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craigtp /
Created May 1, 2020
Notes on Udi Dahan's Advanced Distributed System Design Course

Advanced Distributed System Design Course - Udi Dahan

Notes by Craig Phillips

Fallacies of Distributed Computing

  • There are 11 fallacies of Distributed Computing:
    1. The network is reliable
    2. Latency isn’t a problem
    3. Bandwidth isn’t a problem
    4. The network is secure
    5. The topology won’t change
craigtp / ProbabilityKata2
Last active May 28, 2019 — forked from gregoryyoung/ProbabilityKata2
Probability Kata part 2
View ProbabilityKata2
OK so now you have implemented the kata. Your tests should look something like this:
We can say that the tests define the object "in a calculus of itself".
They are not state based tests, they define how the behaviours of the object interact with each other.
To see the real value of this let's introduce some change ... I hear real system's do this occasionally.
Because this is a high performance system decimal math is too slow. You now need to use floats instead.
Need help on floating point math? Check out:
craigtp / ProbabilityKata
Created May 27, 2019 — forked from gregoryyoung/ProbabilityKata
Greg Young's Probability Kata
View ProbabilityKata
Value objects are an important concept in DDD. This kata is made both to learn value objects and to learn better ways of testing.
Write a probability value object. It should contain the following methods:
Probability CombinedWith(Probability)
Probability InverseOf()
Probability Either(Probability)
if you forget your probability math:
Either:P(A) + P(B) - P(A)P(B)
CombinedWith: P(A)P(B)

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craigtp / touch.ps1
Created Sep 23, 2017
Windows Touch - Update Last Write / Modified Date of files recursively.
View touch.ps1
gci -recu -inc "*.*" | % { $_.LastWriteTime = Get-Date }
craigtp / NumericHelpers.cs
Last active Apr 21, 2017
Provides a function that will allow two imprecise floating point numbers to be compared for "near" equality and also an "IsNumeric" function.
View NumericHelpers.cs
public static class NumericHelpers
// Float point maths is whack. We can't check for absolute equality as floating point numbers are imprecise
// and are subject to rounding issues (See:
// Therefore, we can't check for absolute equality, but instead we have to need to check for values being
// "nearly" equal, which allows a small margin of error (i.e. something known as the "Epsilon" value for
// the given data type for this CPU that this code is running on).
public static bool NearlyEqual(double a, double b, double epsilon)
var absA = Math.Abs(a);
craigtp / GetWindowsProductKey.vbs
Created May 30, 2016
Retrieve Windows Product Key
View GetWindowsProductKey.vbs
Option Explicit
Dim objshell,path,DigitalID, Result
Set objshell = CreateObject("WScript.Shell")
'Set registry key path
Path = "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\"
'Registry key value
DigitalID = objshell.RegRead(Path & "DigitalProductId")
Dim ProductName,ProductID,ProductKey,ProductData
'Get ProductName, ProductID, ProductKey
craigtp / RandomString.cs
Created Apr 29, 2016
RandomString - A class containing methods to produce some handy random string combinations.
View RandomString.cs
using System;
using System.Text;
namespace RandomString
public class RandomString : IDisposable
// Can use the BetterRandom class here or just use the built-in System.Random class.
private BetterRandom random = new BetterRandom();
private const string alpha_selection = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
View TruncateAtWordStringExtension.cs
public static class StringExtentionMethods
public static string TruncateAtWord(this string input, int maxlength, bool addEllipsis)
if (input == null || input.Length <= maxlength) return input;
var ellipsisLengthDeduction = (addEllipsis ? 3 : 0);
var iLastSpace = input.LastIndexOf(" ", (maxlength - ellipsisLengthDeduction), StringComparison.Ordinal);
var iLength = 0;
if (iLastSpace < 0)
craigtp / CleanUpTemporaryASPNETFiles.ps1
Last active Apr 7, 2021
Clean Up Temporary ASP.NET Files with Powershell
View CleanUpTemporaryASPNETFiles.ps1
# Run this as Administrator
net stop w3svc
Get-ChildItem "C:\Windows\Microsoft.NET\Framework*\v*\Temporary ASP.NET Files" -Recurse | Remove-Item -Recurse -Force
net start w3svc