Search Results

Search found 5849 results on 234 pages for 'partition scheme'.

Page 221/234 | < Previous Page | 217 218 219 220 221 222 223 224 225 226 227 228  | Next Page >

• My Thoughts On the Xbox 180

  - by Chris Gardner

  Originally posted on: http://geekswithblogs.net/freestylecoding/archive/2013/06/21/my-thoughts-on-the-xbox-180.aspx Everyone seems to be putting their 0.00237 cents into the wishing well over Microsoft's recent decision to reverse the DRM policy on the Xbox One. However, there have been a few issues that nobody has touched. As such, I have decided to dig 0.00237 cents out of my pocket. First, let me be clear about this point. I do not support the decision to reverse the DRM policy on the Xbox One. I wanted that point to be expressed first and unambiguously. I will say it again. I do not support the decision to reverse the DRM policy on the Xbox One. Now that I have that out of the way, let me go into my rationale. This decision removes most of the cool features that enticed me to pre-order the console. No, I didn't cancel my pre-order. There is still five months before the release of the console, and there is still a plethora of information that we, as consumers, do not have. With that, it should be noted that much of the talk in this post is speculation and rhetoric. I do not have any insider information that you do not possess. The persistent connection would have allowed the console to do many of the functions for which we have been begging. That demo where someone was playing Ryse, seamlessly accepted a multiplayer challenge in Killer Instinct, played the match (and a rematch,) and then jumped back into Ryse. That's gone, if you bought the game on disc. The new, DRM free system will require the disc in the system to play a game. That bullet point where one Xbox Live account could have up to 10 slave accounts so families could play together, no matter where they were located. That's gone as well. The promise of huge, expansive, dynamically changing worlds that was brought to us with the power of cloud computing. Well, "the people" didn't want there to be a forced, persistent connection. As such, developers can't rely on a connection and, as such, that feature is gone. This is akin to the removal of the hard drive on the Xbox 360. The list continues, but the enthusiast press has enumerated the list far better than I wish. All of this is because the Xbox team saw the HUGE success of Steam and decided to borrow a few ideas. Yes, Steam. The service that everyone hated for the first six months (for the same reasons the Xbox One is getting flack.) There was an initial growing pain. However, it is now lauded as the way games distribution should be handled. Unless you are Microsoft. I do find it curious that many of the features were originally announced for the PS4 during its unveiling. However, much of that was left strangely absent for Sony's E3 press conference. Instead, we received a single, static slide that basically said the exact opposite of Microsoft's plans. It is not farfetched to believe that slide came into existence during the approximately seven hours between the two media briefings. The thing that majorly annoys me over this whole kerfuffle is that the single thing that caused the call to arms is, really, not an issue. Microsoft never said they were going to block used sales. They said it was up to the publisher to make that decision. This would have allowed publishers to reclaim some of the costs of development in subsequent sales of the product. If you sell your game to GameStop for 7 USD, GameStop is going to sell it for 55 USD. That is 48 USD pure profit for them. Some publishers asked GameStop for a small cut. Was this a huge, money grubbing scheme? Well, yes, but the idea was that they have to handle server infrastructure for dormant accounts, etc. Of course, GameStop flatly refused, and the Online Pass was born. Fortunately, this trend didn’t last, and most publishers have stopped the practice. The ability to sell "licenses" has already begun to be challenged. Are you living in the EU? If so, companies must allow you to sell digital property. With this precedent in place, it's only a matter of time before other areas follow suit. If GameStop were smart, they should have immediately contacted every publisher out there to get the rights to become a clearing house for these licenses. Then, they keep their business model and could reduce their brick and mortar footprint. The digital landscape is changing. We need to not block this process. As Seth MacFarlane best said "Some issues are so important that you should drag people kicking and screaming." I believe this was said on an episode of Real Time with Bill Maher about the issue of Gay Marriages. Much like the original source, this is an issue that we need to drag people to the correct, progressive position. Microsoft, as a company, actually has the resources to weather the transition period. They have a great pool of first and second party developers that can leverage this new framework to prove the validity. Over time, the third party developers will get excited to use these tools. As an old C++ guy, I resisted C# for years. Now, I think it's one of the best languages I've ever used. I have a server room and a Co-Lo full of servers, so I originally didn't see the value in Azure. Now, I wish I could move every one of my projects into the cloud. I still LOVE getting physical packaging, which my music and games collection will proudly attest. However, I have started to see the value in pure digital, and have found ways to integrate this into the ways I consume those products. I can, honestly, understand how some parts of the population would be very apprehensive about this new landscape. There were valid arguments about people with no internet access. There are ways to combat these problems. These methods do not require us to throw the baby out with the bathwater. However, the number of people in the computer industry that I have seen cry foul is truly appalling. We are the forward looking people that help show how technology can improve people's lives. If we can't see the value of the brief pain involved with an exciting new ecosystem, than who will?

  Read the article

• C#: LINQ vs foreach - Round 1.

  - by James Michael Hare

  So I was reading Peter Kellner's blog entry on Resharper 5.0 and its LINQ refactoring and thought that was very cool.  But that raised a point I had always been curious about in my head -- which is a better choice: manual foreach loops or LINQ?    The answer is not really clear-cut.  There are two sides to any code cost arguments: performance and maintainability.  The first of these is obvious and quantifiable.  Given any two pieces of code that perform the same function, you can run them side-by-side and see which piece of code performs better.   Unfortunately, this is not always a good measure.  Well written assembly language outperforms well written C++ code, but you lose a lot in maintainability which creates a big techncial debt load that is hard to offset as the application ages.  In contrast, higher level constructs make the code more brief and easier to understand, hence reducing technical cost.   Now, obviously in this case we're not talking two separate languages, we're comparing doing something manually in the language versus using a higher-order set of IEnumerable extensions that are in the System.Linq library.   Well, before we discuss any further, let's look at some sample code and the numbers.  First, let's take a look at the for loop and the LINQ expression.  This is just a simple find comparison:       // find implemented via LINQ     public static bool FindViaLinq(IEnumerable<int> list, int target)     {         return list.Any(item => item == target);     }         // find implemented via standard iteration     public static bool FindViaIteration(IEnumerable<int> list, int target)     {         foreach (var i in list)         {             if (i == target)             {                 return true;             }         }           return false;     }   Okay, looking at this from a maintainability point of view, the Linq expression is definitely more concise (8 lines down to 1) and is very readable in intention.  You don't have to actually analyze the behavior of the loop to determine what it's doing.   So let's take a look at performance metrics from 100,000 iterations of these methods on a List<int> of varying sizes filled with random data.  For this test, we fill a target array with 100,000 random integers and then run the exact same pseudo-random targets through both searches.                       List<T> On 100,000 Iterations     Method      Size     Total (ms)  Per Iteration (ms)  % Slower     Any         10       26          0.00046             30.00%     Iteration   10       20          0.00023             -     Any         100      116         0.00201             18.37%     Iteration   100      98          0.00118             -     Any         1000     1058        0.01853             16.78%     Iteration   1000     906         0.01155             -     Any         10,000   10,383      0.18189             17.41%     Iteration   10,000   8843        0.11362             -     Any         100,000  104,004     1.8297              18.27%     Iteration   100,000  87,941      1.13163             -   The LINQ expression is running about 17% slower for average size collections and worse for smaller collections.  Presumably, this is due to the overhead of the state machine used to track the iterators for the yield returns in the LINQ expressions, which seems about right in a tight loop such as this.   So what about other LINQ expressions?  After all, Any() is one of the more trivial ones.  I decided to try the TakeWhile() algorithm using a Count() to get the position stopped like the sample Pete was using in his blog that Resharper refactored for him into LINQ:       // Linq form     public static int GetTargetPosition1(IEnumerable<int> list, int target)     {         return list.TakeWhile(item => item != target).Count();     }       // traditionally iterative form     public static int GetTargetPosition2(IEnumerable<int> list, int target)     {         int count = 0;           foreach (var i in list)         {             if(i == target)             {                 break;             }               ++count;         }           return count;     }   Once again, the LINQ expression is much shorter, easier to read, and should be easier to maintain over time, reducing the cost of technical debt.  So I ran these through the same test data:                       List<T> On 100,000 Iterations     Method      Size     Total (ms)  Per Iteration (ms)  % Slower     TakeWhile   10       41          0.00041             128%     Iteration   10       18          0.00018             -     TakeWhile   100      171         0.00171             88%     Iteration   100      91          0.00091             -     TakeWhile   1000     1604        0.01604             94%     Iteration   1000     825         0.00825             -     TakeWhile   10,000   15765       0.15765             92%     Iteration   10,000   8204        0.08204             -     TakeWhile   100,000  156950      1.5695              92%     Iteration   100,000  81635       0.81635             -     Wow!  I expected some overhead due to the state machines iterators produce, but 90% slower?  That seems a little heavy to me.  So then I thought, well, what if TakeWhile() is not the right tool for the job?  The problem is TakeWhile returns each item for processing using yield return, whereas our for-loop really doesn't care about the item beyond using it as a stop condition to evaluate. So what if that back and forth with the iterator state machine is the problem?  Well, we can quickly create an (albeit ugly) lambda that uses the Any() along with a count in a closure (if a LINQ guru knows a better way PLEASE let me know!), after all , this is more consistent with what we're trying to do, we're trying to find the first occurence of an item and halt once we find it, we just happen to be counting on the way.  This mostly matches Any().       // a new method that uses linq but evaluates the count in a closure.     public static int TakeWhileViaLinq2(IEnumerable<int> list, int target)     {         int count = 0;         list.Any(item =>             {                 if(item == target)                 {                     return true;                 }                   ++count;                 return false;             });         return count;     }     Now how does this one compare?                         List<T> On 100,000 Iterations     Method         Size     Total (ms)  Per Iteration (ms)  % Slower     TakeWhile      10       41          0.00041             128%     Any w/Closure  10       23          0.00023             28%     Iteration      10       18          0.00018             -     TakeWhile      100      171         0.00171             88%     Any w/Closure  100      116         0.00116             27%     Iteration      100      91          0.00091             -     TakeWhile      1000     1604        0.01604             94%     Any w/Closure  1000     1101        0.01101             33%     Iteration      1000     825         0.00825             -     TakeWhile      10,000   15765       0.15765             92%     Any w/Closure  10,000   10802       0.10802             32%     Iteration      10,000   8204        0.08204             -     TakeWhile      100,000  156950      1.5695              92%     Any w/Closure  100,000  108378      1.08378             33%     Iteration      100,000  81635       0.81635             -     Much better!  It seems that the overhead of TakeAny() returning each item and updating the state in the state machine is drastically reduced by using Any() since Any() iterates forward until it finds the value we're looking for -- for the task we're attempting to do.   So the lesson there is, make sure when you use a LINQ expression you're choosing the best expression for the job, because if you're doing more work than you really need, you'll have a slower algorithm.  But this is true of any choice of algorithm or collection in general.     Even with the Any() with the count in the closure it is still about 30% slower, but let's consider that angle carefully.  For a list of 100,000 items, it was the difference between 1.01 ms and 0.82 ms roughly in a List<T>.  That's really not that bad at all in the grand scheme of things.  Even running at 90% slower with TakeWhile(), for the vast majority of my projects, an extra millisecond to save potential errors in the long term and improve maintainability is a small price to pay.  And if your typical list is 1000 items or less we're talking only microseconds worth of difference.   It's like they say: 90% of your performance bottlenecks are in 2% of your code, so over-optimizing almost never pays off.  So personally, I'll take the LINQ expression wherever I can because they will be easier to read and maintain (thus reducing technical debt) and I can rely on Microsoft's development to have coded and unit tested those algorithm fully for me instead of relying on a developer to code the loop logic correctly.   If something's 90% slower, yes, it's worth keeping in mind, but it's really not until you start get magnitudes-of-order slower (10x, 100x, 1000x) that alarm bells should really go off.  And if I ever do need that last millisecond of performance?  Well then I'll optimize JUST THAT problem spot.  To me it's worth it for the readability, speed-to-market, and maintainability.

