diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index 858f13ea147..ce35855f176 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -387,7 +387,7 @@
 		},
 		{
 			"ImportPath": "github.com/mesos/mesos-go/auth",
-			"Rev": "4b1767c0dfc51020e01f35da5b38472f40ce572a"
+			"Rev": "6440c09c9d8a1b365f3c3e9b2297dd856abd017c"
 		},
 		{
 			"ImportPath": "github.com/mesos/mesos-go/detector",
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/auth/sasl/authenticatee_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/auth/sasl/authenticatee_test.go
index 9fd37b6fb96..2a4d5873212 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/auth/sasl/authenticatee_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/auth/sasl/authenticatee_test.go
@@ -65,26 +65,27 @@ func TestAuthticatee_validLogin(t *testing.T) {
 		transport.On("Stop").Return(nil)
 		transport.On("Send", mock.Anything, &server, &mesos.AuthenticateMessage{
 			Pid: proto.String(client.String()),
-		}).Return(nil).Once()
+		}).Return(nil).Run(func(_ mock.Arguments) {
+			transport.Recv(&server, &mesos.AuthenticationMechanismsMessage{
+				Mechanisms: []string{crammd5.Name},
+			})
+		}).Once()
 
 		transport.On("Send", mock.Anything, &server, &mesos.AuthenticationStartMessage{
 			Mechanism: proto.String(crammd5.Name),
 			Data:      proto.String(""), // may be nil, depends on init step
-		}).Return(nil).Once()
-
-		transport.On("Send", mock.Anything, &server, &mesos.AuthenticationStepMessage{
-			Data: []byte(`foo cc7fd96cd80123ea844a7dba29a594ed`),
-		}).Return(nil).Once()
-
-		go func() {
-			transport.Recv(&server, &mesos.AuthenticationMechanismsMessage{
-				Mechanisms: []string{crammd5.Name},
-			})
+		}).Return(nil).Run(func(_ mock.Arguments) {
 			transport.Recv(&server, &mesos.AuthenticationStepMessage{
 				Data: []byte(`lsd;lfkgjs;dlfkgjs;dfklg`),
 			})
+		}).Once()
+
+		transport.On("Send", mock.Anything, &server, &mesos.AuthenticationStepMessage{
+			Data: []byte(`foo cc7fd96cd80123ea844a7dba29a594ed`),
+		}).Return(nil).Run(func(_ mock.Arguments) {
 			transport.Recv(&server, &mesos.AuthenticationCompletedMessage{})
-		}()
+		}).Once()
+
 		return transport
 	})
 	login, err := makeAuthenticatee(handler, factory)
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/factory.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/factory.go
index 7c0554f657a..2cbe78fdd44 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/factory.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/factory.go
@@ -130,7 +130,7 @@ func CreateMasterInfo(pid *upid.UPID) *mesos.MasterInfo {
 		// This is needed for the people cross-compiling from macos to linux.
 		// The cross-compiled version of net.LookupIP() fails to handle plain IPs.
 		// See https://github.com/mesos/mesos-go/pull/117
-        } else if addrs, err := net.LookupIP(pid.Host); err == nil {
+	} else if addrs, err := net.LookupIP(pid.Host); err == nil {
 		for _, ip := range addrs {
 			if ip = ip.To4(); ip != nil {
 				ipv4 = ip
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/interface.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/interface.go
index 03e0bb7cfc0..d9081bbca51 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/interface.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/interface.go
@@ -27,6 +27,21 @@ type MasterChanged interface {
 	OnMasterChanged(*mesos.MasterInfo)
 }
 
+// AllMasters defines an optional interface that, if implemented by the same
+// struct as implements MasterChanged, will receive an additional callbacks
+// independently of leadership changes. it's possible that, as a result of a
+// leadership change, both the OnMasterChanged and UpdatedMasters callbacks
+// would be invoked.
+//
+// **NOTE:** Detector implementations are not required to support this optional
+// interface. Please RTFM of the detector implementation that you want to use.
+type AllMasters interface {
+	// UpdatedMasters is invoked upon a change in the membership of mesos
+	// masters, and is useful to clients that wish to know the entire set
+	// of Mesos masters currently running.
+	UpdatedMasters([]*mesos.MasterInfo)
+}
+
 // func/interface adapter
 type OnMasterChanged func(*mesos.MasterInfo)
 
