup (and maybe a differential backup if available), and then any subsequent log backups. Once the secondary copy is close, transactions can be applied to keep the two in sync. The main aspect of any High Availability system is to have a redundant system that is ready to take over. So the similarity for migration should be obvious. If you need to move a database from one box to another, then introducing a High Availability mechanism can help. By turning on the Full Recovery Model and then taking a backup (so that the now-interesting logs have some context), logs start being kept, and are therefore available for getting the new box ready (even if it’s an upgraded version). When the migration is ready to occur, a failover can be done, letting the new server take over the responsibility of the old, just as if a disaster had happened. Except that this is a planned failover, not a disaster at all. There’s a fine line between a disaster and a migration. Failovers can be useful in patching, upgrading, maintenance, and more. Hopefully, even an unexpected disaster can be seen as just another failover, and there can be an opportunity there – perhaps to get some work done on the principal server to increase robustness. And if I’ve just set up a High Availability system for even the simplest of databases, it’s not necessarily a bad thing. :) So now the personal: It’s been an interesting time recently... June has been somewhat odd. A court case with which I was involved got resolved (through mediation). I can’t go into details, but my lawyers tell me that I’m allowed to say how I feel about it. The answer is ‘lousy’. I don’t regret pursuing it as long as I did – but in the end I had to make a decision regarding the commerciality of letting it continue, and I’m going to look forward to the days when the kind of money I spent on my lawyers is small change. Mind you, if I had a similar situation with an employer, I’d do the same again, but that doesn’t really stop me feeling frustrated about it. The following day I had to fly to country Victoria to see my grandmother, who wasn’t expected to last the weekend. She’s still around a week later as I write this, but her 92-year-old body has basically given up on her. She’s been a Christian all her life, and is looking forward to eternity. We’ll all miss her though, and it’s hard to see my family grieving. Then on Tuesday, I was driving back to the airport with my family to come home, when something really bizarre happened. We were travelling down the freeway, just pulled out to go past a truck (farm-truck sized, not a semi-trailer), when a car-sized mass of metal fell off it. It was something like an industrial air-conditioner, but from where I was sitting, it was just a mass of spinning metal, like something out of a movie (one friend described it as “holidays by Michael Bay”). Somehow, and I’m really don’t know how, the part of it nearest us bounced high enough to clear the car, and there wasn’t even a scratch. We pulled over the check, and I was just thanking God that we’d changed lanes when we had, and that we remained unharmed. I had all kinds of thoughts about what could’ve happened if we’d had something that size land on the windscreen... All this has drilled home that while I feel that I haven’t provided as well for the family as I could’ve done (like by pursuing an expensive legal case), I shouldn’t even consider that I have proper control over things. I get to live life, and make decisions based on what I feel is right at the time. But I’m not going to get everything right, and there will be things that feel like disasters, some which could’ve been in my control and some which are very much beyond my control. The case feels like something I could’ve pursued differently, a disaster that could’ve been avoided in some way. Gran dying is lousy of course. An accident on the freeway would have been awful. I need to recognise that the worst disasters are ones that I can’t affect, and that I need to look at things in context – perhaps seeing everything that happens as a migration instead. Life is never the same from one day to the next. Every event has a before and an after – sometimes it’s clearly positive, sometimes it’s not. I remember good events in my life (such as my wedding), and bad (such as the loss of my father when I was ten, or the back injury I had eight years ago). I’m not suggesting that I know how to view everything from the “God works all things for good” perspective, but I am trying to look at last week as a migration of sorts. Those things are behind me now, and the future is in God’s hands. Hopefully I’ve learned things, and will be able to live accordingly. I’ve come through this time now, and even though I’ll miss Gran, I’ll see her again one day, and the future is bright.

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• Agilist, Heal Thyself!

