org.directwebremoting.impl
Class ThreadDroppingServerLoadMonitor

java.lang.Object
  org.directwebremoting.impl.AbstractServerLoadMonitor
      org.directwebremoting.impl.ThreadDroppingServerLoadMonitor

All Implemented Interfaces:

ServerLoadMonitor

public class ThreadDroppingServerLoadMonitor
extends AbstractServerLoadMonitor
implements ServerLoadMonitor

A smart implementation of ServerLoadMonitor, customized for Jetty. The ThreadDroppingServerLoadMonitor attempts to keep the hit rate down by increasing the disconnected time as usage increases.

Author:

Joe Walker [joe at getahead dot org]

Field Summary

protected int	connectedTime The time we are currently waiting before sending a browser away and asking it to reconnect.
protected int	disconnectedTime How long are we telling users to wait before they come back next
protected HitMonitor	hitMonitor Our record of the server loading
protected int	maxHitsPerSecond Static configuration data: The max number of hits per second.
protected java.util.Random	random We ask clients to wait a random number of millis before they come back to avoid killing the server
protected static int	SECONDS_MONITORED We are recording the number of hits in the last 5 seconds.

Fields inherited from class org.directwebremoting.impl.AbstractServerLoadMonitor

waitControllers

Constructor Summary

ThreadDroppingServerLoadMonitor()

Method Summary

long	getConnectedTime() What's the longest time that we should wait before asking the client to reconnect?
int	getDisconnectedTime() Controller for poll times.
void	setMaxHitsPerSecond(int maxHitsPerSecond)
void	threadWaitEnding(WaitController controller) A thread has just ended a wait period.
void	threadWaitStarting(WaitController controller) A thread is about to begin a wait period.

Methods inherited from class org.directwebremoting.impl.AbstractServerLoadMonitor

shutdown, shutdownRandomWaitControllers

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.directwebremoting.extend.ServerLoadMonitor

shutdown

Field Detail

maxHitsPerSecond

protected int maxHitsPerSecond

Static configuration data: The max number of hits per second. We increase the poll time to compensate and reduce the load. If this number is not at least half maxWaitingThreads then the USAGE_HIGH mode will not exist and the system will sublime from USAGE_LOW to USAGE_DIGG

random

protected java.util.Random random

We ask clients to wait a random number of millis before they come back to avoid killing the server

connectedTime

protected int connectedTime

The time we are currently waiting before sending a browser away and asking it to reconnect.

disconnectedTime

protected int disconnectedTime

How long are we telling users to wait before they come back next

SECONDS_MONITORED

protected static final int SECONDS_MONITORED

We are recording the number of hits in the last 5 seconds. Maybe we should think about making this configurable.

See Also:

Constant Field Values

hitMonitor

protected HitMonitor hitMonitor

Our record of the server loading

Constructor Detail

ThreadDroppingServerLoadMonitor

public ThreadDroppingServerLoadMonitor()

Method Detail

getConnectedTime

public long getConnectedTime()

Description copied from interface: ServerLoadMonitor

What's the longest time that we should wait before asking the client to reconnect?

Specified by:

getConnectedTime in interface ServerLoadMonitor

Returns:

The maximum client connected time

getDisconnectedTime

public int getDisconnectedTime()

Description copied from interface: ServerLoadMonitor

Controller for poll times.

TODO: We should probably get rid of this and leave it to PollHandler?

Specified by:

getDisconnectedTime in interface ServerLoadMonitor

Returns:

How long should this client wait until it next polls?

threadWaitStarting

public void threadWaitStarting(WaitController controller)

Description copied from interface: ServerLoadMonitor

A thread is about to begin a wait period. This can be used by implementations to dynamically adjust the poll timings.

Specified by:

threadWaitStarting in interface ServerLoadMonitor

Overrides:

threadWaitStarting in class AbstractServerLoadMonitor

Parameters:

controller - An object that we can use to control the wait

threadWaitEnding

public void threadWaitEnding(WaitController controller)

Description copied from interface: ServerLoadMonitor

A thread has just ended a wait period. This can be used by implementations to dynamically adjust the poll timings.

Specified by:

threadWaitEnding in interface ServerLoadMonitor

Overrides:

threadWaitEnding in class AbstractServerLoadMonitor

Parameters:

controller - An object that we can use to control the wait

setMaxHitsPerSecond

public void setMaxHitsPerSecond(int maxHitsPerSecond)

Parameters:

maxHitsPerSecond - the maxHitsPerSecond to set