// $Id: TCPPING.java,v 1.28 2006/09/15 16:33:26 belaban Exp $
package org.jgroups.protocols;
import org.jgroups.Address;
import org.jgroups.Event;
import org.jgroups.Message;
import org.jgroups.Global;
import org.jgroups.util.Util;
import org.jgroups.stack.IpAddress;
import java.util.*;
import java.net.UnknownHostException;
/**
* The TCPPING protocol layer retrieves the initial membership in answer to the GMS's
* FIND_INITIAL_MBRS event. The initial membership is retrieved by directly contacting other group
* members, sending point-to-point mebership requests. The responses should allow us to determine
* the coordinator whom we have to contact in case we want to join the group. When we are a server
* (after having received the BECOME_SERVER event), we'll respond to TCPPING requests with a TCPPING
* response.
* <p>
* The FIND_INITIAL_MBRS event will eventually be answered with a FIND_INITIAL_MBRS_OK event up
* the stack.
* <p>
* The TCPPING protocol requires a static conifiguration, which assumes that you to know in advance
* where to find other members of your group. For dynamic discovery, use the PING protocol, which
* uses multicast discovery, or the TCPGOSSIP protocol, which contacts a Gossip Router to acquire
* the initial membership.
*
* @author Bela Ban
*/
public class TCPPING extends Discovery {
int port_range=1; // number of ports to be probed for initial membership
/** List<IpAddress> */
ArrayList initial_hosts=null; // hosts to be contacted for the initial membership
final static String name="TCPPING";
public String getName() {
return name;
}
public boolean setProperties(Properties props) {
String str;
this.props.putAll(props); // redundant
str=props.getProperty("port_range"); // if member cannot be contacted on base port,
if(str != null) { // how many times can we increment the port
port_range=Integer.parseInt(str);
if (port_range < 1) {
port_range = 1;
}
props.remove("port_range");
}
str=Util.getProperty(new String[]{Global.TCPPING_INITIAL_HOSTS}, props, "initial_hosts", false, null);
if(str != null) {
props.remove("initial_hosts");
try {
initial_hosts=createInitialHosts(str);
}
catch(UnknownHostException e) {
log.error("failed creating initial list of hosts", e);
return false;
}
}
return super.setProperties(props);
}
public void localAddressSet(Address addr) {
// Add own address to initial_hosts if not present: we must always be able to ping ourself !
if(initial_hosts != null && addr != null) {
if(initial_hosts.contains(addr)) {
initial_hosts.remove(addr);
if(log.isDebugEnabled()) log.debug("[SET_LOCAL_ADDRESS]: removing my own address (" + addr +
") from initial_hosts; initial_hosts=" + initial_hosts);
}
}
}
public void sendGetMembersRequest() {
Message msg;
for(Iterator it=initial_hosts.iterator(); it.hasNext();) {
Address addr=(Address)it.next();
// if(tmpMbrs.contains(addr)) {
// ; // continue; // changed as suggested by Mark Kopec
// }
msg=new Message(addr, null, null);
msg.putHeader(name, new PingHeader(PingHeader.GET_MBRS_REQ, null));
if(trace) log.trace("[FIND_INITIAL_MBRS] sending PING request to " + msg.getDest());
passDown(new Event(Event.MSG, msg));
}
}
/* -------------------------- Private methods ---------------------------- */
/**
* Input is "daddy[8880],sindhu[8880],camille[5555]. Return List of IpAddresses
*/
private ArrayList createInitialHosts(String l) throws UnknownHostException {
StringTokenizer tok=new StringTokenizer(l, ",");
String t;
IpAddress addr;
ArrayList retval=new ArrayList();
while(tok.hasMoreTokens()) {
try {
t=tok.nextToken().trim();
String host=t.substring(0, t.indexOf('['));
host=host.trim();
int port=Integer.parseInt(t.substring(t.indexOf('[') + 1, t.indexOf(']')));
for(int i=port; i < port + port_range; i++) {
addr=new IpAddress(host, i);
retval.add(addr);
}
}
catch(NumberFormatException e) {
if(log.isErrorEnabled()) log.error("exeption is " + e);
}
}
return retval;
}
}