package org.jgroups.protocols;
import org.jgroups.*;
import org.jgroups.Event;
import org.jgroups.annotations.*;
import org.jgroups.stack.Protocol;
import org.jgroups.util.Util;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import java.util.*;
import java.util.List;
/**
* Discards up or down messages based on a percentage; e.g., setting property 'up' to 0.1 causes 10%
* of all up messages to be discarded. Setting 'down' or 'up' to 0 causes no loss, whereas 1 discards
* all messages (not very useful).
*/
@Unsupported
@MBean(description="Discards messages")
public class DISCARD extends Protocol {
@Property
double up=0.0; // probability of dropping up msgs
@Property
double down=0.0; // probability of dropping down msgs
@Property
boolean excludeItself=true; // if true don't discard messages sent/received in this stack
Address localAddress;
@ManagedAttribute(description="Number of dropped down messages",name="droppedDownMessages")
int num_down=0;
@ManagedAttribute(description="Number of dropped up messages",name="droppedUpMessages")
int num_up=0;
final Set<Address> ignoredMembers = new HashSet<Address>();
final Collection<Address> members=new ArrayList<Address>();
@Property(description="drop all messages (up or down)",writable=true)
boolean discard_all=false;
@Property(description="Number of subsequent unicasts to drop in the down direction",writable=true)
int drop_down_unicasts=0;
@Property(description="Number of subsequent multicasts to drop in the down direction",writable=true)
int drop_down_multicasts=0;
private DiscardDialog discard_dialog=null;
@Property(name="gui", description="use a GUI or not")
protected boolean use_gui=false;
public boolean isDiscardAll() {
return discard_all;
}
public void setDiscardAll(boolean discard_all) {
this.discard_all=discard_all;
}
public boolean isExcludeItself() {
return excludeItself;
}
public void setLocalAddress(Address localAddress){
this.localAddress =localAddress;
if(discard_dialog != null)
discard_dialog.setTitle(localAddress != null? localAddress.toString() : "n/a");
}
public void setExcludeItself(boolean excludeItself) {
this.excludeItself=excludeItself;
}
public double getUpDiscardRate() {
return up;
}
public void setUpDiscardRate(double up) {
this.up=up;
}
public double getDownDiscardRate() {
return down;
}
public void setDownDiscardRate(double down) {
this.down=down;
}
public int getDropDownUnicasts() {
return drop_down_unicasts;
}
/**
* Drop the next N unicasts down the stack
* @param drop_down_unicasts
*/
public void setDropDownUnicasts(int drop_down_unicasts) {
this.drop_down_unicasts=drop_down_unicasts;
}
public int getDropDownMulticasts() {
return drop_down_multicasts;
}
public void setDropDownMulticasts(int drop_down_multicasts) {
this.drop_down_multicasts=drop_down_multicasts;
}
/** Messages from this sender will get dropped */
public void addIgnoreMember(Address sender) {ignoredMembers.add(sender);}
public void removeIgnoredMember(Address member) {ignoredMembers.remove(member);}
public void resetIgnoredMembers() {ignoredMembers.clear();}
@ManagedOperation
public void startGui() {
if(discard_dialog == null) {
discard_dialog=new DiscardDialog();
discard_dialog.init();
discard_dialog.setTitle(localAddress != null? localAddress.toString() : "n/a");
discard_dialog.handleView(members);
}
}
@ManagedOperation
public void stopGui() {
if(discard_dialog != null)
discard_dialog.dispose();
discard_dialog=null;
}
public void start() throws Exception {
super.start();
if(use_gui) {
discard_dialog=new DiscardDialog();
discard_dialog.init();
}
}
public void stop() {
super.stop();
if(discard_dialog != null)
discard_dialog.dispose();
}
public Object up(Event evt) {
Message msg;
double r;
if(evt.getType() == Event.SET_LOCAL_ADDRESS) {
localAddress=(Address)evt.getArg();
if(discard_dialog != null)
discard_dialog.setTitle("Discard dialog (" + localAddress + ")");
}
if(evt.getType() == Event.MSG) {
msg=(Message)evt.getArg();
Address sender=msg.getSrc();
if(discard_all && !sender.equals(localAddress)) {
return null;
}
DiscardHeader dh = (DiscardHeader) msg.getHeader(this.id);
if (dh != null) {
ignoredMembers.clear();
ignoredMembers.addAll(dh.dropMessages);
if (log.isTraceEnabled())
log.trace("will potentially drop messages from " + ignoredMembers);
} else {
boolean dropMessage=ignoredMembers.contains(sender);
if (dropMessage) {
if (log.isTraceEnabled())
log.trace(localAddress + ": dropping message from " + sender);
num_up++;
return null;
}
if (up > 0) {
r = Math.random();
if (r < up) {
if (excludeItself && sender.equals(localAddress)) {
if (log.isTraceEnabled())