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/client_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/client_test.go
index 596ee196624..1ebca734b36 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/client_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/client_test.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"strings"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -237,9 +238,9 @@ func TestWatchChildren_flappy(t *testing.T) {
 	}))
 
 	go c.connect()
-	watchChildrenCount := 0
+	var watchChildrenCount uint64
 	watcherFunc := ChildWatcher(func(zkc *Client, path string) {
-		log.V(1).Infof("ChildWatcher invoked %d", watchChildrenCount)
+		log.V(1).Infof("ChildWatcher invoked %d", atomic.LoadUint64(&watchChildrenCount))
 	})
 	startTime := time.Now()
 	endTime := startTime.Add(2 * time.Second)
@@ -252,7 +253,7 @@ watcherLoop:
 			if _, err := c.watchChildren(currentPath, watcherFunc); err == nil {
 				// watching children succeeded!!
 				t.Logf("child watch success")
-				watchChildrenCount++
+				atomic.AddUint64(&watchChildrenCount, 1)
 			} else {
 				// setting the watch failed
 				t.Logf("setting child watch failed: %v", err)
@@ -264,7 +265,9 @@ watcherLoop:
 		case <-time.After(endTime.Sub(time.Now())):
 		}
 	}
-	assert.Equal(t, 5, watchChildrenCount, "expected watchChildrenCount = 5 instead of %d, should be reinvoked upon initial ChildrenW failures", watchChildrenCount)
+
+	wantChildrenCount := atomic.LoadUint64(&watchChildrenCount)
+	assert.Equal(t, uint64(5), wantChildrenCount, "expected watchChildrenCount = 5 instead of %d, should be reinvoked upon initial ChildrenW failures", wantChildrenCount)
 }
 
 func makeClient() (*Client, error) {
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/detect.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/detect.go
index 3c2cefa235a..48eee4b4140 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/detect.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/detect.go
@@ -112,8 +112,12 @@ func (md *MasterDetector) childrenChanged(zkc *Client, path string, obs detector
 		return
 	}
 
-	topNode := selectTopNode(list)
+	md.notifyMasterChanged(path, list, obs)
+	md.notifyAllMasters(path, list, obs)
+}
 
+func (md *MasterDetector) notifyMasterChanged(path string, list []string, obs detector.MasterChanged) {
+	topNode := selectTopNode(list)
 	if md.leaderNode == topNode {
 		log.V(2).Infof("ignoring children-changed event, leader has not changed: %v", path)
 		return
@@ -124,21 +128,57 @@ func (md *MasterDetector) childrenChanged(zkc *Client, path string, obs detector
 
 	var masterInfo *mesos.MasterInfo
 	if md.leaderNode != "" {
-		data, err := zkc.data(fmt.Sprintf("%s/%s", path, topNode))
-		if err != nil {
-			log.Errorf("unable to retrieve leader data: %v", err.Error())
-			return
-		}
-
-		masterInfo = new(mesos.MasterInfo)
-		err = proto.Unmarshal(data, masterInfo)
-		if err != nil {
-			log.Errorf("unable to unmarshall MasterInfo data from zookeeper: %v", err)
-			return
+		var err error
+		if masterInfo, err = md.pullMasterInfo(path, topNode); err != nil {
+			log.Errorln(err.Error())
 		}
 	}
 	log.V(2).Infof("detected master info: %+v", masterInfo)
-	obs.OnMasterChanged(masterInfo)
+	logPanic(func() { obs.OnMasterChanged(masterInfo) })
+}
+
+// logPanic safely executes the given func, recovering from and logging a panic if one occurs.
+func logPanic(f func()) {
+	defer func() {
+		if r := recover(); r != nil {
+			log.Errorf("recovered from client panic: %v", r)
+		}
+	}()
+	f()
+}
+
+func (md *MasterDetector) pullMasterInfo(path, node string) (*mesos.MasterInfo, error) {
+	data, err := md.client.data(fmt.Sprintf("%s/%s", path, node))
+	if err != nil {
+		return nil, fmt.Errorf("failed to retrieve leader data: %v", err)
+	}
+
+	masterInfo := &mesos.MasterInfo{}
+	err = proto.Unmarshal(data, masterInfo)
+	if err != nil {
+		return nil, fmt.Errorf("failed to unmarshall MasterInfo data from zookeeper: %v", err)
+	}
+	return masterInfo, nil
+}
+
+func (md *MasterDetector) notifyAllMasters(path string, list []string, obs detector.MasterChanged) {
+	all, ok := obs.(detector.AllMasters)
+	if !ok {
+		// not interested in entire master list
+		return
+	}
+	masters := []*mesos.MasterInfo{}
+	for _, node := range list {
+		info, err := md.pullMasterInfo(path, node)
+		if err != nil {
+			log.Errorln(err.Error())
+		} else {
+			masters = append(masters, info)
+		}
+	}
+
+	log.V(2).Infof("notifying of master membership change: %+v", masters)
+	logPanic(func() { all.UpdatedMasters(masters) })
 }
 