  - by Dylan Smith

  I’ve been meaning to blog about a great experience I had earlier in the year at Prairie Dev Con Calgary.  Myself and Steve Rogalsky did a session that we called “Agilist, Heal Thyself!”.  We used a format that was new to me, but that Steve had seen used at another conference.  What we did was start by asking the audience to give us a list of challenges they had had when adopting agile.  We wrote them all down, then had everybody vote on the most interesting ones.  Then we split into two groups, and each group was assigned one of the agile challenges.  We had 20 minutes to discuss the challenge, and suggest solutions or approaches to improve things.  At the end of the 20 minutes, each of the groups gave a brief summary of their discussion and learning's, then we mixed up the groups and repeated with another 2 challenges. The 2 groups I was part of had some really interesting discussions, and suggestions: Unfinished Stories at the end of Sprints The first agile challenge we tackled, was something that every single Scrum team I have worked with has struggled with.  What happens when you get to the end of a Sprint, and there are some stories that are only partially completed.  The team in question was getting very de-moralized as they felt that every Sprint was a failure as they never had a set of fully completed stories. How do you avoid this? and/or what do you do when it happens? There were 2 pieces of advice that were well received: 1. Try to bring stories to completion before starting new ones.  This is advice I give all my Scrum teams.  If you have a 3-week sprint, what happens all too often is you get to the end of week 2, and a lot of stories are almost done; but almost none are completely done.  This is a Bad Thing.  I encourage the teams I work with to only start a new story as a very last resort.  If you finish your task look at the stories in progress and see if there’s anything you can do to help before moving onto a new story.  In the daily standup, put a focus on seeing what stories got completed yesterday, if a few days go by with none getting completed, be sure this fact is visible to the team and do something about it.  Something I’ve been doing recently is introducing WIP (Work In Progress) limits while using Scrum.  My current team has 2-week sprints, and we usually have about a dozen or stories in a sprint.  We instituted a WIP limit of 4 stories.  If 4 stories have been started but not finished then nobody is allowed to start new stories.  This made it obvious very quickly that our QA tasks were our bottleneck (we have 4 devs, but only 1.5 testers).  The WIP limit forced the developers to start to pickup QA tasks before moving onto the next dev tasks, and we ended our sprints with many more stories completely finished than we did before introducing WIP limits. 2. Rather than using time-boxed sprints, why not just do away with them altogether and go to a continuous flow type approach like KanBan.  Limit WIP to keep things under control, but don’t have a fixed time box at the end of which all tasks are supposed to be done.  This eliminates the problem almost entirely.  At some points in the project (releases) you need to be able to burn down all the half finished stories to get a stable release build, but this probably occurs less often than every sprint, and there are alternative approaches to achieve it using branching strategies rather than forcing your team to try to get to Zero WIP every 2-weeks (e.g. when you are ready for a release, create a new branch for any new stories, but finish all existing stories in the current branch and release it). Trying to Introduce Agile into a team with previous Bad Agile Experiences One of the agile adoption challenges somebody described, was he was in a leadership role on a team he had recently joined – lets call him Dave.  