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  • Refactoring FizzBuzz

    - by MarkPearl
    A few years ago I blogger about FizzBuzz, at the time the post was prompted by Scott Hanselman who had podcasted about how surprized he was that some programmers could not even solve the FizzBuzz problem within a reasonable period of time during a job interview. At the time I thought I would give the problem a go in F# and sure enough the solution was fairly simple – I then also did a basic solution in C# but never posted it. Since then I have learned that being able to solve a problem and how you solve the problem are two totally different things. Today I decided to give the problem a retry and see if I had learnt anything new in the last year or so. Here is how my solution looked after refactoring… Solution 1 – Cheap and Nasty public class FizzBuzzCalculator { public string NumberFormat(int number) { var numDivisibleBy3 = (number % 3) == 0; var numDivisibleBy5 = (number % 5) == 0; if (numDivisibleBy3 && numDivisibleBy5) return String.Format("{0} FizzBuz", number); else if (numDivisibleBy3) return String.Format("{0} Fizz", number); else if (numDivisibleBy5) return String.Format("{0} Buz", number); return number.ToString(); } } class Program { static void Main(string[] args) { var fizzBuzz = new FizzBuzzCalculator(); for (int i = 0; i < 100; i++) { Console.WriteLine(fizzBuzz.NumberFormat(i)); } } } My first attempt I just looked at solving the problem – it works, and could be an acceptable solution but tonight I thought I would see how far  I could refactor it… The section I decided to focus on was the mass of if..else code in the NumberFormat method. Solution 2 – Replacing If…Else with a Dictionary public class FizzBuzzCalculator { private readonly Dictionary<Tuple<bool, bool>, string> _mappings; public FizzBuzzCalculator(Dictionary<Tuple<bool, bool>, string> mappings) { _mappings = mappings; } public string NumberFormat(int number) { var numDivisibleBy3 = (number % 3) == 0; var numDivisibleBy5 = (number % 5) == 0; var mappedKey = new Tuple<bool, bool>(numDivisibleBy3, numDivisibleBy5); return String.Format("{0} {1}", number, _mappings[mappedKey]); } } class Program { static void Main(string[] args) { var mappings = new Dictionary<Tuple<bool, bool>, string> { { new Tuple<bool, bool>(true, true), "- FizzBuzz"}, { new Tuple<bool, bool>(true, false), "- Fizz"}, { new Tuple<bool, bool>(false, true), "- Buzz"}, { new Tuple<bool, bool>(false, false), ""} }; var fizzBuzz = new FizzBuzzCalculator(mappings); for (int i = 0; i < 100; i++) { Console.WriteLine(fizzBuzz.NumberFormat(i)); } Console.ReadLine(); } } In my second attempt I looked at removing the if else in the NumberFormat method. A dictionary proved to be useful for this – I added a constructor to the class and injected the dictionary mapping. One could argue that this is totally overkill, but if I was going to use this code in a large system an approach like this makes it easy to put this data in a configuration file, which would up its OC (Open for extensibility, closed for modification principle). I could of course take the OC principle even further – the check for divisibility by 3 and 5 is tightly coupled to this class. If I wanted to make it 4 instead of 3, I would need to adjust this class. This introduces my third refactoring. Solution 3 – Introducing Delegates and Injecting them into the class public delegate bool FizzBuzzComparison(int number); public class FizzBuzzCalculator { private readonly Dictionary<Tuple<bool, bool>, string> _mappings; private readonly FizzBuzzComparison _comparison1; private readonly FizzBuzzComparison _comparison2; public FizzBuzzCalculator(Dictionary<Tuple<bool, bool>, string> mappings, FizzBuzzComparison comparison1, FizzBuzzComparison comparison2) { _mappings = mappings; _comparison1 = comparison1; _comparison2 = comparison2; } public string NumberFormat(int number) { var mappedKey = new Tuple<bool, bool>(_comparison1(number), _comparison2(number)); return String.Format("{0} {1}", number, _mappings[mappedKey]); } } class Program { private static bool DivisibleByNum(int number, int divisor) { return number % divisor == 0; } public static bool Divisibleby3(int number) { return number % 3 == 0; } public static bool Divisibleby5(int number) { return number % 5 == 0; } static void Main(string[] args) { var mappings = new Dictionary<Tuple<bool, bool>, string> { { new Tuple<bool, bool>(true, true), "- FizzBuzz"}, { new Tuple<bool, bool>(true, false), "- Fizz"}, { new Tuple<bool, bool>(false, true), "- Buzz"}, { new Tuple<bool, bool>(false, false), ""} }; var fizzBuzz = new FizzBuzzCalculator(mappings, Divisibleby3, Divisibleby5); for (int i = 0; i < 100; i++) { Console.WriteLine(fizzBuzz.NumberFormat(i)); } Console.ReadLine(); } } I have taken this one step further and introduced delegates that are injected into the FizzBuzz Calculator class, from an OC principle perspective it has probably made it more compliant than the previous Solution 2, but there seems to be a lot of noise. Anonymous Delegates increase the readability level, which is what I have done in Solution 4. Solution 4 – Anon Delegates public delegate bool FizzBuzzComparison(int number); public class FizzBuzzCalculator { private readonly Dictionary<Tuple<bool, bool>, string> _mappings; private readonly FizzBuzzComparison _comparison1; private readonly FizzBuzzComparison _comparison2; public FizzBuzzCalculator(Dictionary<Tuple<bool, bool>, string> mappings, FizzBuzzComparison comparison1, FizzBuzzComparison comparison2) { _mappings = mappings; _comparison1 = comparison1; _comparison2 = comparison2; } public string NumberFormat(int number) { var mappedKey = new Tuple<bool, bool>(_comparison1(number), _comparison2(number)); return String.Format("{0} {1}", number, _mappings[mappedKey]); } } class Program { static void Main(string[] args) { var mappings = new Dictionary<Tuple<bool, bool>, string> { { new Tuple<bool, bool>(true, true), "- FizzBuzz"}, { new Tuple<bool, bool>(true, false), "- Fizz"}, { new Tuple<bool, bool>(false, true), "- Buzz"}, { new Tuple<bool, bool>(false, false), ""} }; var fizzBuzz = new FizzBuzzCalculator(mappings, (n) => n % 3 == 0, (n) => n % 5 == 0); for (int i = 0; i < 100; i++) { Console.WriteLine(fizzBuzz.NumberFormat(i)); } Console.ReadLine(); } }   Using the anonymous delegates I think the noise level has now been reduced. This is where I am going to end this post, I have gone through 4 iterations of the code from the initial solution using If..Else to delegates and dictionaries. I think each approach would have it’s pro’s and con’s and depending on the intention of where the code would be used would be a large determining factor. If you can think of an alternative way to do FizzBuzz, add a comment!

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  • Twice as long and half as long

    - by PointsToShare
    We are in a project and we hit some snags. What’s a snag? An activity that takes longer than expected. Actually it takes longer than the time assigned to it by an over pressed PM who accepts an impossible time table and tries his best to make it possible, but I digress (again!).  So we have snags and we also have the opposite. Let’s call these “cinches”. The question is: how does a combination of snags and cinches affect the project timeline? Well, there is no simple answer. It depends on the projects dependencies as we see in the PERT chart. If all the snags are in the critical path and all the cinches are elsewhere then the cinches don’t help at all. In fact any snag in the critical path will delay the project.  Conversely, a cinch in the critical path will expedite it. A snag outside the critical path might be serious enough to even change the critical path. Thus without the PERT chart, we cannot really tell. Still there is a principle involved – Time and speed are non-linear! Twice as long adds a full unit, half as long only takes ½ unit away. Let’s just investigate a simple project. It consists of two activities – S and C - each estimated to take a week. Alas, S is a snag and really needs twice the time allotted and – a sigh of relief – C is a cinch and will take half the time allotted, so everything is Hun-key-dory, or is it?  Even here the PERT chart is important. We have 2 cases: 1: S depends on C (or vice versa) as in when the two activities are assigned to one employee. Here the estimated time was 1 + 1 and the actual time was 2 + ½ and we are ½ week late or 25% late. 2: S and C are done in parallel. Here the estimated time was 1, but the actual time is 2 – we are a whole week or 100% late. Let’s change the equation a little. S need 1.5 and C needs .5 so in case 1, we have the loss fully compensated by the gain, but in case 2 we are still behind. There are cases where this really makes no difference. This is when the critical path is not affected and we have enough slack in the other paths to counteract the difference between its snags and cinches – Let’s call this difference DSC. So if the slack is greater than DSC the project will not suffer. Conclusion: There is no general rule about snags and cinches. We need to examine each case within its project, still as we saw in the 4 examples above; the snag is generally more powerful than the cinch. Long live Murphy! That’s All Folks

