LoadBalancing (NetPhantom® 7.7 Java API Specification)

java.lang.Object
- se.entra.phantom.server.LoadBalancing

All Implemented Interfaces:

Runnable
```
public class LoadBalancing
extends Object
implements Runnable
```
Handles the load balancing between NetPhantom servers. One server is acting the "controller" and the others are "slaves". The slaves report their concurrent user count and configured maximum amount of users to the controller.
Whenever there is a new client request for a resource that is load balanced, the controller checks which slave (or the controller itself) for the best suited server in terms of concurrent users and maximum amount.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static void`	`dispose()` Disposes of the load balancing at server shut-down (soft or hard).
`static void`	`fillStatisticsList(VirtualCListBox list)` Fills the list box with statistics data from the load balancer.
`static String`	`getControllerHostName()` Gets the controller host name.
`static int`	`getControllerPortNumber()` Gets the port number to the controlling master server for this slave server as configured in Load Balancing for Host address and Port number.
`static int`	`getControllerPortNumber(HttpSession httpSession)` Gets the port number of the current connection that the controller server uses.
`static int`	`getControllerPortNumber(ServerSocketInterface ssi)` Gets the port number of the current connection that the controller server uses.
`static String`	`getFullControllerServerName(HttpSession httpSession)` Gets the full server
`static String`	`getFullControllerServerName(ServerSocketInterface ssi)` Gets the full controller server name.
`static String`	`getPossibleRedirection(ServerSocketInterface ssi, AdminConfigResource resConf, String resource)` Gets a possible redirection (protocol://address/...).
`static boolean`	`handleSlave(AdminCommandProcessor acp)` Handles a new load balancer slave in the controller.
`static void`	`initialize(IniFile ini)` Initializes the load balancing at web server start or restart.
`static boolean`	`isController()` Checks if the server is a controller.
`static boolean`	`isInitialized()` Checks if it's initialized.
`static boolean`	`isSlave()` Checks if a server is a load balancing slave.
`static void`	`onGroupsChanged(Hashtable<String,AdminConfigGroups> old)` Called when groups have been edited and are therefore changed.
`static void`	`onUserChanged(AdminConfigUser user)` Called when a user have been changed.
`static void`	`onUsersChanged(Hashtable<String,AdminConfigUser> old)` Called when users have been edited and are therefore changed.
`static void`	`portStarted(ClientConnectionInterface socket)` Informs the load balancer that a port is started.
`static void`	`portStopped(ClientConnectionInterface socket)` Informs the load balancer that a port is stopped (closed).
`static void`	`requestSlavePerformanceData(Hashtable<String,Object> table, int waitTime)` Request load balancing info from every slave, and in the hashtable, put the name of the slave server as the key and a "new Object()" as the element.
`void`	`run()` The notifyer thread.
`static void`	`setNpAppUsers(int currentCount, int maxCount)` Sets the number of concurrent NetPhantom application users.
`static void`	`setWebRequests(int currentCount, int maxCount)` Sets the number of concurrent Web Server requests not yet processed.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - initialize
```
public static void initialize(IniFile ini)
```
    Initializes the load balancing at web server start or restart.
  - isInitialized
```
public static boolean isInitialized()
```
    Checks if it's initialized.
  - isSlave
```
public static boolean isSlave()
```
    Checks if a server is a load balancing slave.
    
    Returns:
    
    false if service is not started.
  - isController
```
public static boolean isController()
```
    Checks if the server is a controller.
    
    Returns:
    
    false if service is not started.
  - dispose
```
public static void dispose()
```
    Disposes of the load balancing at server shut-down (soft or hard).
  - fillStatisticsList
```
public static void fillStatisticsList(VirtualCListBox list)
```
    Fills the list box with statistics data from the load balancer.
    The list contains:
```
  - Host name
  - Port ID
  - Port Number
  - Current users
  - Maximum users
 
```
  - portStarted
```
public static void portStarted(ClientConnectionInterface socket)
```
    Informs the load balancer that a port is started.
  - portStopped
```
public static void portStopped(ClientConnectionInterface socket)
```
    Informs the load balancer that a port is stopped (closed).
  - handleSlave
```
public static boolean handleSlave(AdminCommandProcessor acp)
```
    Handles a new load balancer slave in the controller. When this function returns, the slave is assumed being "not there".
    No errors are returned, because the load balancer will log the appropriate events.
    
