Search Results

Search found 47615 results on 1905 pages for 'make it useful keep it simple'.

Page 172/1905 | < Previous Page | 168 169 170 171 172 173 174 175 176 177 178 179  | Next Page >

  • How the "migrations" approach makes database continuous integration possible

    - by David Atkinson
    Testing a database upgrade script as part of a continuous integration process will only work if there is an easy way to automate the generation of the upgrade scripts. There are two common approaches to managing upgrade scripts. The first is to maintain a set of scripts as-you-go-along. Many SQL developers I've encountered will store these in a folder prefixed numerically to ensure they are ordered as they are intended to be run. Occasionally there is an accompanying document or a batch file that ensures that the scripts are run in the defined order. Writing these scripts during the course of development requires discipline. It's all too easy to load up the table designer and to make a change directly to the development database, rather than to save off the ALTER statement that is required when the same change is made to production. This discipline can add considerable overhead to the development process. However, come the end of the project, everything is ready for final testing and deployment. The second development paradigm is to not do the above. Changes are made to the development database without considering the incremental update scripts required to effect the changes. At the end of the project, the SQL developer or DBA, is tasked to work out what changes have been made, and to hand-craft the upgrade scripts retrospectively. The end of the project is the wrong time to be doing this, as the pressure is mounting to ship the product. And where data deployment is involved, it is prudent not to feel rushed. Schema comparison tools such as SQL Compare have made this latter technique more bearable. These tools work by analyzing the before and after states of a database schema, and calculating the SQL required to transition the database. Problem solved? Not entirely. Schema comparison tools are huge time savers, but they have their limitations. There are certain changes that can be made to a database that can't be determined purely from observing the static schema states. If a column is split, how do we determine the algorithm required to copy the data into the new columns? If a NOT NULL column is added without a default, how do we populate the new field for existing records in the target? If we rename a table, how do we know we've done a rename, as we could equally have dropped a table and created a new one? All the above are examples of situations where developer intent is required to supplement the script generation engine. SQL Source Control 3 and SQL Compare 10 introduced a new feature, migration scripts, allowing developers to add custom scripts to replace the default script generation behavior. These scripts are committed to source control alongside the schema changes, and are associated with one or more changesets. Before this capability was introduced, any schema change that required additional developer intent would break any attempt at auto-generation of the upgrade script, rendering deployment testing as part of continuous integration useless. SQL Compare will now generate upgrade scripts not only using its diffing engine, but also using the knowledge supplied by developers in the guise of migration scripts. In future posts I will describe the necessary command line syntax to leverage this feature as part of an automated build process such as continuous integration.

    Read the article

  • SQL Relay - G is for GO

    - by fatherjack
    At the SQL Relay event last week all the UK user group leaders did a combined session - The A to Z of SQL - where we all took two letters of the alphabet and gave a 2 minute (it was strictly timed) talk on something SQL related beginning with those letters. It was quite a riot working through 26 different talks in an hour with 25 speaker handovers and the associated switches between SSMS and the slide deck. As a speaker I thoroughly enjoyed it and i hoe we informed as much as  we entertained the...(read more)

    Read the article

  • Single Item Recovery

    One of the more obscure parts of Exchange Server is the Dumpster. This allows the recovery of one or more deleted emails, in much the same way as the recycle bin in Windows, even if the user has purged them. Although it is seen as an alternative to backup, or as a means to document retention, it really provides a separate function, undoing an accidental deletion. Elie explains how to configure deleted retention items and how to recover a purged item.

    Read the article

  • Getting started with Windows Azure

    - by jonhobbs
    Hi All, I'm going to sound like a complete newbie here but here goes... I've just signed up for a Windows Azure account and was hoping to get a simple hello world aspx page up and running in a browser to see how it all works but I can't seem to find a simple guide to getting a very simple web application running. I've got as far as setting up a "service" and going onto the "deploy" page but it's asking me upload an "application package". I've looked on MSDN but there aren't any simple guides, just reams of documentation talking about "roles" and "development fabric". For somebody that is proficient in HTML/CSS and knows a little abit about asp.net it may just as well be in another language. So, does anybody know how to upload a simple aspx page and then access it in a browser? Jon

