Added a mechanism to obtain heap dump

changelog.html

@@ -52,6 +52,9 @@ Upcoming changes</a>
     Reduced the memory footprint used by fingerprints.
   <li class=rfe>
     Added a new extension point to support external login mechanisms.
+  <li class=rfe>
+    Heap dump of running Hudson instance can be obtained by requesting /heapDump from
+    the browser.
   <li class=rfe>
     MavenReporter#postExecute parameter Throwable error is always empty in case of mojo failure
     (<a href="http://issues.hudson-ci.org/browse/HUDSON-8493">issue 8493</a>)

core/src/main/java/hudson/model/Computer.java

@@ -2,7 +2,7 @@
  * The MIT License
  * 
  * Copyright (c) 2004-2010, Sun Microsystems, Inc., Kohsuke Kawaguchi,
- * Red Hat, Inc., Seiji Sogabe, Stephen Connolly, Thomas J. Black, Tom Huybrechts
+ * Red Hat, Inc., Seiji Sogabe, Stephen Connolly, Thomas J. Black, Tom Huybrechts, CloudBees, Inc.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -25,10 +25,12 @@
 package hudson.model;
 
 import hudson.EnvVars;
+import hudson.FilePath;
 import hudson.Util;
 import hudson.cli.declarative.CLIMethod;
 import hudson.console.AnnotatedLargeText;
 import hudson.model.Descriptor.FormException;
+import hudson.model.Hudson.MasterComputer;
 import hudson.model.queue.WorkUnit;
 import hudson.node_monitors.NodeMonitor;
 import hudson.remoting.Channel;
@@ -48,6 +50,7 @@ import hudson.tasks.Publisher;
 import hudson.util.DaemonThreadFactory;
 import hudson.util.ExceptionCatchingThreadFactory;
 import hudson.util.RemotingDiagnostics;
+import hudson.util.RemotingDiagnostics.HeapDump;
 import hudson.util.RunList;
 import hudson.util.Futures;
 import org.kohsuke.stapler.StaplerRequest;
@@ -56,6 +59,7 @@ import org.kohsuke.stapler.QueryParameter;
 import org.kohsuke.stapler.HttpResponses;
 import org.kohsuke.stapler.HttpResponse;
 import org.kohsuke.stapler.HttpRedirect;
+import org.kohsuke.stapler.WebMethod;
 import org.kohsuke.stapler.export.Exported;
 import org.kohsuke.stapler.export.ExportedBean;
 import org.kohsuke.args4j.Option;
@@ -768,6 +772,13 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
         return RemotingDiagnostics.getThreadDump(getChannel());
     }
 
+    /**
+     * Obtains the heap dump.
+     */
+    public HeapDump getHeapDump() throws IOException {
+        return new HeapDump(this,getChannel());
+    }
+
     /**
      * This method tries to compute the name of the host that's reachable by all the other nodes.
      *

core/src/main/java/hudson/model/Hudson.java

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2004-2010, Sun Microsystems, Inc., Kohsuke Kawaguchi,
  * Erik Ramfelt, Koichi Fujikawa, Red Hat, Inc., Seiji Sogabe,
- * Stephen Connolly, Tom Huybrechts, Yahoo! Inc., Alan Harder
+ * Stephen Connolly, Tom Huybrechts, Yahoo! Inc., Alan Harder, CloudBees, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -121,6 +121,7 @@ import hudson.util.Iterators;
 import hudson.util.Memoizer;
 import hudson.util.MultipartFormDataParser;
 import hudson.util.RemotingDiagnostics;
+import hudson.util.RemotingDiagnostics.HeapDump;
 import hudson.util.StreamTaskListener;
 import hudson.util.TextFile;
 import hudson.util.VersionNumber;
@@ -166,6 +167,7 @@ import org.kohsuke.stapler.StaplerProxy;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.StaplerResponse;
 import org.kohsuke.stapler.WebApp;
+import org.kohsuke.stapler.WebMethod;
 import org.kohsuke.stapler.export.Exported;
 import org.kohsuke.stapler.export.ExportedBean;
 import org.kohsuke.stapler.framework.adjunct.AdjunctManager;
@@ -2567,14 +2569,14 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
             bc.commit();
         }
 
-        rsp.sendRedirect(req.getContextPath()+'/');  // go to the top page
+        rsp.sendRedirect(req.getContextPath() + '/');  // go to the top page
     }
 