    Returns:
    
    true for success, false for failure.
  - requestSlavePerformanceData
```
public static void requestSlavePerformanceData(Hashtable<String,Object> table,
                                               int waitTime)
```
    Request load balancing info from every slave, and in the hashtable, put the name of the slave server as the key and a "new Object()" as the element.
  - run
```
public void run()
```
    The notifyer thread.
    
    Specified by:
    
    run in interface Runnable
  - setNpAppUsers
```
public static void setNpAppUsers(int currentCount,
                                 int maxCount)
```
    Sets the number of concurrent NetPhantom application users.
  - setWebRequests
```
public static void setWebRequests(int currentCount,
                                  int maxCount)
```
    Sets the number of concurrent Web Server requests not yet processed.
  - onUserChanged
```
public static void onUserChanged(AdminConfigUser user)
```
    Called when a user have been changed. When this is called, all connected controllers and slaves are informed.
  - onUsersChanged
```
public static void onUsersChanged(Hashtable<String,AdminConfigUser> old)
```
    Called when users have been edited and are therefore changed. This function will inform all connected controllers and/or slaves.
  - onGroupsChanged
```
public static void onGroupsChanged(Hashtable<String,AdminConfigGroups> old)
```
    Called when groups have been edited and are therefore changed. This function will inform all connected controllers and/or slaves.
  - getControllerPortNumber
```
public static int getControllerPortNumber(HttpSession httpSession)
```
    Gets the port number of the current connection that the controller server uses.
    
    Returns:
    
    -1 if not a slave or is not in contact with the controller.
  - getControllerPortNumber
```
public static int getControllerPortNumber(ServerSocketInterface ssi)
```
    Gets the port number of the current connection that the controller server uses.
    
    Returns:
    
    -1 if not a slave or is not in contact with the controller.
  - getControllerPortNumber
```
public static int getControllerPortNumber()
```
    Gets the port number to the controlling master server for this slave server as configured in Load Balancing for Host address and Port number.
    
    Returns:
    
    -1 if not a slave or load balancing is not used.
  - getControllerHostName
```
public static String getControllerHostName()
```
    Gets the controller host name.
    
    Returns:
    
    null if not a slave or is not in contact with the controller.
  - getFullControllerServerName
```
public static String getFullControllerServerName(HttpSession httpSession)
```
    Gets the full server
    
    Returns:
    
    null if not a slave or is not in contact with the controller.
  - getFullControllerServerName
```
public static String getFullControllerServerName(ServerSocketInterface ssi)
```
    Gets the full controller server name.
    
    Returns:
    
    null if not a slave or is not in contact with the controller.
  - getPossibleRedirection
```
public static String getPossibleRedirection(ServerSocketInterface ssi,
                                            AdminConfigResource resConf,
                                            String resource)
```
    Gets a possible redirection (protocol://address/...). The slaves are checked for the most suited one. If the "resConf" parameter is null, the load balancing is assumed on users. Also, the returned string will be "hostname:port", typically used for redirection of NetPhantom Java Applications.
    
    Returns:
    
    null if no redirection is found.

Class LoadBalancing

Method Summary

Methods inherited from class java.lang.Object

Method Detail

initialize

isInitialized

isSlave

isController

dispose

fillStatisticsList

portStarted

portStopped

handleSlave

requestSlavePerformanceData

run

setNpAppUsers

setWebRequests

onUserChanged

onUsersChanged

onGroupsChanged

getControllerPortNumber

getControllerPortNumber

getControllerPortNumber

getControllerHostName

getFullControllerServerName

getFullControllerServerName

getPossibleRedirection