FD_ICMP


1   package org.jgroups.protocols;
2   
3   import org.jgroups.Event;
4   import org.jgroups.Global;
5   import org.jgroups.stack.IpAddress;
6   import org.jgroups.util.Util;
7   
8   import java.lang.reflect.Method  ;
9   import java.net.InetAddress  ;
10  import java.net.NetworkInterface  ;
11  import java.net.UnknownHostException  ;
12  import java.util.Map  ;
13  import java.util.Properties  ;
14  
15  /**
16   * Protocol which uses InetAddress.isReachable() to check whether a given host is up or not,
17   * taking 1 argument; the host name of the host to be pinged.
18   * <em>Note that this protocol only works with JDK 5 !</em>
19   * The implementation of this may or may not use ICMP ! An alternative is to create a TCP connection to port 7 (echo service)
20   * and see whether it works ! This is obviously done in JDK 5, so unless an echo service is configured to run, this
21   * won't work...
22   * @author Bela Ban
23   * @version $Id: FD_ICMP.java,v 1.8 2007/04/27 07:59:19 belaban Exp $
24   */
25  public class FD_ICMP extends FD {
26  
27      /** network interface to be used to send the ICMP packets */
28      private NetworkInterface   intf=null;
29  
30      private InetAddress   bind_addr;
31  
32      private Method   is_reacheable;
33  
34      /** Time-to-live for InetAddress.isReachable() */
35      private int ttl=32;
36  
37  
38  
39      public String   getName() {
40          return "FD_ICMP";
41      }
42  
43  
44      public boolean setProperties(Properties   props) {
45          boolean ignore_systemprops=Util.isBindAddressPropertyIgnored();
46          String   str=Util.getProperty(new String  []{Global.BIND_ADDR, Global.BIND_ADDR_OLD}, props, "bind_addr",
47                               ignore_systemprops, null);
48          if(str != null) {
49              try {
50                  bind_addr=InetAddress.getByName(str);
51              }
52              catch(UnknownHostException   unknown) {
53                  if(log.isFatalEnabled()) log.fatal("(bind_addr): host " + str + " not known");
54                  return false;
55              }
56              props.remove("bind_addr");
57          }
58  
59          str=props.getProperty("ttl");
60          if(str != null) {
61              ttl=Integer.parseInt(str);
62              props.remove("ttl");
63          }
64  
65          super.setProperties(props);
66  
67          try {
68              Class   is_reacheable_class=Util.loadClass("java.net.InetAddress", this.getClass());
69              is_reacheable=is_reacheable_class.getMethod("isReachable", new Class  []{NetworkInterface  .class, int.class, int.class});
70          }
71          catch(ClassNotFoundException   e) {
72              // log.error("failed checking for InetAddress.isReachable() method - requires JDK 5 or higher");
73              Error   error=new NoClassDefFoundError  ("failed checking for InetAddress.isReachable() method - requires JDK 5 or higher");
74              error.initCause(e);
75              throw error;
76          }
77          catch(NoSuchMethodException   e) {
78              // log.error("didn't find InetAddress.isReachable() method - requires JDK 5 or higher");
79              Error   error= new NoSuchMethodError  ("didn't find InetAddress.isReachable() method - requires JDK 5 or higher");
80              error.initCause(e);
81              throw error;
82          }
83  
84  
85          if(!props.isEmpty()) {
86              log.error("the following properties are not recognized: " + props);
87              return false;
88          }
89          return true;
90      }
91  
92  
93      public void init() throws Exception   {
94          super.init();
95          if(bind_addr != null)
96              intf=NetworkInterface.getByInetAddress(bind_addr);
97      }
98  
99      public Object   up(Event evt) {
100         switch(evt.getType()) {
101             case Event.CONFIG:
102                 if(bind_addr == null) {
103                     Map   config=(Map  )evt.getArg();
104                     bind_addr=(InetAddress  )config.get("bind_addr");
105                 }
106                 break;
107         }
108         return super.up(evt);
109     }
110 
111 
112     protected Monitor createMonitor() {
113         return new FD_ICMP.PingMonitor();
114     }
115 
116 
117     /**
118      * Runs InetAddress.isReachable(). Each time the command fails, we increment num_tries. If num_tries > max_tries, we
119      * emit a SUSPECT message. If ping_dest changes, or we do receive traffic from ping_dest, we reset num_tries to 0.
120      */
121     protected class PingMonitor extends Monitor {
122         long start, stop;
123 
124         public void run() {
125             if(ping_dest == null) {
126                 if(log.isWarnEnabled())
127                     log.warn("ping_dest is null: members=" + members + ", pingable_mbrs=" +
128                             pingable_mbrs + ", local_addr=" + local_addr);
129                 return;
130             }
131 
132             // 1. execute ping command
133             InetAddress   host=ping_dest instanceof IpAddress? ((IpAddress)ping_dest).getIpAddress() : null;
134             if(host == null)
135                 throw new IllegalArgumentException  ("ping_dest is not of type IpAddress - FD_ICMP only works with these");
136             try {
137                 if(log.isTraceEnabled())
138                     log.trace("pinging " + host + " (ping_dest=" + ping_dest + ") using interface " + intf);
139                 start=System.currentTimeMillis();
140                 Boolean   rc=(Boolean  )is_reacheable.invoke(host, new Object  []{intf, new Integer  (ttl), new Integer  ((int)timeout)});
141                 stop=System.currentTimeMillis();
142                 num_heartbeats++;
143                 if(rc.booleanValue()) { // success
144                     num_tries=0;
145                     if(log.isTraceEnabled())
146                         log.trace("successfully received response from " + host + " (after " + (stop-start) + "ms)");
147                 }
148                 else { // failure
149                     num_tries++;
150                     if(log.isDebugEnabled())
151                         log.debug("could not ping " + ping_dest + " (tries=" + num_tries + ") after " + (stop-start) + "ms)");
152                 }
153 
154                 if(num_tries >= max_tries) {
155                     if(log.isDebugEnabled())
156                         log.debug("[" + local_addr + "]: could not ping " + ping_dest + " for " + (num_tries +1) +
157                                 " times (" + ((num_tries+1) * timeout) + " milliseconds), suspecting it");
158                     // broadcast a SUSPECT message to all members - loop until
159                     // unsuspect or view change is received
160                     bcast_task.addSuspectedMember(ping_dest);
161                     num_tries=0;
162                     if(stats) {
163                         num_suspect_events++;
164                         suspect_history.add(ping_dest);
165                     }
166                 }
167             }
168             catch(Exception   ex) {
169                 if(log.isErrorEnabled())
170                     log.error("failed pinging " + ping_dest, ex);
171             }
172         }
173     }
174 
175 
176 }
177
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