 // the first call to Detect will kickstart a connection to zookeeper. a nil change listener may
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/detect_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/detect_test.go
index 2cbd1e11b71..de1ce9762a9 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/detect_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/detect_test.go
@@ -8,11 +8,13 @@ import (
 	"testing"
 	"time"
 
+	"github.com/gogo/protobuf/proto"
 	log "github.com/golang/glog"
 	"github.com/mesos/mesos-go/detector"
 	mesos "github.com/mesos/mesos-go/mesosproto"
 	"github.com/samuel/go-zookeeper/zk"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
 )
 
 const (
@@ -324,10 +326,10 @@ func TestMasterDetectMultiple(t *testing.T) {
 	// **** Test 4 consecutive ChildrenChangedEvents ******
 	// setup event changes
 	sequences := [][]string{
-		[]string{"info_014", "info_010", "info_005"},
-		[]string{"info_005", "info_004", "info_022"},
-		[]string{}, // indicates no master
-		[]string{"info_017", "info_099", "info_200"},
+		{"info_014", "info_010", "info_005"},
+		{"info_005", "info_004", "info_022"},
+		{}, // indicates no master
+		{"info_017", "info_099", "info_200"},
 	}
 
 	var wg sync.WaitGroup
@@ -425,3 +427,138 @@ func TestMasterDetect_selectTopNode_mixedEntries(t *testing.T) {
 	node := selectTopNode(nodeList)
 	assert.Equal("info_0000000032", node)
 }
+
+// implements MasterChanged and AllMasters extension
+type allMastersListener struct {
+	mock.Mock
+}
+
+func (a *allMastersListener) OnMasterChanged(mi *mesos.MasterInfo) {
+	a.Called(mi)
+}
+
+func (a *allMastersListener) UpdatedMasters(mi []*mesos.MasterInfo) {
+	a.Called(mi)
+}
+
+func afterFunc(f func()) <-chan struct{} {
+	ch := make(chan struct{})
+	go func() {
+		defer close(ch)
+		f()
+	}()
+	return ch
+}
+
+func fatalAfter(t *testing.T, d time.Duration, f func(), msg string, args ...interface{}) {
+	ch := afterFunc(f)
+	select {
+	case <-ch:
+		return
+	case <-time.After(d):
+		t.Fatalf(msg, args...)
+	}
+}
+
+func TestNotifyAllMasters(t *testing.T) {
+	c, err := newClient(test_zk_hosts, test_zk_path)
+	assert.NoError(t, err)
+
+	childEvents := make(chan zk.Event, 5)
+	connector := NewMockConnector()
+
+	c.setFactory(asFactory(func() (Connector, <-chan zk.Event, error) {
+		sessionEvents := make(chan zk.Event, 1)
+		sessionEvents <- zk.Event{
+			Type:  zk.EventSession,
+			State: zk.StateConnected,
+		}
+		return connector, sessionEvents, nil
+	}))
+
+	md, err := NewMasterDetector(zkurl)
+	defer md.Cancel()
+
+	assert.NoError(t, err)
+
+	c.errorHandler = ErrorHandler(func(c *Client, e error) {
+		t.Fatalf("unexpected error: %v", e)
+	})
+	md.client = c
+
+	listener := &allMastersListener{}
+
+	//-- expect primer
+	var primer sync.WaitGroup
+	ignoreArgs := func(f func()) func(mock.Arguments) {
+		primer.Add(1)
+		return func(_ mock.Arguments) {
+			f()
+		}
+	}
+	connector.On("Children", test_zk_path).Return([]string{}, &zk.Stat{}, nil).Run(ignoreArgs(primer.Done)).Once()
+	listener.On("UpdatedMasters", []*mesos.MasterInfo{}).Return().Run(ignoreArgs(primer.Done)).Once()
+	connector.On("ChildrenW", test_zk_path).Return([]string{test_zk_path}, &zk.Stat{}, (<-chan zk.Event)(childEvents), nil).Run(ignoreArgs(primer.Done)).Once()
+	md.Detect(listener)
+	fatalAfter(t, 3*time.Second, primer.Wait, "timed out waiting for detection primer")
+
+	listener.AssertExpectations(t)
+	connector.AssertExpectations(t)
+
+	//-- test membership changes
+	type expectedGets struct {
+		info []byte
+		err  error
