Software Deployment and Mobility

Introduction

• Deployment is the placing of software on the hardware where it is supposed to run.

• Redeployment / migration of software components while the system is in operation is mobility.

A Wireless Sensor Network System

Deployment and Mobility Challenges

• Geographically Distributed hardware• Heterogeneity of hardware• Different configuration• Differing life span• Versioning• Partial mobility• Locating the hardware/software/service

Deployment Basic Concepts

• Software system is deployed on one or more hardware devices called hosts or sites.

• Each site provides some resources.• E.g. –– Hardware (Memory, CPU)– Network (Protocols and IP port numbers)– Peripheral Devices (hard disks and keyboard)– System Software (OS, drivers)– Other application level software (GUI builders, DB)– Data Resources (data files, GUIDs)

Deployment Basic Concepts contd.

• Software system consists of set of components and connectors.

• Multiple versions of these components and connectors may exist.

• Version is time-ordered revision, platform-specific revision or functional revision.

Deployment Activities

• Planning

• Modeling

• Analysis

• Implementation

Deployment Planning

• In planning stage we consider the behavior of the system and statistics related to that behavior.

• System should ensure certain desired system properties. ( QoS )– Dependability– Availability– Security– Fault-Tolerance– Durability , etc.

Planning Challenges

• Large no. of system parameters• Conflicting service qualities (e.g. Security vs. Efficiency)

• Services & their QoS influence user’s satisfaction

• Space of possible deployment architectures is exponentially large.– c components, h hosts -> hC possible deployments.

Space of possible deployment architectures

Dig : 1

Dig : 2

Example of Multiple Deployment Choices over 2-QoS attributes

Latency

Durability

1

5

4

3

2

1 5 4 3 2 6

Deployment 1

Deployment 2

Deployment 3

Deployment 4

Latency

1 5 4 3 2 6

• Pareto Optimal Solution

• Better-Cheaper-Faster----Pick any two !

• Automated support for deployment modeling and analysis.

Deployment Modeling• Modeling Considerations– Software system elements (components and connectors)• Configuration of these elements• Parameters

– Hardware system elements (host machines, network, devices, controllers, etc.)• Configuration• Parameters

– Set of constraints placed on these elements and/or parameters

– Formal definition of QoS dimensions of interest

Deployment Model

Deployment Analysis

• Putting efforts for Planning and Modeling is worthwhile if the model is used efficiently for deployment.

• Detailed analysis has to be done to ensure that.– Are the shortlisted deployments valid ?– Which one of them is the best ?– Does it exhibit acceptable properties ? Or must an even

better deployment be found ?– What is the best deployment possible for the given

system (Ranking of QoS)

Deployment Implementation

Software Deployment Issues

• Change Management• Dependencies among Components• Coordination• Large-scale Content Delivery• Managing Heterogeneous Platforms• Deployment Process Changeability• Integration with the Internet• Security: Privacy, Authentication, and Integrity

Tool Support

• Functions of deployment tools– Model

– Analyze

– Implement

– Monitor

– Update

DeSi

XTEAM

• Provides ADL extension for mobile systems• Implements a set of dynamic analysis on top

of the model interpreter framework• Model Interpreter framework allows the

architect to implement custom analysis techniques without knowing details of semantic mapping

XTEAM

XTEAM Deployment Model and Analysis

Software Mobility

• Physical Mobility• Code Mobility / Logical Mobility– Stateful Mobility (Strong Mobility)– Stateless Mobility (Weak Mobility)

• Code Paradigms– Fixed Code Paradigm• Client-Server

– Mobile Code Paradigm

Mobile Code Paradigms

• Remote EvaluationSource Host Destination Host

Know-how Resources

Destination Host

Source Host

Result

Know-how

Resources

• Code-on-Demand

Destination Host Source Host

Know-how Resources

Source Host

Destination Host

Result

Know-how

Resources

• Mobile AgentHost 1

Host 2

Destination Host

Know-how

Resources 1

Resources 2

State

State

Know-how

Resources 1

Architecture-based Dynamic Adaptation Model

Key Aspects

• Planning (Top Part)• Analysis (Top Part)• implementation should never be modified

without understanding the architectural implications of that modification (Bottom Part)

Code Migration Challenges

Challenges• Availability

• State Management

• Scheduling of migration

• Performance

• Locating code and resources

• Security threat

• Energy Consumption

Mobility Deployment

Maintains State No State

Downtime Not running

Choosing time of migration to maintain performance

Does not affect performance

Time constrained Allows more planning and analysis

Summary• What is Deployment and Mobility ?• Challenges• Deployment Activities– Planning, Modeling, Analysis & Implementation

• Tools Support• Mobility• Mobile Code Paradigm– Remote evaluation, C-O-D, Mobile Agent

References• A Characterization Framework for Software

Deployment Technologies – Antonio Carzaniga, Alfonso Fuggetta, Richard S. Hall,

Dennis Heimbigner, Andre van der Hoek and Alexander L. Wolf

• Software architecture and mobility A roadmap– Nenad Medvidovic, George Edwards

• An architecture-driven software mobility framework – Sam Malek, George Edwards, Yuriy Brun, Hossein

Tajalli, Joshua Garcia, Ivo Krka, Nenad Medvidovic, Marija Mikic-Rakic, Gaurav S. Sukhatme