Wednesday, December 19, 2012

Windows 8 RDP with blank password

If you want to enable Remote Desktop with a blank password on window 8, this is the same procedure as enabling rdp on windows 7 instructions can be found here

As a collegue suggested enabling this is a security risk.

Saturday, July 28, 2012

Migrating Legacy Applications

Legacy Systems

Legacy systems are systems that have grown over the years and became harder and harder to change and or are build on outdated technologies. Since business is changing rapidly these systems no longer can keep up the pace. Certainly in people that sell services products that are sold can be very complex, take for instance insurances.

Often these systems are the core of the systems, if these systems go down you the company looses money, in certain areas you can loose thousands of dollars per minute you are down.

Symptoms

Signs that tell you that your current system will become unstable can be:

  • Downtime
  • More and more bugs, regression
  • Implementing new features takes longer and longer
  • Solving bugs takes longer
  • Unable to scale up your system
  • Upstaffing of your operational team

More about these symptoms you can read about here.

Usually when you start experiencing the negatives effects of these systems your legacy system will need to be changed quite urgently.

These symptoms will result into an increased TCO. Keeping the system operational will become increasingly difficult since people that operate these systems become older, skills required will become very rare.

 

Approaches

There are several different approaches that can be taken to modernize your legacy system.

  • Garbage in-garbage out: for certain languages there are tools that convert your source code from one language to another like vb6 to vb .net, vb .net to c#
  • Big Bang Migration: full migration of a system, you rewrite your whole application at once ant one magic day you put everything at once in production.
  • Incremental Migration: You partition your system in smaller subsystems and you put your system in production increment per increment.

 

Migration by tool

This approach can work if for instance you need to upgrade your system from one version to another. The biggest risk here is that when you do this you will not solve the fact that your software is difficult to adapt. It's an illusion that a system will be easier to adapt in a new technology than it was in the older one. What can be an added value of new technology is better development tools helping you with better support for refactoring to bring your system in a condition that is more suited to change and easier to change.

 

Big Bang Migration

This approach where you rewrite application from scratch and migrate your data from the old system to the new system. The biggest risk here is that when your project fails the entire project fails, the outcome becomes more unpredictable the bigger the project gets. The risk in this undertaking are generally huge and need to be assessed carefully.

This approach can be successful in projects that are quite small, your data is of high quality, you know your data structures and don't have a lot of dependencies on other systems.

There also is no guarantee that the new system you build will not start to show the same symptoms as your old one. If you do not put in place good programming techniques and adhere very strict quality guidelines the chance is big that the new system will become hard to change quite quickly.

Another downside is that business will not stop the evolve either you will be faced with the fact that you will need to implement old functionalities and in the mean time keep track of new developments also.

The cost is very high since you need to be operating your legacy system and in the meanwhile develop a new one which requires input from the people that are operating your legacy system which will have low availability due to the fact the need to keep the business afloat.

This approach is often chosen but often fails or costs enormous amounts of money.

Incremental Migration

When performing an incremental migration. You will have to divide your legacy system into smaller functional components and migrate each one step by step. The partitioning needs to be done just-in-time, enough to keep you busy.

The huge upside of this approach is that its the risks are highly controllable and that if something goes wrong the feedback is rapid and the impact of the failure is limited and predictable.
Another big advantage is also that you will be forced to build your system in such a way that is easily extended and changed.

The downside of this is that the people that operate your legacy system need to be actively involved with the new developments since they have indispensable knowledge about how the old system and the business operates, since they are responsible for operating the old system their availability might be quite limited. Combined with a significant increase in cost having to keep two teams.

It need to be taken in mind also that when doing an incremental modernization that every step you take needs to able to be rolled back so in the beginning this will require a significant effort to easily and rapidly deploy and rollback your changes.

Sunday, July 08, 2012

Git and Visual Studio 2012


Some points to take into mind when using Git in combination with Visual Studio 2012, Resharper and NUGet.
Manually add following entries to your .gitignore file
  • packages/
  • TestResults/
#################
## Visual Studio
#################

## Ignore Visual Studio temporary files, build results, and
## files generated by popular Visual Studio add-ons.

# User-specific files
*.suo
*.user
*.sln.docstates

# Build results
[Dd]ebug/
[Rr]elease/
*_i.c
*_p.c
*.ilk
*.meta
*.obj
*.pch
*.pdb
*.pgc
*.pgd
*.rsp
*.sbr
*.tlb
*.tli
*.tlh
*.tmp
*.vspscc
.builds
*.dotCover
bin/

packages/
TestResults/


# Visual Studio profiler
*.psess
*.vsp

# ReSharper is a .NET coding add-in
_ReSharper*

# Installshield output folder
[Ee]xpress

# DocProject is a documentation generator add-in
DocProject/buildhelp/
DocProject/Help/*.HxT
DocProject/Help/*.HxC
DocProject/Help/*.hhc
DocProject/Help/*.hhk
DocProject/Help/*.hhp
DocProject/Help/Html2
DocProject/Help/html