This team was currently very waterfall in their ALM process, but they were about to start on a new green-field project.  Dave wanted to use this new project as an opportunity to do things the “right way”, using an Agile methodology like Scrum, adopting TDD, automated builds, proper branching strategies, etc.  The problem he was facing is everybody else on the team had previously gone through an “Agile Adoption” that was a horrible failure.  Dave blamed this failure on the consultant brought in previously to lead this agile transition, but regardless of the reason, the team had very negative feelings towards agile, and was very resistant to trying it out again.  Dave possibly had the authority to try to force the team to adopt Agile practices, but we all know that doesn’t work very well.  What was Dave to do? Ultimately, the best advice was to question *why* did Dave want to adopt all these various practices. Rather than trying to convince his team that these were the “right way” to run a dev project, and trying to do a Big Bang approach to introducing change.  He would be better served by identifying problems the team currently faces, have a discussion with the team to get everybody to agree that specific problems existed, then have an open discussion about ways to address those problems.  This way Dave could incrementally introduce agile practices, and he doesn’t even need to identify them as “agile” practices if he doesn’t want to.  For example, when we discussed with Dave, he said probably the teams biggest problem was long periods without feedback from users, then finding out too late that the software is not going to meet their needs.  Rather than Dave jumping right to introducing Scrum and all it entails, it would be easier to get buy-in from team if he framed it as a discussion of existing problems, and brainstorming possible solutions.  And possibly most importantly, don’t try to do massive changes all at once with a team that has not bought-into those changes.  Taking an incremental approach has a greater chance of success. I see something similar in my day job all the time too.  Clients who for one reason or another claim to not be fans of agile (or not ready for agile yet).  But then they go on to ask me to help them get shorter feedback cycles, quicker delivery cycles, iterative development processes, etc.  It’s kind of funny at times, sometimes you just need to phrase the suggestions in terms they are using and avoid the word “agile”. PS – I haven’t blogged all that much over the past couple of years, but in an attempt to motivate myself, a few of us have accepted a blogger challenge.  There’s 6 of us who have all put some money into a pool, and the agreement is that we each need to blog at least once every 2-weeks.  The first 2-week period that we miss we’re eliminated.  Last person standing gets the money.  So expect at least one blog post every couple of weeks for the near future (I hope!).  And check out the blogs of the other 5 people in this blogger challenge: Steve Rogalsky: http://winnipegagilist.blogspot.ca Aaron Kowall: http://www.geekswithblogs.net/caffeinatedgeek Tyler Doerkson: http://blog.tylerdoerksen.com David Alpert: http://www.spinthemoose.com Dave White: http://www.agileramblings.com (note: site not available yet.  should be shortly or he owes me some money!)