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  • Create a Remote Git Repository from an Existing XCode Repository

    - by codeWithoutFear
    Introduction Distributed version control systems (VCS’s), like Git, provide a rich set of features for managing source code.  Many development tools, including XCode, provide built-in support for various VCS’s.  These tools provide simple configuration with limited customization to get you up and running quickly while still providing the safety net of basic version control. I hate losing (and re-doing) work.  I have OCD when it comes to saving and versioning source code.  Save early, save often, and commit to the VCS often.  I also hate merging code.  Smaller and more frequent commits enable me to minimize merge time and effort as well. The work flow I prefer even for personal exploratory projects is: Make small local changes to the codebase to create an incrementally improved (and working) system. Commit these changes to the local repository.  Local repositories are quick to access, function even while offline, and provides the confidence to continue making bold changes to the system.  After all, I can easily recover to a recent working state. Repeat 1 & 2 until the codebase contains “significant” functionality and I have connectivity to the remote repository. Push the accumulated changes to the remote repository.  The smaller the change set, the less likely extensive merging will be required.  Smaller is better, IMHO. The remote repository typically has a greater degree of fault tolerance and active management dedicated to it.  This can be as simple as a network share that is backed up nightly or as complex as dedicated hardware with specialized server-side processing and significant administrative monitoring. XCode’s out-of-the-box Git integration enables steps 1 and 2 above.  Time Machine backups of the local repository add an additional degree of fault tolerance, but do not support collaboration or take advantage of managed infrastructure such as on-premises or cloud-based storage. Creating a Remote Repository These are the steps I use to enable the full workflow identified above.  For simplicity the “remote” repository is created on the local file system.  This location could easily be on a mounted network volume. Create a Test Project My project is called HelloGit and is located at /Users/Don/Dev/HelloGit.  Be sure to commit all outstanding changes.  XCode always leaves a single changed file for me after the project is created and the initial commit is submitted. Clone the Local Repository We want to clone the XCode-created Git repository to the location where the remote repository will reside.  In this case it will be /Users/Don/Dev/RemoteHelloGit. Open the Terminal application. Clone the local repository to the remote repository location: git clone /Users/Don/Dev/HelloGit /Users/Don/Dev/RemoteHelloGit Convert the Remote Repository to a Bare Repository The remote repository only needs to contain the Git database.  It does not need a checked out branch or local files. Go to the remote repository folder: cd /Users/Don/Dev/RemoteHelloGit Indicate the repository is “bare”: git config --bool core.bare true Remove files, leaving the .git folder: rm -R * Remove the “origin” remote: git remote rm origin Configure the Local Repository The local repository should reference the remote repository.  The remote name “origin” is used by convention to indicate the originating repository.  This is set automatically when a repository is cloned.  We will use the “origin” name here to reflect that relationship. Go to the local repository folder: cd /Users/Don/Dev/HelloGit Add the remote: git remote add origin /Users/Don/Dev/RemoteHelloGit Test Connectivity Any changes made to the local Git repository can be pushed to the remote repository subject to the merging rules Git enforces. Create a new local file: date > date.txt /li> Add the new file to the local index: git add date.txt Commit the change to the local repository: git commit -m "New file: date.txt" Push the change to the remote repository: git push origin master Now you can save, commit, and push/pull to your OCD hearts’ content! Code without fear! --Don

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  • Moodle 2 pages loading up to 2000% faster

    - by TJ
    On average our Moodle 2 pages were loading in 2.8 seconds, now they load in as little as 0.12 seconds, so that’s like 2333.333% faster!What was it I hear you say?Well it was the database connection, or more correctly the database library. I was using FreeTDS http://docs.moodle.org/22/en/Installing_MSSQL_for_PHP, but now I’m using the new Microsoft Drivers 3.0 for PHP for SQL Server http://www.microsoft.com/en-us/download/details.aspx?id=20098. I’m in a Windows Server IT department, and in both our live and development environments, we have Moodle 2.2.3, IIS 7.5, and PHP 5.3.10 running on two Windows Server 2008 R2 servers and using MS Network Load Balancing.Since moving to Moodle 2, the pages have always loaded much more slowly than they did in Moodle 1.9, I’ve been chasing this issue for quite a while. I had previously tried the Microsoft Drivers for PHP for SQL Server 2.0, but my testing showed it was slower than the FreeTDS driver.Then yesterday I found Microsoft had released the new version, Microsoft Drivers 3.0 for PHP for SQL Server, so I thought I’d give it a run, and wow what a difference it made.Pages that were loading in 2.8 seconds, now they load in as little as 0.12 seconds, 2333.333% faster…I have more testing to do, but so far it’s looking good, I have scheduled multi user load testing for early next week (fingers crossed).To make the change all I need to do was,download the driverscopy the relevant files to PHP\ext (for us they were php_pdo_sqlsrv_53_nts.dll and php_sqlsrv_53_nts.dll) install the Microsoft SQL Server 2012 Native Client x64 http://www.microsoft.com/en-us/download/details.aspx?id=29065 add to PHP.ini, extension=php_pdo_sqlsrv_53_nts.dll, extension=php_sqlsrv_53_nts.dllremove form PHP.ini, extension=php_dblib.dllvchange in PHP.ini, mssql.textlimit = 20971520 and mssql.textsize = 20971520change Moodle config.php, $CFG->dbtype = 'sqlsrv'; and 'dbpersist' => Trueand then reboot and test…I've browsed courses, backed up/restored some really large and complicated courses, deleted courses etc. etc. all good.Still more testing to do but, hey this is good start...Hope this helps anyone experiencing the same slowness…

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  • SQL Constraints &ndash; CHECK and NOCHECK

    - by David Turner
    One performance issue i faced at a recent project was with the way that our constraints were being managed, we were using Subsonic as our ORM, and it has a useful tool for generating your ORM code called SubStage – once configured, you can regenerate your DAL code easily based on your database schema, and it can even be integrated into your build as a pre-build event if you want to do this.  SubStage also offers the useful feature of being able to generate DDL scripts for your entire database, and can script your data for you too. The problem came when we decided to use the generate scripts feature to migrate the database onto a test database instance – it turns out that the DDL scripts that it generates include the WITH NOCHECK option, so when we executed them on the test instance, and performed some testing, we found that performance wasn’t as expected. A constraint can be disabled, enabled but not trusted, or enabled and trusted.  When it is disabled, data can be inserted that violates the constraint because it is not being enforced, this is useful for bulk load scenarios where performance is important.  So what does it mean to say that a constraint is trusted or not trusted?  Well this refers to the SQL Server Query Optimizer, and whether it trusts that the constraint is valid.  If it trusts the constraint then it doesn’t check it is valid when executing a query, so the query can be executed much faster. Here is an example base in this article on TechNet, here we create two tables with a Foreign Key constraint between them, and add a single row to each.  We then query the tables: 1 DROP TABLE t2 2 DROP TABLE t1 3 GO 4 5 CREATE TABLE t1(col1 int NOT NULL PRIMARY KEY) 6 CREATE TABLE t2(col1 int NOT NULL) 7 8 ALTER TABLE t2 WITH CHECK ADD CONSTRAINT fk_t2_t1 FOREIGN KEY(col1) 9 REFERENCES t1(col1) 10 11 INSERT INTO t1 VALUES(1) 12 INSERT INTO t2 VALUES(1) 13 GO14 15 SELECT COUNT(*) FROM t2 16 WHERE EXISTS17 (SELECT *18 FROM t1 19 WHERE t1.col1 = t2.col1) This all works fine, and in this scenario the constraint is enabled and trusted.  We can verify this by executing the following SQL to query the ‘is_disabled’ and ‘is_not_trusted’ properties: 1 select name, is_disabled, is_not_trusted from sys.foreign_keys This gives the following result: We can disable the constraint using this SQL: 1 alter table t2 NOCHECK CONSTRAINT fk_t2_t1 And when we query the constraints again, we see that the constraint is disabled and not trusted: So the constraint won’t be enforced and we can insert data into the table t2 that doesn’t match the data in t1, but we don’t want to do this, so we can enable the constraint again using this SQL: 1 alter table t2 CHECK CONSTRAINT fk_t2_t1 But when we query the constraints again, we see that the constraint is enabled, but it is still not trusted: This means that the optimizer will check the constraint each time a query is executed over it, which will impact the performance of the query, and this is definitely not what we want, so we need to make the constraint trusted by the optimizer again.  First we should check that our constraints haven’t been violated, which we can do by running DBCC: 1 DBCC CHECKCONSTRAINTS (t2) Hopefully you see the following message indicating that DBCC completed without finding any violations of your constraint: Having verified that the constraint was not violated while it was disabled, we can simply execute the following SQL:   1 alter table t2 WITH CHECK CHECK CONSTRAINT fk_t2_t1 At first glance this looks like it must be a typo to have the keyword CHECK repeated twice in succession, but it is the correct syntax and when we query the constraints properties, we find that it is now trusted again: To fix our specific problem, we created a script that checked all constraints on our tables, using the following syntax: 1 ALTER TABLE t2 WITH CHECK CHECK CONSTRAINT ALL

