oracle.toplink.remotecommand
Class DiscoveryManager

java.lang.Object
java.lang.Thread
oracle.toplink.remotecommand.DiscoveryManager

All Implemented Interfaces:

java.lang.Runnable

public class DiscoveryManager

extends java.lang.Thread

Purpose: Detects new members of a logical TopLink cluster.

Description: Each RemoteCommandManager has its own DiscoveryManager, which handles the detection of other remote command services as they become available. The DiscoveryManager is an active object (in that it extends Thread) and becomes a separate thread when it is started using startDiscovery().

Discovery is done through the use of a multicast. Each discovery manager joins the multicast group and announces itself to the group. As it receives service announcements from other discovery managers it notifies the RCM to establish connections to and from the new service.

Since:

OracleAS TopLink 10g (9.0.4)

See Also:

RemoteCommandManager, MulticastSocket

Field Summary

static int	DEFAULT_ANNOUNCEMENT_DELAY
static java.lang.String	DEFAULT_MULTICAST_GROUP Default value constants
static int	DEFAULT_MULTICAST_PORT

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

DiscoveryManager(RemoteCommandManager mgr)
Constructors to create a discvovery manager.

DiscoveryManager(java.lang.String address, int port, int delay, RemoteCommandManager mgr)

DiscoveryManager(java.lang.String address, int port, RemoteCommandManager mgr)

Method Summary

int	getAnnouncementDelay() PUBLIC: Return the amount of time in millis that the service should wait between the time that this Remote Service is available and a session announcement is sent out to other discovery managers.
java.lang.String	getMulticastGroupAddress() PUBLIC: Return the host adddress of the multicast group.
int	getMulticastPort() PUBLIC: Return the multicast port used for discovery.
boolean	isDiscoveryStopped() ADVANCED: Return true if discovery has been stopped at the time this method is called.
void	setAnnouncementDelay(int millisecondsToDelay) PUBLIC: Set the amount of time in millis that the service should wait between the time that this Remote Service is available and a session announcement is sent out to other discovery managers.
void	setMulticastGroupAddress(java.lang.String address) PUBLIC: Set the host adddress of the multicast group.
void	setMulticastPort(int port) PUBLIC: Set the multicast port used for discovery.
void	startDiscovery() ADVANCED: Announce the local service and join the cluster
void	stopDiscovery() ADVANCED: Stop accepting announcements from other services becoming available.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_MULTICAST_GROUP

public static final java.lang.String DEFAULT_MULTICAST_GROUP

Default value constants

See Also:

Constant Field Values

DEFAULT_MULTICAST_PORT

public static final int DEFAULT_MULTICAST_PORT

See Also:

Constant Field Values

DEFAULT_ANNOUNCEMENT_DELAY

public static final int DEFAULT_ANNOUNCEMENT_DELAY

See Also:

Constant Field Values

Constructor Detail

DiscoveryManager

public DiscoveryManager(RemoteCommandManager mgr)

Constructors to create a discvovery manager.

DiscoveryManager

public DiscoveryManager(java.lang.String address,
                        int port,
                        RemoteCommandManager mgr)

DiscoveryManager

public DiscoveryManager(java.lang.String address,
                        int port,
                        int delay,
                        RemoteCommandManager mgr)

Method Detail

startDiscovery

public void startDiscovery()

ADVANCED: Announce the local service and join the cluster

stopDiscovery

public void stopDiscovery()

ADVANCED: Stop accepting announcements from other services becoming available. Note that this does not remove the local service from the cluster.

isDiscoveryStopped

public boolean isDiscoveryStopped()

ADVANCED: Return true if discovery has been stopped at the time this method is called. If false is returned then it is undefined whether discovery is started or stopped. It may be started, or it may be in the process of starting or stopping.

setAnnouncementDelay

public void setAnnouncementDelay(int millisecondsToDelay)

PUBLIC: Set the amount of time in millis that the service should wait between the time that this Remote Service is available and a session announcement is sent out to other discovery managers. This may be needed to give some systems more time to post their connections into the naming service. Takes effect the next time listening is started.

getAnnouncementDelay

public int getAnnouncementDelay()

PUBLIC: Return the amount of time in millis that the service should wait between the time that this Remote Service is available and a session announcement is sent out to other discovery managers.

getMulticastGroupAddress

public java.lang.String getMulticastGroupAddress()

PUBLIC: Return the host adddress of the multicast group.

setMulticastGroupAddress

public void setMulticastGroupAddress(java.lang.String address)

PUBLIC: Set the host adddress of the multicast group. Takes effect the next time listening is started.

setMulticastPort

public void setMulticastPort(int port)

PUBLIC: Set the multicast port used for discovery. Takes effect the next time listening is started.

getMulticastPort

public int getMulticastPort()

PUBLIC: Return the multicast port used for discovery.