+	}
+	tt := []struct {
+		zkEntry   []string
+		gets      []expectedGets
+		leaderIdx int
+	}{
+		{[]string{"info_004"}, []expectedGets{{newTestMasterInfo(1), nil}}, 0},
+		{[]string{"info_007", "info_005", "info_006"}, []expectedGets{{newTestMasterInfo(2), nil}, {newTestMasterInfo(3), nil}, {newTestMasterInfo(4), nil}}, 1},
+		{nil, nil, -1},
+	}
+	for j, tc := range tt {
+		// expectations
+		var tcwait sync.WaitGroup
+		ignoreArgs = func(f func()) func(mock.Arguments) {
+			tcwait.Add(1)
+			return func(_ mock.Arguments) {
+				f()
+			}
+		}
+
+		expectedInfos := []*mesos.MasterInfo{}
+		for i, zke := range tc.zkEntry {
+			connector.On("Get", fmt.Sprintf("%s/%s", test_zk_path, zke)).Return(tc.gets[i].info, &zk.Stat{}, tc.gets[i].err).Run(ignoreArgs(tcwait.Done)).Once()
+			masterInfo := &mesos.MasterInfo{}
+			err = proto.Unmarshal(tc.gets[i].info, masterInfo)
+			if err != nil {
+				t.Fatalf("failed to unmarshall MasterInfo data: %v", err)
+			}
+			expectedInfos = append(expectedInfos, masterInfo)
+		}
+		if len(tc.zkEntry) > 0 {
+			connector.On("Get", fmt.Sprintf("%s/%s", test_zk_path, tc.zkEntry[tc.leaderIdx])).Return(
+				tc.gets[tc.leaderIdx].info, &zk.Stat{}, tc.gets[tc.leaderIdx].err).Run(ignoreArgs(tcwait.Done)).Once()
+		}
+		connector.On("Children", test_zk_path).Return(tc.zkEntry, &zk.Stat{}, nil).Run(ignoreArgs(tcwait.Done)).Once()
+		listener.On("OnMasterChanged", mock.AnythingOfType("*mesosproto.MasterInfo")).Return().Run(ignoreArgs(tcwait.Done)).Once()
+		listener.On("UpdatedMasters", expectedInfos).Return().Run(ignoreArgs(tcwait.Done)).Once()
+		connector.On("ChildrenW", test_zk_path).Return([]string{test_zk_path}, &zk.Stat{}, (<-chan zk.Event)(childEvents), nil).Run(ignoreArgs(tcwait.Done)).Once()
+
+		// fire the event that triggers the test case
+		childEvents <- zk.Event{
+			Type: zk.EventNodeChildrenChanged,
+			Path: test_zk_path,
+		}
+
+		// allow plenty of time for all the async processing to happen
+		fatalAfter(t, 5*time.Second, tcwait.Wait, "timed out waiting for all-masters test case %d", j+1)
+		listener.AssertExpectations(t)
+		connector.AssertExpectations(t)
+	}
+
+	connector.On("Close").Return(nil)
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/doc.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/doc.go
new file mode 100644
index 00000000000..010ba055d85
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/detector/zoo/doc.go
@@ -0,0 +1,3 @@
+// Zookeeper-based mesos-master leaderhip detection.
+// Implements support for optional detector.AllMasters interface.
+package zoo
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example-executor b/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example-executor
new file mode 100755
index 00000000000..540c230027f
Binary files /dev/null and b/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example-executor differ
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example-scheduler b/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example-scheduler
new file mode 100755
index 00000000000..932556ff1e6
Binary files /dev/null and b/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example-scheduler differ
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example_executor.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example_executor.go
new file mode 100644
index 00000000000..91c9d624193
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example_executor.go
@@ -0,0 +1,121 @@
+// +build example-exec