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  • .NET vs Windows 8: Rematch!

    - by simonc
    So, although you will be able to use your existing .NET skills to develop Metro apps, it turns out Microsoft are limiting Visual Studio 2011 Express to Metro-only. From the Express website: Visual Studio 11 Express for Windows 8 provides tools for Metro style app development. To create desktop apps, you need to use Visual Studio 11 Professional, or higher. Oh dear. To develop any sort of non-Metro application, you will need to pay for at least VS Professional. I suspect Microsoft (or at least, certain groups within Microsoft) have a very explicit strategy in mind. By making VS Express Metro-only, developers who don't want to pay for Professional will be forced to make their simple one-shot or open-source application in Metro. This increases the number of applications available for Windows 8 and Windows mobile devices, which in turn make those platforms more attractive for consumers. When you use the free VS 11 Express, instead of paying Microsoft, you provide them a service by making applications for Metro, which in turn makes Microsoft's mobile offering more attractive to consumers, increasing their market share. Of course, it remains to be seen if developers forced to jump onto the Metro bandwagon will simply jump ship to Android or iOS instead. At least, that's what I think is going on. With Microsoft, who really knows? Cross posted from Simple Talk.

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  • Addicted to the MIX Buzz

    - by Dave Campbell
    Well it's the Friday before MIX10, and I'm officially of no use to anybody. I'll be driving up to 'Vegas Sunday ... hopefully rolling in mid-late afternoon, checking in at my $31.50/night (including WiFi) Motel, and getting registered then hanging out around registration to see who is there. First organized thing to do is 9PM, so I'm open to suggestions Sunday evening... maybe we can get a gang together for dinner ?? Monday is the Keynote ... I'm addicted to the buzz in the ballroom the first day, hope to be close to the front, trying to live blog. Then straight to Ballroom A and stake out the spot I'll be in for all 3 days, and you all know why :) I've tagged 40 sessions that I 'want' to see, and there's only 12 slots... damn... if I could, I'd try the Multiplicity thing, but I'm afraid I'd get the idiot first try -- or maybe got that one already :) ... but at least I tagged them to make it easy to find after the videos are up. Stuff going on Sunday, Monday, and Tuesday night. I'm staying over for an event on Thursday, and driving back on Friday. I'm not sure how much blogging I'll be doing, but I'll try to hit some 'Cream high spots. I'm sure everyone #NotAtMIX is going to be tuned into the sessions online. I'll be wearing TShirts with WynApse.com and SilverlightCream.com printed on the back... so if you see some old curmudgeon with such a shirt, IT'S ME! I look forward to seeing all the people I only see once or twice a year, and meeting ones I haven't met yet What a week... Bring It On and Stay in the 'Light! Technorati Tags: Silverlight    Silverlight 4    MIX10

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  • Network communications mechanisms for SQL Server

    - by Akshay Deep Lamba
    Problem I am trying to understand how SQL Server communicates on the network, because I'm having to tell my networking team what ports to open up on the firewall for an edge web server to communicate back to the SQL Server on the inside. What do I need to know? Solution In order to understand what needs to be opened where, let's first talk briefly about the two main protocols that are in common use today: TCP - Transmission Control Protocol UDP - User Datagram Protocol Both are part of the TCP/IP suite of protocols. We'll start with TCP. TCP TCP is the main protocol by which clients communicate with SQL Server. Actually, it is more correct to say that clients and SQL Server use Tabular Data Stream (TDS), but TDS actually sits on top of TCP and when we're talking about Windows and firewalls and other networking devices, that's the protocol that rules and controls are built around. So we'll just speak in terms of TCP. TCP is a connection-oriented protocol. What that means is that the two systems negotiate the connection and both agree to it. Think of it like a phone call. While one person initiates the phone call, the other person has to agree to take it and both people can end the phone call at any time. TCP is the same way. Both systems have to agree to the communications, but either side can end it at any time. In addition, there is functionality built into TCP to ensure that all communications can be disassembled and reassembled as necessary so it can pass over various network devices and be put together again properly in the right order. It also has mechanisms to handle and retransmit lost communications. Because of this functionality, TCP is the protocol used by many different network applications. The way the applications all can share is through the use of ports. When a service, like SQL Server, comes up on a system, it must listen on a port. For a default SQL Server instance, the default port is 1433. Clients connect to the port via the TCP protocol, the connection is negotiated and agreed to, and then the two sides can transfer information as needed until either side decides to end the communication. In actuality, both sides will have a port to use for the communications, but since the client's port is typically determined semi-randomly, when we're talking about firewalls and the like, typically we're interested in the port the server or service is using. UDP UDP, unlike TCP, is not connection oriented. A "client" can send a UDP communications to anyone it wants. There's nothing in place to negotiate a communications connection, there's nothing in the protocol itself to coordinate order of communications or anything like that. If that's needed, it's got to be handled by the application or by a protocol built on top of UDP being used by the application. If you think of TCP as a phone call, think of UDP as a postcard. I can put a postcard in the mail to anyone I want, and so long as it is addressed properly and has a stamp on it, the postal service will pick it up. Now, what happens it afterwards is not guaranteed. There's no mechanism for retransmission of lost communications. It's great for short communications that doesn't necessarily need an acknowledgement. Because multiple network applications could be communicating via UDP, it uses ports, just like TCP. The SQL Browser or the SQL Server Listener Service uses UDP. Network Communications - Talking to SQL Server When an instance of SQL Server is set up, what TCP port it listens on depends. A default instance will be set up to listen on port 1433. A named instance will be set to a random port chosen during installation. In addition, a named instance will be configured to allow it to change that port dynamically. What this means is that when a named instance starts up, if it finds something already using the port it normally uses, it'll pick a new port. If you have a named instance, and you have connections coming across a firewall, you're going to want to use SQL Server Configuration Manager to set a static port. This will allow the networking and security folks to configure their devices for maximum protection. While you can change the network port for a default instance of SQL Server, most people don't. Network Communications - Finding a SQL Server When just the name is specified for a client to connect to SQL Server, for instance, MySQLServer, this is an attempt to connect to the default instance. In this case the client will automatically attempt to communicate to port 1433 on MySQLServer. If you've switched the port for the default instance, you'll need to tell the client the proper port, usually by specifying the following syntax in the connection string: <server>,<port>. For instance, if you moved SQL Server to listen on 14330, you'd use MySQLServer,14330 instead of just MySQLServer. However, because a named instance sets up its port dynamically by default, the client never knows at the outset what the port is it should talk to. That's what the SQL Browser or the SQL Server Listener Service (SQL Server 2000) is for. In this case, the client sends a communication via the UDP protocol to port 1434. It asks, "Where is the named instance?" So if I was running a named instance called SQL2008R2, it would be asking the SQL Browser, "Hey, how do I talk to MySQLServer\SQL2008R2?" The SQL Browser would then send back a communications from UDP port 1434 back to the client telling the client how to talk to the named instance. Of course, you can skip all of this of you set that named instance's port statically. Then you can use the <server>,<port> mechanism to connect and the client won't try to talk to the SQL Browser service. It'll simply try to make the connection. So, for instance, is the SQL2008R2 instance was listening on port 20080, specifying MySQLServer,20080 would attempt a connection to the named instance. Network Communications - Named Pipes Named pipes is an older network library communications mechanism and it's generally not used any longer. It shouldn't be used across a firewall. However, if for some reason you need to connect to SQL Server with it, this protocol also sits on top of TCP. Named Pipes is actually used by the operating system and it has its own mechanism within the protocol to determine where to route communications. As far as network communications is concerned, it listens on TCP port 445. This is true whether we're talking about a default or named instance of SQL Server. The Summary Table To put all this together, here is what you need to know: Type of Communication Protocol Used Default Port Finding a SQL Server or SQL Server Named Instance UDP 1434 Communicating with a default instance of SQL Server TCP 1433 Communicating with a named instance of SQL Server TCP * Determined dynamically at start up Communicating with SQL Server via Named Pipes TCP 445