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• First PC Build (Part 1)

  - by Anthony Trudeau

  Originally posted on: http://geekswithblogs.net/tonyt/archive/2014/08/05/157959.aspxA couple of months ago I made the decision to build myself a new computer. The intended use is gaming and for using the last real version of Photoshop. I was motivated by the poor state of console gaming and a simple desire to do something I haven’t done before – build a PC from the ground up. I’ve been using PCs for more than two decades. I’ve replaced a component hear and there, but for the last 10 years or so I’ve only used laptops. Therefore, this article will be written from the perspective of someone familiar with PCs, but completely new at building. I’m not an expert and this is not a definitive guide for building a PC, but I do hope that it encourages you to try it yourself. Component List Research There was a lot of research necessary, because building a PC is completely new to me, and I haven’t kept up with what’s out there. The first thing you want to do is nail down what your goals are. Your goals are going to be driven by what you want to do with your computer and personal choice. Don’t neglect the second one, because if you’re doing this for fun you want to get what you want. In my case, I focused on three things: performance, longevity, and aesthetics. The performance aspect is important for gaming and Photoshop. This will drive what components you get. For example, heavy gaming use is going to drive your choice of graphics card. Longevity is relevant to me, because I don’t want to be changing things out anytime soon for the next hot game. The consequence of performance and longevity is cost. Finally, aesthetics was my next consideration. I could have just built a box, but it wouldn’t have been nearly as fun for me. Aesthetics might not be important to you. They are for me. I also like gadgets and that played into at least one purchase for this build. I used PC Part Picker to put together my component list. I found it invaluable during the process and I’d recommend it to everyone. One caveat is that I wouldn’t trust the compatibility aspects. It does a pretty good job of not steering you wrong, but do your own research. The rest of it isn’t really sexy. I started out with what appealed to me and then I made changes and additions as I dived deep into researching each component and interaction I could find. The resources I used are innumerable. I used reviews, product descriptions, forum posts (praises and problems), et al. to assist me. I also asked friends into gaming what they thought about my component list. And when I got near the end I posted my list to the Reddit /r/buildapc forum. I cannot stress the value of extra sets of eyeballs and first hand experiences. Some of the resources I used: PC Part Picker Tom’s Hardware bit-tech Reddit Purchase PC Part Picker favors certain vendors. You should look at others too. In my case I found their favorites to be the best. My priorities were out-the-door price and shipping time. I knew that once I started getting parts I’d want to start building. Luckily, I timed it well and everything arrived within the span of a few days. Here are my opinions on the vendors I ended up using in alphabetical order. Amazon.com is a good, reliable choice. They have excellent customer service in my experience, and I knew I wouldn’t have trouble with them. However, shipping time is often a problem when you use their free shipping unless you order expensive items (I’ve found items over $100 ship quickly). Ultimately though, price wasn’t always the best and their collection of sales tax in my state turned me off them. I did purchase my case from them. I ordered the mouse as well, but I cancelled after it was stuck four days in a “shipping soon” state. I purchased the mouse locally. Best Buy is not my favorite place to do business. There’s a lot of history with poor, uninterested sales representatives and they used to have a lot of bad anti-consumer policies. That’s a lot better now, but the bad taste is still in my mouth. I ended up purchasing the accessories from them including mouse (locally) and headphones. NCIX is a company that I’ve never heard of before. It popped up as a recommendation for my CPU cooler on PC Part Picker. I didn’t do a lot of research on the company, because their policy on you buying insurance for your orders turned me off. That policy makes it clear to me that the company finds me responsible for the shipment once it leaves their dock. That’s not right, and may run afoul of state laws. Regardless they shipped my CPU cooler quickly and I didn’t have a problem. NewEgg.com is a well known company. I had never done business with them, but I’m glad I did. They shipped quickly and provided good visibility over everything. The prices were also the best in most cases. My main complaint is that they have a lot of exchange only return policies on components. To their credit those policies are listed in the cart underneath each item. The visibility tells me that they’re not playing any shenanigans and made me comfortable dealing with that risk. The vast majority of what I ordered came from them. Coming Next In the next part I’ll tackle my build experience.