    Read the article

  • .NET Security Part 2

    - by Simon Cooper
    So, how do you create partial-trust appdomains? Where do you come across them? There are two main situations in which your assembly runs as partially-trusted using the Microsoft .NET stack: Creating a CLR assembly in SQL Server with anything other than the UNSAFE permission set. The permissions available in each permission set are given here. Loading an assembly in ASP.NET in any trust level other than Full. Information on ASP.NET trust levels can be found here. You can configure the specific permissions available to assemblies using ASP.NET policy files. Alternatively, you can create your own partially-trusted appdomain in code and directly control the permissions and the full-trust API available to the assemblies you load into the appdomain. This is the scenario I’ll be concentrating on in this post. Creating a partially-trusted appdomain There is a single overload of AppDomain.CreateDomain that allows you to specify the permissions granted to assemblies in that appdomain – this one. This is the only call that allows you to specify a PermissionSet for the domain. All the other calls simply use the permissions of the calling code. If the permissions are restricted, then the resulting appdomain is referred to as a sandboxed domain. There are three things you need to create a sandboxed domain: The specific permissions granted to all assemblies in the domain. The application base (aka working directory) of the domain. The list of assemblies that have full-trust if they are loaded into the sandboxed domain. The third item is what allows us to have a fully-trusted API that is callable by partially-trusted code. I’ll be looking at the details of this in a later post. Granting permissions to the appdomain Firstly, the permissions granted to the appdomain. This is encapsulated in a PermissionSet object, initialized either with no permissions or full-trust permissions. For sandboxed appdomains, the PermissionSet is initialized with no permissions, then you add permissions you want assemblies loaded into that appdomain to have by default: PermissionSet restrictedPerms = new PermissionSet(PermissionState.None); // all assemblies need Execution permission to run at all restrictedPerms.AddPermission( new SecurityPermission(SecurityPermissionFlag.Execution)); // grant general read access to C:\config.xml restrictedPerms.AddPermission( new FileIOPermission(FileIOPermissionAccess.Read, @"C:\config.xml")); // grant permission to perform DNS lookups restrictedPerms.AddPermission( new DnsPermission(PermissionState.Unrestricted)); It’s important to point out that the permissions granted to an appdomain, and so to all assemblies loaded into that appdomain, are usable without needing to go through any SafeCritical code (see my last post if you’re unsure what SafeCritical code is). That is, partially-trusted code loaded into an appdomain with the above permissions (and so running under the Transparent security level) is able to create and manipulate a FileStream object to read from C:\config.xml directly. It is only for operations requiring permissions that are not granted to the appdomain that partially-trusted code is required to call a SafeCritical method that then asserts the missing permissions and performs the operation safely on behalf of the partially-trusted code. The application base of the domain This is simply set as a property on an AppDomainSetup object, and is used as the default directory assemblies are loaded from: AppDomainSetup appDomainSetup = new AppDomainSetup { ApplicationBase = @"C:\temp\sandbox", }; If you’ve read the documentation around sandboxed appdomains, you’ll notice that it mentions a security hole if this parameter is set correctly. I’ll be looking at this, and other pitfalls, that will break the sandbox when using sandboxed appdomains, in a later post. Full-trust assemblies in the appdomain Finally, we need the strong names of the assemblies that, when loaded into the appdomain, will be run as full-trust, irregardless of the permissions specified on the appdomain. These assemblies will contain methods and classes decorated with SafeCritical and Critical attributes. I’ll be covering the details of creating full-trust APIs for partial-trust appdomains in a later post. This is how you get the strongnames of an assembly to be executed as full-trust in the sandbox: // get the Assembly object for the assembly Assembly assemblyWithApi = ... // get the StrongName from the assembly's collection of evidence StrongName apiStrongName = assemblyWithApi.Evidence.GetHostEvidence<StrongName>(); Creating the sandboxed appdomain So, putting these three together, you create the appdomain like so: AppDomain sandbox = AppDomain.CreateDomain( "Sandbox", null, appDomainSetup, restrictedPerms, apiStrongName); You can then load and execute assemblies in this appdomain like any other. For example, to load an assembly into the appdomain and get an instance of the Sandboxed.Entrypoint class, implementing IEntrypoint, you do this: IEntrypoint o = (IEntrypoint)sandbox.CreateInstanceFromAndUnwrap( "C:\temp\sandbox\SandboxedAssembly.dll", "Sandboxed.Entrypoint"); // call method the Execute method on this object within the sandbox o.Execute(); The second parameter to CreateDomain is for security evidence used in the appdomain. This was a feature of the .NET 2 security model, and has been (mostly) obsoleted in the .NET 4 model. Unless the evidence is needed elsewhere (eg. isolated storage), you can pass in null for this parameter. Conclusion That’s the basics of sandboxed appdomains. The most important object is the PermissionSet that defines the permissions available to assemblies running in the appdomain; it is this object that defines the appdomain as full or partial-trust. The appdomain also needs a default directory used for assembly lookups as the ApplicationBase parameter, and you can specify an optional list of the strongnames of assemblies that will be given full-trust permissions if they are loaded into the sandboxed appdomain. Next time, I’ll be looking closer at full-trust assemblies running in a sandboxed appdomain, and what you need to do to make an API available to partial-trust code.

    Read the article

  • SharePoint, HTTP Modules, and Page Validation

    - by Damon Armstrong
    Sometimes I really believe that SharePoint actively thwarts my attempts to get it to do what I want.  First you look at something and say, wow, that should work.  Then you realize it doesn’t.  Then you have an epiphany and see a workaround.  And when you almost have that work around working… well then SharePoint says no again.  Then it’s off on another whirl-wind adventure to find a work around for the workaround.  I had one of those issues today, but I think I finally got past the last roadblock. So, I was writing an HTTP module as a workaround for another problem.  Everything looked like it was working great because I had been slowly adding code into the HTTP module bit by bit in a prototyping effort.  Finally I put in the last bit of code in place… and I started to get an error: “The security validation for this page is invalid. Click Back in your Web browser, refresh the page, and try your operation again.” This is not an uncommon error – it normally occurs when you are updating an item on a GET request and you have not marked the web containing the item with AllowUnsafeUpdates.  One issue, however, is that I wasn’t updating anything in my code.  I was, however, getting an SPWeb object so I decided to set the AllowUnsafeUpdates property on it to true for good measure. Once that was in place, I ran it again… “The security validation for this page is invalid. Click Back in your Web browser, refresh the page, and try your operation again.” WTF?!?!  I really expected that setting the AllowUnsafeUpdates property on the SPWeb would fix the issue, but clearly that was not the case.  I have had occasion to disassemble some SharePoint code with .NET Reflector in the past, and one of the things SharePoint abuses a bit more than it should is the HttpContext.  One way to avoid this abuse is to clear out the HttpContext while your code runs and then set it back once you are done.  I tried this next, and everything worked out just like I had expected.  So, if you are building an HTTP Module for SharePoint and some code that you are running ends up giving you a security validation error, remember to try running that code with AllowUnsafeUpdates turned on and try running the code with the HttpContext nulled out (just remember to set it back after your code runs or else you’ll really jack things up).

