org.qbroker.cluster

Class SerialPortNode

java.lang.Object

org.qbroker.cluster.SerialPortNode

All Implemented Interfaces:

java.lang.Runnable, ClusterNode

public class SerialPortNode
extends java.lang.Object
implements ClusterNode, java.lang.Runnable

SerialPortNode is a two-node cluster on a serial communication port. The cluster contains only 2 SerialPortNodes communicating with each other via serial line. One of the nodes is the manager that supervises the entire group or cluster. The other node is the worker reporting to the manager and watching its behavior closely. In case that the manager quits or the node misses certain number of heartbeats from the manager, the worker node will take over to be the new manager and resumes to work. Any new node can join the group anytime as long as there is a room available in the group. Any worker can leave the group anytime freely. If the last node quits, the cluster goes down.

SerialPortNode is supposed to run at backgroud. It is designed to be a black automaton box. It will automatically maitain the state of the cluster. But if the outLink is defined, it will also send the state information and relays the data. The applicarion on the node can send data to any node via the API of relay().

A SerialPortNode may be in one of the following states:
NODE_NEW: just starting up, not joining the cluster yet
NODE_RUNNING: joined in the cluster and running OK
NODE_STANDBY: joined in the cluster but still in transient state
NODE_TIMEOUT: missed a fixed number of heartbeats from the node
NODE_DOWN: no longer active

Author:

yannanlu@yahoo.com

Field Summary

Fields inherited from interface org.qbroker.cluster.ClusterNode

ACTION_ADD, ACTION_CHK, ACTION_DEL, ACTION_IGR, ACTION_MOD, ACTION_OVR, ACTION_VOTE, DEBUG_ALL, DEBUG_CHECK, DEBUG_CLOSE, DEBUG_EXAM, DEBUG_HBEAT, DEBUG_INIT, DEBUG_NONE, DEBUG_RELAY, HB_ECOUNT, HB_ETIME, HB_PCOUNT, HB_PTIME, HB_SIZE, HB_TYPE, NODE_DOWN, NODE_NEW, NODE_RUNNING, NODE_STANDBY, NODE_TIMEOUT, RCVR_COMM, RCVR_JMS, RCVR_NONE, RCVR_TCP, RCVR_UDP

Constructor Summary

Constructors

Constructor and Description
SerialPortNode(java.util.Map props)

Method Summary

Modifier and Type	Method and Description
void	close() closes the node and all resources
int	getDebug() returns the debug mode of the node
int	getRole() returns the role of the node
int	getSize() returns the size of the cluster
int	getStatus() returns the status of the node
int	getTimeout() returns the sessionTimeout of the node
java.lang.String	getURI() returns the URI of the node
boolean	isMaster()
static void	main(java.lang.String[] args)
int	relay(Event data, int waitTime) It is the API for application to send data to the node or group asynchronously.
void	run()
void	setDebug(int debug) sets the debug mode of the node
void	start() It starts the cluster node and supervises its state.
void	start(XQueue out, int begin, int len) It starts the cluster node and supervises its state.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SerialPortNode

public SerialPortNode(java.util.Map props)

Method Detail

run

public void run()

Specified by:

run in interface java.lang.Runnable

close

public void close()

Description copied from interface: ClusterNode

closes the node and all resources

Specified by:

close in interface ClusterNode

relay

public int relay(Event data,
                 int waitTime)

It is the API for application to send data to the node or group asynchronously. It returns a non-negative number for success, or -1 otherwise.

Specified by:

relay in interface ClusterNode

isMaster

public boolean isMaster()

Specified by:

isMaster in interface ClusterNode

getRole

public int getRole()

Description copied from interface: ClusterNode

returns the role of the node

Specified by:

getRole in interface ClusterNode

getStatus

public int getStatus()

Description copied from interface: ClusterNode

returns the status of the node

Specified by:

getStatus in interface ClusterNode

getTimeout

public int getTimeout()

Description copied from interface: ClusterNode

returns the sessionTimeout of the node

Specified by:

getTimeout in interface ClusterNode

getURI

public java.lang.String getURI()

Description copied from interface: ClusterNode

returns the URI of the node

Specified by:

getURI in interface ClusterNode

getSize

public int getSize()

Description copied from interface: ClusterNode

returns the size of the cluster

Specified by:

getSize in interface ClusterNode

getDebug

public int getDebug()

Description copied from interface: ClusterNode

returns the debug mode of the node

Specified by:

getDebug in interface ClusterNode

setDebug

public void setDebug(int debug)

Description copied from interface: ClusterNode

sets the debug mode of the node

Specified by:

setDebug in interface ClusterNode

start

public void start()

It starts the cluster node and supervises its state.

start

public void start(XQueue out,
                  int begin,
                  int len)

It starts the cluster node and supervises its state. With the communication XQueue defined, the cluster node will escalate or relay events to/from external caller via the XQueue. The cluster node will keep running until its shutdown.

Specified by:

start in interface ClusterNode

main

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