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  • Repository and Ticket management in a Windows Environment

    - by saifkhan
    I’ve been using AxoSoft’s bug tracking application for a while, although and excellent piece of software I had some issues with it ·         It was SLOOOW (both desktop and web). I don’t care what Axosoft says, I tired multiple servers etc. I’ve been long enough in this field to tell you when something is not right with an app. ·         The cost! It’s not feasible for a small team.   I must say though, that they have some nice features which are not commonly found on other bug tracking software. I wouldn’t go on to list any here. I would prefer you download and try their app and see for yourself. In my quest to find a replacement, I tried a few. The successor had to satisfy the following ·         A 99.99% Windows Environment. ·         Bug Tracking. ·         Ticket Management (power users and project managers can open tickets on projects). ·         Repository (I decided to merge bug tracking and repository to get my team to be more productive). ·         Unlimited users. ·         Cost. Being the head of IT security for the firm I work for, making the decision to move data offsite was a hard decision to make, but turned out to be one I am not regretting so far. My choice was down to Altassian JIRA and codebaseHQ. I ended up going with the latter… (I still love the greenhopper from Altassian…its freaking cool!) CodebaseHQ is nice and simple and has all the features I needed. I’ve been using them for a few months now and very happy. Their pricing…well, see for yourself. I was also able to get our SVN data… (Yes, SVN! I don’t go near the Visual Sourcesafe thing…it’s not that safe (pardon the pun). I am hearing some nice things about TFS 2010) over to codebaseHQ. We use VisualSVN to access repositories. …so if you are a Windows developer (or team) codebaseHQ is worth checking out!

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  • System Center Service Manager 2010 SP1 Resource Links

    - by Mickey Gousset
    System Center Service Manager is a new product that Microsoft released last year to handle incident/problem/change management.  Currently the latest version is System Center Service Manager SP1, and there is a Cumulative Update for SP1 that you should grab as well. A strong ecosystem is starting to spring up around this product, with tools and connectors that fill needs not build into the product.  To find the latest list of these items, you need to do to the SCSM 2010 Downloads page.  Here you can find a list of the latest tools and add-ons from Microsoft, as well as third-party vendors.  The Microsoft Exchange connector, and the Powershell Cmdlets are definitely worth it to download and install.

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  • Visual Studio 2010 Is Here!

    - by Bill Evjen
    I think back to the days of the first versions of Visual Studio (when it was called Visual Studio .NET, remember?) and I think about how far Microsoft has come with this IDE. It really is the best IDE on the market. There is so much to this IDE it is amazing. It now can really handle managing your complete software application development lifecycle. For me, it is (besides Windows 7) the best and most successful product Microsoft has developed. You can obviously get this now and it is available on MSDN and some other places: MSDN Visual Studio Trial Editions Visual Studio 2010 Express Editions (free) You will also find great info at the Visual Studio Developer Center. Some other interesting tidbits of info: JetBrain’s ReSharper 5.0 has been released for VS2010 Oracle will have the new Oracle Dev Tools for VS2010 within one month - http://bit.ly/9gC9NE Visual Studio 64-bit - Why there is no 64-bit version of VS - http://bit.ly/dhhwAj In installing this version of Visual Studio, if you have been working on the previous RC builds, then you are going to want to uninstall these previous editions of the 2010 product. You can do this through the Add Remove Programs dialog and you are going to want to select the appropriate item from the long list of Visual Studio items. You are then going to want to step through the Visual Studio dialog (it will seem as if you are installing it again) – and you will then come to a point where you can select the option to Uninstall the entire application. If you have installed the Silverlight 4 RC stuff, then you are also going to want to uninstall this and you are also going to want to uninstall the “Update for Visual Studio 2010 (KB976272)” before installing Silverlight RC2 – which you can find on www.silverlight.net. Technorati Tags: vs2010,.net,visualstudio,microsoft

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  • Organization &amp; Architecture UNISA Studies &ndash; Chap 5

    - by MarkPearl
    Learning Outcomes Describe the operation of a memory cell Explain the difference between DRAM and SRAM Discuss the different types of ROM Explain the concepts of a hard failure and a soft error respectively Describe SDRAM organization Semiconductor Main Memory The two traditional forms of RAM used in computers are DRAM and SRAM DRAM (Dynamic RAM) Divided into two technologies… Dynamic Static Dynamic RAM is made with cells that store data as charge on capacitors. The presence or absence of charge in a capacitor is interpreted as a binary 1 or 0. Because capacitors have natural tendency to discharge, dynamic RAM requires periodic charge refreshing to maintain data storage. The term dynamic refers to the tendency of the stored charge to leak away, even with power continuously applied. Although the DRAM cell is used to store a single bit (0 or 1), it is essentially an analogue device. The capacitor can store any charge value within a range, a threshold value determines whether the charge is interpreted as a 1 or 0. SRAM (Static RAM) SRAM is a digital device that uses the same logic elements used in the processor. In SRAM, binary values are stored using traditional flip flop logic configurations. SRAM will hold its data as along as power is supplied to it. Unlike DRAM, no refresh is required to retain data. SRAM vs. DRAM DRAM is simpler and smaller than SRAM. Thus it is more dense and less expensive than SRAM. The cost of the refreshing circuitry for DRAM needs to be considered, but if the machine requires a large amount of memory, DRAM turns out to be cheaper than SRAM. SRAMS are somewhat faster than DRAM, thus SRAM is generally used for cache memory and DRAM is used for main memory. Types of ROM Read Only Memory (ROM) contains a permanent pattern of data that cannot be changed. ROM is non volatile meaning no power source is required to maintain the bit values in memory. While it is possible to read a ROM, it is not possible to write new data into it. An important application of ROM is microprogramming, other applications include library subroutines for frequently wanted functions, System programs, Function tables. A ROM is created like any other integrated circuit chip, with the data actually wired into the chip as part of the fabrication process. To reduce costs of fabrication, we have PROMS. PROMS are… Written only once Non-volatile Written after fabrication Another variation of ROM is the read-mostly memory, which is useful for applications in which read operations are far more frequent than write operations, but for which non volatile storage is required. There are three common forms of read-mostly memory, namely… EPROM EEPROM Flash memory Error Correction Semiconductor memory is subject to errors, which can be classed into two categories… Hard failure – Permanent physical defect so that the memory cell or cells cannot reliably store data Soft failure – Random error that alters the contents of one or more memory cells without damaging the memory (common cause includes power supply issues, etc.) Most modern main memory systems include logic for both detecting and correcting errors. Error detection works as follows… When data is to be read into memory, a calculation is performed on the data to produce a code Both the code and the data are stored When the previously stored word is read out, the code is used to detect and possibly correct errors The error checking provides one of 3 possible results… No errors are detected – the fetched data bits are sent out An error is detected, and it is possible to correct the error. The data bits plus error correction bits are fed into a corrector, which produces a corrected set of bits to be sent out An error is detected, but it is not possible to correct it. This condition is reported Hamming Code See wiki for detailed explanation. We will probably need to know how to do a hemming code – refer to the textbook (pg. 188 – 189) Advanced DRAM organization One of the most critical system bottlenecks when using high-performance processors is the interface to main memory. This interface is the most important pathway in the entire computer system. The basic building block of main memory remains the DRAM chip. In recent years a number of enhancements to the basic DRAM architecture have been explored, and some of these are now on the market including… SDRAM (Synchronous DRAM) DDR-DRAM RDRAM SDRAM (Synchronous DRAM) SDRAM exchanges data with the processor synchronized to an external clock signal and running at the full speed of the processor/memory bus without imposing wait states. SDRAM employs a burst mode to eliminate the address setup time and row and column line precharge time after the first access In burst mode a series of data bits can be clocked out rapidly after the first bit has been accessed SDRAM has a multiple bank internal architecture that improves opportunities for on chip parallelism SDRAM performs best when it is transferring large blocks of data serially There is now an enhanced version of SDRAM known as double data rate SDRAM or DDR-SDRAM that overcomes the once-per-cycle limitation of SDRAM