  Read the article

• SQL SERVER – Updating Data in A Columnstore Index

  - by pinaldave

  So far I have written two articles on Columnstore Indexes, and both of them got very interesting readership. In fact, just recently I got a query on my previous article on Columnstore Index. Read the following two articles to get familiar with the Columnstore Index. They will give you a reference to the question which was asked by a certain reader: SQL SERVER – Fundamentals of Columnstore Index SQL SERVER – How to Ignore Columnstore Index Usage in Query Here is the reader’s question: ” When I tried to update my table after creating the Columnstore index, it gives me an error. What should I do?” When the Columnstore index is created on the table, the table becomes Read-Only table and it does not let any insert/update/delete on the table. The basic understanding is that Columnstore Index will be created on the table that is very huge and holds lots of data. If a table is small enough, there is no need to create a Columnstore index. The regular index should just help it. The reason why Columnstore index was needed is because the table was so big that retrieving the data was taking a really, really long time. Now, updating such a huge table is always a challenge by itself. If the Columnstore Index is created on the table, and the table needs to be updated, you need to know that there are various ways to update it. The easiest way is to disable the Index and enable it. Consider the following code: USE AdventureWorks GO -- Create New Table CREATE TABLE [dbo].[MySalesOrderDetail]( [SalesOrderID] [int] NOT NULL, [SalesOrderDetailID] [int] NOT NULL, [CarrierTrackingNumber] [nvarchar](25) NULL, [OrderQty] [smallint] NOT NULL, [ProductID] [int] NOT NULL, [SpecialOfferID] [int] NOT NULL, [UnitPrice] [money] NOT NULL, [UnitPriceDiscount] [money] NOT NULL, [LineTotal] [numeric](38, 6) NOT NULL, [rowguid] [uniqueidentifier] NOT NULL, [ModifiedDate] [datetime] NOT NULL ) ON [PRIMARY] GO -- Create clustered index CREATE CLUSTERED INDEX [CL_MySalesOrderDetail] ON [dbo].[MySalesOrderDetail] ( [SalesOrderDetailID]) GO -- Create Sample Data Table -- WARNING: This Query may run upto 2-10 minutes based on your systems resources INSERT INTO [dbo].[MySalesOrderDetail] SELECT S1.* FROM Sales.SalesOrderDetail S1 GO 100 -- Create ColumnStore Index CREATE NONCLUSTERED COLUMNSTORE INDEX [IX_MySalesOrderDetail_ColumnStore] ON [MySalesOrderDetail] (UnitPrice, OrderQty, ProductID) GO -- Attempt to Update the table UPDATE [dbo].[MySalesOrderDetail] SET OrderQty = OrderQty +1 WHERE [SalesOrderID] = 43659 GO /* It will throw following error Msg 35330, Level 15, State 1, Line 2 UPDATE statement failed because data cannot be updated in a table with a columnstore index. Consider disabling the columnstore index before issuing the UPDATE statement, then rebuilding the columnstore index after UPDATE is complete. */ A similar error also shows up for Insert/Delete function. Here is the workaround. Disable the Columnstore Index and performance update, enable the Columnstore Index: -- Disable the Columnstore Index ALTER INDEX [IX_MySalesOrderDetail_ColumnStore] ON [dbo].[MySalesOrderDetail] DISABLE GO -- Attempt to Update the table UPDATE [dbo].[MySalesOrderDetail] SET OrderQty = OrderQty +1 WHERE [SalesOrderID] = 43659 GO -- Rebuild the Columnstore Index ALTER INDEX [IX_MySalesOrderDetail_ColumnStore] ON [dbo].[MySalesOrderDetail] REBUILD GO This time it will not throw an error while the update of the table goes successfully. Let us do a cleanup of our tables using this code: -- Cleanup DROP INDEX [IX_MySalesOrderDetail_ColumnStore] ON [dbo].[MySalesOrderDetail] GO TRUNCATE TABLE dbo.MySalesOrderDetail GO DROP TABLE dbo.MySalesOrderDetail GO In the next post we will see how we can use Partition to update the Columnstore Index. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Index, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

  Read the article

• Reg Gets a Job at Red Gate (and what happens behind the scenes)

  - by red(at)work

  Mr Reg Gater works at one of Cambridge’s many high-tech companies. He doesn’t love his job, but he puts up with it because... well, it could be worse. Every day he drives to work around the Red Gate roundabout, wondering what his boss is going to blame him for today, and wondering if there could be a better job out there for him. By late morning he already feels like handing his notice in. He got the hacky look from his boss for being 5 minutes late, and then they ran out of tea. Again. He goes to the local sandwich shop for lunch, and picks up a Red Gate job menu and a Book of Red Gate while he’s waiting for his order. That night, he goes along to Cambridge Geek Nights and sees some very enthusiastic Red Gaters talking about the work they do; it sounds interesting and, of all things, fun. He takes a quick look at the job vacancies on the Red Gate website, and an hour later realises he’s still there – looking at videos, photos and people profiles. He especially likes the Red Gate’s Got Talent page, and is very impressed with Simon Johnson’s marathon time. He thinks that he’d quite like to work with such awesome people. It just so happens that Red Gate recently decided that they wanted to hire another hot shot team member. Behind the scenes, the wheels were set in motion: the recruitment team met with the hiring manager to understand exactly what they’re looking for, and to decide what interview tests to do, who will do the interviews, and to kick-start any interview training those people might need. Next up, a job description and job advert were written, and the job was put on the market. Reg applies, and his CV lands in the Recruitment team’s inbox and they open it up with eager anticipation that Reg could be the next awesome new starter. He looks good, and in a jiffy they’ve arranged an interview. Reg arrives for his interview, and is greeted by a smiley receptionist. She offers him a selection of drinks and he feels instantly relaxed. A couple of interviews and an assessment later, he gets a job offer. We make his day and he makes ours by accepting, and becoming one of the 60 new starters so far this year. Behind the scenes, things start moving all over again. The HR team arranges for a “Welcome” goodie box to be whisked out to him, prepares his contract, sends an email to Information Services (Or IS for short - we’ll come back to them), keeps in touch with Reg to make sure he knows what to expect on his first day, and of course asks him to fill in the all-important wiki questionnaire so his new colleagues can start to get to know him before he even joins. Meanwhile, the IS team see an email in SupportWorks from HR. They see that Reg will be starting in the sales team in a few days’ time, and they know exactly what to do. They pull out a new machine, and within minutes have used their automated deployment software to install every piece of software that a new recruit could ever need. They also check with Reg’s new manager to see if he has any special requirements that they could help with. Reg starts and is amazed to find a fully configured machine sitting on his desk, complete with stationery and all the other tools he’ll need to do his job. He feels even more cared for after he gets a workstation assessment, and realises he’d be comfier with an ergonomic keyboard and a footstool. They arrive minutes later, just like that. His manager starts him off on his induction and sales training. Along with job-specific training, he’ll also have a buddy to help him find his feet, and loads of pre-arranged demos and introductions. Reg settles in nicely, and is great at his job. He enjoys the canteen, and regularly eats one of the 40,000 meals provided each year. He gets used to the selection of teas that are available, develops a taste for champagne launch parties, and has his fair share of the 25,000 cups of coffee downed at Red Gate towers each year. He goes along to some Feel Good Fund events, and donates a little something to charity in exchange for a turn on the chocolate fountain. He’s looking a little scruffy, so he decides to get his hair cut in between meetings, just in time for the Red Gate birthday company photo. Reg starts a new project: identifying existing customers to up-sell to new bundles. He talks with the web team to generate lists of qualifying customers who haven’t recently been sent marketing emails, and sends emails out, using a new in-house developed tool to schedule follow-up calls in CRM for the same group. The customer responds, saying they’d like to upgrade but are having a licensing problem – Reg sends the issue to Support, and it gets routed to the web team. The team identifies a workaround, and the bug gets scheduled into the next maintenance release in a fortnight’s time (hey; they got lucky). With all the new stuff Reg is working on, he realises that he’d be way more efficient if he had a third monitor. He speaks to IS and they get him one - no argument. He also needs a test machine and then some extra memory. Done. He then thinks he needs an iPad, and goes to ask for one. He gets told to stop pushing his luck. Some time later, Reg’s wife has a baby, so Reg gets 2 weeks of paid paternity leave and a bunch of flowers sent to his house. He signs up to the childcare scheme so that he doesn’t have to pay National Insurance on the first £243 of his childcare. The accounts team makes it all happen seamlessly, as they did with his Give As You Earn payments, which come out of his wages and go straight to his favorite charity. Reg’s sales career is going well. He’s grateful for the help that he gets from the product support team. How do they answer all those 900-ish support calls so effortlessly each month? He’s impressed with the patches that are sent out to customers who find “interesting behavior” in their tools, and to the customers who just must have that new feature. A little later in his career at Red Gate, Reg decides that he’d like to learn about management. He goes on some management training specially customised for Red Gate, joins the Management Book Club, and gets together with other new managers to brainstorm how to get the most out of one to one meetings with his team. Reg decides to go for a game of Foosball to celebrate his good fortune with his team, and has to wait for Finance to finish. While he’s waiting, he reflects on the wonderful time he’s had at Red Gate. He can’t put his finger on what it is exactly, but he knows he’s on to a good thing. All of the stuff that happened to Reg didn’t just happen magically. We’ve got teams of people working relentlessly behind the scenes to make sure that everyone here is comfortable, safe, well fed and caffeinated to the max.

  Read the article

• Ubuntu 11.04 and 10.04 hang with black screen while installing from USB disk

  - by Bill

  I've been trying to install Ubuntu 11.04 from a USB flash stick and each time I try to boot from the USB key one of two things happen: A) The screen that asks you what you would like to do (e.g. run Ubuntu from the USB key or install it) shows up and the countdown to the default option starts to count down but as soon as I either touch the keyboard (sometimes I press enter or the arrow keys to select an option) or the countdown gets to zero the screen just locks up and nothing happens no matter how long I wait. B) When I boot from the USB key the screen will flicker for a second and then go black with a flashing white underscore at the top left corner of the screen. Again it doesn't matter how long I wait, nothing happens and pressing keys doesn't do a thing. The very first time I tried to install it I got a terminal-like screen that said something about a directory called 'casper' having an error of some sort. I have tried installing from USB using both 11.04 and 10.10. I'm about to try 10.04. I have read tons of forum posts about this but so far I haven't seen anything in the solutions that apply to me. My intention is to dual boot Windows 7 and Ubuntu. I must keep Windows as I am required to use Visual Studio for one of my college courses. Right now I'm using Wubi but I really want a full install. I can't use LVPM because it doesn't work with the version of Wubi I used. So now I'm thinking my best bet is to try to get a clean install working. I'd also convert Wubi to a full install too but there's no solution as far as I've read. So could someone tell me a reason why this is happening or if there's something I can do to get around the problem? I'm using a Gateway LT2802u netbook with and Intel Atom N455 processor, 1GB RAM, Intel Graphics Media Accelerator 3150 graphics card, and a 250GB HDD. I don't have anything on my current Wubi install that I can't replace so keep in mind when answering that I don't care if I lose my current settings and files from Wubi. Thanks everyone! UPDATE I just answered my own question so in case anyone else is having this same problem using similar hardware, do the following: When I first tried installing 11.04 I used the recommended universal installer tool to create the USB live/installation disk. That caused the original problem. Note that I had already downloaded the 11.04 ISO and did not use the included downloader from the USB creator. After that failed I used the same USB creator but had it download 10.10 for me. It also failed with the same issue. I repeated this process with unetbootin as well for both versions. Finally, I downloaded the Ubuntu 10.04 ISO and used the recommended USB creator once again. There was an error while creating the USB live install so I reformatted the USB key as FAT32 and tried again. It created the USB key. I then booted from the USB flash drive and selected "Install Ubuntu" (exact wording was different). It worked! It took me through the process that you see shown in pictures on the Ubuntu website. I let it create the appropriate partitions for me and it simply worked. I did get a few errors while the system tried to restart after it installed. It hung on a terminal-like screen but I pressed ENTER and it restarted. I booted into Windows 7, it checked the disks as it sensed that I messed with a partition, then it booted into Windows normally. Now I'm going to uninstall Wubi and update my new full install of Ubuntu! I'm excited to get the benefits of a full install now. So in the end, hopefully someone can learn from what I did.