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• I Know What I Did This Summer: Put Down Trex Decking

  - by thatjeffsmith

  If you’re wondering why I would bore everyone with my pictures and frequent status updates/tweets from the past week – it’s so I could document the process of refurbishing my deck, or what some would call a porch. When we go to take a vacation, buy a car, do anything – we also read personal blogs to get the real story. So, if you’re curious about what it takes to tackle this sort of project, read on. Skills/Equipment/Manpower We Possessed I took the old decking out by myself. I’m about 230 lbs, more than 6′ tall, and I’m pretty healthy. This took about 8 hours over two afternoons. Three of us put the deck back together. My wife has two engineering degrees. Her father also has two engineering degrees. Lots of brainpower available here. Also, her dad ran the public works department for a country for more than 20 years – so lots and lots of practical experience on hand. We had a compound mitre saw, a skilsaw, 2-3 crowbars, a framing hammer, 3 cordless drills, a corded drill, lots of sawhorses, a power sander, an angle grinder, a 10×10 Coleman canopy tent, a Ford F-150 pickup truck, outdoor speakers and lots of iTunes playlists, plenty of water and cold beer. Why We Did This Our deck was relatively young – it was built in 2005. However, the pressure treated boards must not have been adequately maintained before we bought the house. I had powerwashed the deck every other year and had it stained a few times. The boards just rotted. We’re going to be in the house for a long time, and we wanted something that would look nice and require little maintenance. More bad deck boards The deck boards were in bad shape Things We Learned The two most important things: The hidden fasteners have to be put in JUST right. Wedge them into the grooved board, then bend down the bit that is screwed down. We didn’t do this on the first board and couldn’t get the second board to fit nearly close enough. Watching the official TREX YouTube video helped immensely, and we should have watched that first. When pre-drilling holes for the boards that need screwed down – DO NOT pre-drill through the underlying framing wood. ONLY pre-drill through the TREX itself. The screw won’t seat in the board properly. Instead of sitting down flush with the board, it will stop at the top of the board and just spin. I had to call the the place that sold me the screws to find this out. So about a third of our screws look like crap. If it doesn’t look or feel right – stop everything and pick up your computer or your phone. It’s not right, and it will be much easier to stop and find out why. We didn’t do this, and now I’m going to see every screw that’s not flush with the boards and get upset. Oh well. The Process How much time did it take? Well I spent about 8 hours taking the deck apart. And then the 3 of use spent 8 hours the first day, 10 hours the second day, 8 hours the third, and another 6 hours on the fourth day. That’s like 104 man-hours. We supposedly saved four or five thousand dollars in labor, but don’t do the math here or you might get a bit upset. The main thing is that we got what we wanted, and there won’t be any surprises later. Now for some pictures… This 6”+ pry bar made the destruction of the old deck much easier Most of the joists, once exposed, were OK. This joist wasn’t sitting on ANYTHING before. We think a lazy gas person cut the board to sneak a gas line in. Awesome… These monster lag bolts had to be accounted for when putting in the additional framing The border pattern Sheri wanted to put in required a lot more framing. These were the first boards to go down – we screwed them in as there was no way to attach clips I sat, kicked in the boards, and then drilled these clips in – but my wife was able to go MUCH faster by using her hands to lock the boards in and drill on her knees. I liked locking the board in with my feet when they needed to be ‘encouraged’ to go straight. The first board took FOREVER to go in, but then when we got rolling, we were able to put in a 20′ board in less than 10 minutes. This was end of construction day #2 – we got much further than we thought we would. Ah, the dreaded last 10% – what to do here? Remember those ‘floating’ stringers? Yeah, we fixed that up a bit, too. My wife used a website (and her brain) to calculate exactly how to cut the stringers to give us the rise/run we needed with the proper clearance and all that jazz. The stairs with stringers and toe kicks – this was worth the effort It started raining on us as I screwed down the steps – this we managed to get our shade tent up on the deck to protect us from the rain too The stairs, finished Finished, mostly Good corner shot The top of the stairs Stairs, looking down Celebratory beer In Summary There are a few things we’re not happy with. I think we can fix them up – but later. I have a few things left to finish, rewire the lighting, get the gas grille put back in, and rehang some screen doors. I was expecting this to be a lot worse than it was. If I didn’t have the help, I would have never done it myself. But I’m glad that I did have that help and did do that project. It’s not often you get to spend that kind of qualify time with family and building cool stuff.

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• Secure Your Wireless Router: 8 Things You Can Do Right Now