    Read the article

  • Creating an ITemplate from a String

    - by Damon
    I do a lot of work with control templates, and one of the pieces of functionality that I've always wanted is the ability to build a ITemplate from a string.  Throughout the years, the topic has come up from time to time, and I never really found anything about how to do it. though I have run across a number of postings from people who are also wanting the same capability.  As I was messing around with things the other day, I stumbled on how to make it work and I feel really foolish for not figuring it out sooner. ITemplate is an interface that exposes a single method named InstantiateIn.  I've been searching for years for some magical .NET framework component that would take a string and convert it into an ITemplate, when all along I could just build my own.  Here's the code: /// <summary> ///   Allows string-based ITempalte implementations /// </summary> public class StringTemplate : ITemplate {     #region Constructor(s)     ////////////////////////////////////////////////////////////////////////////////////////////     /// <summary>     ///   Constructor     /// </summary>     /// <param name="template">String based version of the control template.</param>     public StringTemplate(string template)     {         Template = template;     }     /// <summary>     ///   Constructor     /// </summary>     /// <param name="template">String based version of the control template.</param>     /// <param name="copyToContainer">True to copy intermediate container contents to the instantiation container, False to leave the intermediate container in place.</param>     public StringTemplate(string template, bool copyToContainer)     {         Template = template;         CopyToContainer = copyToContainer;     }     ////////////////////////////////////////////////////////////////////////////////////////////     #endregion     #region Properties     ////////////////////////////////////////////////////////////////////////////////////////////     /// <summary>     ///   String based template     /// </summary>     public string Template     {         get;         set;     }     /// <summary>     ///   When a StringTemplate is instantiated it is created inside an intermediate control     ///   due to limitations of the .NET Framework.  Specifying True for the CopyToContainer     ///   property copies all the controls from the intermediate container into instantiation     ///   container passed to the InstantiateIn method.     /// </summary>     public bool CopyToContainer     {         get;         set;     }     ////////////////////////////////////////////////////////////////////////////////////////////     #endregion     #region ITemplate Members     ////////////////////////////////////////////////////////////////////////////////////////////     /// <summary>     ///   Creates the template in the specified control.     /// </summary>     /// <param name="container">Control in which to make the template</param>     public void InstantiateIn(Control container)     {         Control tempContainer = container.Page.ParseControl(Template);         if (CopyToContainer)         {             for (int i = tempContainer.Controls.Count - 1; i >= 0; i--)             {                 Control tempControl = tempContainer.Controls[i];                 tempContainer.Controls.RemoveAt(i);                 container.Controls.AddAt(0, tempControl);             }                         }         else         {             container.Controls.Add(tempContainer);         }     }     ////////////////////////////////////////////////////////////////////////////////////////////     #endregion } //class Converting a string into a user control is fairly easy using the ParseControl method from a Page object.  Fortunately, the container passed into the InstantiateIn method has a Page property.  One caveat, however, is that the Page property only has a reference to a Page if the container is located ON the page.  If you run into this problem, you may have to find a creative way to get the Page reference (you can add it to the constructor, store it in the request context, etc).  Another issue that I ran into is that the ParseControl creates a new control, parses the string template, places any controls defined in the template onto the new control it created, and returns that new control with the template on it.  You cannot pass in your own container. Adding this directly to the container provided as a parameter in the InstantiateIn means that you end up with an additional "level" in the control hierarchy.  To avoid this, I added code in that removes each control from the intermediate container and places it into the actual container.  I am not, however, sure about the performance penalty associated with moving a bunch of control from one place to another, nor am I completely sure if doing such a move completely screws something up if you have a code behind, etc.  It seems to work when it's just a template, but my testing was ever-so-slightly shy of thorough when it comes to other crazy scenarios.  As a catch-all, I added a Boolean property called CopyToContainer that allows you to turn the copying on or off depending on your desires and needs. Technorati Tags: .NET,ASP.NET,ITemplate,Development,C#,Custom Controls,Server Controls

    Read the article

  • Database Documentation - Lands of Trolls: Why and How?

    When database documentation is mentioned in an IT Department, everybody nods wisely, yet everyone does their best to avoid doing it. Attention to the database documentation can be the best invertment in time a development group can make. It is essential, and no system can be properly maintained without it. Feodor gives a sensible explanation and guideline for the unloved task of creating database documentation.