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	exec "github.com/mesos/mesos-go/executor"
+	mesos "github.com/mesos/mesos-go/mesosproto"
+)
+
+type exampleExecutor struct {
+	tasksLaunched int
+}
+
+func newExampleExecutor() *exampleExecutor {
+	return &exampleExecutor{tasksLaunched: 0}
+}
+
+func (exec *exampleExecutor) Registered(driver exec.ExecutorDriver, execInfo *mesos.ExecutorInfo, fwinfo *mesos.FrameworkInfo, slaveInfo *mesos.SlaveInfo) {
+	fmt.Println("Registered Executor on slave ", slaveInfo.GetHostname())
+}
+
+func (exec *exampleExecutor) Reregistered(driver exec.ExecutorDriver, slaveInfo *mesos.SlaveInfo) {
+	fmt.Println("Re-registered Executor on slave ", slaveInfo.GetHostname())
+}
+
+func (exec *exampleExecutor) Disconnected(exec.ExecutorDriver) {
+	fmt.Println("Executor disconnected.")
+}
+
+func (exec *exampleExecutor) LaunchTask(driver exec.ExecutorDriver, taskInfo *mesos.TaskInfo) {
+	fmt.Println("Launching task", taskInfo.GetName(), "with command", taskInfo.Command.GetValue())
+
+	runStatus := &mesos.TaskStatus{
+		TaskId: taskInfo.GetTaskId(),
+		State:  mesos.TaskState_TASK_RUNNING.Enum(),
+	}
+	_, err := driver.SendStatusUpdate(runStatus)
+	if err != nil {
+		fmt.Println("Got error", err)
+	}
+
+	exec.tasksLaunched++
+	fmt.Println("Total tasks launched ", exec.tasksLaunched)
+	//
+	// this is where one would perform the requested task
+	//
+
+	// finish task
+	fmt.Println("Finishing task", taskInfo.GetName())
+	finStatus := &mesos.TaskStatus{
+		TaskId: taskInfo.GetTaskId(),
+		State:  mesos.TaskState_TASK_FINISHED.Enum(),
+	}
+	_, err = driver.SendStatusUpdate(finStatus)
+	if err != nil {
+		fmt.Println("Got error", err)
+	}
+	fmt.Println("Task finished", taskInfo.GetName())
+}
+
+func (exec *exampleExecutor) KillTask(exec.ExecutorDriver, *mesos.TaskID) {
+	fmt.Println("Kill task")
+}
+
+func (exec *exampleExecutor) FrameworkMessage(driver exec.ExecutorDriver, msg string) {
+	fmt.Println("Got framework message: ", msg)
+}
+
+func (exec *exampleExecutor) Shutdown(exec.ExecutorDriver) {
+	fmt.Println("Shutting down the executor")
+}
+
+func (exec *exampleExecutor) Error(driver exec.ExecutorDriver, err string) {
+	fmt.Println("Got error message:", err)
+}
+
+// -------------------------- func inits () ----------------- //
+func init() {
+	flag.Parse()
+}
+
+func main() {
+	fmt.Println("Starting Example Executor (Go)")
+
+	dconfig := exec.DriverConfig{
+		Executor: newExampleExecutor(),
+	}
+	driver, err := exec.NewMesosExecutorDriver(dconfig)
+
+	if err != nil {
+		fmt.Println("Unable to create a ExecutorDriver ", err.Error())
+	}
+
+	_, err = driver.Start()
+	if err != nil {
+		fmt.Println("Got error:", err)
+		return
+	}
+	fmt.Println("Executor process has started and running.")
+	driver.Join()
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example_scheduler.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example_scheduler.go
new file mode 100644
index 00000000000..5db1dcd3d9d
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/examples/example_scheduler.go
@@ -0,0 +1,294 @@
+// +build example-sched
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"net/http"
+	"strconv"
+	"strings"
+
+	"github.com/gogo/protobuf/proto"
+	log "github.com/golang/glog"
+	"github.com/mesos/mesos-go/auth"
+	"github.com/mesos/mesos-go/auth/sasl"
+	"github.com/mesos/mesos-go/auth/sasl/mech"
+	mesos "github.com/mesos/mesos-go/mesosproto"
+	util "github.com/mesos/mesos-go/mesosutil"
+	sched "github.com/mesos/mesos-go/scheduler"
+	"golang.org/x/net/context"
+)
+
+const (
+	CPUS_PER_TASK       = 1