     /**
      * Accepts the new description.
      */
     public synchronized void doSubmitDescription( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
-        getPrimaryView().doSubmitDescription(req,rsp);
+        getPrimaryView().doSubmitDescription(req, rsp);
     }
 
     /**
@@ -2582,7 +2584,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      *      Use {@link #doQuietDown()} instead.
      */
     public synchronized void doQuietDown(StaplerResponse rsp) throws IOException, ServletException {
-        doQuietDown().generateResponse(null,rsp,this);
+        doQuietDown().generateResponse(null, rsp, this);
     }
 
     public synchronized HttpRedirect doQuietDown() throws IOException {
@@ -2637,7 +2639,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      * @since 1.319
      */
     public TopLevelItem createProjectFromXML(String name, InputStream xml) throws IOException {
-        return itemGroupMixIn.createProjectFromXML(name,xml);
+        return itemGroupMixIn.createProjectFromXML(name, xml);
     }
 
     /**
@@ -2652,7 +2654,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      */
     @SuppressWarnings({"unchecked"})
     public <T extends TopLevelItem> T copy(T src, String name) throws IOException {
-        return itemGroupMixIn.copy(src,name);
+        return itemGroupMixIn.copy(src, name);
     }
 
     // a little more convenient overloading that assumes the caller gives us the right type
@@ -2765,7 +2767,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      * Logs out the user.
      */
     public void doLogout( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
-        securityRealm.doLogout(req,rsp);
+        securityRealm.doLogout(req, rsp);
     }
 
     /**
@@ -2798,7 +2800,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
         checkPermission(ADMINISTER);
 
         // engage "loading ..." UI and then run the actual task in a separate thread
-        servletContext.setAttribute("app",new HudsonIsLoading());
+        servletContext.setAttribute("app", new HudsonIsLoading());
 
         new Thread("Hudson config reload thread") {
             @Override
@@ -2823,7 +2825,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      * Reloads the configuration synchronously.
      */
     public void reload() throws IOException, InterruptedException, ReactorException {
-        executeReactor(null,loadTasks());
+        executeReactor(null, loadTasks());
         User.reload();
         servletContext.setAttribute("app", this);
     }
@@ -2856,6 +2858,13 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
         rsp.getWriter().println("GCed");
     }
 
+    /**
+     * Obtains the heap dump.
+     */
+    public HeapDump getHeapDump() throws IOException {
+        return new HeapDump(this,MasterComputer.localChannel);
+    }
+
     /**
      * Simulates OutOfMemoryError.
      * Useful to make sure OutOfMemoryHeapDump setting.
@@ -2960,7 +2969,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
     public void restart() throws RestartNotSupportedException {
         final Lifecycle lifecycle = Lifecycle.get();
         lifecycle.verifyRestartable(); // verify that Hudson is restartable
-        servletContext.setAttribute("app",new HudsonIsRestarting());
+        servletContext.setAttribute("app", new HudsonIsRestarting());
 
         new Thread("restart thread") {
             final String exitUser = getAuthentication().getName();
@@ -3151,7 +3160,7 @@ public final class Hudson extends Node implements ItemGroup<TopLevelItem>, Stapl
      * Sign up for the user account.
      */
     public void doSignup( StaplerRequest req, StaplerResponse rsp ) throws IOException, ServletException {
-        req.getView(getSecurityRealm(),"signup.jelly").forward(req,rsp);
+        req.getView(getSecurityRealm(), "signup.jelly").forward(req, rsp);
     }
 
     /**

core/src/main/java/hudson/util/RemotingDiagnostics.java

 /*
  * The MIT License
  * 
- * Copyright (c) 2004-2010, Sun Microsystems, Inc., Kohsuke Kawaguchi
+ * Copyright (c) 2004-2010, Sun Microsystems, Inc., Kohsuke Kawaguchi, CloudBees, Inc.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -24,15 +24,25 @@
 package hudson.util;
 
 import groovy.lang.GroovyShell;
+import hudson.FilePath;
 import hudson.Functions;
 import hudson.model.Hudson;
 import hudson.remoting.Callable;
-import hudson.remoting.VirtualChannel;
 import hudson.remoting.DelegatingCallable;
+import hudson.remoting.VirtualChannel;
+import hudson.security.AccessControlled;
+import org.kohsuke.stapler.StaplerRequest;
+import org.kohsuke.stapler.StaplerResponse;
+import org.kohsuke.stapler.WebMethod;
 