  - by Chris Hoffman

  A security researcher recently discovered a backdoor in many D-Link routers, allowing anyone to access the router without knowing the username or password. This isn’t the first router security issue and won’t be the last. To protect yourself, you should ensure that your router is configured securely. This is about more than just enabling Wi-Fi encryption and not hosting an open Wi-Fi network. Disable Remote Access Routers offer a web interface, allowing you to configure them through a browser. The router runs a web server and makes this web page available when you’re on the router’s local network. However, most routers offer a “remote access” feature that allows you to access this web interface from anywhere in the world. Even if you set a username and password, if you have a D-Link router affected by this vulnerability, anyone would be able to log in without any credentials. If you have remote access disabled, you’d be safe from people remotely accessing your router and tampering with it. To do this, open your router’s web interface and look for the “Remote Access,” “Remote Administration,” or “Remote Management” feature. Ensure it’s disabled — it should be disabled by default on most routers, but it’s good to check. Update the Firmware Like our operating systems, web browsers, and every other piece of software we use, router software isn’t perfect. The router’s firmware — essentially the software running on the router — may have security flaws. Router manufacturers may release firmware updates that fix such security holes, although they quickly discontinue support for most routers and move on to the next models. Unfortunately, most routers don’t have an auto-update feature like Windows and our web browsers do — you have to check your router manufacturer’s website for a firmware update and install it manually via the router’s web interface. Check to be sure your router has the latest available firmware installed. Change Default Login Credentials Many routers have default login credentials that are fairly obvious, such as the password “admin”. If someone gained access to your router’s web interface through some sort of vulnerability or just by logging onto your Wi-Fi network, it would be easy to log in and tamper with the router’s settings. To avoid this, change the router’s password to a non-default password that an attacker couldn’t easily guess. Some routers even allow you to change the username you use to log into your router. Lock Down Wi-Fi Access If someone gains access to your Wi-Fi network, they could attempt to tamper with your router — or just do other bad things like snoop on your local file shares or use your connection to downloaded copyrighted content and get you in trouble. Running an open Wi-Fi network can be dangerous. To prevent this, ensure your router’s Wi-Fi is secure. This is pretty simple: Set it to use WPA2 encryption and use a reasonably secure passphrase. Don’t use the weaker WEP encryption or set an obvious passphrase like “password”. Disable UPnP A variety of UPnP flaws have been found in consumer routers. Tens of millions of consumer routers respond to UPnP requests from the Internet, allowing attackers on the Internet to remotely configure your router. Flash applets in your browser could use UPnP to open ports, making your computer more vulnerable. UPnP is fairly insecure for a variety of reasons. To avoid UPnP-based problems, disable UPnP on your router via its web interface. If you use software that needs ports forwarded — such as a BitTorrent client, game server, or communications program — you’ll have to forward ports on your router without relying on UPnP. Log Out of the Router’s Web Interface When You’re Done Configuring It Cross site scripting (XSS) flaws have been found in some routers. A router with such an XSS flaw could be controlled by a malicious web page, allowing the web page to configure settings while you’re logged in. If your router is using its default username and password, it would be easy for the malicious web page to gain access. Even if you changed your router’s password, it would be theoretically possible for a website to use your logged-in session to access your router and modify its settings. To prevent this, just log out of your router when you’re done configuring it — if you can’t do that, you may want to clear your browser cookies. This isn’t something to be too paranoid about, but logging out of your router when you’re done using it is a quick and easy thing to do. Change the Router’s Local IP Address If you’re really paranoid, you may be able to change your router’s local IP address. For example, if its default address is 192.168.0.1, you could change it to 192.168.0.150. If the router itself were vulnerable and some sort of malicious script in your web browser attempted to exploit a cross site scripting vulnerability, accessing known-vulnerable routers at their local IP address and tampering with them, the attack would fail. This step isn’t completely necessary, especially since it wouldn’t protect against local attackers — if someone were on your network or software was running on your PC, they’d be able to determine your router’s IP address and connect to it. Install Third-Party Firmwares If you’re really worried about security, you could also install a third-party firmware such as DD-WRT or OpenWRT. You won’t find obscure back doors added by the router’s manufacturer in these alternative firmwares. Consumer routers are shaping up to be a perfect storm of security problems — they’re not automatically updated with new security patches, they’re connected directly to the Internet, manufacturers quickly stop supporting them, and many consumer routers seem to be full of bad code that leads to UPnP exploits and easy-to-exploit backdoors. It’s smart to take some basic precautions. Image Credit: Nuscreen on Flickr     

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• exportfs: internal: no supported addresses in nfs_client

  - by Brian

  I am trying to set up a NFS server on an AWS instance running SLES11. After installing nfs-utils, I tried to export a test share. Here is what my /etc/exports file looks like: /opt/share1 ec2-50-16-224-79.compute-1.amazonaws.com(rw,async) export -ar returns the following message: exportfs: internal: no supported addresses in nfs_client domU-12-31-38-04-7E-02.compute-1.internal:/opt/share1: No such file or directory Any idea what the no supported addresses error means? Thanks!