# Click-Once directory
publish

# Others
[Bb]in
[Oo]bj
sql
TestResults
*.Cache
ClientBin
stylecop.*
~$*
*.dbmdl
Generated_Code #added for RIA/Silverlight projects

# Backup & report files from converting an old project file to a newer
# Visual Studio version. Backup files are not needed, because we have git ;-)
_UpgradeReport_Files/
Backup*/
UpgradeLog*.XML



############
## Windows
############

# Windows image file caches
Thumbs.db

# Folder config file
Desktop.ini


#############
## Python
#############

*.py[co]

# Packages
*.egg
*.egg-info
dist
build
eggs
parts
bin
var
sdist
develop-eggs
.installed.cfg

# Installer logs
pip-log.txt

# Unit test / coverage reports
.coverage
.tox

#Translations
*.mo

#Mr Developer
.mr.developer.cfg

# Mac crap
.DS_Store

Saturday, July 07, 2012

SharpPOS: The Personae


Manager

basil Basil is a restaurant owner. At the end of the day he would like to have an overview of what has been paid by what means. At the end of the month he would like to have an overview of how much has been sold per day per tax category so he can pass this information to his accountant.

Waiter

manuel001 Manuel is a waiter at basil’s restaurant. When he takes orders from customers he writes it down on a notepad, after he has written down the order he walks to the cash register and copies the information in the POS, if an order contains food it should be printed automatically to a secondary printer which is located in the kitchen, so the chef knows what dishes he has to prepare.

When a customer asks for the check Manual wants to be able to print an overview of what the customer has ordered and the total amount that he needs to pay. After getting the money from the customer he enters the amount that has been paid, the system should indicate how much money he has to render.

At the end of his shift he needs to close his shift and an oveview should be printed of how much he has sold, so he can count the money that is in the register

Friday, July 06, 2012

New Project

A few weekends ago a friend of mine lost his POS program during renovations. I told him maybe I could help him out and find him a new (open source) alternative instead of having to buy a new one. I deceided to give OpenBravoPOS a go, it is a neat system with tons of functionalities. However it has some quirks the most important one is that the Close Cash report, that is printed at the end of the day has not the possibility to print the total amount that has been sold per tax category, so it needs to be calculated afterwards which is a bit a pain in the ass... 

Other things I noticed is entering products is really, but really a painful experience, reference and barcode need to be unique... when in fact we don’t need neither the reference neither the barcode. When entering the price of the product you need to set the amount of tax before you can enter the sell price + tax because the base of the calculation is the price excluding the tax is a bit annoying also. 

So I came up with the idea to write him a brand new program called SharpPOS. First thing I did was write up the personas, I wrote one for the owner and one for a waitress. Then I went forward to identify the Minimal Marketable Product which was quit ok. the goal of my little project is to show the real power of Agile.
update: project canceled due to changed legislation

Wednesday, May 02, 2012

Certified Scrum Professional

Last week the scrum Alliance CSP certification got approved!



Friday, February 17, 2012

The difference between a Mock and a Stub

Many people have a lot of problems to understand the difference between a Mock and a Stub. Marting Fowler states that a Mock is about behaviour verification and a Stub is about state verification
From: http://martinfowler.com/articles/mocksArentStubs.html





  • Dummy objects are passed around but never actually used. Usually they are just used to fill parameter lists.
  • Fake objects actually have working implementations, but usually take some shortcut which makes them not suitable for production (an in memory database is a good example).
  • Stubs provide canned answers to calls made during the test, usually not responding at all to anything outside what's programmed in for the test. Stubs may also record information about calls, such as an email gateway stub that remembers the messages it 'sent', or maybe only how many messages it 'sent'.
  • Mocks are what we are talking about here: objects pre-programmed with expectations which form a specification of the calls they are expected to receive. 


  • I am going to try to explain you in one simple example the difference...
    The classes involved:
    FileProcessor: The actual business logic, that we are trying to test, the Subject Under Test
    File: some file we are processing
    FileValidator: Performs some logic on the file to see if it contains errors
    FileMover: Moves the file to a specific location depending on the results returned by the FileValidator

    public class FileProcessor{
            private readonly IFileMover _FileMover;
            private readonly IFileValidator _FileValidator;

            //Constructor
            public FileProcessor(IFileMover fileMover, IFileValidator fileValidator){
                       IFileMover _FileMover = fileMover;
                       IFileValidator _FileValidator = fileValidator;
            }

            public void Process(File file){
                 ValidationResults result = _FileValidator.Validate(file);

                 if(result.IsValid){
                      _FileMover.Succes(file)
                 }else{
                      _FileMover.Error(file)
                  }
            }
    }

    public interface IFileMover{
           void Success(File file);
           void Error(File file);
    }

    public class ValidationResults{
                public virtual bool IsValid{
                     get;
                }
    }

    public interface IFileValidor{
           ValidationResults Validate(File file);
    }

