ns2 project in Tennessee

ns2 project in Tennessee

       ns2 project in Tennessee the success of this and other protocols and the proper

functionality of the agents rely on having a suitable naming

(identification) scheme for the agents. Many ns2 project in Tennessee mechanisms

can be used; however, for the system to be scalable, the

naming scheme needs to be scalable also. One suitable

scheme is the hierarchical naming used for the Internet.

Here, the leaders on the top level of the ns2 project in Tennessee hierarchy take a

common root name followed by each machine/cluster

name. The next levels use their leader’s name as a prefix

to their names. For example, assume that the ns2 project in Tennessee structure

shown in Fig. 2 belongs to UNL and, then, the top-level

leaders can be UNL.L1, UNL.L2, and UNL.L3. Leader 4 is

then called UNL.L3.L4 and the agents under leader 2, for example, are called UNL.L2.A1, UNL.L2.A2, etc. Such a

scheme, while potentially complicated for ns2 project in Tennessee a small system,

allows the system to systematically grow without any need

to change previously assigned names or the ns2 project in Tennessee naming scheme

itself. This also allows agents to use the machines’ actual

Internet URLs as their names, thus allowing ns2 project in Tennessee  easy access

through the Internet. Adopting this scheme, however,

requires some form of neighbor discovery ns2 project in Tennessee mechanism as

in IPv6 [14] to ensure the use of unique names for the

participating agents. In general, the overhead incurred in

constructing a hierarchical structure is relatively high, thus

it may not benefit a system with a small number of nodes.

However, it is essential in two environments:

1. The system is composed of multiple ns2 project in Tennessee smaller

systems (clusters, NOW, multiprocessor machines,

etc.) that do not have full connectivity to all their

nodes. Thus, the head node in each subsystem is

assigned a leader that is responsible of connecting

it to other subsystems. 2. The system includes ns2 project in Tennessee  very large clusters comprising

tens/hundreds of nodes, thus accessing all nodes in

a linear fashion is very time consuming. Here, the

threshold needs to be selected to optimize the

utilization of the suitable structure. Analytical

models or experimental evaluations can be used to

select that value. This protocol is used in case a ns2 project in Tennessee leader fails to respond to an

AM message sent by another leader. If a leader Lx at one

level times out before receiving an AMA response from

another leader, say Ly, the following steps are taken by Lx

to try to recover from the problem. 1. Lx broadcasts the problem to all other leaders at the

same level using the LNRM and informs them that it

will try to solve the problem. 2. Lx pings the node/machine where Ly resides to see

if it is connected and up. 3. If the node is still up, then a. Lx initiates a remote agent activation command

to reactivate the agent using the AAM and b. when the new agent is up, Lx activates it as a

leader and sends it all relevant leader information. The new leader, Ly, uses the startup

protocol to restore its information. 4. If the agent does not ns2 project in Tennessee reinitialize (e.g., has been

deleted from the node) or the node does not respond if a connection exists to another node in the

cluster, Lx activates that node’s agent as a

leader. The new leader then assumes ns2 project in Tennessee its new

role and updates its routing and resource

information using the startup protocol,

b. if no connection exists, Lx reports the problem to

the administrator and excludes all routing

information to the cluster led by Ly from the

routing tables.