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  • What is the SharePoint Action Framework and Why do I need it ?

    - by SAF
    For those out there that are a little curious as to whether SAF is any use to your organisation, please read this FAQ.  What is SAF ? SAF is free to use. SAF is the "SharePoint Action Framework", it was built by myself and Hugo (plus a few others along the way). SAF is written entirely in C# code available from : http://saf.codeplex.com.   SAF is a way to automate SharePoint configuration changes. An Action is a command/class/task/script written in C# that performs a unit of execution against SharePoint such as "CreateWeb"  or "AddLookupColumn". A SAF Macro is collection of one or more Actions. SAF Macro can be run from Msbuild, a Feature, StsAdm or common plain old .Net code. Parameters can be passed to a Macro at run-time from a variety of sources such as "Environment Variable", "*.config", "Msbuild Properties", Feature Properties, command line args, .net code. SAF emits lots of trace statements at run-time, these can be viewed using "DebugView". One Action can pass parameters to another Action. Parameters can be set using Expression Syntax such as "DateTime.Now".  You should consider SAF is you suffer from one of the following symptoms... "Our developers write lots of code to deploy changes at release time - it's always rushed" "I don't want my developers shelling out to Powershell or Stsadm from a Feature". "We have loads of Console applications now, I have lost track of where they are, or what they do" "We seem to be writing similar scripts against SharePoint in lots of ways, testing is hard". "My scripts often have lots of errors - they are done at the last minute". "When something goes wrong - I have no idea what went wrong or how to solve it". "Our Features get stuck and bomb out half way through - there no way to roll them back". "We have tons of Features now - I can't keep track". "We deploy Features to run one-off tasks" "We have a library of reusable scripts, but, we can only run it in one way, sometimes we want to run it from MSbuild and a Feature". "I want to automate the deployment of changes to our development environment". "I would like to run a housekeeping task on a scheduled basis"   So I like the sound of SAF - what's the problems ?  Realistically, there are few things that need to be considered: Someone on your team will need to spend a day or 2 understanding SAF and deciding exactly how you want to use it. I would suggest a Tech Lead, SysAdm or SP Architect will need to download it, try out the examples, look through the unit tests. Ask us questions. Although, SAF can be downloaded and set to go in a few minutes, you will still need to address issues such as - "Do you want to execute your Macros in MsBuild or from a Feature ?" You will need to decide who is going to do your deployments - is it each developer to themself, or do you require a dedicated Build Manager ? As most environments (Dev, QA, Live etc) require different settings (e.g. Urls, Database names, accounts etc), you will more than likely want to define these and set a properties file up for each environment. (These can then be injected into Saf at run-time). There may be no Action to solve your particular problem. If this is the case, suggest it to us - we can try and write it, or write it yourself. It's very easy to write a new Action - we have an approach to easily unit test it, document it and author it. For example, I wrote one to deploy  a WSP in 2 hours the other day. Alternatively, Saf can also call Stsadm commands and Powershell scripts.   Anyway, I do hope this helps! If you still need help, or a quick start, we can also offer consultancy around SAF. If you want to know more give us a call or drop an email to [email protected]

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  • 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!

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  • Top 10 Browser Productivity Tips

    - by Renso
    Originally posted on: http://geekswithblogs.net/renso/archive/2013/10/14/top-10-browser-productivity-tips.aspxYou don’t have to be a geek to be a productive browser user. The tips below have been selected by actions users take most of the time to navigate a web-site but use long-standing keyboard or mouse actions to get them done, when there are keyboard short-cuts you can use instead. Since you hands are already on the keyboard it is almost always faster to sue a keyboard shortcut to get something done that you usually used the mouse for. For example right-clicking on something to copy it and then doing to same for pasting something is very time consuming, keyboard shortcuts have been created that simplify the task. All it takes are a few memory brain cells to remember them. Here are the tips, in no particular order:   Tip 1 Hold down the spacebar on your keyboard to page to the end of your web page rather than using your mouse. This is really a slow way of doing it. If you want to page one page at a time, hit the spacebar once, and again to page again. But if you want to page all the way to the end of the web page simply hit Ctrl+End (that is hold down the Ctrl key and hit the End button on your keyboard). To get to the top of your web page, simply hit Ctrl + Home to go all the way to the top of your web page. Tip 2 Where are my downloads? Some folks run downloads again-and-again because they do not know where the last one went and they do not see the popup, or browser note on their web page in the footer, etc. Simply hit Ctrl+J. Works in most browsers. Tip 3 Selecting a US state from a drop down box. Don’t use the mouse, takes just way too long to scroll. When you tab to the drop down box or click on it with your mouse, simply hit the first character of the state and it will be selected. For Texas for example hit the letter “T” twice on your keyboard to get to it. The same concept can be applied to any drop down box that is alphabetical or numerically sorted. Tip 4 Fixing spelling errors. All modern-day browsers support this now. You see the red wavy lines underscoring a word, yes it is a spelling error. How do you fix it? Don’t overtype it or try and fix it manually, fist right-click on it and a list of suggestions comes up. If it does not show up, like my name “Renso” and you know how to spell your name as in this example, look further down the list of options (the little window popup that appears when you right click) and you should see an option to “Add to Dictionary”. Be warned, when you add it, it only adds it to the browser you’re using’s dictionary. If you use Google Chrome, Firefox and IE, each one will have their own list. Tip 5 So you have trouble seeing the text on the screen. Or you are looking at a photo, for example in Facebook. You want to zoom in to read better or zoom into a photo a bit more. Hit Ctrl++ (hold down Ctrl key and hit the plus key – actually it’s the equal key but it is easier to remember that it is plus for bigger). Hit the minus to zoom out. Now you can’t remember what the original size was since you were so excited to hit it 20 times, or was that 21… Simply hit Ctrl+0 (that is zero) and it will reset it to the default. Tip 6 So you closed a couple of tabs in your browser. Suddenly you remember something you wanted to double-check something on one of the tabs, you cannot remember the URL ad the tab is gone forever, or is it? Simply hit Ctrl+Shift+t and it will bring back your tabs one by one each time you click the T. This has also been a great way for me to quickly close some tabs because I don’t want my boss to see I’m shopping and then hitting Ctrl+Shift+t to quickly get it back and complete my check-put and purchase. Or, for parents, when you walk into your daughter’s room and you see she quickly clicks and closes a window/tab in here browser. Not to worry my little darling, daddy will Ctrl+Shift+t and see what boys on Facebook you were talking too… Tip 7 The web browser is frozen on your PC/Laptop/Whatever, in this example it may be your Internet Explorer browser. I don’t mention Firefox or Chrome here because it probably never happens in their world. You cannot close it, it won’t respond to anything you have done s far except for the next step you are about to take, which is throw your two-day old coffee on your keyboard. This happens especially on sites that want to force you to complete a purchase order. Hit Ctrl+Alt+Del on your keyboard on any version of windows, select TASK MANAGER. In the  First Tab, which is the Process Tab, look for the item in question. In this example you should see Internet Explorer. Right-click it and select “End Task”. It will force the thread out of memory and terminate that process. You can of course do this with any program running under your account. Tip 8 This is a personal favorite of mine. To select words in the paragraph without using the mouse. You don’t want to select one character at a time like when you use the Ctrl+arrows as it can be very slow if you want to select a lot of text. You also want to select whole words. Simply use the Ctrl+Shift_arrow (right or left depending which direction you want to go. Tip 9 I was a bit reluctant to add this one, but being in the professional services industry still come across many-a-folk that simply can’t copy-and-paste them-all text or images that reside on them screens, y’all. Ctrl+c to copy and Ctrl+v to paste it. Works a lot faster than using the mouse. You may be asking: “Well why in the devil did they not use Ctrl+p for paste…. because that is for printing. This is of course not limited to the browser world, it applies to almost any piece of software running on PC or Mac. Go try it on an image on your browser, right-click it and select copy. Open a word document and Ctrl+v to paste the image in there. Please consider copyright laws. Tip 10 Getting rid of annoying ads. Now this only works when you load a web page, meaning when you get back to the same page later you will have to do this again and you will need to learn a tool to do it, WELL WORTH IT. For example, I use GrooveShark to listen to music but I don’t like the ads they show. Install a tool like Firebug for Firefox or use the Ctrl+Shift+I on Chrome to bring up the developer toolbar. Shows at the bottom of the page. With Firefox, once you have installed Firebug as an add-on, a yellow bug should appear on the top right-hand-side of your browser, click on it to display the developer toolbar. You will need to learn how to use it, but once you know how to select an item/section on the window (usually just right-click the add you don’t want to see and select “Inspect Element”, the developer toolbar will appear (if not already there)) and then simply hit delete and it will remove the add from the screen. If you don’t know HTML you may need to play with it a bit, but once you understand how it works can open up a whole new world for you on how web pages actually work. If you can think of any others that have saved you a ton of time please let me know so I can add them to a top 99 list.