log.trace("excluding itself");
} else {
if (log.isTraceEnabled())
log.trace(localAddress + ": dropping message from " + sender);
num_up++;
return null;
}
}
}
}
}
return up_prot.up(evt);
}
public Object down(Event evt) {
Message msg;
double r;
switch(evt.getType()) {
case Event.MSG:
msg=(Message)evt.getArg();
Address dest=msg.getDest();
boolean multicast=dest == null;
if(msg.getSrc() == null)
msg.setSrc(localAddress);
if(discard_all) {
if(dest == null || dest.equals(localAddress)) {
//System.out.println("[" + localAddress + "] down(): looping back " + msg + ", hdrs:\n" + msg.getHeaders());
loopback(msg);
}
return null;
}
if(!multicast && drop_down_unicasts > 0) {
drop_down_unicasts=Math.max(0, drop_down_unicasts -1);
return null;
}
if(multicast && drop_down_multicasts > 0) {
drop_down_multicasts=Math.max(0, drop_down_multicasts -1);
return null;
}
if(down > 0) {
r=Math.random();
if(r < down) {
if(excludeItself && msg.getSrc().equals(localAddress)) {
if(log.isTraceEnabled()) log.trace("excluding itself");
}
else {
if(log.isTraceEnabled())
log.trace("dropping message");
num_down++;
return null;
}
}
}
break;
case Event.VIEW_CHANGE:
View view=(View)evt.getArg();
List<Address> mbrs=view.getMembers();
members.clear();
members.addAll(mbrs);
ignoredMembers.retainAll(mbrs); // remove all non members
if(discard_dialog != null)
discard_dialog.handleView(mbrs);
break;
case Event.SET_LOCAL_ADDRESS:
localAddress=(Address)evt.getArg();
if(discard_dialog != null)
discard_dialog.setTitle("Discard dialog (" + localAddress + ")");
break;
}
return down_prot.down(evt);
}
private void loopback(Message msg) {
final Message rsp=msg.copy(true);
if(rsp.getSrc() == null)
rsp.setSrc(localAddress);
// pretty inefficient: creates one thread per message, okay for testing only
Thread thread=new Thread(new Runnable() {
public void run() {
up_prot.up(new Event(Event.MSG, rsp));
}
});
thread.start();
}
public void resetStats() {
super.resetStats();
num_down=num_up=0;
}
public static class DiscardHeader extends Header {
private final Set<Address> dropMessages;
public DiscardHeader() {
this.dropMessages= new HashSet<Address>();
}
public DiscardHeader(Set<Address> ignoredAddresses) {
super();
this.dropMessages= ignoredAddresses;
}
public void readFrom(DataInput in) throws Exception {
int size = in.readShort();
if (size > 0) {
dropMessages.clear();
for (int i = 0; i < size; i++) {
dropMessages.add(Util.readAddress(in));
}
}
}
public void writeTo(DataOutput out) throws Exception {
if (dropMessages != null && !dropMessages.isEmpty()) {
out.writeShort(dropMessages.size());
for (Address addr: dropMessages) {
Util.writeAddress(addr, out);
}
} else {
out.writeShort(0);
}
}
public int size() {
return (int)Util.size(dropMessages);
}
}
private class DiscardDialog extends JFrame implements ActionListener {
private JButton start_discarding_button=new JButton("start discarding");
private JButton stop_discarding_button=new JButton("stop discarding");
JPanel checkboxes=new JPanel();
private DiscardDialog() {
}
void init() {
getContentPane().setLayout(new BoxLayout(getContentPane(), BoxLayout.Y_AXIS));
checkboxes.setLayout(new BoxLayout(checkboxes, BoxLayout.Y_AXIS));
getContentPane().add(start_discarding_button);
getContentPane().add(stop_discarding_button);
start_discarding_button.addActionListener(this);
stop_discarding_button.addActionListener(this);
getContentPane().add(checkboxes);
pack();
setVisible(true);
setTitle(localAddress != null? localAddress.toString() : "n/a");
}
public void actionPerformed(ActionEvent e) {
String command=e.getActionCommand();
if(command.startsWith("start")) {
discard_all=true;
}
else if(command.startsWith("stop")) {
discard_all=false;
Component[] comps=checkboxes.getComponents();
for(Component c: comps) {
if(c instanceof JCheckBox) {
((JCheckBox)c).setSelected(false);
}
}
}
}
void handleView(Collection<Address> mbrs) {
checkboxes.removeAll();
for(final Address addr: mbrs) {
final MyCheckBox box=new MyCheckBox("discard traffic from " + addr, addr);
box.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(box.isSelected()) {
ignoredMembers.add(addr);
}
else {
ignoredMembers.remove(addr);
}
}
});
checkboxes.add(box);
}
for(Component comp: checkboxes.getComponents()) {
MyCheckBox box=(MyCheckBox)comp;
if(ignoredMembers.contains(box.mbr))
box.setSelected(true);
}
pack();
}
}
private static class MyCheckBox extends JCheckBox {
final Address mbr;
public MyCheckBox(String name, Address member) {
super(name);
this.mbr=member;
}
public String toString() {
return super.toString() + " [mbr=" + mbr + "]";
}
}
}