  Read the article

• Contracting as a Software Developer in the UK

  - by Frez

  Normal 0 false false false EN-GB X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi; mso-fareast-language:EN-US;} Having had some 15 years’ experience of working as a software contractor, I am often asked by developers who work as permanent employees (permies) about the pros and cons of working as a software consultant through my own limited company and whether the move would be a good one for them. Whilst it is possible to contract using other financial vehicles such as umbrella companies, this article will only consider limited companies as that is what I have experience of using. Contracting or consultancy requires a different mind-set from being a permanent member of staff, and not all developers are capable of this shift in attitude. Whilst you can look forward to an increase in the money you take home, there are real risks and expenses you would not normally be exposed to as a permie. So let us have a look at the pros and cons: Pros: More money There is no doubt that whilst you are working on contracts you will earn significantly more than you would as a permanent employee. Furthermore, working through a limited company is more tax efficient. Less politics You really have no need to involve yourself in office politics. When the end of the day comes you can go home and not think or worry about the power struggles within the company you are contracted to. Your career progression is not tied to the company. Expenses from gross income All your expenses of trading as a business will come out of your company’s gross income, i.e. before tax. This covers travelling expenses provided you have not been at the same client/location for more than two years, internet subscriptions, professional subscriptions, software, hardware, accountancy services and so on. Cons: Work is more transient Contracts typically range from a couple of weeks to a year, although will most likely start at 3 months. However, most contracts are extended either because the project you have been brought in to help with takes longer to deliver than expected, the client decides they can use you on other aspects of the project, or the client decides they would like to use you on other projects. The temporary nature of the work means that you will have down-time between contracts while you secure new opportunities during which time your company will have no income. You may need to attend several interviews before securing a new contract. Accountancy expenses Your company is a separate entity and there are accountancy requirements which, unless you like paperwork, means your company will need to appoint an accountant to prepare your company’s accounts. It may also be worth purchasing some accountancy software, so talk to your accountant about this as they may prefer you to use a particular software package so they can integrate it with their systems. VAT You will need to register your company for VAT. This is tax neutral for you as the VAT you charge your clients you will pass onto the government less any VAT you are reclaiming from expenses, but it is additional paperwork to undertake each quarter. It is worth checking out the Fixed Rate VAT Scheme that is available, particularly after the initial expenses of setting up your company are over. No training Clients take you on based on your skills, not to train you when they will lose that investment at the end of the contract, so understand that it is unlikely you will receive any training funded by a client. However, learning new skills during a contract is possible and you may choose to accept a contract on a lower rate if this is guaranteed as it will help secure future contracts. No financial extras You will have no free pension, life, accident, sickness or medical insurance unless you choose to purchase them yourself. A financial advisor can give you all the necessary advice in this area, and it is worth taking seriously. A year after I started as a consultant I contracted a serious illness, this kept me off work for over two months, my client was very understanding and it could have been much worse, so it is worth considering what your options might be in the case of illness, death and retirement. Agencies Whilst it is possible to work directly for end clients there are pros and cons of working through an agency.  The main advantage is cash flow, you invoice the agency and they typically pay you within a week, whereas working directly for a client could have you waiting up to three months to be paid. The downside of working for agencies, especially in the current difficult times, is that they may go out of business and you then have difficulty getting the money you are owed. Tax investigation It is possible that the Inland Revenue may decide to investigate your company for compliance with tax law. Insurance is available to cover you for this. My personal recommendation would be to join the PCG as this insurance is included as a benefit of membership, Professional Indemnity Some agencies require that you are covered by professional indemnity insurance; this is a cost you would not incur as a permie. Travel Unless you live in an area that has an abundance of opportunities, such as central London, it is likely that you will be travelling further, longer and with more expense than if you were permanently employed at a local company. This not only affects you monetarily, but also your quality of life and the ability to keep fit and healthy. Obtaining finance If you want to secure a mortgage on a property it can be more difficult or expensive, especially if you do not have three years of audited accounts to show a mortgage lender.   Caveat This post is my personal opinion and should not be used as a definitive guide or recommendation to contracting and whether it is suitable for you as an individual, i.e. I accept no responsibility if you decide to take up contracting based on this post and you fare badly for whatever reason.

  Read the article

• Deploy Oracle Management Agent using RPM File

  - by cristiano.toni

  Normal 0 21 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tableau Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times","serif"; mso-ansi-language:FR;} 1) Create a rpm package on Enterprise Manager 12c a) as Root : # yum install rpmbuild # mkdir /usr/lib/oracle b) as oracle user # cd $<OMS_HOME>/bin/ # emcli get_supported_platforms ----------------------------------------------- Version = 12.1.0.3.0  Platform = Linux x86-64 ----------------------------------------------- Platforms list displayed successfully. #  emcli get_agentimage_rpm -destination=/tmp/agentRPM -platform="Linux x86-64" \ -version=12.1.0.3.0 Platform:Linux x86-64 Destination:/tmp/agentRPM Exalogic:false  Checking for disk space requirements...  === Partition Detail === Space free : 6 GB Space required : 1 GB RPM creation in progress ... Check the logs at /Oracle/gc_inst/em/EMGC_OMS1/sysman/emcli/setup/.emcli/get_agentimage_rpm_date-PM.log Copying agent image from software library to /tmp/agentRPM Setting property ORACLE_HOME to:/Oracle/middleware/oms calling pulloneoffs with arguments:/Oracle/middleware/oms/Oracle/middleware/oms/sysman/agent/ \ 12.1.0.3.0_AgentCore_226.zip12.1.0.3.0Linux x86-64/tmp/agentRPMtrue Agent Image copied successfully... Creation of RPM started... RPM creation successful. Agent image to rpm conversion completed successfully 2) Copy it on all new hosts and install it.  As Root user : c) check and install rpm file # rpm -ivh --test oracle-agt-12.1.0.3.0-1.0.x86_64.rpm  Preparing...                ########################################### [100%] # rpm -ivh oracle-agt-12.1.0.3.0-1.0.x86_64.rpm  Preparing...                ########################################### [100%] Running the prereq    1:oracle-agt             ########################################### [100%] Agent RPM installation is completed successfully. Now to configure the agent follow the below steps: 1. Edit the properties file: /usr/lib/oracle/agent/agent.properties with the correct values 2. Execute the script /etc/init.d/oracle-agt RESPONSE_FILE=/usr/lib/oracle/agent/agent.properties d) create a user for the agent: # useradd -m -d /home/em12adm -s /bin/bash -g dba -G oinstall em12adm # passwd em12adm e) Edit file /usr/lib/oracle/agent/agent.properties # vi /usr/lib/oracle/agent/agent.properties  OMS_HOST=<host_Enterprise_Manager> OMS_PORT=<HTTPS Upload Port > AGENT_REGISTRATION_PASSWORD=oracle AGENT_USERNAME=em12adm AGENT_GROUP=dba ORACLE_HOSTNAME=oraclevm-mgmt # chown -R em12adm:dba /usr/lib/oracle/agent/ Start agent and register the new host server on EM12c   #  /etc/init.d/oracle-agt RESPONSE_FILE=/usr/lib/oracle/agent/agent.properties Now you have registered on EM12C your new target host.

  Read the article

• Serial plans: Threshold / Parallel_degree_limit = 1

  - by jean-pierre.dijcks

  As a very short follow up on the previous post. So here is some more on getting a serial plan and why that happens Another reason - compared to the auto DOP is not on as we looked at in the earlier post - and often more prevalent to get a serial plan is if the plan simply does not take long enough to consider a parallel path. The resulting plan and note looks like this (note that this is a serial plan!): explain plan for select count(1) from sales; SELECT PLAN_TABLE_OUTPUT FROM TABLE(DBMS_XPLAN.DISPLAY()); PLAN_TABLE_OUTPUT -------------------------------------------------------------------------------- Plan hash value: 672559287 -------------------------------------------------------------------------------------- | Id  | Operation            | Name  | Rows  | Cost (%CPU)| Time     | Pstart| Pstop | -------------------------------------------------------------------------------------- PLAN_TABLE_OUTPUT -------------------------------------------------------------------------------- |   0 | SELECT STATEMENT     |       |     1 |     5   (0)| 00:00:01 |       |     | |   1 |  SORT AGGREGATE      |       |     1 |            |          |       |     | |   2 |   PARTITION RANGE ALL|       |   960 |     5   (0)| 00:00:01 |     1 |  16 | |   3 |    TABLE ACCESS FULL | SALES |   960 |     5   (0)| 00:00:01 |     1 |  16 | Note -----    - automatic DOP: Computed Degree of Parallelism is 1 because of parallel threshold 14 rows selected. The parallel threshold is referring to parallel_min_time_threshold and since I did not change the default (10s) the plan is not being considered for a parallel degree computation and is therefore staying with the serial execution. Now we go into the land of crazy: Assume I do want this DOP=1 to happen, I could set the parameter in the init.ora, but to highlight it in this case I changed it on the session: alter session set parallel_degree_limit = 1; The result I get is: ERROR: ORA-02097: parameter cannot be modified because specified value is invalid ORA-00096: invalid value 1 for parameter parallel_degree_limit, must be from among CPU IO AUTO INTEGER>=2 Which of course makes perfect sense...

  Read the article

• Why do we need different CPU architecture for server & mini/mainframe & mixed-core?