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  • HOWTO Turn off SPARC T4 or Intel AES-NI crypto acceleration.

    - by darrenm
    Since we released hardware crypto acceleration for SPARC T4 and Intel AES-NI support we have had a common question come up: 'How do I test without the hardware crypto acceleration?'. Initially this came up just for development use so developers can do unit testing on a machine that has hardware offload but still cover the code paths for a machine that doesn't (our integration and release testing would run on all supported types of hardware anyway).  I've also seen it asked in a customer context too so that we can show that there is a performance gain from the hardware crypto acceleration, (not just the fact that SPARC T4 much faster performing processor than T3) and measure what it is for their application. With SPARC T2/T3 we could easily disable the hardware crypto offload by running 'cryptoadm disable provider=n2cp/0'.  We can't do that with SPARC T4 or with Intel AES-NI because in both of those classes of processor the encryption doesn't require a device driver instead it is unprivileged user land callable instructions. Turns out there is away to do this by using features of the Solaris runtime loader (ld.so.1). First I need to expose a little bit of implementation detail about how the Solaris Cryptographic Framework is implemented in Solaris 11.  One of the new Solaris 11 features of the linker/loader is the ability to have a single ELF object that has multiple different implementations of the same functions that are selected at runtime based on the capabilities of the machine.  The alternate to this is having the application coded to call getisax() and make the choice itself.  We use this functionality of the linker/loader when we build the userland libraries for the Solaris Cryptographic Framework (specifically libmd.so, and the unfortunately misnamed due to historical reasons libsoftcrypto.so) The Solaris linker/loader allows control of a lot of its functionality via environment variables, we can use that to control the version of the cryptographic functions we run.  To do this we simply export the LD_HWCAP environment variable with values that tell ld.so.1 to not select the HWCAP section matching certain features even if isainfo says they are present.  For SPARC T4 that would be: export LD_HWCAP="-aes -des -md5 -sha256 -sha512 -mont -mpul" and for Intel systems with AES-NI support: export LD_HWCAP="-aes" This will work for consumers of the Solaris Cryptographic Framework that use the Solaris PKCS#11 libraries or use libmd.so interfaces directly.  It also works for the Oracle DB and Java JCE.  However does not work for the default enabled OpenSSL "t4" or "aes-ni" engines (unfortunately) because they do explicit calls to getisax() themselves rather than using multiple ELF cap sections. However we can still use OpenSSL to demonstrate this by explicitly selecting "pkcs11" engine  using only a single process and thread.  $ openssl speed -engine pkcs11 -evp aes-128-cbc ... type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes aes-128-cbc 54170.81k 187416.00k 489725.70k 805445.63k 1018880.00k $ LD_HWCAP="-aes" openssl speed -engine pkcs11 -evp aes-128-cbc ... type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes aes-128-cbc 29376.37k 58328.13k 79031.55k 86738.26k 89191.77k We can clearly see the difference this makes in the case where AES offload to the SPARC T4 was disabled. The "t4" engine is faster than the pkcs11 one because there is less overhead (again on a SPARC T4-1 using only a single process/thread - using -multi you will get even bigger numbers). $ openssl speed -evp aes-128-cbc ... type 16 bytes 64 bytes 256 bytes 1024 bytes 8192 bytes aes-128-cbc 85526.61k 89298.84k 91970.30k 92662.78k 92842.67k Yet another cool feature of the Solaris linker/loader, thanks Rod and Ali. Note these above openssl speed output is not intended to show the actual performance of any particular benchmark just that there is a significant improvement from using hardware acceleration on SPARC T4. For cryptographic performance benchmarks see the http://blogs.oracle.com/BestPerf/ postings.

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  • Presenting at VS Live! Orlando in December

    - by Steve Michelotti
    I’ll be presenting at VS Live! December 10-14 in Orlando, FL. I’ll be presenting Azure Web Sites. This is the session abstract: Azure Web Sites brings a whole new level of power and simplicity to cloud computing. This demo-heavy session will show numerous features that allow you to deploy your site in a matter of seconds. Whether you are building a completely custom app or deploying from one of the numerous templates provided (such as WordPress), you’ll be up and running in no time. Want to use Node.js or PHP and deploy from Git? No problem! Azure Web Sites gives you the power of elastic scaling while still providing streamlined development and an effortless deployment experience. This presentation will also cover features including monitoring, custom domains, working with SQL databases or more!   SPECIAL OFFER: As a speaker, I can extend $500 savings on the 5-day package. Register here: http://bit.ly/VOSPK19Reg  and use code VOSPK19. The great part about Visual Studio Live!: four events in one! This year, the event will be co-located with SQL Server Live!, SharePoint Live!, and Cloud & Virtualization Live!. You can customize your conference agenda and attend ANY sessions from all four events. Register now: http://bit.ly/VOSPK19Reg

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  • DRY and SRP

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

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  • App Fabric Service Bus and Access Control Pricing

    - by kaleidoscope
    The Service Bus costs $3.99 per Connection-month on a consumption basis for individually provisioned connections. Data transfers charges would also apply. Or, if you are able to forecast your needs ahead of time, you can purchase “Packs” of Connections. For example: $9.95 for a pack of 5 Connections, $49.75 for a pack of 25, $199.00 for a pack of 100, or $995 for a pack of 500, plus data transfer charges. Connection Packs represent an effective rate of $1.99 per Connection-month. Access Control will be priced at $1.99 per 100,000 Transactions, which includes token requests and management operations, plus associated data transfer. Typically, Service Bus developers depend on Access Control to secure their Connections. More Information: http://azurefeeds.com/post/865/Announcing_Windows_Azure_platform_commercial_offer_availability_and_updated_AppFabric_pricing.aspx   Amit, S

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  • Getting App.config to be configuration specific in VS2010