    Read the article

  • F# and the rose-tinted reflection

    - by CliveT
    We're already seeing increasing use of many cores on client desktops. It is a change that has been long predicted. It is not just a change in architecture, but our notions of efficiency in a program. No longer can we focus on the asymptotic complexity of an algorithm by counting the steps that a single core processor would take to execute it. Instead we'll soon be more concerned about the scalability of the algorithm and how well we can increase the performance as we increase the number of cores. This may even lead us to throw away our most efficient algorithms, and switch to less efficient algorithms that scale better. We might even be willing to waste cycles in order to speculatively execute at the algorithm rather than the hardware level. State is the big headache in this parallel world. At the hardware level, main memory doesn't necessarily contain the definitive value corresponding to a particular address. An update to a location might still be held in a CPU's local cache and it might be some time before the value gets propagated. To get the latest value, and the notion of "latest" takes a lot of defining in this world of rapidly mutating state, the CPUs may well need to communicate to decide who has the definitive value of a particular address in order to avoid lost updates. At the user program level, this means programmers will need to lock objects before modifying them, or attempt to avoid the overhead of locking by understanding the memory models at a very deep level. I think it's this need to avoid statefulness that has led to the recent resurgence of interest in functional languages. In the 1980s, functional languages started getting traction when research was carried out into how programs in such languages could be auto-parallelised. Sadly, the impracticality of some of the languages, the overheads of communication during this parallel execution, and rapid improvements in compiler technology on stock hardware meant that the functional languages fell by the wayside. The one thing that these languages were good at was getting rid of implicit state, and this single idea seems like a solution to the problems we are going to face in the coming years. Whether these languages will catch on is hard to predict. The mindset for writing a program in a functional language is really very different from the way that object-oriented problem decomposition happens - one has to focus on the verbs instead of the nouns, which takes some getting used to. There are a number of hybrid functional/object languages that have been becoming more popular in recent times. These half-way houses make it easy to use functional ideas for some parts of the program while still allowing access to the underlying object-focused platform without a great deal of impedance mismatch. One example is F# running on the CLR which, in Visual Studio 2010, has because a first class member of the pack. Inside Visual Studio 2010, the tooling for F# has improved to the point where it is easy to set breakpoints and watch values change while debugging at the source level. In my opinion, it is the tooling support that will enable the widespread adoption of functional languages - without this support, people will put off any transition into the functional world for as long as they possibly can. Without tool support it will make it hard to learn these languages. One tool that doesn't currently support F# is Reflector. The idea of decompiling IL to a functional language is daunting, but F# is potentially so important I couldn't dismiss the idea. As I'm currently developing Reflector 6.5, I thought it wise to take four days just to see how far I could get in doing so, even if it achieved little more than to be clearer on how much was possible, and how long it might take. You can read what happened here, and of the insights it gave us on ways to improve the tool.

    Read the article

  • OCS Disaster Recovery – Part 1

    Office Communications Server stores its data in a variety of locations, which can make backing it up and disaster recovery a slightly tricky business. Thankfully, Johan Velduis is here to tell which databases and fileshares we need to worry about, and give us peace of mind.

    Read the article

  • 5 Reasons why I hate WPF

    - by Richard Mitchell
    I decided to use writing a new tool as a way to learn WPF and MVVM and I thought I'd write down a few of my problems as a way of cathartic release. I decided to read a book before attempting WPF for the first time as I've heard others complain about the steep learning curve. I chose the rather excellent "WPF 4 Unleashed" by Adam Nathan to read through and "Pro WPF in C# 2010" by Matthew MacDonald as a reference whilst I programmed. 1 - Poor editing support for XAML The first thing I think any...(read more)

    Read the article

  • New SQL Code Deployment Book and Damn I Need to Blog More

    - by Rodney
    Select datediff(d,'02/19/2009',getdate()) This value returned from the above SELECT statement  is 398 and that is the number of days since my last blog post.  As I was formulating my apology for this hiatus from blogging, it dawned on me that I also do not twitter (sorry tweet) and as apologies beget apologies, I then realized that instead of catching up on the backlog of blogs, I should write a book about what I have been most focused on in the past year, one month and 3 days.  That focus is my day job, which of course, most of us have. And that day job we share is why most of us read blogs, tweets, articles and even books in the first place. So my focus for the past year has been SQL code deployments and all of that entails. I am fortunate that Redgate has agreed to entertain my crazy notion of writing an entire book about this subject, which I have tentatively titled, "The Sound and the Fury". Wait..that is not right. Oh yes, a title more befiting a techical tome but with as much profundity, "Standardizing SQL Server Code Deployements - A Redgate Guide". The great American novel must wait a few more years. As I begin this journey, I am inviting you to assist me in the discovery process and even be interviewed and included in the book itself. How do you do deployments in your company? Do you have a documented process or no process? Do you do code review or cross your fingers? Do you work for a small company or a Fortune 100 company? Government regulations or  garage? It does not  matter to me. I am not here to judge. I worked for both companies myself and have seen many things that you can relate to.  If you would like to participate and are one of the 3 people still reading this blog after 398 days, please fill out my survey and let's get started.  http://www.surveymonkey.com/s/RRG86RH  

    Read the article

  • The emergence of Atlassian's Bamboo (and a free SQL Source Control license offer!)

    - by David Atkinson
    The rise in demand for database continuous integration has forced me to skill-up in various new tools and technologies, particularly build servers. We have been using JetBrain's TeamCity here at Red Gate for a couple of years now, having replaced the ageing CruiseControl.NET, so it was a natural choice for us to use this for our database CI demos. Most of our early adopter customers have also transitioned away from CruiseControl, the majority to TeamCity and Microsoft's TeamBuild. However, more recently, for reasons we've yet to fully comprehend, we've observed a significant surge in the number of evaluators for Atlassian's Bamboo. I installed this a couple of weeks back to satisfy myself that it works seamlessly with Red Gate tools. As you would expect Bamboo's UI has the same clean feel found in any Atlassian tool (we use JIRA extensively here at Red Gate). In the coming weeks I will post a short step-by-step guide to setting up SQL Server continuous integration using the Red Gate command lines. To help us further optimize the integration between these tools I'd be very keen to hear from any Bamboo users who also use Red Gate tools who might be willing to participate in usability tests and other similar research in exchange for Amazon vouchers. If you are interested in helping out please contact me at David dot Atkinson at red-gate.com I recently spoke with Sarah, the product marketing manager for Bamboo, and we ended up having a detailed conversation about database CI, which has been meticulously documented in the form of a blog post on Atlassian's website: http://blogs.atlassian.com/2012/05/database-continuous-integration-redgate/ We've also managed to persuade Red Gate marketing to provide a great free-tool offer, provide a free SQL Source Control or SQL Connect license to Atlassian users provided it is claimed before the end of June! Full details are at the bottom of the post. Technorati Tags: sql server

