[JENKINS-35190] Do not even consult PingFailureAnalyzer if ping fails…

… on the agent side. (#2377)

core/src/main/java/hudson/slaves/ChannelPinger.java

@@ -88,7 +88,7 @@ public void install(Channel channel) {
 
         // set up ping from both directions, so that in case of a router dropping a connection,
         // both sides can notice it and take compensation actions.
-        setUpPingForChannel(channel, pingInterval);
+        setUpPingForChannel(channel, pingInterval, true);
     }
 
     private static class SetUpRemotePing extends MasterToSlaveCallable<Void, IOException> {
@@ -99,18 +99,20 @@ public SetUpRemotePing(int pingInterval) {
         }
 
         public Void call() throws IOException {
-            setUpPingForChannel(Channel.current(), pingInterval);
+            setUpPingForChannel(Channel.current(), pingInterval, false);
             return null;
         }
     }
 
-    private static void setUpPingForChannel(final Channel channel, int interval) {
+    private static void setUpPingForChannel(final Channel channel, int interval, final boolean analysis) {
+        LOGGER.log(FINE, "setting up ping on {0} at interval {1}m", new Object[] {channel.getName(), interval});
         final AtomicBoolean isInClosed = new AtomicBoolean(false);
         final PingThread t = new PingThread(channel, interval * 60 * 1000) {
+            @Override
             protected void onDead(Throwable cause) {
                 try {
-                    for (PingFailureAnalyzer pfa : PingFailureAnalyzer.all()) {
-                        pfa.onPingFailure(channel,cause);
+                    if (analysis) {
+                        analyze(cause);
                     }
                     if (isInClosed.get()) {
                         LOGGER.log(FINE,"Ping failed after the channel "+channel.getName()+" is already partially closed.",cause);
@@ -122,6 +124,14 @@ protected void onDead(Throwable cause) {
                     LOGGER.log(SEVERE,"Failed to terminate the channel "+channel.getName(),e);
                 }
             }
+            /** Keep in a separate method so we do not even try to do class loading on {@link PingFailureAnalyzer} from an agent JVM. */
+            private void analyze(Throwable cause) throws IOException {
+                for (PingFailureAnalyzer pfa : PingFailureAnalyzer.all()) {
+                    pfa.onPingFailure(channel,cause);
+                }
+            }
+            @Deprecated
+            @Override
             protected void onDead() {
                 onDead(null);
             }