diff --git a/jetty-client/src/main/java/org/eclipse/jetty/client/ConnectionPool.java b/jetty-client/src/main/java/org/eclipse/jetty/client/ConnectionPool.java
index eeadbba1e27..0af5286126a 100644
--- a/jetty-client/src/main/java/org/eclipse/jetty/client/ConnectionPool.java
+++ b/jetty-client/src/main/java/org/eclipse/jetty/client/ConnectionPool.java
@@ -106,6 +106,8 @@ public class ConnectionPool implements Closeable, Dumpable
                             LOG.debug("Connection {}/{} creation succeeded {}", next, maxConnections, connection);
                         if (activate(connection))
                             connectionPromise.succeeded(connection);
+                        else
+                            connectionPromise.failed(new IllegalStateException("Active connection overflow"));
                     }
 
                     @Override
diff --git a/jetty-io/src/main/java/org/eclipse/jetty/io/AbstractEndPoint.java b/jetty-io/src/main/java/org/eclipse/jetty/io/AbstractEndPoint.java
index d9bbae3c955..627d7e30411 100644
--- a/jetty-io/src/main/java/org/eclipse/jetty/io/AbstractEndPoint.java
+++ b/jetty-io/src/main/java/org/eclipse/jetty/io/AbstractEndPoint.java
@@ -172,7 +172,7 @@ public abstract class AbstractEndPoint extends IdleTimeout implements EndPoint
     @Override
     public String toString()
     {
-        return String.format("%s@%x{%s<->%d,%s,%s,%s,%s,%s,%d,%s}",
+        return String.format("%s@%x{%s<->%d,%s,%s,%s,%s,%s,%d/%d,%s}",
                 getClass().getSimpleName(),
                 hashCode(),
                 getRemoteAddress(),
@@ -182,6 +182,7 @@ public abstract class AbstractEndPoint extends IdleTimeout implements EndPoint
                 isOutputShutdown()?"OSHUT":"out",
                 _fillInterest.isInterested()?"R":"-",
                 _writeFlusher.isInProgress()?"W":"-",
+                getIdleFor(),
                 getIdleTimeout(),
                 getConnection()==null?null:getConnection().getClass().getSimpleName());
     }
diff --git a/jetty-io/src/main/java/org/eclipse/jetty/io/IdleTimeout.java b/jetty-io/src/main/java/org/eclipse/jetty/io/IdleTimeout.java
index de2a86895d9..b2c8713c7df 100644
--- a/jetty-io/src/main/java/org/eclipse/jetty/io/IdleTimeout.java
+++ b/jetty-io/src/main/java/org/eclipse/jetty/io/IdleTimeout.java
@@ -71,6 +71,11 @@ public abstract class IdleTimeout
         return _idleTimestamp;
     }
 
+    public long getIdleFor()
+    {
+        return System.currentTimeMillis() - getIdleTimestamp();
+    }
+
     public long getIdleTimeout()
     {
         return _idleTimeout;
diff --git a/jetty-util/src/main/java/org/eclipse/jetty/util/thread/ScheduledExecutorScheduler.java b/jetty-util/src/main/java/org/eclipse/jetty/util/thread/ScheduledExecutorScheduler.java
index a812026fcc3..2cb14b5ab2f 100644
--- a/jetty-util/src/main/java/org/eclipse/jetty/util/thread/ScheduledExecutorScheduler.java
+++ b/jetty-util/src/main/java/org/eclipse/jetty/util/thread/ScheduledExecutorScheduler.java
@@ -18,13 +18,17 @@
 
 package org.eclipse.jetty.util.thread;
 
-import java.util.concurrent.BlockingQueue;
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.ScheduledThreadPoolExecutor;
 import java.util.concurrent.ThreadFactory;
 import java.util.concurrent.TimeUnit;
 
 import org.eclipse.jetty.util.component.AbstractLifeCycle;
+import org.eclipse.jetty.util.component.ContainerLifeCycle;
+import org.eclipse.jetty.util.component.Dumpable;
 
 /**
  * Implementation of {@link Scheduler} based on JDK's {@link ScheduledThreadPoolExecutor}.
@@ -34,12 +38,13 @@ import org.eclipse.jetty.util.component.AbstractLifeCycle;
  * queue even if the task did not fire, which provides a huge benefit in the performance
  * of garbage collection in young generation.
  */
-public class ScheduledExecutorScheduler extends AbstractLifeCycle implements Scheduler
+public class ScheduledExecutorScheduler extends AbstractLifeCycle implements Scheduler, Dumpable
 {
     private final String name;
     private final boolean daemon;
+    private final ClassLoader classloader;
     private volatile ScheduledThreadPoolExecutor scheduler;
-    private ClassLoader classloader;
+    private volatile Thread thread;
 
     public ScheduledExecutorScheduler()
     {
@@ -66,7 +71,7 @@ public class ScheduledExecutorScheduler extends AbstractLifeCycle implements Sch
             @Override
             public Thread newThread(Runnable r)
             {
-                Thread thread = new Thread(r, name);
+                Thread thread = ScheduledExecutorScheduler.this.thread = new Thread(r, name);
                 thread.setDaemon(daemon);
                 thread.setContextClassLoader(classloader);
                 return thread;
@@ -76,8 +81,6 @@ public class ScheduledExecutorScheduler extends AbstractLifeCycle implements Sch
         super.doStart();
     }
 
-    
-
     @Override
     protected void doStop() throws Exception
     {
@@ -92,7 +95,24 @@ public class ScheduledExecutorScheduler extends AbstractLifeCycle implements Sch
         ScheduledFuture<?> result = scheduler.schedule(task, delay, unit);
         return new ScheduledFutureTask(result);
     }
- 
+
+    @Override
+    public String dump()
+    {
+        return ContainerLifeCycle.dump(this);
+    }
+
+    @Override
+    public void dump(Appendable out, String indent) throws IOException
+    {
+        ContainerLifeCycle.dumpObject(out, this);
+        Thread thread = this.thread;
+        if (thread != null)
+        {
+            List<StackTraceElement> frames = Arrays.asList(thread.getStackTrace());
+            ContainerLifeCycle.dump(out, indent, frames);
+        }
+    }
 
     private class ScheduledFutureTask implements Task
     {