    Read the article

  • One eye on my dinner and one eye on SQL server

    - by fatherjack
    LiveJournal Tags: RedGate,Work Life Balance,Tips and Tricks,SQL Server This is somewhere between a Tweet and a proper blog article - would that be a Bleet? Anyway, I was at a local restaurant yesterday and after placing my order I was thinking about having to get home and log in to check some SQL Servers and then the thought came to me that as we were near civilisation there was likely to be a 3G signal that might actually make using the web browser on my phone bearable. It was surprisingly fast on my HTC Desire, it was almost as good as Wi-Fi. RedGate SQL Monitor works fine on the default HTC browser and here is the proof, me checking the servers while I am waiting for the meal to arrive. Everything checked out OK so I had the evening free from SQL Server. You can get a free 14 day full trial of a SQL Monitor from RedGate here or find out more about it at The Future of Monitoring. Disclosure: I am a friend of RedGate and as such regularly make positive comments about their products. I don't get paid for it but I do get free licenses for testing and reviewing purposes.

    Read the article

  • PASS 13 Dispatches: moving to the cloud

    - by Tony Davis
    PASS Summit 13, Day 1 keynote by Quentin Clarke and we're hearing about “redefiniing mission critical in the cloud”. With a move to the Windows Azure cloud comes the promise of capacity on demand, automatic HA, backups, patching and so on, as well as passing responsibility to MS for managing hardware, upgrades and so on. However, for many databases and applications the best route to the cloud is not necessarily obvious. For most, the path of least resistance is IaaS – SQL Server in a Azure VM. It removes the hardware burden but you still have to manage your databases and implementing HA for SQL Server is your responsibility. Also, scaling up comes at quite a cost – the biggest VM (8 CPU cores, 56 GB RAM, 16 1TB drives with 500 IOPS each) weighs in at over over $4500 per month. With PaaS, in the form of Windows SQL Database, you get a “3-copies replica set” so HA comes out-of the box, and removes the majority of the administration burden, but you are moving your database into a very different environment. For a start, it's a shared environment, with other customers using the same compute nodes in the cluster, and potentially even sharing the same database (multi-tenancy). Unless you pay for SQL DB Premium edition, the resources available for your workload will depends on how nicely others “play” in the shared environment. You'll potentially need to do a lot of tuning, and application rewriting to avoid throttling issues, optimising application-database communication to deal with increased latency between the two, and so on. You'll need aggressive application caching. You'll also need retry logic and to deal with (expected) node failure and the need to reconnect. In Tuesday's PASS Summit pre-con from the SQLCAT team, they spent a lot of time covering some of the telemetric techniques (collect into Azure storage the necessary monitoring data) to perform capacity planning, work out the hotspots and bottlenecks in your cloud applications. Tools like WAD (Windows Azure Diagnostics), performance counters SQL Database DMVs, and others, will be essential. Of course, to truly exploit the vast horizontal scaling that is available from the existence of thousands of compute nodes, you'll also need to need to consider how to “shard” your data so Azure can move it between nodes at will. Finding the right path to the Cloud isn't easy, but it's coming. I spoke to people one year ago who saw no real benefit in trying to move their infrastructure and databases to the cloud, but now at their company, it's the conversation that won't go away. Tony.  