    - by MarkPearl
    I recently wanted to have a console application that had configuration specific settings. For instance, if I had two configurations “Debug” and “Release”, depending on the currently selected configuration I wanted it to use a specific configuration file (either debug or config). If you are wanting to do something similar, here is a potential solution that worked for me. Setting up a demo app to illustrate the point First, let’s set up an application that will demonstrate the most basic concept. using System; using System.Configuration; namespace ConsoleSpecificConfiguration { class Program { static void Main(string[] args) { Console.WriteLine("Config"); Console.WriteLine(ConfigurationManager.AppSettings["Example Config"]); Console.ReadLine(); } } }   This does a really simple thing. Display a config when run. To do this, you also need a config file set up. My default looks as follows… <?xml version="1.0" encoding="utf-8" ?> <configuration> <appSettings> <add key="Example Config" value="Default"/> </appSettings> </configuration>   Your entire solution will look as follows… Running the project you will get the following amazing output…   Let’s now say instead of having one config file we want depending on whether we are running in “Debug” or “Release” for the solution configuration we want different config settings to be propagated across you can do the following… Step 1 – Create alternate config Files First add additional config files to your solution. You should have some form of naming convention for these config files, I have decided to follow a similar convention to the one used for web.config, so in my instance I am going to add a App.Debug.config and a App.Release.config file BUT you can follow any naming convention you want provided you wire up the rest of the approach to use this convention. My files look as follows.. App.Debug.config <?xml version="1.0" encoding="utf-8" ?> <configuration> <appSettings> <add key="Example Config" value="Debug"/> </appSettings> </configuration>   App.Release.config <?xml version="1.0" encoding="utf-8" ?> <configuration> <appSettings> <add key="Example Config" value="Release"/> </appSettings> </configuration>   Your solution will now look as follows… Step 2 – Create a bat file that will overwrite files The next step is to create a bat file that will overwrite one file with another. If you right click on the solution in the solution explorer there will be a menu option to add new items to the solution. Create a text file called “copyifnewer.bat” which will be our copy script. It’s contents should look as follows… @echo off echo Comparing two files: %1 with %2 if not exist %1 goto File1NotFound if not exist %2 goto File2NotFound fc %1 %2 /A if %ERRORLEVEL%==0 GOTO NoCopy echo Files are not the same. Copying %1 over %2 copy %1 %2 /y & goto END :NoCopy echo Files are the same. Did nothing goto END :File1NotFound echo %1 not found. goto END :File2NotFound copy %1 %2 /y goto END :END echo Done. Your solution should now look as follows…   Step 3 – Customize the Post Build event command line We now need to wire up everything – which we will do using the post build event command line in VS2010. Right click on your project and go to it’s properties We are now going to wire up the script so that when we build our project it will overwrite the default App.config with whatever file we want. The syntax goes as follows… call "$(SolutionDir)copyifnewer.bat" "$(ProjectDir)App.$(ConfigurationName).config" "$(ProjectDir)$(OutDir)\$(TargetFileName).config" Testing it If I now change my project configuration to Release   And then run my application I get the following output… Toggling between Release and Debug mode will show that the config file is changing each time. And that is it!

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  • My Codemash 2011 Retrospective

    - by Greg Malcolm
    I just got back from Codemash yesterday, and still on an adrenaline buzz. Here's my take on this years encounter: The Awesome Nearly everybody in one place Codemash is the ultimate place to catch up with community friends. This is my 3rd year visiting and I've got to know a great number of very cool people through various conferences, Give Camps and other community events. I'm finding more and more that Codemash is the best place to catch up with everybody regardless of technology interest or location. Of course I always make a whole bunch more friends while I'm there! Yay! Open Spaced I found the open spaces didn't work so well last year. This year things went a lot smoother and the topics were engaging and fresh. While I miss Alan Steven's approach of running it like an agile project, it was very cool to see that it evolving. Laptops were often cracked open, not just once but frequently! For example: Jasmine - Paired on a javascript kata using the Jasmine javascript test runner J - Sat in on a J demo from local J enthusiast, Tracy Harms Watir - More pairing, this time using Ruby with the watir-webdriver through cucumber. I'd mostly forgotten that Cucumber runs just fine without Rails. It made a change to do without. The other spaces were engaging too, but I think that's enough for that topic. Javascript Shenanigans I've already mentioned that I attended a Jasmine kata session. Jasmine is close to my heart right now every since I discovered it while on the hunt for a decent Javascript testing framework for a javascript koans project earlier this year. Well, it also got covered in the Java Precompiler and Pillar's vendor session, which was great to see. Node.js was also a reoccurring theme. Node.js in a nutshell? It's an extremely scalable Event based I/O server which runs on Javascript. I'd already encountered through a Startup Weekend project and have been noticing increasing interest of late. After encountering more node.js driven excitement from my peers at codemash I absolutely had to attend the open space on it. At least 20 people turned up and by the end we had some answers, a whole ton of new questions and an impromptu user group in the form of a twitter channel (#nodemash). I have no idea where this is going to go or how big it is going to become, but if it can cross the chasm into the enterprise it could become huge... Scala Koans I'm a bit of a Koans addict, and I really need more exposure to functional languages so I gave the Scala Koans precompiler a try. Great fun! I'm really glad I attended because I found I had a whole ton of questions. Currently the koans are available here, and the answers are here. Opportunities While we're on the subject can we change the subject now? Hai Gregory, You really need to keep the drinking for later in the day. I mean seriously, you're 34 and you still do this every single time! Sure, you made it to Chad Fowler keynote ok, but you looking a rather pale weren't you? Also might have been nice to attend 'Netflicks in the Cloud' instead of 'Sleeping It Off For People Who Should Know Better'. Kthxbye PS: Stop talking to yourself Not that I entirely regret it, I've had some of my greatest insights through late night drunken conversations at the CodeMash bar. Just might be nice to reign it in a little and get something out of the next morning too. Diversity This is something that is in the back of my mind because of conversations at Codemash as well as throughout the year; I'm realizing more and more how discouraging the IT profession is for women. I notice in the community there has been a lot of attention paid to stamping out harrasment, which is good, but there also seems to be a massive PR issue. I really don't have any solutions, but I figure it can't hurt to pay more attention to whats going on... And in Other News I now have a picture of Chad Fowler giving me more cowbell! Sadly I managed to lose the cowbell later on. Hopefully it's gone to a Better Place. The Womack Family Band joined in with the musicians jam this year. There's my cowbell again! Why must you hide from me? I also finally went in the water for the first time in all the I've been coming to codemash. Why did I wait so long?!?

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  • How to Create SharePoint List and Insert List Item programmatically from a Windows Forms Application.

    - by Michael M. Bangoy
    In this post I’m going to demonstrate how to create SharePoint List and also Insert Items on the List from a Windows Forms Application. 1. Open Visual Studio and create a new project. On the project template select Windows Form Application under C#. 2. In order to communicate with Sharepoint from a Windows Forms Application we need to add the 2 Sharepoint Client DLL located in c:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\ISAPI.  3. Select the Microsoft.Sharepoint.Client.dll and Microsoft.Sharepoint.Client.Runtime.dll. (Your solution should look like the one below) 4. Open the Form1 in design view and from the Toolbox menu add a button on the form surface. Your form should look like the one below. 5. Double click the button to open the code view. Add Using statement to reference the Sharepoint Client Library then create method for the Create List. Your code should like the codes below. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Security; using System.Windows.Forms; using SP = Microsoft.SharePoint.Client; namespace ClientObjectModel {     public partial class Form1 : Form     {         // url of the Sharepoint site         const string _context = "urlofthesharepointsite";         public Form1()         {             InitializeComponent();         }         private void Form1_Load(object sender, EventArgs e)         {                    }         private void cmdcreate_Click(object sender, EventArgs e)         {             try             {                 // declare the ClientContext Object                 SP.ClientContext _clientcontext = new SP.ClientContext(_context);                 SP.Web _site = _clientcontext.Web;                 // declare a ListCreationInfo                 SP.ListCreationInformation _listcreationinfo = new SP.ListCreationInformation();                 // set the Title and the Template of the List to be created                 _listcreationinfo.Title = "NewListFromCOM";                 _listcreationinfo.TemplateType = (int)SP.ListTemplateType.GenericList;                 // Call the add method to the ListCreatedInfo                 SP.List _list = _site.Lists.Add(_listcreationinfo);                 // Add Description field to the List                 SP.Field _Description = _list.Fields.AddFieldAsXml(@"                                     <Field Type='Text'                                         DisplayName='Description'>                                     </Field>", true, SP.AddFieldOptions.AddToDefaultContentType);                 // declare the List item Creation object for creating List Item                 SP.ListItemCreationInformation _itemcreationinfo = new SP.ListItemCreationInformation();                 // call the additem method of the list to insert a new List Item                 SP.ListItem _item = _list.AddItem(_itemcreationinfo);                 _item["Title"] = "New Item from Client Object Model";                 _item["Description"] = "This item was added by a Windows Forms Application";                 // call the update method                 _item.Update();                 // execute the query of the clientcontext                 _clientcontext.ExecuteQuery();                 // dispose the clientcontext                 _clientcontext.Dispose();                 MessageBox.Show("List Creation Successfull");             }             catch(Exception ex)             {                 MessageBox.Show("Error creating list" + ex.ToString());             }          }     } } 6. Hit F5 to run the application. A message will be displayed on the screen if the operation is successful and also if it fails. 7. To make that the operation of our Windows Form Application has really created the List and Inserted an item on it. Let’s open our SharePoint site. Once the SharePoint is open click on the Site Actions then View All Site Content. 7. Click the List to open it and check if an Item is inserted. That’s it. Hope this helps.