    We need to create a dummy called DummyValidationResults

    public class DummyValidationResults: ValidationResults{
             public virtual bool IsValid{
                    get{ return false;}
             }
    }

    Now we create a Mock MockFileMover

    public class MockFileMover: IFileMover{

        public void Success(File file){
               this.SucessCalled++;
         }

        public void Error(File file){
             this.ErrorCalled++;
        }

        public int SuccesCalled{get; private set;}
        public int ErrorCalled{get; private set;}
    }

    We create a Stub named StubFileValidator

    public class StubFileValidator: IFileValidator{
         public ValidationResults Validate(File file){
            return new DummyValidationResult();
        }
    }


    now when we would like the test the Fileprocessor we can write:
        File aFile = new FakeFile();
        MockFileMover fileMover =  new MockFileMover()
        FileProcessor processor = new FileProcessor(new MockFileMover(), new StubFileValidator());
        processor.process(aFile);

        Assert.AreEqual(1,fileMover.ErrorWasCalled);
        Assert.AreEqual(0,fileMover.SuccessWasCalled);

    So what is the difference?
    The stub returns a predetermined answer what needs to happen and the path through the code dictates it will always be called. As you can see the methods of the mock are enclosed in decision logic in this case an if statement (this can as wel be a try catch switch or whatever), then we verify if the correct method on the mock has been called... so the mock is responsible for failing or succeeding the test...

    Friday, November 18, 2011

    Executing all SQL files in a folder

    SET dbName=RemmicomMeetingDb
    SET sqlCmdCommand=sqlcmd -S . -E -i

    %sqlCmdCommand% "DropAndCreateDb.sql"

    FOR /F %%i IN ('dir /b /on *.sql') DO %sqlCmdCommand% %%i -d %dbName%

    Monday, November 07, 2011

    Incremental Software Delivery

    What i see occur quite often is that User Stories are to big, resulting in work that is not done at the end of the sprint.

    Lets take a look at the story below:


    As an office manager I would like to be able to lookup contacts quickly so that I can quickly find someone's contact details.

    clip_image001[1]

    Acceptance criteria

    • Given an Office Manager enters "como" When I press the search button Then he/she should see the contact details of everyone who's full name contains "como"
    • Given an Office Manager enters"ce" When I press the search button Then he/she should see the contact details off everyone's title containing "ce"
    • ...

    Now if we think about this for a second, we could start to break down the tasks as follows:
    • Create the database tables
    • Create the data access layer
    • Create the DTO's
    • Create the UI
    • Create the service layer
    If we stop and think about this a second it does not really make sense in a incremental delivery mindset. If you reflect on this from a Form Follows Function Perspective, that the shape of an object should be based upon its purpose. This is a faulty breakup of the feature we are trying to build, since we are going to make the purpose - storing the data in a database and then transfer it to a screen - take precedence over the function, searching contact details.
    It makes more sense tobreak up the screen in functional components as shown below:
    clip_image002
    Then we could break the feature up as follows:
    • Display Search Results
    • Enter Search Criteria
    • Display status message "x out of Y contacts"
    This will require developers to shift there mind from "Horizontal thinking" - thinking in terms of technical layers, to vertical thinking - what I often refer to as "Slicing the Cake". This enables you to incremental delivery of features and get earlier feedback.
    The most important thing is the green grid displaying the search results. From a technical perspective this seems a bit weird, since we autmatically think that its not usable once we have hundreds of contacts. But this mindset is wrong, it is workable, whether its practical that is another thing.
    If we would take this approach we could deliver the following screen to the Product Owner:
    clip_image003
    If he can get his hands on this he can allready take a look and maybe he could allready experience this bit of functionality and conclude he would like to add some fields to the grid like email and phone, that he did not think of immediately.
    So an extra task is added to the story "Add email and phone fields to the grid"
    In the meanwhile wile the product owner is allready playing around with the screen we can allready add the yellow part to the screen:
    clip_image004
    This will enable very short continuous feedback loops, moreover working like this will help you deliver functionality sprint after sprint.
    This is what the end result could look like
    clip_image005
    As you see apparently there was no more time for the status message at the bottom of the screen and this task has been removed from the story another change from the initial version is also the "Search" button.
    Find here an overview of what was implemented and what was removed:
    As an office manager I would like to lookup contacts quickly so that I can quickly find someone's contact details.
    1. Display search results: Done
    1. Enter Search Criteria: Done
    1. Display status message "x out y contacts": removed
    1. Add phone and email fields to the grid: Done
    1. Filter results grid when typing text: Done
    1. Remove search button: Done
    There is one caveat with this approach, business user tend to like alot to add stuff, but they really dislike removing stuff… But this is where the timebox principle kicks in, if for instance there would be no more time left than the 2 last tasks (tasks 5 and 6) than the Product Owner might still choose to accept the story as done and the Functionality could potentially be shipped.

    Friday, September 30, 2011

    Scrum.org PSM II Certification

    I reached a major milestone and obtained my Professional Scrum Master Certification II last week. A put alot of effort in it and it paid of.