Escaping DLL Hell

João Bragança//github.com/thefringeninja//the.fringe.ninja/blog@thefringeninja

eVision SoftwareSafety Software for Oil & GasDen Haag, Netherlands//evision-software.com

Computing circa 1992●Premium PC

o486 DX2o16 MB Ramo$3-$5k

Computing circa 1992●Premium PC

o486 DX2o16 MB Ramo$3-$5k

●Windows 3.1

Computing circa 1992●Premium PC

o486 DX2o16 MB Ramo$3-$5k

●Windows 3.1●Extremely Limited by Today’s Standards

Computing circa 1992●Premium PC

o486 DX2o16 MB Ramo$3-$5k

●Windows 3.1●Extremely Limited by Today’s Standards●Shared Memory

2001 - .NET Framework 1.0●AppDomain

2001 - .NET Framework 1.0●AppDomain●Global Assembly Cache

Problems●Pain of Manually Loading Assemblies

Problems●Pain of Manually Loading Assemblies●Must use Child AppDomain + Marshalling

Problems●Pain of Manually Loading Assemblies●Must use Child AppDomain + Marshalling●Strong Naming

Escaping DLL GAC Hell

2010 - .Net Package Managers●OpenWrap

2010 - .Net Package Managers●OpenWrap●NuPack

2010 - .Net Package Managers●OpenWrap●NuPack●NuGet

Problems●Assembly Binding Redirect - Never Works

Right

Problems●Assembly Binding Redirect - Never Works

Right●Requires SemVer be Followed - It Isn’t

Problems●Assembly Binding Redirect - Never Works

Right●Requires SemVer be Followed - It Isn’t●Strong Naming (again)

Escaping DLL GAC Nuget Hell

Escaping DLL GAC Nuget Hell

SHARED DEPENDENCIES

Solution

(Some) Upfront Design

Solution

Service Oriented Architecture

Service Oriented Architecture●CORBA

Service Oriented Architecture●CORBA●DCOM

Service Oriented Architecture●CORBA●DCOM●Web Services (WCF)

Service Oriented Architecture●CORBA●DCOM●Web Services (WCF)●Micro Services

Service Oriented Architecture●CORBA●DCOM●Web Services (WCF)●Micro Services●Nano Services

Service Oriented Architecture●CORBA●DCOM●Web Services (WCF)●Micro Services●Nano Services●Femto Services

Service Oriented Architecture●CORBA●DCOM●Web Services (WCF)●Micro Services●Nano Services●Femto Services

Service Oriented Architecture●CORBA●DCOM●Web Services (WCF)●Micro Services●Nano Services●Femto Services

Service Oriented ArchitectureJust Services.

Service Oriented Architecture●[A Service is] a logical representation of a

repeatable business activity that has a specified outcome

Service Oriented Architecture●[A Service is] a logical representation of a

repeatable business activity that has a specified outcome

●Is self-contained

Service Oriented Architecture●[A Service is] a logical representation of a

repeatable business activity that has a specified outcome

●Is self-contained●May be composed of other services

Service Oriented Architecture●[A Service is] a logical representation of a

repeatable business activity that has a specified outcome

●Is self-contained●May be composed of other services●Is a “black box” to consumers of the service

Service Oriented Architecture●[A Service is] a logical representation of a

repeatable business activity that has a specified outcome

●Is self-contained●May be composed of other services●Is a “black box” to consumers of the service●These are just fancy words for “a function.”

Service Oriented Architecturepublic delegate Task<decimal> GetAccountBalance(string accountNumber)

Service Oriented Architecture●Use these functions for inter-component

communication

Service Oriented Architecture●Use these functions for inter-component

communication●Keep boundaries crisp

Onion Architecture

Solution

Onion Architecture

Onion Architecture●Center Takes No Dependencies

Onion Architecture●Center Takes No Dependencies●Ports and Adapters

Onion Architecture●Center Takes No Dependencies●Ports and Adapters●Dependencies Point Inwards

Onion Architecture●Center Takes No Dependencies●Ports and Adapters●Dependencies Point Inwards●Keep Implementations on the Outside

oDatabaseoHttp

OWIN

Solution

OWIN●The only dependency is on mscorlib.

OWINAppFunc:

Func<IDictionary<string, object>, Task>

MidFunc:Func<AppFunc, AppFunc>

OWIN●The only dependency is on mscorlib●Reduces Δ between production and

development

OWIN●The only dependency is on mscorlib.●Reduces Δ between production and

development●Fast integration tests - possible to test entire

pipeline in memory

ILMerge / ILRepack

Solution

ILMerge / ILRepack●Merges multiple assemblies into one

ILMerge / ILRepack●Merges multiple assemblies into one●Internalization

ILMerge / ILRepack●Merges multiple assemblies into one●Internalization●Virtually eliminates shared dependency

problem

Source Packages

Solution

Source Packages●SimpleJson

Source Packages●SimpleJson●LibLog

Source Packages●SimpleJson●LibLog●netfx-Guard

Putting it Together

Solution

Putting it Together

Sales

Putting it Together

Sales Ware-house

Putting it Together

Sales Ware-house

GetInventoryCountFunc<string, Task<int>>

IsItemAvailableFunc<string, int, Task<bool>>

Putting it Together

Sales Ware-house

GetInventoryCountFunc<string, string,

Task<int>>

IsItemAvailableFunc<string, int, Task<bool>>

Questions?

Resources●//github.com/gluck/il-repack●//owin.org●//github.com/damianh/LimitsMiddleware●//github.com/damianh/LibLog

João Bragança//github.com/thefringeninja//the.fringe.ninja/blog@thefringeninja