ClusterNode

All Known Implementing Classes:

PacketNode, SerialPortNode, UnicastNode
```
public interface ClusterNode
```
ClusterNode is an automaton node of a cluster. The cluster may contain many nodes or members communicating with each other via the network. One of the nodes is the manager that supervises the entire cluster. The rest of nodes are workers or monitors reporting to the manager and watching its behavior closely. In case that the manager quits or any node misses certain number of heartbeats from the manager, the rest of the workers will elect a new manager and resume to work. Any new node can join the cluster anytime as long as it is allowed and there is a room available in the cluster. Any worker can leave the cluster anytime at its wish. If the last member quits, the cluster goes down.

ClusterNode is supposed to run at backgroud. It is required to be an automaton that maintains its own state according to certain predefined rules automatically. It communicates with outside through an XQueue and APIs via Events. The application is supposed to listen to the XQueue to monitor the status of the cluster. To actively control the cluster, application should use relay() API to pass opaque data or instructions. ClusterNode is supposed to be able to intercept the instructions or relay the data to the cluster or other nodes.

A ClusterNode 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NODE_DOWN: no longer active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
Modifier and Type	Field and Description
`static int`	`ACTION_ADD`
`static int`	`ACTION_CHK`
`static int`	`ACTION_DEL`
`static int`	`ACTION_IGR`
`static int`	`ACTION_MOD`
`static int`	`ACTION_OVR`
`static int`	`ACTION_VOTE`
`static int`	`DEBUG_ALL`
`static int`	`DEBUG_CHECK`
`static int`	`DEBUG_CLOSE`
`static int`	`DEBUG_EXAM`
`static int`	`DEBUG_HBEAT`
`static int`	`DEBUG_INIT`
`static int`	`DEBUG_NONE`
`static int`	`DEBUG_RELAY`
`static int`	`HB_ECOUNT`
`static int`	`HB_ETIME`
`static int`	`HB_PCOUNT`
`static int`	`HB_PTIME`
`static int`	`HB_SIZE`
`static int`	`HB_TYPE`
`static int`	`NODE_DOWN`
`static int`	`NODE_NEW`
`static int`	`NODE_RUNNING`
`static int`	`NODE_STANDBY`
`static int`	`NODE_TIMEOUT`
`static int`	`RCVR_COMM`
`static int`	`RCVR_JMS`
`static int`	`RCVR_NONE`
`static int`	`RCVR_TCP`
`static int`	`RCVR_UDP`

Method Summary

All Methods Instance Methods Abstract Methods
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()`
`int`	`relay(Event data, int waitTime)` It is the API to for application to send data to the cluster asynchronously.
`void`	`setDebug(int mode)` sets the debug mode of the node
`void`	`start(XQueue out, int begin, int len)` It starts the cluster node with partitioned XQueue as the escalation channel, and supervises the cluster.

- Field Detail
  - NODE_NEW
```
static final int NODE_NEW
```
    See Also:
    
    Constant Field Values
  - NODE_RUNNING
```
static final int NODE_RUNNING
```
    See Also:
    
    Constant Field Values
  - NODE_STANDBY
```
static final int NODE_STANDBY
```
    See Also:
    
    Constant Field Values
  - NODE_TIMEOUT
```
static final int NODE_TIMEOUT
```
    See Also:
    
    Constant Field Values
  - NODE_DOWN
```
static final int NODE_DOWN
```
    See Also:
    
    Constant Field Values
  - RCVR_NONE
```
static final int RCVR_NONE
```
    See Also:
    
    Constant Field Values
  - RCVR_COMM
```
static final int RCVR_COMM
```
    See Also:
    
    Constant Field Values
  - RCVR_UDP
```
static final int RCVR_UDP
```
    See Also:
    
    Constant Field Values
  - RCVR_TCP
```
static final int RCVR_TCP
```
    See Also:
    
    Constant Field Values
  - RCVR_JMS
```
static final int RCVR_JMS
```
    See Also:
    
    Constant Field Values
  - HB_SIZE
```
static final int HB_SIZE
```
    See Also:
    
    Constant Field Values
  - HB_TYPE
```
static final int HB_TYPE
```
    See Also:
    
    Constant Field Values
  - HB_PCOUNT
```
static final int HB_PCOUNT
```
    See Also:
    