    Read the article

  • .NET Security Part 3

    - by Simon Cooper
    You write a security-related application that allows addins to be used. These addins (as dlls) can be downloaded from anywhere, and, if allowed to run full-trust, could open a security hole in your application. So you want to restrict what the addin dlls can do, using a sandboxed appdomain, as explained in my previous posts. But there needs to be an interaction between the code running in the sandbox and the code that created the sandbox, so the sandboxed code can control or react to things that happen in the controlling application. Sandboxed code needs to be able to call code outside the sandbox. Now, there are various methods of allowing cross-appdomain calls, the two main ones being .NET Remoting with MarshalByRefObject, and WCF named pipes. I’m not going to cover the details of setting up such mechanisms here, or which you should choose for your specific situation; there are plenty of blogs and tutorials covering such issues elsewhere. What I’m going to concentrate on here is the more general problem of running fully-trusted code within a sandbox, which is required in most methods of app-domain communication and control. Defining assemblies as fully-trusted In my last post, I mentioned that when you create a sandboxed appdomain, you can pass in a list of assembly strongnames that run as full-trust within the appdomain: // get the Assembly object for the assembly Assembly assemblyWithApi = ... // get the StrongName from the assembly's collection of evidence StrongName apiStrongName = assemblyWithApi.Evidence.GetHostEvidence<StrongName>(); // create the sandbox AppDomain sandbox = AppDomain.CreateDomain( "Sandbox", null, appDomainSetup, restrictedPerms, apiStrongName); Any assembly that is loaded into the sandbox with a strong name the same as one in the list of full-trust strong names is unconditionally given full-trust permissions within the sandbox, irregardless of permissions and sandbox setup. This is very powerful! You should only use this for assemblies that you trust as much as the code creating the sandbox. So now you have a class that you want the sandboxed code to call: // within assemblyWithApi public class MyApi { public static void MethodToDoThings() { ... } } // within the sandboxed dll public class UntrustedSandboxedClass { public void DodgyMethod() { ... MyApi.MethodToDoThings(); ... } } However, if you try to do this, you get quite an ugly exception: MethodAccessException: Attempt by security transparent method ‘UntrustedSandboxedClass.DodgyMethod()’ to access security critical method ‘MyApi.MethodToDoThings()’ failed. Security transparency, which I covered in my first post in the series, has entered the picture. Partially-trusted code runs at the Transparent security level, fully-trusted code runs at the Critical security level, and Transparent code cannot under any circumstances call Critical code. Security transparency and AllowPartiallyTrustedCallersAttribute So the solution is easy, right? Make MethodToDoThings SafeCritical, then the transparent code running in the sandbox can call the api: [SecuritySafeCritical] public static void MethodToDoThings() { ... } However, this doesn’t solve the problem. When you try again, exactly the same exception is thrown; MethodToDoThings is still running as Critical code. What’s going on? By default, a fully-trusted assembly always runs Critical code, irregardless of any security attributes on its types and methods. This is because it may not have been designed in a secure way when called from transparent code – as we’ll see in the next post, it is easy to open a security hole despite all the security protections .NET 4 offers. When exposing an assembly to be called from partially-trusted code, the entire assembly needs a security audit to decide what should be transparent, safe critical, or critical, and close any potential security holes. This is where AllowPartiallyTrustedCallersAttribute (APTCA) comes in. Without this attribute, fully-trusted assemblies run Critical code, and partially-trusted assemblies run Transparent code. When this attribute is applied to an assembly, it confirms that the assembly has had a full security audit, and it is safe to be called from untrusted code. All code in that assembly runs as Transparent, but SecurityCriticalAttribute and SecuritySafeCriticalAttribute can be applied to individual types and methods to make those run at the Critical or SafeCritical levels, with all the restrictions that entails. So, to allow the sandboxed assembly to call the full-trust API assembly, simply add APCTA to the API assembly: [assembly: AllowPartiallyTrustedCallers] and everything works as you expect. The sandboxed dll can call your API dll, and from there communicate with the rest of the application. Conclusion That’s the basics of running a full-trust assembly in a sandboxed appdomain, and allowing a sandboxed assembly to access it. The key is AllowPartiallyTrustedCallersAttribute, which is what lets partially-trusted code call a fully-trusted assembly. However, an assembly with APTCA applied to it means that you have run a full security audit of every type and member in the assembly. If you don’t, then you could inadvertently open a security hole. I’ll be looking at ways this can happen in my next post.

    Read the article

  • Kill a tree, save your website? Content strategy in action, part III

    - by Roger Hart
    A lot has been written about how driving content strategy from within an organisation is hard. And that's true. Red Gate is pretty receptive to new ideas, so although I've not had a total walk in the park, it's been a hike with charming scenery. But I'm one of the lucky ones. Lots of people are involved in content, and depending on your organisation some of those people might be the kind who'll gleefully call themselves "stakeholders". People holding a stake generally want to stick it through something's heart and bury it at a crossroads. Winning them over is not always easy. (Richard Ingram has made a nice visual summary of how this can feel - Content strategy Snakes & ladders - pdf ) So yes, a lot of content strategy advocates are having a hard time. And sure, we've got a nice opportunity to get together and have a hug and a cry, but in the interim we could use a hand. What to do? My preferred approach is, I'll confess, brutal. I'd like nothing so much as to take a scorched earth approach to our website. Burn it, salt the ground, and build the new one right: focusing on clearly delineated business and user content goals, and instrumented so we can tell if we're doing it right. I'm never getting buy-in for that, but a boy can dream. So how about just getting buy-in for some small, tenable improvements? Easier, but still non-trivial. I sat down for a chat with our marketing and design guys. It seemed like a good place to start, even if they weren't up for my "Ctrl-A + Delete"  solution. We talked through some of this stuff, and we pretty much agreed that our content is a bit more broken than we'd ideally like. But to get everybody on board, the problems needed visibility. Doing a visual content inventory Print out the internet. Make a Wall Of Content. Seriously. If you've already done a content inventory, you know your architecture, and you know the scale of the problem. But it's quite likely that very few other people do. So make it big and visual. I'm going to carbon hell, but it seems to be working. This morning, I printed out a tiny, tiny part of our website: the non-support content pertaining to SQL Compare I made big, visual, A3 blowups of each page, and covered a wall with them. A page per web page, spread over something like 6M x 2M, with metrics, right in front of people. Even if nobody reads it (and they are doing) the sheer scale is shocking. 53 pages, all told. Some are redundant, some outdated, some trivial, a few fantastic, and frighteningly many that are great ideas delivered not-quite-right. You have to stand quite far away to get it all in your field of vision. For a lot of today, a whole bunch of folks have been gawping in amazement, talking each other through it, peering at the details, and generally getting excited about content. Developers, sales guys, our CEO, the marketing folks - they're engaged. Will it last? I make no promises. But this sort of wave of interest is vital to getting a content strategy project kicked off. While the content strategist is a saucer-eyed orphan in the cupboard under the stairs, they're not getting a whole lot done. Of course, just printing the site won't necessarily cut it. You have to know your content, and be able to talk about it. Ideally, you'll also have page view and time-on-page metrics. One of the most powerful things you can do is, when people are staring at your wall of content, ask them what they think half of it is for. Pretty soon, you've made a case for content strategy. We're also going to get folks to mark it up - cover it with notes and post-its, let us know how they feel about our content. I'll be blogging about how that goes, but it's exciting. Different business functions have different needs from content, so the more exposure the content gets, and the more feedback, the more you know about those needs. Fingers crossed for awesome.