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  • C#/.NET Little Wonders &ndash; Cross Calling Constructors

    - by James Michael Hare
    Just a small post today, it’s the final iteration before our release and things are crazy here!  This is another little tidbit that I love using, and it should be fairly common knowledge, yet I’ve noticed many times that less experienced developers tend to have redundant constructor code when they overload their constructors. The Problem – repetitive code is less maintainable Let’s say you were designing a messaging system, and so you want to create a class to represent the properties for a Receiver, so perhaps you design a ReceiverProperties class to represent this collection of properties. Perhaps, you decide to make ReceiverProperties immutable, and so you have several constructors that you can use for alternative construction: 1: // Constructs a set of receiver properties. 2: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable, bool isBuffered) 3: { 4: ReceiverType = receiverType; 5: Source = source; 6: IsDurable = isDurable; 7: IsBuffered = isBuffered; 8: } 9: 10: // Constructs a set of receiver properties with buffering on by default. 11: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable) 12: { 13: ReceiverType = receiverType; 14: Source = source; 15: IsDurable = isDurable; 16: IsBuffered = true; 17: } 18:  19: // Constructs a set of receiver properties with buffering on and durability off. 20: public ReceiverProperties(ReceiverType receiverType, string source) 21: { 22: ReceiverType = receiverType; 23: Source = source; 24: IsDurable = false; 25: IsBuffered = true; 26: } Note: keep in mind this is just a simple example for illustration, and in same cases default parameters can also help clean this up, but they have issues of their own. While strictly speaking, there is nothing wrong with this code, logically, it suffers from maintainability flaws.  Consider what happens if you add a new property to the class?  You have to remember to guarantee that it is set appropriately in every constructor call. This can cause subtle bugs and becomes even uglier when the constructors do more complex logic, error handling, or there are numerous potential overloads (especially if you can’t easily see them all on one screen’s height). The Solution – cross-calling constructors I’d wager nearly everyone knows how to call your base class’s constructor, but you can also cross-call to one of the constructors in the same class by using the this keyword in the same way you use base to call a base constructor. 1: // Constructs a set of receiver properties. 2: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable, bool isBuffered) 3: { 4: ReceiverType = receiverType; 5: Source = source; 6: IsDurable = isDurable; 7: IsBuffered = isBuffered; 8: } 9: 10: // Constructs a set of receiver properties with buffering on by default. 11: public ReceiverProperties(ReceiverType receiverType, string source, bool isDurable) 12: : this(receiverType, source, isDurable, true) 13: { 14: } 15:  16: // Constructs a set of receiver properties with buffering on and durability off. 17: public ReceiverProperties(ReceiverType receiverType, string source) 18: : this(receiverType, source, false, true) 19: { 20: } Notice, there is much less code.  In addition, the code you have has no repetitive logic.  You can define the main constructor that takes all arguments, and the remaining constructors with defaults simply cross-call the main constructor, passing in the defaults. Yes, in some cases default parameters can ease some of this for you, but default parameters only work for compile-time constants (null, string and number literals).  For example, if you were creating a TradingDataAdapter that relied on an implementation of ITradingDao which is the data access object to retreive records from the database, you might want two constructors: one that takes an ITradingDao reference, and a default constructor which constructs a specific ITradingDao for ease of use: 1: public TradingDataAdapter(ITradingDao dao) 2: { 3: _tradingDao = dao; 4:  5: // other constructor logic 6: } 7:  8: public TradingDataAdapter() 9: { 10: _tradingDao = new SqlTradingDao(); 11:  12: // same constructor logic as above 13: }   As you can see, this isn’t something we can solve with a default parameter, but we could with cross-calling constructors: 1: public TradingDataAdapter(ITradingDao dao) 2: { 3: _tradingDao = dao; 4:  5: // other constructor logic 6: } 7:  8: public TradingDataAdapter() 9: : this(new SqlTradingDao()) 10: { 11: }   So in cases like this where you have constructors with non compiler-time constant defaults, default parameters can’t help you and cross-calling constructors is one of your best options. Summary When you have just one constructor doing the job of initializing the class, you can consolidate all your logic and error-handling in one place, thus ensuring that your behavior will be consistent across the constructor calls. This makes the code more maintainable and even easier to read.  There will be some cases where cross-calling constructors may be sub-optimal or not possible (if, for example, the overloaded constructors take completely different types and are not just “defaulting” behaviors). You can also use default parameters, of course, but default parameter behavior in a class hierarchy can be problematic (default values are not inherited and in fact can differ) so sometimes multiple constructors are actually preferable. Regardless of why you may need to have multiple constructors, consider cross-calling where you can to reduce redundant logic and clean up the code.   Technorati Tags: C#,.NET,Little Wonders

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  • Multitenant Design for SQL Azure: White Paper Available

    - by Herve Roggero
    Cloud computing is about scaling out all your application tiers, from web application to the database layer. In fact, the whole promise of Azure is to pay for just what you need. You need more IIS servers? No problemo... just spin another web server. You expect to double your storage needs for Azure Tables? No problemo; you are covered there too... just pay for your storage needs. But what about the database tier, SQL Azure? How do you add new databases easily, and transparently, so that your application simply uses more of SQL Azure if its needs to? Without changing a single line of code? And what if you need to scale back down? Welcome to the world of database scalability. There are many terms that describe database scalability, including data federation, multitenant designs, and even NoSQL depending on the technical solution you are implementing.  Because SQL Azure is a transactional database system, NoSQL is not really an option. However data federation and multitenant designs offer some very interesting scalability options that are worth considering. Data federation, a feature of SQL Azure that will be offered in the future, offers very interesting capabilities available natively on the SQL Azure platform. More to come in a few weeks... Multitenant designs on the other hand are design practices and technologies designed to help you reach flexible scalability options not available otherwise. The first incarnation of such a method was made available on CodePlex as an open source project (http://enzosqlshard.codeplex.com).  This project was an attempt to provide a sharding library for educational purposes.  All that sounds really cool... and really esoteric... almost a form of database "voodoo"... However after being on multiple Azure projects I am starting to see a real need. Customers want to be able to free themselves from the database tier, so that if they have 10 new customers tomorrow, all they need to do is add 2 more SQL Azure instances. It's that simple. How you achieve this, and suggested application design guidelines, are available in a white paper I just published.  The white paper offers two primary sections. The first section describes the business and technical problem at hand, and how to classify it according to specific design patterns. For example, I discuss compressed shards through schema separation. The second section offers a method for addressing the needs of a multitenant design using a new library, the big bother of the codeplex project mentioned previously (that I created earlier this year), complete with management interface and such. A Beta of this platform will be made available within weeks; as soon as the documentation will be ready.   I would like to ask you to drop me a quick email at [email protected] if you are going to download the white paper. It's not required, but it would help me get in touch with you for feedback.  You can download this white paper here:   http://www.bluesyntax.net/files/EnzoFramework.pdf . Thank you, and I am looking for feedback, thoughts and implementation opportunities.

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