    Constant Field Values
  - HB_ECOUNT
```
static final int HB_ECOUNT
```
    See Also:
    
    Constant Field Values
  - HB_PTIME
```
static final int HB_PTIME
```
    See Also:
    
    Constant Field Values
  - HB_ETIME
```
static final int HB_ETIME
```
    See Also:
    
    Constant Field Values
  - ACTION_MOD
```
static final int ACTION_MOD
```
    See Also:
    
    Constant Field Values
  - ACTION_ADD
```
static final int ACTION_ADD
```
    See Also:
    
    Constant Field Values
  - ACTION_DEL
```
static final int ACTION_DEL
```
    See Also:
    
    Constant Field Values
  - ACTION_OVR
```
static final int ACTION_OVR
```
    See Also:
    
    Constant Field Values
  - ACTION_IGR
```
static final int ACTION_IGR
```
    See Also:
    
    Constant Field Values
  - ACTION_CHK
```
static final int ACTION_CHK
```
    See Also:
    
    Constant Field Values
  - ACTION_VOTE
```
static final int ACTION_VOTE
```
    See Also:
    
    Constant Field Values
  - DEBUG_NONE
```
static final int DEBUG_NONE
```
    See Also:
    
    Constant Field Values
  - DEBUG_INIT
```
static final int DEBUG_INIT
```
    See Also:
    
    Constant Field Values
  - DEBUG_EXAM
```
static final int DEBUG_EXAM
```
    See Also:
    
    Constant Field Values
  - DEBUG_CHECK
```
static final int DEBUG_CHECK
```
    See Also:
    
    Constant Field Values
  - DEBUG_RELAY
```
static final int DEBUG_RELAY
```
    See Also:
    
    Constant Field Values
  - DEBUG_CLOSE
```
static final int DEBUG_CLOSE
```
    See Also:
    
    Constant Field Values
  - DEBUG_HBEAT
```
static final int DEBUG_HBEAT
```
    See Also:
    
    Constant Field Values
  - DEBUG_ALL
```
static final int DEBUG_ALL
```
    See Also:
    
    Constant Field Values
- Method Detail
  - start
```
void start(XQueue out,
           int begin,
           int len)
```
    It starts the cluster node with partitioned XQueue as the escalation channel, and supervises the cluster.
  - relay
```
int relay(Event data,
          int waitTime)
```
    It is the API to for application to send data to the cluster asynchronously. It returns a non-negative number for success, or -1 otherwise. Event is used to carry opaque data as the escalations or instructions. The API in turn relays the data to the cluster or the specific node. Waittime is the millisecond for the API to wait if the communication is busy.
  - close
```
void close()
```
    closes the node and all resources
  - isMaster
```
boolean isMaster()
```
  - getRole
```
int getRole()
```
    returns the role of the node
  - getStatus
```
int getStatus()
```
    returns the status of the node
  - getTimeout
```
int getTimeout()
```
    returns the sessionTimeout of the node
  - getURI
```
java.lang.String getURI()
```
    returns the URI of the node
  - getSize
```
int getSize()
```
    returns the size of the cluster
  - getDebug
```
int getDebug()
```
    returns the debug mode of the node
  - setDebug
```
void setDebug(int mode)
```
    sets the debug mode of the node

Interface ClusterNode

Field Summary

Method Summary

Field Detail

NODE_NEW

NODE_RUNNING

NODE_STANDBY

NODE_TIMEOUT

NODE_DOWN

RCVR_NONE

RCVR_COMM

RCVR_UDP

RCVR_TCP

RCVR_JMS

HB_SIZE

HB_TYPE

HB_PCOUNT

HB_ECOUNT

HB_PTIME

HB_ETIME

ACTION_MOD

ACTION_ADD

ACTION_DEL

ACTION_OVR

ACTION_IGR

ACTION_CHK

ACTION_VOTE

DEBUG_NONE

DEBUG_INIT

DEBUG_EXAM

DEBUG_CHECK

DEBUG_RELAY

DEBUG_CLOSE

DEBUG_HBEAT

DEBUG_ALL

Method Detail

start

relay

close

isMaster

getRole

getStatus

getTimeout

getURI

getSize

getDebug

setDebug