ns2 project in Nevada

ns2 project in Nevada

     ns2 project in Nevada the client services class uses two types of classes for

communication between clients and agents and among

agents. The agentClient provides APIs to manage, control,

and send requests for an agent and it is  ns2 project in Nevada used for direct

communication between the client and a given agent or

among agents. In addition, the agentGroup provides APIs to

manage, control, and send requests for a group of agents

using the agentClient to individually ns2 project in Nevada communicate information

to all agents in the group. For example, when a job is

initiated, the request and schedule objects are ns2 project in Nevada passed to the

agentGroup, which uses the agentClient to pass them to

individual agents. Both agentClient and agentGroup are also

used as API for developing distributed applications. When

a programming model is developed using the runtime

support environment, the interprocess ns2 project in Nevada communications are

handled in different ways. Point-to-point communications,

for example, can be implemented directly by the ns2 project in Nevada programming

model. However, if the nodes/machines involved are

not within a single cluster, the agents can assist ns2 project in Nevada the

communications by providing routing mechanisms between

the different nodes. In addition, group communications

such as broadcast and multicast can be provided by

the runtime environment rather than the programming

model to achieve efficient distribution and ns2 project in Nevada response times. The system allows multiple users to execute multiple jobs

simultaneously. To properly manage these jobs, each job

has multiple levels of identification, starting with a unique

job ID assigned by the system. The user ID and the program

name further distinguish different jobs. Within each job,

thread IDs are used to identify the remote threads of the job.

Executing user threads on remote machines ns2 project in Nevada exposes these

machines to many “alien” threats, raising security and

integrity concerns. Therefore, these machines must be

protected to ensure safe execution. Java’s default security

manager provides some level of protection by checking

operations against defined security policies ns2 project in Nevada before execution.

However, the security manager in Java has some

restrictions, thus many functions have been modified or

rewritten for our system. More specifically, two modes of

execution are used to provide a robust and secure

environment: 1. The Agent Mode in which no restrictions are

imposed. A thread running in this mode has full

control of all the resources and operations in the

system. All agents run in agent mode. 2. The User Mode in which restrictions are applied to

limit the user access to the system resources. Some

operations, such as deleting files, creating a ns2 project in Nevada subprocess,

using system calls, modifying system properties,

and writing files, are disabled in this mode.

With the security modes in place, the user processes have

full access to resources on their local machines (where the

user job was initiated), but limited and controlled access to

all remote machines’ resources (since they are running in

user mode). To provide users with access to necessary

resources for their application, the root (master) process

executes on the user’s local machine. However, the ns2 project in Nevada user has the option to override this setting and allow the root process

to execute on a remote machine; however, the application

will have limited access to the system’s resources.