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• Protected object this object on the rompager server is protected

  - by Sami-L

  I have a windows home server, when I connect to any web site in it I get an authentication window with the next message: "http://mydomain.com site requires user name and password, the site says: "SmartAX". Then when I close the window I get an error page saying: Protected object this object on the rompager server is protected Could you please have an idea on this, have it relation with ADSL router ?

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• DNS Client Event 1012: Error reading local hosts file

  - by Sam

  My notebook boots extreme slowly and shows loads of the following error in the event log: Error reading local hosts file Source: DNS Client Events EventID: 1012 The computer is quite new, I kind of just finished installing. So I don't feel like installing everything again (especially since this probably would result in the same problem anyway). Any idea how to resolve this? Thanks, Sam

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• version mismatch error

  - by Niall

  I am trying to install a newer version of an application that i have installed (autodata). When i install the newer version of the software, when it is installed and tries to run i get the following error I have tried to full remove the old version before installing the newer version (and i think i have) but it still is not working... does anyone know how to solve this? I have tried to use Revo Unstaller Pro to uninstall autodata but am still getting the same error, have no idea why I am getting this

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• Install cURL in Linksys router WRT54GL with DD-WRT

  - by levhita

  I'm using the mini-generic version, there isn't really too much extra room in the jffs partition to install cURL, LibOpenSSL, zLib and libcurl. As ipkg suggest is needed. And when I try to install into RAM it fails to. Any Idea?

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• How long do DDoS attacks last?

  - by Susan

  I realize the answer to this question will vary, which is why I'm asking it. If you've suffered a DDoS attack before - how long did it last? Just trying to get an idea of how long we'll have to continue to wage this battle (going on a couple weeks now).

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• How to set ulimits in Solaris 10

  - by James Bradley

  I normally use pam_limits.so and /etc/security/limits.conf to set ulimits on filesize/cputime etc for the regular users logging in to my server running Ubuntu. Can anyone give the best way of doing similar with Solaris 10. I think it is done using /etc/system but have no idea what to add to the file or indeed if it is the correct file. I'm particularly interested in setting up ulimit -f without going down the .profile route.

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• Installing gitweb failed: No package gitweb available

  - by logii

  I have tried installing gitweb via ssh and failed. Below is what I get. root@server [~]# yum install gitweb Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * rpmforge: ftp-stud.fht-esslingen.de rpmforge | 1.1 kB 00:00 rpmforge/primary | 3.8 MB 00:19 rpmforge 10502/10502 Excluding Packages in global exclude list Finished Setting up Install Process No package gitweb available. Nothing to do Anyone has any idea of what else is missing?

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• FreeBSD 8 Kernel Configuration Error Using the VESA Option

  - by gvkv

  I'm trying to reconfigure FreeBSD 8 (amd64) to allow for a high resolution terminal by following these instructions. The problem is that when I add the two lines: options VESA options SC_PIXEL_MODE and try to build: make buildkernel KERNCONF=VESAKERN I get the following error: /usr/src/sys/amd64/conf/VESAKERN: unknown option "VESA" and I have no idea why.

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• Invalid XML Character in a Word 2007 (docx) document

  - by user29799

  Hi, I've written a Word 2007 document and now I can't open it. The error I get is: The file ... cannot be opened because there are problems with the contents. Details: Illegal xml character. Location: Part: /word/header3.xml, Line:2 Column:1511 Any idea how I can recover the file? Thanks, Sagee.

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• sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 7F0CEB10 command returns error

  - by nyamka

  I'm trying to install Mongodb on Ubuntu 12 but when I run this command: sudo apt-key adv --keyserver keyserver.ubuntu.com --recv 7F0CEB10 This returned the error below: keyserver.ubuntu.com host not found gpgkeys: HTTP fetch error 7: couldn't connect: no such file or directory gpg:no valid openPGP data found gpg: Total number processes :0 I turned off Firewall on Iptables, but it don't work. Is there any idea?

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