    Read the article

  • SQLBeat Episode 11 – Ted the Fred Krueger Halloween SQL

    - by SQLBeat
    In this episode of the SQLBeat Podcast I speak conversationally (Ok I will just say I converse) with Ted Krueger about Elm Street, where he works as a DBA who stores nightmares in SQL Server database tables. The joke about it being BLOB storage is only one of several that may scare you away from this Halloween Special. If you like listening to two SQL guys talking about the bands they used to be in, rainbow trout and video games, come on in. Bwaaaa Haaaa Haaa…..Ok I will stop. Download the MP3

    Read the article

  • Anatomy of a .NET Assembly - PE Headers

    - by Simon Cooper
    Today, I'll be starting a look at what exactly is inside a .NET assembly - how the metadata and IL is stored, how Windows knows how to load it, and what all those bytes are actually doing. First of all, we need to understand the PE file format. PE files .NET assemblies are built on top of the PE (Portable Executable) file format that is used for all Windows executables and dlls, which itself is built on top of the MSDOS executable file format. The reason for this is that when .NET 1 was released, it wasn't a built-in part of the operating system like it is nowadays. Prior to Windows XP, .NET executables had to load like any other executable, had to execute native code to start the CLR to read & execute the rest of the file. However, starting with Windows XP, the operating system loader knows natively how to deal with .NET assemblies, rendering most of this legacy code & structure unnecessary. It still is part of the spec, and so is part of every .NET assembly. The result of this is that there are a lot of structure values in the assembly that simply aren't meaningful in a .NET assembly, as they refer to features that aren't needed. These are either set to zero or to certain pre-defined values, specified in the CLR spec. There are also several fields that specify the size of other datastructures in the file, which I will generally be glossing over in this initial post. Structure of a PE file Most of a PE file is split up into separate sections; each section stores different types of data. For instance, the .text section stores all the executable code; .rsrc stores unmanaged resources, .debug contains debugging information, and so on. Each section has a section header associated with it; this specifies whether the section is executable, read-only or read/write, whether it can be cached... When an exe or dll is loaded, each section can be mapped into a different location in memory as the OS loader sees fit. In order to reliably address a particular location within a file, most file offsets are specified using a Relative Virtual Address (RVA). This specifies the offset from the start of each section, rather than the offset within the executable file on disk, so the various sections can be moved around in memory without breaking anything. The mapping from RVA to file offset is done using the section headers, which specify the range of RVAs which are valid within that section. For example, if the .rsrc section header specifies that the base RVA is 0x4000, and the section starts at file offset 0xa00, then an RVA of 0x401d (offset 0x1d within the .rsrc section) corresponds to a file offset of 0xa1d. Because each section has its own base RVA, each valid RVA has a one-to-one mapping with a particular file offset. PE headers As I said above, most of the header information isn't relevant to .NET assemblies. To help show what's going on, I've created a diagram identifying all the various parts of the first 512 bytes of a .NET executable assembly. I've highlighted the relevant bytes that I will refer to in this post: Bear in mind that all numbers are stored in the assembly in little-endian format; the hex number 0x0123 will appear as 23 01 in the diagram. The first 64 bytes of every file is the DOS header. This starts with the magic number 'MZ' (0x4D, 0x5A in hex), identifying this file as an executable file of some sort (an .exe or .dll). Most of the rest of this header is zeroed out. The important part of this header is at offset 0x3C - this contains the file offset of the PE signature (0x80). Between the DOS header & PE signature is the DOS stub - this is a stub program that simply prints out 'This program cannot be run in DOS mode.\r\n' to the console. I will be having a closer look at this stub later on. The PE signature starts at offset 0x80, with the magic number 'PE\0\0' (0x50, 0x45, 0x00, 0x00), identifying this file as a PE executable, followed by the PE file header (also known as the COFF header). The relevant field in this header is in the last two bytes, and it specifies whether the file is an executable or a dll; bit 0x2000 is set for a dll. Next up is the PE standard fields, which start with a magic number of 0x010b for x86 and AnyCPU assemblies, and 0x20b for x64 assemblies. Most of the rest of the fields are to do with the CLR loader stub, which I will be covering in a later post. After the PE standard fields comes the NT-specific fields; again, most of these are not relevant for .NET assemblies. The one that is is the highlighted Subsystem field, and specifies if this is a GUI or console app - 0x20 for a GUI app, 0x30 for a console app. Data directories & section headers After the PE and COFF headers come the data directories; each directory specifies the RVA (first 4 bytes) and size (next 4 bytes) of various important parts of the executable. The only relevant ones are the 2nd (Import table), 13th (Import Address table), and 15th (CLI header). The Import and Import Address table are only used by the startup stub, so we will look at those later on. The 15th points to the CLI header, where the CLR-specific metadata begins. After the data directories comes the section headers; one for each section in the file. Each header starts with the section's ASCII name, null-padded to 8 bytes. Again, most of each header is irrelevant, but I've highlighted the base RVA and file offset in each header. In the diagram, you can see the following sections: .text: base RVA 0x2000, file offset 0x200 .rsrc: base RVA 0x4000, file offset 0xa00 .reloc: base RVA 0x6000, file offset 0x1000 The .text section contains all the CLR metadata and code, and so is by far the largest in .NET assemblies. The .rsrc section contains the data you see in the Details page in the right-click file properties page, but is otherwise unused. The .reloc section contains address relocations, which we will look at when we study the CLR startup stub. What about the CLR? As you can see, most of the first 512 bytes of an assembly are largely irrelevant to the CLR, and only a few bytes specify needed things like the bitness (AnyCPU/x86 or x64), whether this is an exe or dll, and the type of app this is. There are some bytes that I haven't covered that affect the layout of the file (eg. the file alignment, which determines where in a file each section can start). These values are pretty much constant in most .NET assemblies, and don't affect the CLR data directly. Conclusion To summarize, the important data in the first 512 bytes of a file is: DOS header. This contains a pointer to the PE signature. DOS stub, which we'll be looking at in a later post. PE signature PE file header (aka COFF header). This specifies whether the file is an exe or a dll. PE standard fields. This specifies whether the file is AnyCPU/32bit or 64bit. PE NT-specific fields. This specifies what type of app this is, if it is an app. Data directories. The 15th entry (at offset 0x168) contains the RVA and size of the CLI header inside the .text section. Section headers. These are used to map between RVA and file offset. The important one is .text, which is where all the CLR data is stored. In my next post, we'll start looking at the metadata used by the CLR directly, which is all inside the .text section.