  - by claws

  Hello, I was just wondering what other CPU architectures are available other than INTEL & AMD. So, found List of CPU architectures on Wikipedia. It categorizes notable CPU architectures into following categories. Embedded CPU architectures Microcomputer CPU architectures Workstation/Server CPU architectures Mini/Mainframe CPU architectures Mixed core CPU architectures I was analyzing the purposes and have few doubts. I taking Microcomputer CPU (PC) architecture as reference and comparing others. Embedded CPU architecture: They are a completely new world. Embedded systems are small & do very specific task mostly real time & low power consuming so we do not need so many & such wide registers available in a microcomputer CPU (typical PC). In other words we do need a new small & tiny architecture. Hence new architecture & new instruction RISC. The above point also clarifies why do we need a separate operating system (RTOS). Workstation/Server CPU architectures I don't know what is a workstation. Someone clarify regarding the workstation. As of the server. It is dedicated to run a specific software (server software like httpd, mysql etc.). Even if other processes run we need to give server process priority therefore there is a need for new scheduling scheme and thus we need operating system different than general purpose one. If you have any more points for the need of server OS please mention. But I don't get why do we need a new CPU Architecture. Why cant Microcomputer CPU architecture do the job. Can someone please clarify? Mini/Mainframe CPU architectures Again I don't know what are these & what miniframes or mainframes used for? I just know they are very big and occupy complete floor. But I never read about some real world problems they are trying to solve. If any one working on one of these. Share your knowledge. Can some one clarify its purpose & why is it that microcomputer CPU archicture not suitable for it? Is there a new kind of operating system for this too? Why? Mixed core CPU architectures Never heard of these. If possible please keep your answer in this format: XYZ CPU architectures Purpose of XYZ Need for a new architecture. why can't current microcomputer CPU architecture work? They go upto 3GHZ & have upto 8 cores. Need for a new Operating System Why do we need a new kind of operating system for this kind of archictures?

  Read the article

• Nginx traffic is going to wrong upsteam when mixing named servers and default servers

  - by Morgan

  I have the below config file for nginx. The problem is all traffic is going to upstream clustera. How do I configure nginx to only send traffic for example.com to clustera and all the rest to clusterb? user www-data; worker_processes 1; error_log /var/log/nginx/error.log; pid /var/run/nginx.pid; events { worker_connections 1024; } http { include /etc/nginx/mime.types; log_format cache '\n*** $remote_addr [$time_local] ' '[$upstream_cache_status] $upstream_response_time ' '$host "$request" ($status) $body_bytes_sent ' '"$http_referer" "$http_user_agent" ' 'Cache-Control: $upstream_http_cache_control ' 'Expires: $upstream_http_expires ' ; access_log /var/log/nginx/access.log cache; sendfile on; keepalive_timeout 65; gzip on; gzip_vary on; gzip_comp_level 6; gzip_proxied any; gzip_disable "MSIE [1-6]\.(?!.*SV1)"; gzip_buffers 16 8k; include /etc/nginx/conf.d/*.conf; proxy_cache_key "$scheme$host$request_uri"; proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=main:10m max_size=1g inactive=30m; upstream clustera { ip_hash; server a.example.com:80; } upstream clusterb { ip_hash; server b.example.com:80; } client_max_body_size 20m; client_body_buffer_size 128k; proxy_connect_timeout 300; proxy_send_timeout 300; proxy_read_timeout 300; # host for example.com should send traffic to clustera server { listen 80; server_name example.com; location ~*(png|jpeg|jpg|gif|ico|css|js)$ { proxy_pass http://clustera; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_cache main; proxy_cache_valid 200 5m; proxy_cache_valid 302 1m; } location / { proxy_pass http://clustera; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } } # host for everyone else. traffic goes to clusterb server { listen 80; server_name _; if ( $http_user_agent ~* (spider|crawler|slurp) ) { return 503; } set $slow 0; if ( $http_user_agent ~* (bot) ) { set $slow 1; } if ( $slow ) { set $limit_rate 1k; } location ~*(png|jpeg|jpg|gif|ico|css|js)$ { proxy_pass http://clusterb; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_cache main; proxy_cache_valid 200 5m; proxy_cache_valid 302 1m; } location /images { proxy_pass http://clisterb; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_cache main; proxy_cache_valid 200 5m; proxy_cache_valid 302 1m; } location / { proxy_pass http://clusterb; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } } }

  Read the article

• How to redirect http requests to https (nginx)

  - by spuder

  There appear to be many questions and guides out there that instruct how to setup nginx to redirect http requests to https. Many are outdated, or just flat out wrong. # MANAGED BY PUPPET upstream gitlab { server unix:/home/git/gitlab/tmp/sockets/gitlab.socket; } # setup server with or without https depending on gitlab::gitlab_ssl variable server { listen *:80; server_name gitlab.localdomain; server_tokens off; root /nowhere; rewrite ^ https://$server_name$request_uri permanent; } server { listen *:443 ssl default_server; server_name gitlab.localdomain; server_tokens off; root /home/git/gitlab/public; ssl on; ssl_certificate /etc/ssl/certs/ssl-cert-snakeoil.pem; ssl_certificate_key /etc/ssl/private/ssl-cert-snakeoil.key; ssl_protocols SSLv3 TLSv1 TLSv1.1 TLSv1.2; ssl_ciphers AES:HIGH:!ADH:!MDF; ssl_prefer_server_ciphers on; # individual nginx logs for this gitlab vhost access_log /var/log/nginx/gitlab_access.log; error_log /var/log/nginx/gitlab_error.log; location / { # serve static files from defined root folder;. # @gitlab is a named location for the upstream fallback, see below try_files $uri $uri/index.html $uri.html @gitlab; } # if a file, which is not found in the root folder is requested, # then the proxy pass the request to the upsteam (gitlab puma) location @gitlab { proxy_read_timeout 300; # https://github.com/gitlabhq/gitlabhq/issues/694 proxy_connect_timeout 300; # https://github.com/gitlabhq/gitlabhq/issues/694 proxy_redirect off; proxy_set_header X-Forwarded-Proto $scheme; proxy_set_header X-Forwarded-Ssl on; proxy_set_header Host $http_host; proxy_set_header X-Real-IP $remote_addr; proxy_pass http://gitlab; } } I've restarted after every configuration change, and yet I still only get the 'Welcome to nginx' page when visiting http://192.168.33.10. whereas https://192.168.33.10 works perfectly. Why will nginx still not redirect http requests to https? I've also tried the following configurations listen *:80; server_name <%= @fqdn %>; #root /nowhere; #rewrite ^ https://$server_name$request_uri? permanent; #rewrite ^ https://$server_name$request_uri permanent; #return 301 https://$server_name$request_uri; #return 301 http://$server_name$request_uri; #return 301 http://192.168.33.10$request_uri; return 301 http://$host$request_uri; The logs tailf /var/log/nginx/access.log 192.168.33.1 - - [22/Oct/2013:03:41:39 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Firefox/24.0" 192.168.33.1 - - [22/Oct/2013:03:44:43 +0000] "GET / HTTP/1.1" 200 133 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Firefox/24.0" tailf /var/log/nginx/gitlab_error.lob 2013/10/22 02:29:14 [crit] 27226#0: *1 connect() to unix:/home/git/gitlab/tmp/sockets/gitlab.socket failed (2: No such file or directory) while connecting to upstream, client: 192.168.33.1, server: gitlab.localdomain, request: "GET / HTTP/1.1", upstream: "http://unix:/home/git/gitlab/tmp/sockets/gitlab.socket:/", host: "192.168.33.10" Resources http://wiki.nginx.org/Pitfalls How to make nginx redirect How to force or redirect to SSL in nginx? nginx ssl redirect Nginx & Https Redirection https://www.tinywp.in/301-redirect-wordpress/ How to force or redirect to SSL in nginx?

  Read the article

• SQL Sentry Truth-Telling and Disk Configuration

  - by AjarnMark

  Recently, SQL Sentry told me something about my SQL Server disk configurations that I just didn’t want to believe, but alas, it was true. Several days ago I posted my First Impressions of the SQL Sentry Power Suite.  Today’s post could fall into the category of, “Hey, as long as you have that fancy tool…”  Unfortunately, it also falls into the category of an overloaded worker taking someone else’s word for the truth, not verifying it with independent fact-checking, and then making decisions based on that.  Here’s my story… I’m not exactly an Accidental DBA (or Involuntary DBA as Paul Randal calls it).  I came to this company five years ago as a lead application developer with extensive experience in database design and development.  I worked my way into management, and along the way, took over the DBA responsibilities.  Fortunately, our systems run pretty smoothly most of the time, but I’m always looking for ways to make them better and to fit into my understanding of best practices.  When I took over as DBA, I inherited a SQL 2000 server with about 30 databases on it supporting our main systems, and a SQL 2005 server with multiple instances.  Both of these servers were configured with the Operating System and Application files on the C drive, data files on a different drive letter, and log files on a third drive letter.  Even before I took over as DBA, I verified that this was true with a previous server administrator, and that these represented actual separate disks.  He stated that they did, and I thought that all was well. Then one day, I’m poking around inside the SQL Sentry Performance Advisor, checking out features as I am evaluating whether to purchase the product, and I come across a Disk Configuration section.  The first thing I notice is that the drives do not have the proper partition offset, which was not at all surprising to me given the age of the installation and the relative newness of that topic.  But what threw me for a loop was that the graphic display appeared to be telling me that I did not in fact have three separate drives (or arrays) but rather had two, and that the log files were merely on a separate volume on the same physical array as the OS.  I figured that I must be reading it wrong so I scanned the Help file, but that just seemed to confirm my interpretation.  Then I thought, “there must be something wrong with the demo version of the software!  This can’t be right!”  But just to double-check, I went to our current server admin to talk it over with him, and sure enough, SQL Sentry was telling the truth! I was stunned!  I quickly went through the grieving process…denial…anger…reconciliation.  Here was something that I thought was such a basic truth that was turned upside down.  OK, granted, this wasn’t disastrous.  Our databases didn’t suddenly grind to a halt.  I didn’t get calls late at night inquiring about the sudden downturn in performance.  But it was a bit of a shock to the system, in a good way, to jolt me out of taking what I had believed as the truth for granted, and instead to Trust, but Verify! Yes, before someone else points it out, I know that there are”free” disk management tools built-in to Windows that would have told me the same thing if I had only looked at them; I did not have to buy a fancy tool to tell me that, but the fact is, until I was evaluating the tool, I had just gone with what I was told, and never bothered to check what was actually there. So, what things do you believe to be true but you actually never verified?

