edu.jhu.cnds.Frugal
Class FrugalManagerServer

java.lang.Object
  |
  +--java.rmi.server.RemoteObject
        |
        +--java.rmi.server.RemoteServer
              |
              +--java.rmi.server.UnicastRemoteObject
                    |
                    +--edu.jhu.cnds.Frugal.FrugalManagerServer

public class FrugalManagerServer

extends java.rmi.server.UnicastRemoteObject

implements FrugalServiceRemote

A server class, designed to register Frugal Manager implementations with lookup services.

This class also takes responsibility for updating Frugal Resource classes with information about the global maximum load and the number of Frugal Resources available. Obviously, the Frugal Manager defines the global state relative to the lookup services and groups it monitors itself. If there are several FrugalManagerServers running, viewing different but intersecting sets of groups and services, the Frugal Resource classes they manage in common can display inconsistent information. The Frugal Managers will continue to behave correctly relative to the world they know of. Frugal Resources have no functional reason to monitor the lookup services. They use the global state only to display their cost to users using lookup browsers. Therefore, this behavior is not likely to change.

Version:

2.0

Author:

R. Sean Borgstrom

See Also:

Serialized Form

Field Summary

protected net.jini.lookup.JoinManager	isabella Workhorse server class from Sun.
protected net.jini.lease.LeaseRenewalManager	serviceLease LeaseRenewalManager for this class' leases.

Fields inherited from class java.rmi.server.RemoteObject

ref

Constructor Summary

FrugalManagerServer(java.lang.String[] argv)
Loads persistent data, creates an implementation of the Frugal Manager service, and registers it.

Method Summary

void	checkpoint() Saves recent changes to this class' persistent data.
void	dock() Kills the service.
java.lang.Object	getAdmin() Returns an administrative interface for the relevant Frugal Manager.
net.jini.lookup.JoinManager	getIsabella() Returns this class' JoinManager.
java.io.File	getMonument() Returns the persistent storage for this server.
protected void	inform(FrugalResourceRemote r) Informs a Frugal Resource of the global state.
static void	main(java.lang.String[] argv) Starts the server running.
void	setMonument(java.io.File monument) Sets the persistent storage for this server.
protected void	startAdjutant() Initializes a FrugalManagerEars class that watches for Frugal Resources.
protected void	update() Updates known Frugal Resources every minute with information about the global state.

Methods inherited from class java.rmi.server.UnicastRemoteObject

clone, exportObject, exportObject, exportObject, unexportObject

Methods inherited from class java.rmi.server.RemoteServer

getClientHost, getLog, setLog

Methods inherited from class java.rmi.server.RemoteObject

equals, getRef, hashCode, toString, toStub

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

serviceLease

protected transient net.jini.lease.LeaseRenewalManager serviceLease

LeaseRenewalManager for this class' leases.

isabella

protected net.jini.lookup.JoinManager isabella

Workhorse server class from Sun.

Constructor Detail

FrugalManagerServer

public FrugalManagerServer(java.lang.String[] argv)
                    throws java.io.IOException,
                           java.lang.ClassNotFoundException,
                           java.rmi.RemoteException

Loads persistent data, creates an implementation of the Frugal Manager service, and registers it.

Parameters:

argv - These should be the same arguments as those passed to main.

Method Detail

main

public static void main(java.lang.String[] argv)

Starts the server running. Invoke with -f [logfile] on the first execution to create the persistent storage logfile and store a unique ID string. Otherwise, invoke with [logfile] to read from persistent storage.

Parameters:

argv - List of command-line argument strings.

startAdjutant

protected void startAdjutant()
                      throws java.rmi.RemoteException

Initializes a FrugalManagerEars class that watches for Frugal Resources.

update

protected void update()
               throws java.io.IOException

Updates known Frugal Resources every minute with information about the global state. Two Managers accessing different groups and lookup services will have different pictures of the global state. In this case, the entry beans of various Frugal Resources might display inconsistent information. However, the Managers will not behave inconsistently - their behavior remains correct.

dock

public void dock()

Kills the service.

getMonument

public java.io.File getMonument()

Returns the persistent storage for this server.

Returns:

The file where the server stores its ID and other persistent attributes.

setMonument

public void setMonument(java.io.File monument)

Sets the persistent storage for this server.

Parameters:

monument - The new persistent storage location.

getIsabella

public net.jini.lookup.JoinManager getIsabella()

Returns this class' JoinManager.

Returns:

A workhorse class for service registration.

getAdmin

public java.lang.Object getAdmin()
                          throws java.rmi.RemoteException

Returns an administrative interface for the relevant Frugal Manager.

Returns:

An administrative interface for the relevant Frugal Manager.

checkpoint

public void checkpoint()
                throws java.io.IOException,
                       java.lang.ClassNotFoundException

Saves recent changes to this class' persistent data.

inform

protected void inform(FrugalResourceRemote r)
               throws java.rmi.RemoteException

Informs a Frugal Resource of the global state.

Parameters:

r - A Frugal Resource that may not yet know the global state.