package org.jgroups.protocols;
import org.jgroups.Event;
import org.jgroups.Global;
import org.jgroups.annotations.Experimental;
import org.jgroups.annotations.LocalAddress;
import org.jgroups.annotations.Property;
import org.jgroups.conf.PropertyConverters;
import org.jgroups.stack.IpAddress;
import org.jgroups.util.Util;
import java.lang.reflect.Method;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.util.Map;
/**
* Protocol which uses InetAddress.isReachable() to check whether a given host
* is up or not, taking 1 argument; the host name of the host to be pinged.
* <em>Note that this protocol only works with JDK 5 !</em> The implementation
* of this may or may not use ICMP ! An alternative is to create a TCP
* connection to port 7 (echo service) and see whether it works ! This is
* obviously done in JDK 5, so unless an echo service is configured to run, this
* won't work...
*
* @author Bela Ban
*/
@Experimental
public class FD_ICMP extends FD {
/** network interface to be used to send the ICMP packets */
private NetworkInterface intf=null;
@LocalAddress
@Property(name="bind_addr",
description="The NIC on which the ServerSocket should listen on. " +
"The following special values are also recognized: GLOBAL, SITE_LOCAL, LINK_LOCAL and NON_LOOPBACK",
systemProperty={Global.BIND_ADDR, Global.BIND_ADDR_OLD},
defaultValueIPv4=Global.NON_LOOPBACK_ADDRESS, defaultValueIPv6=Global.NON_LOOPBACK_ADDRESS)
private InetAddress bind_addr=null ;
@Property(name="bind_interface", converter=PropertyConverters.BindInterface.class,
description="The interface (NIC) which should be used by this transport", dependsUpon="bind_addr")
protected String bind_interface_str=null;
private Method is_reacheable;
/** Time-to-live for InetAddress.isReachable() */
@Property
private int ttl=32;
public void init() throws Exception {
super.init();
if(bind_addr != null)
intf=NetworkInterface.getByInetAddress(bind_addr);
try {
Class<?> is_reacheable_class=Util.loadClass("java.net.InetAddress", this.getClass());
is_reacheable=is_reacheable_class.getMethod("isReachable", NetworkInterface.class, int.class, int.class);
}
catch(ClassNotFoundException e) {
// should never happen since we require JDK 1.5
Error error=new NoClassDefFoundError("failed checking for InetAddress.isReachable() method - requires JDK 5 or higher");
error.initCause(e);
throw error;
}
catch(NoSuchMethodException e) {
// log.error("didn't find InetAddress.isReachable() method - requires JDK 5 or higher");
Error error=new NoSuchMethodError("didn't find InetAddress.isReachable() method - requires JDK 5 or higher");
error.initCause(e);
throw error;
}
}
public Object up(Event evt) {
switch(evt.getType()) {
case Event.CONFIG:
if(bind_addr == null) {
Map<String,Object> config=(Map<String,Object>)evt.getArg();
bind_addr=(InetAddress)config.get("bind_addr");
}
break;
}
return super.up(evt);
}
protected Monitor createMonitor() {
return new FD_ICMP.PingMonitor();
}
/**
* Runs InetAddress.isReachable(). Each time the command fails, we increment num_tries. If num_tries > max_tries, we
* emit a SUSPECT message. If ping_dest changes, or we do receive traffic from ping_dest, we reset num_tries to 0.
*/
protected class PingMonitor extends Monitor {
long start, stop;
public void run() {
if(ping_dest == null) {
if(log.isWarnEnabled())
log.warn("ping_dest is null: members=" + members + ", pingable_mbrs=" +
pingable_mbrs + ", local_addr=" + local_addr);
return;
}
// 1. execute ping command
InetAddress host=ping_dest instanceof IpAddress? ((IpAddress)ping_dest).getIpAddress() : null;
if(host == null)
throw new IllegalArgumentException("ping_dest is not of type IpAddress - FD_ICMP only works with these");
try {
if(log.isTraceEnabled())
log.trace("pinging " + host + " (ping_dest=" + ping_dest + ") using interface " + intf);
start=System.currentTimeMillis();
Boolean rc=(Boolean)is_reacheable.invoke(host, intf, new Integer(ttl), new Integer((int)timeout));
stop=System.currentTimeMillis();
num_heartbeats++;
if(rc.booleanValue()) { // success
num_tries=0;
if(log.isTraceEnabled())
log.trace("successfully received response from " + host + " (after " + (stop-start) + "ms)");
}
else { // failure
num_tries++;
if(log.isDebugEnabled())
log.debug("could not ping " + ping_dest + " (tries=" + num_tries + ") after " + (stop-start) + "ms)");
}
if(num_tries >= max_tries) {
if(log.isDebugEnabled())
log.debug("[" + local_addr + "]: could not ping " + ping_dest + " for " + (num_tries +1) +
" times (" + ((num_tries+1) * timeout) + " milliseconds), suspecting it");
// broadcast a SUSPECT message to all members - loop until
// unsuspect or view change is received
bcast_task.addSuspectedMember(ping_dest);
num_tries=0;
if(stats) {
num_suspect_events++;
suspect_history.add(ping_dest);
}
}
}
catch(Exception ex) {
if(log.isErrorEnabled())
log.error("failed pinging " + ping_dest, ex);
}
}
}
}