  Read the article

• The Great Divorce

  - by BlackRabbitCoder

  I have a confession to make: I've been in an abusive relationship for more than 17 years now.  Yes, I am not ashamed to admit it, but I'm finally doing something about it. I met her in college, she was new and sexy and amazingly fast -- and I'd never met anything like her before.  Her style and her power captivated me and I couldn't wait to learn more about her.  I took a chance on her, and though I learned a lot from her -- and will always be grateful for my time with her -- I think it's time to move on. Her name was C++, and she so outshone my previous love, C, that any thoughts of going back evaporated in the heat of this new romance.  She promised me she'd be gentle and not hurt me the way C did.  She promised me she'd clean-up after herself better than C did.  She promised me she'd be less enigmatic and easier to keep happy than C was.  But I was deceived.  Oh sure, as far as truth goes, it wasn't a complete lie.  To some extent she was more fun, more powerful, safer, and easier to maintain.  But it just wasn't good enough -- or at least it's not good enough now. I loved C++, some part of me still does, it's my first-love of programming languages and I recognize its raw power, its blazing speed, and its improvements over its predecessor.  But with today's hardware, at speeds we could only dream to conceive of twenty years ago, that need for speed -- at the cost of all else -- has died, and that has left my feelings for C++ moribund. If I ever need to write an operating system or a device driver, then I might need that speed.  But 99% of the time I don't.  I'm a business-type programmer and chances are 90% of you are too, and even the ones who need speed at all costs may be surprised by how much you sacrifice for that.   That's not to say that I don't want my software to perform, and it's not to say that in the business world we don't care about speed or that our job is somehow less difficult or technical.  There's many times we write programs to handle millions of real-time updates or handle thousands of financial transactions or tracking trading algorithms where every second counts.  But if I choose to write my code in C++ purely for speed chances are I'll never notice the speed increase -- and equally true chances are it will be far more prone to crash and far less easy to maintain.  Nearly without fail, it's the macro-optimizations you need, not the micro-optimizations.  If I choose to write a O(n2) algorithm when I could have used a O(n) algorithm -- that can kill me.  If I choose to go to the database to load a piece of unchanging data every time instead of caching it on first load -- that too can kill me.  And if I cross the network multiple times for pieces of data instead of getting it all at once -- yes that can also kill me.  But choosing an overly powerful and dangerous mid-level language to squeeze out every last drop of performance will realistically not make stock orders process any faster, and more likely than not open up the system to more risk of crashes and resource leaks. And that's when my love for C++ began to die.  When I noticed that I didn't need that speed anymore.  That that speed was really kind of a lie.  Sure, I can be super efficient and pack bits in a byte instead of using separate boolean values.  Sure, I can use an unsigned char instead of an int.  But in the grand scheme of things it doesn't matter as much as you think it does.  The key is maintainability, and that's where C++ failed me.  I like to tell the other developers I work with that there's two levels of correctness in coding: Is it immediately correct? Will it stay correct? That is, you can hack together any piece of code and make it correct to satisfy a task at hand, but if a new developer can't come in tomorrow and make a fairly significant change to it without jeopardizing that correctness, it won't stay correct. Some people laugh at me when I say I now prefer maintainability over speed.  But that is exactly the point.  If you focus solely on speed you tend to produce code that is much harder to maintain over the long hall, and that's a load of technical debt most shops can't afford to carry and end up completely scrapping code before it's time.  When good code is written well for maintainability, though, it can be correct both now and in the future. And you know the best part is?  My new love is nearly as fast as C++, and in some cases even faster -- and better than that, I know C# will treat me right.  Her creators have poured hundreds of thousands of hours of time into making her the sexy beast she is today.  They made her easy to understand and not an enigmatic mess.  They made her consistent and not moody and amorphous.  And they made her perform as fast as I care to go by optimizing her both at compile time and a run-time. Her code is so elegant and easy on the eyes that I'm not worried where she will run to or what she'll pull behind my back.  She is powerful enough to handle all my tasks, fast enough to execute them with blazing speed, maintainable enough so that I can rely on even fairly new peers to modify my work, and rich enough to allow me to satisfy any need.  C# doesn't ask me to clean up her messes!  She cleans up after herself and she tries to make my life easier for me by taking on most of those optimization tasks C++ asked me to take upon myself.  Now, there are many of you who would say that I am the cause of my own grief, that it was my fault C++ didn't behave because I didn't pay enough attention to her.  That I alone caused the pain she inflicted on me.  And to some extent, you have a point.  But she was so high maintenance, requiring me to know every twist and turn of her vast and unrestrained power that any wrong term or bout of forgetfulness was met with painful reminders that she wasn't going to watch my back when I made a mistake.  But C#, she loves me when I'm good, and she loves me when I'm bad, and together we make beautiful code that is both fast and safe. So that's why I'm leaving C++ behind.  She says she's changing for me, but I have no interest in what C++0x may bring.  Oh, I'll still keep in touch, and maybe I'll see her now and again when she brings her problems to my door and asks for some attention -- for I always have a soft spot for her, you see.  But she's out of my house now.  I have three kids and a dog and a cat, and all require me to clean up after them, why should I have to clean up after my programming language as well?

  Read the article

• SQL Azure: Notes on Building a Shard Technology

  - by Herve Roggero

  In Chapter 10 of the book on SQL Azure (http://www.apress.com/book/view/9781430229612) I am co-authoring, I am digging deeper in what it takes to write a Shard. It's actually a pretty cool exercise, and I wanted to share some thoughts on how I am designing the technology. A Shard is a technology that spreads the load of database requests over multiple databases, as transparently as possible. The type of shard I am building is called a Vertical Partition Shard  (VPS). A VPS is a mechanism by which the data is stored in one or more databases behind the scenes, but your code has no idea at design time which data is in which database. It's like having a mini cloud for records instead of services. Imagine you have three SQL Azure databases that have the same schema (DB1, DB2 and DB3), you would like to issue a SELECT * FROM Users on all three databases, concatenate the results into a single resultset, and order by last name. Imagine you want to ensure your code doesn't need to change if you add a new database to the shard (DB4). Now imagine that you want to make sure all three databases are queried at the same time, in a multi-threaded manner so your code doesn't have to wait for three database calls sequentially. Then, imagine you would like to obtain a breadcrumb (in the form of a new, virtual column) that gives you a hint as to which database a record came from, so that you could update it if needed. Now imagine all that is done through the standard SqlClient library... and you have the Shard I am currently building. Here are some lessons learned and techniques I am using with this shard: Parellel Processing: Querying databases in parallel is not too hard using the Task Parallel Library; all you need is to lock your resources when needed Deleting/Updating Data: That's not too bad either as long as you have a breadcrumb. However it becomes more difficult if you need to update a single record and you don't know in which database it is. Inserting Data: I am using a round-robin approach in which each new insert request is directed to the next database in the shard. Not sure how to deal with Bulk Loads just yet... Shard Databases:  I use a static collection of SqlConnection objects which needs to be loaded once; from there on all the Shard commands use this collection Extension Methods: In order to make it look like the Shard commands are part of the SqlClient class I use extension methods. For example I added ExecuteShardQuery and ExecuteShardNonQuery methods to SqlClient. Exceptions: Capturing exceptions in a multi-threaded code is interesting... but I kept it simple for now. I am using the ConcurrentQueue to store my exceptions. Database GUID: Every database in the shard is given a GUID, which is calculated based on the connection string's values. DataTable. The Shard methods return a DataTable object which can be bound to objects.  I will be sharing the code soon as an open-source project in CodePlex. Please stay tuned on twitter to know when it will be available (@hroggero). Or check www.bluesyntax.net for updates on the shard. Thanks!

  Read the article

• SQL SERVER – Create a Very First Report with the Report Wizard

  - by Pinal Dave

  This example is from the Beginning SSRS by Kathi Kellenberger. Supporting files are available with a free download from the www.Joes2Pros.com web site. What is the report Wizard? In today’s world automation is all around you. Henry Ford began building his Model T automobiles on a moving assembly line a century ago and changed the world. The moving assembly line allowed Ford to build identical cars quickly and cheaply. Henry Ford said in his autobiography “Any customer can have a car painted any color that he wants so long as it is black.” Today you can buy a car straight from the factory with your choice of several colors and with many options like back up cameras, built-in navigation systems and heated leather seats. The assembly lines now use robots to perform some tasks along with human workers. When you order your new car, if you want something special, not offered by the manufacturer, you will have to find a way to add it later. In computer software, we also have “assembly lines” called wizards. A wizard will ask you a series of questions, often branching to specific questions based on earlier answers, until you get to the end of the wizard. These wizards are used for many things, from something simple like setting up a rule in Outlook to performing administrative tasks on a server. Often, a wizard will get you part of the way to the end result, enough to get much of the tedious work out of the way. Once you get the product from the wizard, if the wizard is not capable of doing something you need, you can tweak the results. Create a Report with the Report Wizard Let’s get started with your first report!  Launch SQL Server Data Tools (SSDT) from the Start menu under SQL Server 2012. Once SSDT is running, click New Project to launch the New Project dialog box. On the left side of the screen expand Business Intelligence and select Reporting Services. Configure the properties as shown in . Be sure to select Report Server Project Wizard as the type of report and to save the project in the C:\Joes2Pros\SSRSCompanionFiles\Chapter3\Project folder. Click OK and wait for the Report Wizard to launch. Click Next on the Welcome screen.  On the Select the Data Source screen, make sure that New data source is selected. Type JProCo as the data source name. Make sure that Microsoft SQL Server is selected in the Type dropdown. Click Edit to configure the connection string on the Connection Properties dialog box. If your SQL Server database server is installed on your local computer, type in localhost for the Server name and select the JProCo database from the Select or enter a database name dropdown. Click OK to dismiss the Connection Properties dialog box. Check Make this a shared data source and click Next. On the Design the Query screen, you can use the query builder to build a query if you wish. Since this post is not meant to teach you T-SQL queries, you will copy all queries from files that have been provided for you. In the C:\Joes2Pros\SSRSCompanionFiles\Chapter3\Resources folder open the sales by employee.sql file. Copy and paste the code from the file into the Query string Text Box. Click Next. On the Select the Report Type screen, choose Tabular and click Next. On the Design the Table screen, you have to figure out the groupings of the report. How do you do this? Well, you often need to know a bit about the data and report requirements. I often draw the report out on paper first to help me determine the groups. In the case of this report, I could group the data several ways. Do I want to see the data grouped by Year and Month? Do I want to see the data grouped by Employee or Category? The only thing I know for sure about this ahead of time is that the TotalSales goes in the Details section. Let’s assume that the CIO asked to see the data grouped first by Year and Month, then by Category. Let’s move the fields to the right-hand side. This is done by selecting Page > Group or Details >, as shown in, and click Next. On the Choose the Table Layout screen, select Stepped and check Include subtotals and Enable drilldown, as shown in. On the Choose the Style screen, choose any color scheme you wish (unlike the Model T) and click Next. I chose the default, Slate. On the Choose the Deployment Location screen, change the Deployment folder to Chapter 3 and click Next. At the Completing the Wizard screen, name your report Employee Sales and click Finish. After clicking Finish, the report and a shared data source will appear in the Solution Explorer and the report will also be visible in Design view. Click the Preview tab at the top. This report expects the user to supply a year which the report will then use as a filter. Type in a year between 2006 and 2013 and click View Report. Click the plus sign next to the Sales Year to expand the report to see the months, then expand again to see the categories and finally the details. You now have the assembly line report completed, and you probably already have some ideas on how to improve the report. Tomorrow’s Post Tomorrow’s blog post will show how to create your own data sources and data sets in SSRS. If you want to learn SSRS in easy to simple words – I strongly recommend you to get Beginning SSRS book from Joes 2 Pros. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL Tagged: Reporting Services, SSRS