    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

  • Making the WPeFfort

    - by Laila
    Microsoft Visual Studio 2010 will be launched on April 12th. The basic layout looks pretty much as it did, so it is not immediately obvious on first inspection that it was completely rewritten in the Windows Presentation Foundation (WPF). The current VS 2008 codebase had reached the end of its life; It was getting slow to initialize and sluggish to run, and was never going to allow for multi-monitor support or easier extensibility. It can't have been an easy decision to rewrite Visual Studio, but the gamble seems to have paid off. Although certain bugs in the betas caused some anxiety about performance, these seem to have been fixed, and the new Visual Studio is definitely faster. In rewriting the codebase, it has been possible to make obvious improvements, such as being able to run different windows on different monitors, and you only being presented with the Toolbox controls and References that are appropriate to your target .NET version. There is also an IntelliTrace debugger, and Intellisense has been improved by virtue of separating a 'Suggestion Mode' and 'Completion Mode' (with its 'Generate From.' 'Highlight References.', and 'Navigate to...' features). At the same time, there has been quite a clearout; Certain features that had been tucked away in the previous versions, such as Brief or Emacs emulation support, have been dropped. (Yes, they were being used!) There are a lot of features that didn't require the rewrite, but are welcome. It is now easier to develop WPF applications (e.g. drag-and-drop Databinding), and there is support for Azure. There are more, and better templates and the design tools are greatly improved (e.g. Expression Web, Expression Blend, WPF Sketchflow, Silverlight designer, Document Map Margin and Inline Call Hierarchy). Sharepoint is better supported, and Office apps will benefit from C#'s support of optional and named arguments, and allowing several Office Solutions within a Deployment package. Most importantly, it is a vote of confidence in the WPF. VS 2010 is the essential missing component that has been impeding the faster adoption of WPF. The fact that it is actually now written in WPF should now reassure the doubters, and convince more developers to make the move from WinForms to WPF. In using WPF, the developers of Visual Studio have had the clout to fix some issues which have been bothering WPF developers for some time (such as blurred text). Do you see a brighter future as a result of transferring from WinForms to WPF? I'd love to know what you think. Cheers, Laila

    Read the article

  • The emergence of Atlassian's Bamboo (and a free SQL Source Control license offer!)

    - by David Atkinson
    The rise in demand for database continuous integration has forced me to skill-up in various new tools and technologies, particularly build servers. We have been using JetBrain's TeamCity here at Red Gate for a couple of years now, having replaced the ageing CruiseControl.NET, so it was a natural choice for us to use this for our database CI demos. Most of our early adopter customers have also transitioned away from CruiseControl, the majority to TeamCity and Microsoft's TeamBuild. However, more recently, for reasons we've yet to fully comprehend, we've observed a significant surge in the number of evaluators for Atlassian's Bamboo. I installed this a couple of weeks back to satisfy myself that it works seamlessly with Red Gate tools. As you would expect Bamboo's UI has the same clean feel found in any Atlassian tool (we use JIRA extensively here at Red Gate). In the coming weeks I will post a short step-by-step guide to setting up SQL Server continuous integration using the Red Gate command lines. To help us further optimize the integration between these tools I'd be very keen to hear from any Bamboo users who also use Red Gate tools who might be willing to participate in usability tests and other similar research in exchange for Amazon vouchers. If you are interested in helping out please contact me at David dot Atkinson at red-gate.com I recently spoke with Sarah, the product marketing manager for Bamboo, and we ended up having a detailed conversation about database CI, which has been meticulously documented in the form of a blog post on Atlassian's website: http://blogs.atlassian.com/2012/05/database-continuous-integration-redgate/ We've also managed to persuade Red Gate marketing to provide a great free-tool offer, provide a free SQL Source Control or SQL Connect license to Atlassian users provided it is claimed before the end of June! Full details are at the bottom of the post. Technorati Tags: sql server

    Read the article

  • Using LINQ Lambda Expressions to Design Customizable Generic Components

    LINQ makes code easier to write and maintain by abstracting the data source. It provides a uniform way to handle widely diverse data structures within an application. LINQ’s Lambda syntax is clever enough even to allow you to create generic building blocks with hooks into which you can inject arbitrary functions. Michael Sorens explains, and demonstrates with examples.

    Read the article

< Previous Page | 168 169 170 171 172 173 174 175 176 177 178 179  | Next Page >