Day-2

5/24/2000


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Table of Contents

Day-2

PPT Slide

Architecture and Object Model

Legion philosophy

Flexibility and extensibility

Legion Object Model

The object model

Core Object Classes

Host objects

Vaults

Class roles and responsibilities

For example...

Classes are objects too

Naming

Legion Object Identifiers (LOID)

Object Addresses

Binding Agents

Typical binding process

Binding failure

binding failure (2)

Legion Security “You can’t build a fence around a global system”

Flexibility

Performance

Trust

Ease of Use

Scalability

Compatibility

Access Control Predicates

Key Distribution

Security and System Configuration

Running Legion at a site

Option 1 Single Generic User

Single User Issues

Basic Issues

An Alternate Picture

Design Properties

Must be careful

Process Control Daemon (PCD) Interface

PCD Implementation

PCD Status

Option 2 - Generic Accounts

Option 3 - Use native user id

We have three choices

PCD Unix Host Object

Object Activation

Object Deactivation

New commands

Creating a PCD Host

The Care and Feeding Of a Legion System Legion 1.6.4

Outline

Before Starting a System

Starting a System

First time startup

Adding to an Existing System

Useful stuff

Other useful scripts

Shutting Down a System

Resource Management in Legion

Outline

Motivation and Philosophy

Motivation

Philosophy

Allocation via Negotiation

Allocation via Negotiation - Motivation

Realization of Allocation via Negotiation

Application-Specific Allocation

Application-Specific Allocation: Motivation

A Better Model: Application-Specific Allocation

Realization of Application-Specific Allocation

Allocation Process Model

Allocation Process

Allocation Decision Process

Legion Approach to Resource Management

Legion Approach

Legion Approach

Resource Management Layers

Resource Management Layers

PPT Slide

The Players

Legion Information Framework

Information Framework

Legion Collection Objects

Simple Collection Interface

Collections and Scheduling

Allocation Enactment

The Players: Interfaces

The Players: Interfaces (cont'd)

Placement Enactment

Steps in Object Placement

Locate Resources

Gather Description Information

Placement Decision

Implement Decision

Reflective Graph Event Model

Reflection

Self-Representation

Graphs

Implicit Parameters

Graph annotations

Events

Events

Protocol Stack

Events & Handlers

Adding new component

Events Recap

Graphs & Events

Graphs as Event Handlers

Event Remote Notification

Special case: Exception Propagation

Author: grimshaw