  Read the article

• Generate a merge statement from table structure

  - by Nigel Rivett

  This code generates a merge statement joining on he natural key and checking all other columns to see if they have changed. The full version deals with type 2 processing and an audit trail but this version is useful. Just the insert or update part is handy too. Change the table at the top (spt_values in master in the version) and the join columns for the merge in @nk. The output generated is at the top and the code to run to generate it below. Output merge spt_values a using spt_values b on a.name = b.name and a.number = b.number and a.type = b.type when matched and (1=0 or (a.low b.low) or (a.low is null and b.low is not null) or (a.low is not null and b.low is null) or (a.high b.high) or (a.high is null and b.high is not null) or (a.high is not null and b.high is null) or (a.status b.status) or (a.status is null and b.status is not null) or (a.status is not null and b.status is null) ) then update set low = b.low , high = b.high , status = b.status when not matched by target then insert ( name , number , type , low , high , status ) values ( b.name , b.number , b.type , b.low , b.high , b.status ); Generator set nocount on declare @t varchar(128) = 'spt_values' declare @i int = 0 -- this is the natural key on the table used for the merge statement join declare @nk table (ColName varchar(128)) insert @nk select 'Number' insert @nk select 'Name' insert @nk select 'Type' declare @cols table (seq int, nkseq int, type int, colname varchar(128)) ;with cte as ( select ordinal_position, type = case when columnproperty(object_id(@t), COLUMN_NAME,'IsIdentity') = 1 then 3 when nk.ColName is not null then 1 else 0 end, COLUMN_NAME from information_schema.columns c left join @nk nk on c.column_name = nk.ColName where table_name = @t ) insert @cols (seq, nkseq, type, colname) select ordinal_position, row_number() over (partition by type order by ordinal_position) , type, COLUMN_NAME from cte declare @result table (i int, j int, k int, data varchar(500)) select @i = @i + 1 insert @result (i, data) select @i, 'merge ' + @t + ' a' select @i = @i + 1 insert @result (i, data) select @i, ' using cte b' select @i = @i + 1 insert @result (i, j, data) select @i, nkseq, ' ' + case when nkseq = 1 then 'on' else 'and' end + ' a.' + ColName + ' = b.' + ColName from @cols where type = 1 select @i = @i + 1 insert @result (i, data) select @i, ' when matched and (1=0' select @i = @i + 1 insert @result (i, j, k, data) select @i, seq, 1, ' or (a.' + ColName + ' b.' + ColName + ')' + ' or (a.' + ColName + ' is null and b.' + ColName + ' is not null)' + ' or (a.' + ColName + ' is not null and b.' + ColName + ' is null)' from @cols where type 1 select @i = @i + 1 insert @result (i, data) select @i, ' )' select @i = @i + 1 insert @result (i, data) select @i, ' then update set' select @i = @i + 1 insert @result (i, j, data) select @i, nkseq, ' ' + case when nkseq = 1 then ' ' else ', ' end + colname + ' = b.' + colname from @cols where type = 0 select @i = @i + 1 insert @result (i, data) select @i, ' when not matched by target then insert' select @i = @i + 1 insert @result (i, data) select @i, ' (' select @i = @i + 1 insert @result (i, j, data) select @i, seq, ' ' + case when seq = 1 then ' ' else ', ' end + colname from @cols where type 3 select @i = @i + 1 insert @result (i, data) select @i, ' )' select @i = @i + 1 insert @result (i, data) select @i, ' values' select @i = @i + 1 insert @result (i, data) select @i, ' (' select @i = @i + 1 insert @result (i, j, data) select @i, seq, ' ' + case when seq = 1 then ' ' else ', ' end + 'b.' + colname from @cols where type 3 select @i = @i + 1 insert @result (i, data) select @i, ' );' select data from @result order by i,j,k,data

  Read the article

• How does Trash Can works? Where can i find official specification / documentation / reference about it?

  - by MestreLion

  When trying to manage trash can from mounted NTFS volumes, I ended up reading FreeDesktop.org's reference on it. Poking around and doing some tests, I realized Ubuntu/Gnome does not follow the specs 100%. Here's why: For non-/ partitions, it always use <driveroot>/.Trash-<uid>, It never used <driveroot>/.Trash/<uid>, even when i created it in advance. While this works, its annoying: if i have 15 users, i end up with 15 /.Trash-xxx folders in my drive, while the other approach would still give a single folder (with 15 sub-folders). That "pollution" in my drives is very unpleasant. And specs say "If an $topdir/.Trash directory is absent, an $topdir/.Trash-$uid directory is to be used". Well, it IS present, so why it never uses it? root trash does not work, at least not out of the box. Open nautilus as root and click on trash, it gives error. Try to delete any file, it says "it cant move to trash". Ok, i know this can be fixed by creating /root/.local/share. But specs says "A “home trash” directory SHOULD be automatically created for any new user. If this directory is needed for a trashing operation but does not exist, the implementation SHOULD automatically create it, without any warnings or delays.". Why error then? Bug? Why do i must change /etc/fstab entries for mounted volumes, adding options like uid and guid, if the volumes are already mounted as RW for everyone? These are just some examples of deviation from standard. So, the question is: "If Ubuntu does not adhere 100% to the spec, HOW exactly does the trash work? WHERE can i find technical reference about Ubuntu's implementation of the trash?" By the way: if Ubuntu does happen to follow specs, please tell me what am i doing wrong, specially regarding the /.Trash-<uid> vs /.Trash/<uid> issue. Thanks! EDIT: Some more info: If a given fs has no support for sticky bit (VFAT, NTFS), it probably dont have for permitions either (at least VFAT surely doesnt). So what prevents one user for purging / restoring other users ./Trash-xxx ? If one can read/write his own Trash, he can also do the same for the whole drive, including other's trashes, isnt it? Or does Gnome has any "extra" protection on ./Trash-xxx folders on VFAT/NTFS fs? If Linux can "emulate" file permitions on NTFS mounting by editing /fstab uid and gid options, can it also "emulate" the sticky bit? I would really want to use /.Trash/xxx format... For the root issue: for the / partition, i can trash as root, and it goes to /root/.local/shate/Trash. But if i click on Nautilus "Trash" (as root), i get an error. Dont you? So files are correctly trashed, but i cant access it. All i can do is manually "purge" them (by deleting files on /root/.local/shate/Trash), but restoring would be very tricky (opening info files and manually moving, etc) For non-/ partitions (or at least for VFAT/NTFS), I can not even trash as root: it does not create a ./Trash-0 folder, it simply says "Cannot trash, want to permantly delete?" Why? About fstab: i use it for a permanent mount for my NTFS partitions. I have several, and if not "pre-mounted" they really cluttter desktop and/or Nautilus. Id rather have it pre mounted, integrated in my fs, in mounts like /data , /windows/xp , /windows/vista , and so on, and leave /media and its "mount/unmount" flexibility just for truly removable drives Si, if Ubuntu/Gnome truly follow the spec, is there any way to fix the root issues and to "emulate" the sticky bit for (at least) my fstab'ed NTFS fixed partitions?

  Read the article

• nginx + php-fpm cycle redirection error on linode new vps

  - by chifliiiii

  I'm new to nginx, and I'm trying to make my first server run. I followed this guide as I'm trying to use it for a multisite wordpress site. After installing everything, I get a 500 Internal server error. If I check logs, I see this: 012/09/27 08:55:54 [error] 11565#0: *8 rewrite or internal redirection cycle while internally redirecting to "/index.html", client: xxx.xxx.xxx.xxx, server: localhost, request: "GET /favicon.ico HTTP/1.1", host: "www.mydomain.com" 2012/09/27 08:59:32 [error] 11618#0: *1 rewrite or internal redirection cycle while internally redirecting to "/index.html", client: xxx.xxx.xxx.xxx, server: localhost, request: "GET /phpmyadmin HTTP/1.1", host: "www.mydomain.com" My conf files are the following: nano /etc/nginx/sites-available/mydomain.com server { listen 80 default_server; server_name mydomain.com *.mydomain.com; root /srv/www/aciup.com/public; access_log /srv/www/mydomain.com/log/access.log; error_log /srv/www/mydomain.com/log/error.log; location / { index index.php; try_files $uri $uri/ /index.php?$args; } # Add trailing slash to */wp-admin requests. rewrite /wp-admin$ $scheme://$host$uri/ permanent; # Directives to send expires headers and turn off 404 error logging. location ~* \.(js|css|png|jpg|jpeg|gif|ico)$ { expires 24h; log_not_found off; } # this prevents hidden files (beginning with a period) from being served location ~ /\. { access_log off; log_not_found off; deny all; } # Pass uploaded files to wp-includes/ms-files.php. rewrite /files/$ /index.php last; if ($uri !~ wp-content/plugins) { rewrite /files/(.+)$ /wp-includes/ms-files.php?file=$1 last; } # Rewrite multisite '.../wp-.*' and '.../*.php'. if (!-e $request_filename) { rewrite ^/[_0-9a-zA-Z-]+(/wp-.*) $1 last; rewrite ^/[_0-9a-zA-Z-]+.*(/wp-admin/.*\.php)$ $1 last; rewrite ^/[_0-9a-zA-Z-]+(/.*\.php)$ $1 last; } location ~ \.php$ { client_max_body_size 25M; fastcgi_pass unix:/var/run/php5-fpm.sock; fastcgi_index index.php; include /etc/nginx/fastcgi_params; } } nano /etc/nginx/nginx.conf user www-data; worker_processes 4; worker_cpu_affinity 0001 0010 0100 1000; error_log /var/log/nginx/error.log; pid /var/run/nginx.pid; events { worker_connections 2048; } http { include /etc/nginx/mime.types; access_log /var/log/nginx/access.log; sendfile on; tcp_nopush on; keepalive_timeout 5; tcp_nodelay on; server_tokens off; gzip on; gzip_types text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript; gzip_disable "MSIE [1-6]\.(?!.*SV1)"; include /etc/nginx/conf.d/*.conf; include /etc/nginx/sites-enabled/*; } Any help will be appreciated.

  Read the article

• How does the Trash Can work, and where can I find official documentation, reference, or specification for it?

  - by MestreLion

  When trying to manage trash can from mounted NTFS volumes, I ended up reading FreeDesktop.org's reference on it. Poking around and doing some tests, I realized Ubuntu/Gnome does not follow the specs 100%. Here's why: For non-/ partitions, it always uses <driveroot>/.Trash-<uid>, It never used <driveroot>/.Trash/<uid>, even when i created it in advance. While this works, it's annoying: if I have 15 users, I end up with 15 /.Trash-xxx folders in my drive, while the other approach would still give a single folder (with 15 sub-folders). That "pollution" in my drives is very unpleasant. And specs say "If an $topdir/.Trash directory is absent, an $topdir/.Trash-$uid directory is to be used". Well, it IS present, so why does it never use it? root trash does not work, at least not out of the box. Open nautilus as root and click on trash; it gives an error. Try to delete any file, it says "it can't move to trash". Ok, I know this can be fixed by creating /root/.local/share. But specs says "A “home trash” directory SHOULD be automatically created for any new user. If this directory is needed for a trashing operation but does not exist, the implementation SHOULD automatically create it, without any warnings or delays.". Why the error then? Bug? Why must I change /etc/fstab entries for mounted volumes, adding options like uid and guid, if the volumes are already mounted as RW for everyone? These are just some examples of deviation from the standard. So, the question is: "If Ubuntu does not adhere 100% to the spec, HOW exactly does the trash work? WHERE can i find a technical reference for Ubuntu's implementation of the trash?" By the way: if Ubuntu does happen to follow specs, please tell me what I am doing wrong, especially regarding the /.Trash-<uid> vs /.Trash/<uid> issue. Thanks! EDIT: Some more info: If a given fs has no support for the sticky bit (VFAT, NTFS), it probably doesn't have for permissions either (at least VFAT surely doesn't). So what prevents one user from purging / restoring other users' ./Trash-xxx ? If one can read/write his own Trash, one can do the same for the whole drive, including other's trashes, correct? Or does Gnome have some kind of "extra" protection on ./Trash-xxx folders on VFAT/NTFS fs? If Linux can "emulate" file permissions on NTFS mounting by editing /fstab uid and gid options, can it also "emulate" the sticky bit? I would really prefer to use /.Trash/xxx format... For the root issue: for the / partition, I can use trash as root, and it goes to /root/.local/shate/Trash. But if I click on Nautilus "Trash" (as root), I get an error. Don't you? So files are correctly trashed, but I can't access it. All I can do is manually "purge" them (by deleting files on /root/.local/shate/Trash), but restoring would be very tricky (opening info files and manually moving, etc.). For non-/ partitions (or at least for VFAT/NTFS), I can not even use trash as root: it does not create a ./Trash-0 folder, it simply says "Cannot trash, want to permanently delete?" Why? About fstab: i use it for a permanent mount for my NTFS partitions. I have several, and if not "pre-mounted" they really clutter the desktop and/or Nautilus. I'd rather have it pre-mounted, integrated in my fs, in mounts like /data , /windows/xp , /windows/vista , and so on, and leave /media and its "mount/unmount" flexibility just for truly removable drives. So, if Ubuntu/Gnome truly follows the spec, is there any way to fix the root issues and to "emulate" the sticky bit for (at least) my fstab'ed NTFS fixed partitions?

