PowerMess

a simple chaos generator written in powershell witch monitors and manipulates processes to create chaos senarios

features

• Cpu Limit
• Memory Limit
• Random Fault

Cpu Limit

Monitors Process Cpu time (total time the process spend on any core of cpu (physical/virtual)) if cpu time passes a threshold kills the process

New-CpuLimit -MaxCputime 2 -ProcessName firefox

Memory Limit

Monitors Process Private Memory Size which is the actual used memory (not reserved memory) if Private Memory Size a threshold kills the process

New-MemoryLimit  -MaxPrivateMemory 200 -ProcessName firefox

Random Fault

Kills Process with a uniform probablilty

Probability argument is percent

New-RandomKill -Probability 2 -ProcessName firefox

ProcessName accepts wildcard names e.g. fire* instead of firefox

Also there is a little tool witch helps in scenario desctiption

Start-Chaos

arguments:

• StartAfter: delay before applying chaos in seconds
• StopAfter: retry count of same chaos
• Body: any of chaos options described before or combination of them

Start-Chaos -StartAfter 15 -StopAfter 10  -Body { 
    New-MemoryLimit  -MaxPrivateMemory 200 -ProcessName firefox 
    New-RandomKill -Probability 2 -ProcessName firefox
    ...
}

technology independant

this project injects faults in process level so is doesnt matter what application is running on it. therefore can be used with any technology.

How To Use

Create a powershell script and import ChaosContainer Module

Import-Module src\ChaosContainer.psm1

Describe your scenario using chaos commands

Start-Chaos -StartAfter 0  -StopAfter 1  -Body { 
    New-RandomKill   -Probability 2 -ProcessName firefox 
}
Start-Chaos -StartAfter 5  -StopAfter 1  -Body { 
    New-CpuLimit     -MaxCputime 2 -ProcessName firefox 
}
Start-Chaos -StartAfter 15 -StopAfter 10  -Body { 
    New-MemoryLimit  -MaxPrivateMemory 200 -ProcessName firefox 
}

run the script

PS> ./yourscriptname.ps1

complete code (TestBench.ps1 in src folder)

Import-Module src\ChaosContainer.psm1

Start-Chaos -StartAfter 0 -StopAfter 1 -Body { 
    New-RandomKill   -Probability 2 -ProcessName firefox 
}
Start-Chaos -StartAfter 5 -StopAfter 1 -Body { 
    New-CpuLimit     -MaxCputime 2 -ProcessName firefox 
}
Start-Chaos -StartAfter 15 -StopAfter 10 -Body { 
    New-MemoryLimit  -MaxPrivateMemory 200 -ProcessName firefox 
}