ISY 201 - Chapter 10: Management of Network Functions

Memory Management (in DO/S)

-For each node, the MM uses a kernel with a paging algorithm to track the amount of memory that's available. -On a local level, the MM allocates pages based on the local policy -Global level: it receives requests from the process manager to provide memory to new or expanding client or server processes -to control demand, the MM handles requests from the process manager to allocate and deallocate spac e based on the network's usage patterns

Process Management (in DO/S)

-provides the policies and mechanisms to create, delete, abort, name, rename, find, schedule, block, run, and synchronize -Manages the states of execution: READY, RUNNING< and WAIT -Each CPU in the network is required to have its own run-time kernel that manages the hardware -Responsible for the following tasks: creating objects, dispatching objects, scheduling objects, synchronization operations on objects, communicating among objects, and deleting objects

Sever Process

A logical unit composed of one or more device drivers, a device manager, and a network server module needed to control clusters or similar devices in a process-based, distributed operating system environment

Distributed Processing

A method of data processing in which files are stored at many different locations and in which processing takes place at different sites

Arbitration Rule

A policy that's used to resolve conflicts between jobs of equal priority. That is, it typically dictates the order in which jobs of the same priority are to be executed. Two examples of these rules are Last-in-First-Out and FIFO

Object-Based DO/S

A view of distributed OS where each hardware unit is bundled with its required operational software, forming a discrete object to be handled as an entity.\ -Clumps each type of hardware with its necessary operational software into discrete objects that are manipulated as a unit. -Views objects as *abstract entities* -In this set up, process management becomes

Process-Based DO/S

A view of distributed operating systems that encompasses all the system's processes and resources -provides process mamagement through the use of client/server process synchronized and linked together throught messages and ports -The major emphasis is on processes and messages and how they provide the basic features essential to process management, such as process creation scheduling, pausing, communications, and Identification.

Distributed Operating SYstem (DO/S)

An operating system that provides global control for a distributed computing system, allowing its resources to be managed in a unified way. -Resources owned by global OS -Local resources are managed by global OS -Access is allowed according to the policy of the global OS -Requests are passed directly from node via the OS

Object

Any one of the may entities that constitute a computer system, such as CPUs, terminals, disk drives, files or databases -Have a set of unchanging properties that defines them and their behavior within the context of their defined parameters -Identified by the set of operations one can send it

Abstract Entities

Data types that can go through a change of state, act according to set patters, be manipulated, or exist in relation to other objects in a manner appropriate to the object's semantics in the system.

Decision Mode

Determines which policies are used when scheduling a resource. -Options include preemptive, nonpreemptive, Round Robin, etc.

Priority Function

Gives the scheduling algorithm the policy that's used to assign an order to processes in the execution cycle. This priority is often determined using a calculation that's based on system characteristics, such as occurence of events, tasks recurrence, system loading levels, or program run time characteristics. -Examples of run-time characteristics are most time remaining, least time remaining, etc

Kernel Level

In an object-based distributed operating system, it provides the basic mechanisms for dynamically building parts of the OS by creating, managing, scheduling, synchronizing, and deleting objects, and it does so dynamically. -Kernel also has ultimate responsibility for the network's capability lists --Each site has a *capability manager* and a *directory* -Kernel is also responsible for process synchronization mechanisms and communication support.

Directory

Lists the location for all capabilities in the system. Guides local requests for capabilities to the sites on which they're located

Kernel

The part of the OS that resides in main memory and performs the most essential tasks, such as managing memory and handling input and output from secondary storage.

Network Operating System (NOS)

The software that manages network resources for a node on a network and may provide security and access control. -Local resources are owned by each local node -Local resources are managed by local OS -Access is allowed according to the policies of the local OS -Requests are passed from one local OS to another via the NOS

Version Control

The tracking and updating of a specific release of a piece of hardware or software.

Decision Mode, Priority Function, and Arbitration Rule

Three Parts of the Scheduling function (in Process management DO/S)

Kernel resource

To globally manage the network's entire suite of resources, a DO/S is typically constructed with a replicated ________ OS. Low level, hardware-control software (firmware) with system-level software for _________ management.

Primitives

Well-defined, predictable, low-level operating system mechanism that allow higher-level OS components to perform their functions without considering direct hardware manipulation -Such as "send and receive"

Synchronization

_________ is key in a network process management

Capability Manager

maintains the capability list for its objects