  Read the article

• Swap not available on System Monitor

  - by Zaki

  I had a swap partition of 1GB (RAM 1GB, Ubuntu 12.04 lts). Now swap is not shown on System Monitor neither can I hibernate my pc (sudo pm-hibernate). blkid output: /dev/sda1: UUID="B8B4FBB1B4FB706C" TYPE="ntfs" /dev/sda2: UUID="2ea7d608-2d89-4e41-9436-d05cb3ce8871" TYPE="swap" /dev/sda3: UUID="3219d03a-67e4-454b-8ce7-a27831846e35" TYPE="ext4" /dev/sda5: LABEL="Softwares" UUID="AC1CC3301CC2F47C" TYPE="ntfs" /dev/sda6: LABEL="Education" UUID="1E103E6C103E4B53" TYPE="ntfs" /dev/sda7: LABEL="Recreation" UUID="2CC8D181C8D149AA" TYPE="ntfs" /dev/sda8: LABEL="Miscellaneous" UUID="0274D6B174D6A727" TYPE="ntfs" /etc/fstab # <file system> <mount point> <type> <options> <dump> <pass> proc /proc proc nodev,noexec,nosuid 0 0 # / was on /dev/sda6 during installation UUID=3219d03a-67e4-454b-8ce7-a27831846e35 / ext4 errors=remount-ro 0 1 # swap was on /dev/sda5 during installation UUID=2ea7d608-2d89-4e41-9436-d05cb3ce8871 none swap sw 0 0 free -m total used free shared buffers cached Mem: 991 867 123 0 27 418 -/+ buffers/cache: 421 569 Swap: 0 0 0 cat /proc/swaps Filename Type Size Used Priority fdisk -l Disk /dev/sda: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x9f369f36 Device Boot Start End Blocks Id System /dev/sda1 * 63 31471334 15735636 7 HPFS/NTFS/exFAT /dev/sda2 31471616 33470447 999416 82 Linux swap / Solaris /dev/sda3 33472512 62539775 14533632 83 Linux /dev/sda4 62541045 312592769 125025862+ f W95 Ext'd (LBA) /dev/sda5 62541108 125066024 31262458+ 7 HPFS/NTFS/exFAT /dev/sda6 125066088 187591004 31262458+ 7 HPFS/NTFS/exFAT /dev/sda7 187591068 250115984 31262458+ 7 HPFS/NTFS/exFAT /dev/sda8 250116048 312576704 31230328+ 7 HPFS/NTFS/exFAT swapon --all swapon: /dev/sda2: swapon failed: Invalid argument dmesg | grep -A 5 -B 5 -i swap [ 9.487404] EXT4-fs (sda3): ext4_orphan_cleanup: deleting unreferenced inode 131645 [ 9.487413] EXT4-fs (sda3): ext4_orphan_cleanup: deleting unreferenced inode 131330 [ 9.487418] EXT4-fs (sda3): 16 orphan inodes deleted [ 9.487420] EXT4-fs (sda3): recovery complete [ 9.578600] EXT4-fs (sda3): mounted filesystem with ordered data mode. Opts: (null) [ 20.580539] Swap area shorter than signature indicates [ 20.588363] IPv6: ADDRCONF(NETDEV_UP): eth0: link is not ready [ 20.619443] udevd[330]: starting version 175 [ 20.649959] lp: driver loaded but no devices found [ 20.662972] [drm] Initialized drm 1.1.0 20060810 [ 20.675515] i915 0000:00:02.0: setting latency timer to 64 -- [ 72.288573] PM: thaw of drv:sr dev:3:0:0:0 complete after 178.143 msecs [ 72.288578] PM: thaw of drv:scsi_device dev:3:0:0:0 complete after 178.136 msecs [ 72.299677] PM: thaw of drv:scsi_device dev:2:0:0:0 complete after 189.270 msecs [ 72.309473] PM: thaw of devices complete after 202.763 msecs [ 72.309668] PM: writing image. [ 72.309670] PM: Cannot find swap device, try swapon -a. [ 72.309699] PM: Cannot get swap writer [ 72.329896] Restarting tasks ... done. [ 72.331777] PM: Basic memory bitmaps freed [ 72.331792] video LNXVIDEO:00: Restoring backlight state [ 72.420048] option1 ttyUSB0: option_instat_callback: error -84 [ 72.804047] option1 ttyUSB0: option_instat_callback: error -84 -- [ 145.960625] sd 7:0:0:0: Attached scsi generic sg2 type 0 [ 145.972036] sd 7:0:0:0: [sdb] Attached SCSI removable disk [ 172.430508] PPP BSD Compression module registered [ 172.455583] PPP Deflate Compression module registered [ 332.260789] type=1400 audit(1381814763.342:27): apparmor="DENIED" operation="capable" parent=1 profile="/usr/sbin/cupsd" pid=636 comm="cupsd" pid=636 comm="cupsd" capability=36 capname="block_suspend" [ 1913.030998] Swap area shorter than signature indicates [ 2022.530155] type=1400 audit(1381816453.610:28): apparmor="DENIED" operation="capable" parent=1 profile="/usr/sbin/cupsd" pid=636 comm="cupsd" pid=636 comm="cupsd" capability=36 capname="block_suspend" [ 4062.729509] Swap area shorter than signature indicates Please help. Thanks in advance. df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 14G 6.1G 7.0G 47% / udev 488M 4.0K 488M 1% /dev tmpfs 199M 868K 198M 1% /run none 5.0M 4.0K 5.0M 1% /run/lock none 496M 224K 496M 1% /run/shm

  Read the article

• Things I've noticed with DVCS

  - by Wes McClure

  Things I encourage: Frequent local commits This way you don't have to be bothered by changes others are making to the central repository while working on a handful of related tasks.  It's a good idea to try to work on one task at a time and commit all changes at partitioned stopping points.  A local commit doesn't have to build, just FYI, so a stopping point doesn't mean a build point nor a point that you can push centrally.  There should be several of these in any given day.  2 hours is a good indicator that you might not be leveraging the power of frequent local commits.  Once you have verified a set of changes works, save them away, otherwise run the risk of introducing bugs into it when working on the next task.  The notion of a task By task I mean a related set of changes that can be completed in a few hours or less.  In the same token don’t make your tasks so small that critically related changes aren’t grouped together.  Use your intuition and the rest of these principles and I think you will find what is comfortable for you. Partial commits Sometimes one task explodes or unknowingly encompasses other tasks, at this point, try to get to a stopping point on part of the work you are doing and commit it so you can get that out of the way to focus on the remainder.  This will often entail committing part of the work and continuing on the rest. Outstanding changes as a guide If you don't commit often it might mean you are not leveraging your version control history to help guide your work.  It's a great way to see what has changed and might be causing problems.  The longer you wait, the more that has changed and the harder it is to test/debug what your changes are doing! This is a reason why I am so picky about my VCS tools on the client side and why I talk a lot about the quality of a diff tool and the ability to integrate that with a simple view of everything that has changed.  This is why I love using TortoiseHg and SmartGit: they show changed files, a diff (or two way diff with SmartGit) of the current selected file and a commit message all in one window that I keep maximized on one monitor at all times. Throw away / stash commits There is extreme value in being able to throw away a commit (or stash it) that is getting out of hand.  If you do not commit often you will have to isolate the work you want to commit from the work you want to throw away, which is wasted productivity and highly prone to errors.  I find myself doing this about once a week, especially when doing exploratory re-factoring.  It's much easier if I can just revert all outstanding changes. Sync with the central repository daily The rest of us depend on your changes.  Don't let them sit on your computer longer than they have to.  Waiting increases the chances of merge conflict which just decreases productivity.  It also prohibits us from doing deploys when people say they are done but have not merged centrally.  This should be done daily!  Find a way to partition the work you are doing so that you can sync at least once daily. Things I discourage: Lots of partial commits right at the end of a series of changes If you notice lots of partial commits at the end of a set of changes, it's likely because you weren't frequently committing, nor were you watching for the size of the task expanding beyond a single commit.  Chances are this cost you productivity if you use your outstanding changes as a guide, since you would have an ever growing list of changes. Committing single files Committing single files means you waited too long and no longer understand all the changes involved.  It may mean there were overlapping changes in single files that cannot be isolated.  In either case, go back to the suggestions above to avoid this.  Committing frequently does not mean committing frequently right at the end of a day's work. It should be spaced out over the course of several tasks, not all at the end in a 5 minute window.

  Read the article

• Converting a PV vm back into an HVM vm

  - by wim.coekaerts

  I have been doing some Oracle VM benchmark stuff in the last week or 2 in my off hours and yesterday I wanted to convert one of my VMs that was based on a paravirt kernel into a vm that just boots as a regular hardware virt VM with a standard x86-64 kernel. It took me a little while to figure out the fastest way so now that I have it pretty much down I wanted to share the steps. A PV kernel uses pygrub and a paravirt kernel image that lives on the vm image virtual disk. since this disk image does not have to be bootable it doesn't contain a boot sector and if you just restart the VM in hvm mode the virtual bios will just not do much as it can't start the boot process from disk The first thing I do is make a backup of my vm.cfg file :-) and then edit it as follows : the original file contains : bootloader = '/usr/bin/pygrub' I replace that with : acpi = 1 apic = 1 builder = 'hvm' device_model = '/usr/lib/xen/bin/qemu-dm' kernel = '/usr/lib/xen/boot/hvmloader' then changing the disk files. I change my xvd disks to hd disks and I copy over the iso image of my instal lDVD. In the case of my VM template it was based on OL5U4 So I downloaded Enterprise-R5-U4-Server-x86_64-dvd.iso and added it as a cd device. disk = ['file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/System.img,xvda,w', 'file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/Oracle11202RAC_x86_64-xvdb.img,xvdb,w', ] to disk = ['file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/System.img,hda,w', 'file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/Oracle11202RAC_x86_64-xvdb.img,hdb,w', 'file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/Enterprise-R5-U4-Server-x86_64-dvd.iso, hdc:cdrom,r', ] boot='d' for the network devices (vifs) I change : vif = ['bridge=xenbr2,type=netfront'] to vif = ['bridge=xenbr2,type=ioemu'] That should do it. Next, inside the VM, I copy over the regular kernel rpm that I want to end up running in hvm mode. In this example case it was : kernel-2.6.18-164.0.0.0.1.el5.x8664.rpm. I will use that later on in the process. I put this kernel simply in /root At this point I just start the vm with xm create vm.cfg and start my vnc console to the vm console. Oracle Linux will boot from the iso image, I just go through the install steps and click on UPgrade existing (not re-install). Because the VM is the same as the ISO the install won't actually do anything and it will run through instantly. When the "Reboot" button pops up, don't reboot. Switch to the command prompt console. hi alt-f2 to go to the shell prompt. Now it's easy : umount /mnt/sysimage/boot cd /mnt/sysimage chroot . mount /dev/hda1 (if that was your /boot partition) export PATH=/sbin:$PATH (just to clean that up) edit /etc/modprobe.conf and comment out the xen modules (just put a # in front) Install grub. if your /boot is hda1 then that is (hd0,0) $ grub root (hd0,0) setup (hd0) exit grub now you have a good bootsector, grub installed and you have your grub.conf file Install the new kernel cd root (this is your old /root in your pv image) rpm -ivh remove (or comment out) boot='d' in your vm.cfg restart the VM and you should be good to go, regular grub should start and load your environment. Caveats : this assumes you used labels for your filesystems. if /etc/fstab were to have devices listed then you would have to rename these device before rebooting as well. If you had a /dev/xvda disk then this would be /dev/hda or /dev/sda. All in all it is a relatively short and simple process.