+import javax.management.JMException;
+import javax.management.MBeanServer;
+import javax.management.ObjectName;
+import java.io.File;
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.lang.management.ManagementFactory;
 import java.lang.management.ThreadInfo;
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -43,7 +53,7 @@ import java.util.TreeMap;
  * Various remoting operations related to diagnostics.
  *
  * <p>
- * These code are useful whereever {@link VirtualChannel} is used, such as master, slaves, Maven JVMs, etc.
+ * These code are useful wherever {@link VirtualChannel} is used, such as master, slaves, Maven JVMs, etc.
  *
  * @author Kohsuke Kawaguchi
  * @since 1.175
@@ -129,4 +139,65 @@ public final class RemotingDiagnostics {
             return out.toString();
         }
     }
+
+    /**
+     * Obtains the heap dump in an HPROF file.
+     */
+    public static FilePath getHeapDump(VirtualChannel channel) throws IOException, InterruptedException {
+        return channel.call(new Callable<FilePath, IOException>() {
+            public FilePath call() throws IOException {
+                final File hprof = File.createTempFile("hudson-heapdump", "hprof");
+                hprof.delete();
+                try {
+                    MBeanServer server = ManagementFactory.getPlatformMBeanServer();
+                    server.invoke(new ObjectName("com.sun.management:type=HotSpotDiagnostic"), "dumpHeap",
+                            new Object[]{hprof.getAbsolutePath(), true}, new String[]{String.class.getName(), boolean.class.getName()});
+
+                    return new FilePath(hprof);
+                } catch (JMException e) {
+                    throw new IOException2(e);
+                }
+            }
+
+            private static final long serialVersionUID = 1L;
+        });
+    }
+
+    /**
+     * Heap dump, exposable to URL via Stapler.
+     *
+     */
+    public static class HeapDump {
+        private final AccessControlled owner;
+        private final VirtualChannel channel;
+
+        public HeapDump(AccessControlled owner, VirtualChannel channel) {
+            this.owner = owner;
+            this.channel = channel;
+        }
+
+        /**
+         * Obtains the heap dump.
+         */
+        public void doIndex(StaplerResponse rsp) throws IOException {
+            rsp.sendRedirect("heapdump.hprof");
+        }
+
+        @WebMethod(name="heapdump.hprof")
+        public void doHeapDump(StaplerRequest req, StaplerResponse rsp) throws IOException, InterruptedException {
+            owner.checkPermission(Hudson.ADMINISTER);
+            rsp.setContentType("application/octet-stream");
+
+            FilePath dump = obtain();
+            try {
+                dump.copyTo(rsp.getCompressedOutputStream(req));
+            } finally {
+                dump.delete();
+            }
+        }
+
+        public FilePath obtain() throws IOException, InterruptedException {
+            return RemotingDiagnostics.getHeapDump(channel);
+        }
+    }
 }

maven-plugin/src/main/java/hudson/maven/MavenProbeAction.java

 /*
  * The MIT License
  * 
- * Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi
+ * Copyright (c) 2004-2009, Sun Microsystems, Inc., Kohsuke Kawaguchi, CloudBees, Inc.
  * 
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -24,13 +24,16 @@
 package hudson.maven;
 
 import hudson.EnvVars;
+import hudson.FilePath;
 import hudson.model.AbstractProject;
 import hudson.model.Action;
 import hudson.model.Hudson;
 import hudson.remoting.Channel;
 import hudson.util.RemotingDiagnostics;
+import hudson.util.RemotingDiagnostics.HeapDump;
 import org.kohsuke.stapler.StaplerRequest;
 import org.kohsuke.stapler.StaplerResponse;
+import org.kohsuke.stapler.WebMethod;
 
 import javax.servlet.ServletException;
 import java.io.IOException;
@@ -112,4 +115,11 @@ public final class MavenProbeAction implements Action {
 
         req.getView(this,"_script.jelly").forward(req,rsp);
     }
+
+    /**
+     * Obtains the heap dump.
+     */
+    public HeapDump getHeapDump() throws IOException {
+        return new HeapDump(owner,channel);
+    }
 }