  Read the article

• Converting a PV vm back into an HVM vm

  - by wim.coekaerts

  I have been doing some Oracle VM benchmark stuff in the last week or 2 in my off hours and yesterday I wanted to convert one of my VMs that was based on a paravirt kernel into a vm that just boots as a regular hardware virt VM with a standard x86-64 kernel. It took me a little while to figure out the fastest way so now that I have it pretty much down I wanted to share the steps. A PV kernel uses pygrub and a paravirt kernel image that lives on the vm image virtual disk. since this disk image does not have to be bootable it doesn't contain a boot sector and if you just restart the VM in hvm mode the virtual bios will just not do much as it can't start the boot process from disk The first thing I do is make a backup of my vm.cfg file :-) and then edit it as follows : the original file contains : bootloader = '/usr/bin/pygrub' I replace that with : acpi = 1 apic = 1 builder = 'hvm' device_model = '/usr/lib/xen/bin/qemu-dm' kernel = '/usr/lib/xen/boot/hvmloader' then changing the disk files. I change my xvd disks to hd disks and I copy over the iso image of my instal lDVD. In the case of my VM template it was based on OL5U4 So I downloaded Enterprise-R5-U4-Server-x86_64-dvd.iso and added it as a cd device. disk = ['file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/System.img,xvda,w', 'file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/Oracle11202RAC_x86_64-xvdb.img,xvdb,w', ] to disk = ['file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/System.img,hda,w', 'file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/Oracle11202RAC_x86_64-xvdb.img,hdb,w', 'file:/ovs/OVM_EL5U4_X86_64_11202RAC_PVM/Enterprise-R5-U4-Server-x86_64-dvd.iso, hdc:cdrom,r', ] boot='d' for the network devices (vifs) I change : vif = ['bridge=xenbr2,type=netfront'] to vif = ['bridge=xenbr2,type=ioemu'] That should do it. Next, inside the VM, I copy over the regular kernel rpm that I want to end up running in hvm mode. In this example case it was : kernel-2.6.18-164.0.0.0.1.el5.x8664.rpm. I will use that later on in the process. I put this kernel simply in /root At this point I just start the vm with xm create vm.cfg and start my vnc console to the vm console. Oracle Linux will boot from the iso image, I just go through the install steps and click on UPgrade existing (not re-install). Because the VM is the same as the ISO the install won't actually do anything and it will run through instantly. When the "Reboot" button pops up, don't reboot. Switch to the command prompt console. hi alt-f2 to go to the shell prompt. Now it's easy : umount /mnt/sysimage/boot cd /mnt/sysimage chroot . mount /dev/hda1 (if that was your /boot partition) export PATH=/sbin:$PATH (just to clean that up) edit /etc/modprobe.conf and comment out the xen modules (just put a # in front) Install grub. if your /boot is hda1 then that is (hd0,0) $ grub root (hd0,0) setup (hd0) exit grub now you have a good bootsector, grub installed and you have your grub.conf file Install the new kernel cd root (this is your old /root in your pv image) rpm -ivh remove (or comment out) boot='d' in your vm.cfg restart the VM and you should be good to go, regular grub should start and load your environment. Caveats : this assumes you used labels for your filesystems. if /etc/fstab were to have devices listed then you would have to rename these device before rebooting as well. If you had a /dev/xvda disk then this would be /dev/hda or /dev/sda. All in all it is a relatively short and simple process.

  Read the article

• Columnstore Case Study #1: MSIT SONAR Aggregations

  - by aspiringgeek

  Preamble This is the first in a series of posts documenting big wins encountered using columnstore indexes in SQL Server 2012 & 2014.  Many of these can be found in this deck along with details such as internals, best practices, caveats, etc.  The purpose of sharing the case studies in this context is to provide an easy-to-consume quick-reference alternative. Why Columnstore? If we’re looking for a subset of columns from one or a few rows, given the right indexes, SQL Server can do a superlative job of providing an answer. If we’re asking a question which by design needs to hit lots of rows—DW, reporting, aggregations, grouping, scans, etc., SQL Server has never had a good mechanism—until columnstore. Columnstore indexes were introduced in SQL Server 2012. However, they're still largely unknown. Some adoption blockers existed; yet columnstore was nonetheless a game changer for many apps.  In SQL Server 2014, potential blockers have been largely removed & they're going to profoundly change the way we interact with our data.  The purpose of this series is to share the performance benefits of columnstore & documenting columnstore is a compelling reason to upgrade to SQL Server 2014. App: MSIT SONAR Aggregations At MSIT, performance & configuration data is captured by SCOM. We archive much of the data in a partitioned data warehouse table in SQL Server 2012 for reporting via an application called SONAR.  By definition, this is a primary use case for columnstore—report queries requiring aggregation over large numbers of rows.  New data is refreshed each night by an automated table partitioning mechanism—a best practices scenario for columnstore. The Win Compared to performance using classic indexing which resulted in the expected query plan selection including partition elimination vs. SQL Server 2012 nonclustered columnstore, query performance increased significantly.  Logical reads were reduced by over a factor of 50; both CPU & duration improved by factors of 20 or more.  Other than creating the columnstore index, no special modifications or tweaks to the app or databases schema were necessary to achieve the performance improvements.  Existing nonclustered indexes were rendered superfluous & were deleted, thus mitigating maintenance challenges such as defragging as well as conserving disk capacity. Details The table provides the raw data & summarizes the performance deltas. Logical Reads (8K pages) CPU (ms) Durn (ms) Columnstore 160,323 20,360 9,786 Conventional Table & Indexes 9,053,423 549,608 193,903 ? x56 x27 x20 The charts provide additional perspective of this data.  "Conventional vs. Columnstore Metrics" document the raw data.  Note on this linear display the magnitude of the conventional index performance vs. columnstore.  The “Metrics (?)” chart expresses these values as a ratio. Summary For DW, reports, & other BI workloads, columnstore often provides significant performance enhancements relative to conventional indexing.  I have documented here, the first in a series of reports on columnstore implementations, results from an initial implementation at MSIT in which logical reads were reduced by over a factor of 50; both CPU & duration improved by factors of 20 or more.  Subsequent features in this series document performance enhancements that are even more significant. 

  Read the article

• Master-slave vs. peer-to-peer archictecture: benefits and problems

  - by Ashok_Ora

  Normal 0 false false false EN-US X-NONE X-NONE Almost two decades ago, I was a member of a database development team that introduced adaptive locking. Locking, the most popular concurrency control technique in database systems, is pessimistic. Locking ensures that two or more conflicting operations on the same data item don’t “trample” on each other’s toes, resulting in data corruption. In a nutshell, here’s the issue we were trying to address. In everyday life, traffic lights serve the same purpose. They ensure that traffic flows smoothly and when everyone follows the rules, there are no accidents at intersections. As I mentioned earlier, the problem with typical locking protocols is that they are pessimistic. Regardless of whether there is another conflicting operation in the system or not, you have to hold a lock! Acquiring and releasing locks can be quite expensive, depending on how many objects the transaction touches. Every transaction has to pay this penalty. To use the earlier traffic light analogy, if you have ever waited at a red light in the middle of nowhere with no one on the road, wondering why you need to wait when there’s clearly no danger of a collision, you know what I mean. The adaptive locking scheme that we invented was able to minimize the number of locks that a transaction held, by detecting whether there were one or more transactions that needed conflicting eyou could get by without holding any lock at all. In many “well-behaved” workloads, there are few conflicts, so this optimization is a huge win. If, on the other hand, there are many concurrent, conflicting requests, the algorithm gracefully degrades to the “normal” behavior with minimal cost. We were able to reduce the number of lock requests per TPC-B transaction from 178 requests down to 2! Wow! This is a dramatic improvement in concurrency as well as transaction latency. The lesson from this exercise was that if you can identify the common scenario and optimize for that case so that only the uncommon scenarios are more expensive, you can make dramatic improvements in performance without sacrificing correctness. So how does this relate to the architecture and design of some of the modern NoSQL systems? NoSQL systems can be broadly classified as master-slave sharded, or peer-to-peer sharded systems. NoSQL systems with a peer-to-peer architecture have an interesting way of handling changes. Whenever an item is changed, the client (or an intermediary) propagates the changes synchronously or asynchronously to multiple copies (for availability) of the data. Since the change can be propagated asynchronously, during some interval in time, it will be the case that some copies have received the update, and others haven’t. What happens if someone tries to read the item during this interval? The client in a peer-to-peer system will fetch the same item from multiple copies and compare them to each other. If they’re all the same, then every copy that was queried has the same (and up-to-date) value of the data item, so all’s good. If not, then the system provides a mechanism to reconcile the discrepancy and to update stale copies. So what’s the problem with this? There are two major issues: First, IT’S HORRIBLY PESSIMISTIC because, in the common case, it is unlikely that the same data item will be updated and read from different locations at around the same time! For every read operation, you have to read from multiple copies. That’s a pretty expensive, especially if the data are stored in multiple geographically separate locations and network latencies are high. Second, if the copies are not all the same, the application has to reconcile the differences and propagate the correct value to the out-dated copies. This means that the application program has to handle discrepancies in the different versions of the data item and resolve the issue (which can further add to cost and operation latency). Resolving discrepancies is only one part of the problem. What if the same data item was updated independently on two different nodes (copies)? In that case, due to the asynchronous nature of change propagation, you might land up with different versions of the data item in different copies. In this case, the application program also has to resolve conflicts and then propagate the correct value to the copies that are out-dated or have incorrect versions. This can get really complicated. My hunch is that there are many peer-to-peer-based applications that don’t handle this correctly, and worse, don’t even know it. Imagine have 100s of millions of records in your database – how can you tell whether a particular data item is incorrect or out of date? And what price are you willing to pay for ensuring that the data can be trusted? Multiple network messages per read request? Discrepancy and conflict resolution logic in the application, and potentially, additional messages? All this overhead, when all you were trying to do was to read a data item. Wouldn’t it be simpler to avoid this problem in the first place? Master-slave architectures like the Oracle NoSQL Database handles this very elegantly. A change to a data item is always sent to the master copy. Consequently, the master copy always has the most current and authoritative version of the data item. The master is also responsible for propagating the change to the other copies (for availability and read scalability). Client drivers are aware of master copies and replicas, and client drivers are also aware of the “currency” of a replica. In other words, each NoSQL Database client knows how stale a replica is. This vastly simplifies the job of the application developer. If the application needs the most current version of the data item, the client driver will automatically route the request to the master copy. If the application is willing to tolerate some staleness of data (e.g. a version that is no more than 1 second out of date), the client can easily determine which replica (or set of replicas) can satisfy the request, and route the request to the most efficient copy. This results in a dramatic simplification in application logic and also minimizes network requests (the driver will only send the request to exactl the right replica, not many). So, back to my original point. A well designed and well architected system minimizes or eliminates unnecessary overhead and avoids pessimistic algorithms wherever possible in order to deliver a highly efficient and high performance system. If you’ve every programmed an Oracle NoSQL Database application, you’ll know the difference! /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

  Read the article

< Previous Page | 217 218 219 220 221 222 223 224 225 226 227 228  | Next Page >