+	MEM_PER_TASK        = 128
+	defaultArtifactPort = 12345
+)
+
+var (
+	address      = flag.String("address", "127.0.0.1", "Binding address for artifact server")
+	artifactPort = flag.Int("artifactPort", defaultArtifactPort, "Binding port for artifact server")
+	authProvider = flag.String("mesos_authentication_provider", sasl.ProviderName,
+		fmt.Sprintf("Authentication provider to use, default is SASL that supports mechanisms: %+v", mech.ListSupported()))
+	master              = flag.String("master", "127.0.0.1:5050", "Master address <ip:port>")
+	executorPath        = flag.String("executor", "./example_executor", "Path to test executor")
+	taskCount           = flag.String("task-count", "5", "Total task count to run.")
+	mesosAuthPrincipal  = flag.String("mesos_authentication_principal", "", "Mesos authentication principal.")
+	mesosAuthSecretFile = flag.String("mesos_authentication_secret_file", "", "Mesos authentication secret file.")
+)
+
+type ExampleScheduler struct {
+	executor      *mesos.ExecutorInfo
+	tasksLaunched int
+	tasksFinished int
+	totalTasks    int
+}
+
+func newExampleScheduler(exec *mesos.ExecutorInfo) *ExampleScheduler {
+	total, err := strconv.Atoi(*taskCount)
+	if err != nil {
+		total = 5
+	}
+	return &ExampleScheduler{
+		executor:      exec,
+		tasksLaunched: 0,
+		tasksFinished: 0,
+		totalTasks:    total,
+	}
+}
+
+func (sched *ExampleScheduler) Registered(driver sched.SchedulerDriver, frameworkId *mesos.FrameworkID, masterInfo *mesos.MasterInfo) {
+	log.Infoln("Framework Registered with Master ", masterInfo)
+}
+
+func (sched *ExampleScheduler) Reregistered(driver sched.SchedulerDriver, masterInfo *mesos.MasterInfo) {
+	log.Infoln("Framework Re-Registered with Master ", masterInfo)
+}
+
+func (sched *ExampleScheduler) Disconnected(sched.SchedulerDriver) {}
+
+func (sched *ExampleScheduler) ResourceOffers(driver sched.SchedulerDriver, offers []*mesos.Offer) {
+
+	for _, offer := range offers {
+		cpuResources := util.FilterResources(offer.Resources, func(res *mesos.Resource) bool {
+			return res.GetName() == "cpus"
+		})
+		cpus := 0.0
+		for _, res := range cpuResources {
+			cpus += res.GetScalar().GetValue()
+		}
+
+		memResources := util.FilterResources(offer.Resources, func(res *mesos.Resource) bool {
+			return res.GetName() == "mem"
+		})
+		mems := 0.0
+		for _, res := range memResources {
+			mems += res.GetScalar().GetValue()
+		}
+
+		log.Infoln("Received Offer <", offer.Id.GetValue(), "> with cpus=", cpus, " mem=", mems)
+
+		remainingCpus := cpus
+		remainingMems := mems
+
+		var tasks []*mesos.TaskInfo
+		for sched.tasksLaunched < sched.totalTasks &&
+			CPUS_PER_TASK <= remainingCpus &&
+			MEM_PER_TASK <= remainingMems {
+
+			sched.tasksLaunched++
+
+			taskId := &mesos.TaskID{
+				Value: proto.String(strconv.Itoa(sched.tasksLaunched)),
+			}
+
+			task := &mesos.TaskInfo{
+				Name:     proto.String("go-task-" + taskId.GetValue()),
+				TaskId:   taskId,
+				SlaveId:  offer.SlaveId,
+				Executor: sched.executor,
+				Resources: []*mesos.Resource{
+					util.NewScalarResource("cpus", CPUS_PER_TASK),
+					util.NewScalarResource("mem", MEM_PER_TASK),
+				},
+			}
+			log.Infof("Prepared task: %s with offer %s for launch\n", task.GetName(), offer.Id.GetValue())
+
+			tasks = append(tasks, task)
+			remainingCpus -= CPUS_PER_TASK
+			remainingMems -= MEM_PER_TASK
+		}
+		log.Infoln("Launching ", len(tasks), "tasks for offer", offer.Id.GetValue())
+		driver.LaunchTasks([]*mesos.OfferID{offer.Id}, tasks, &mesos.Filters{RefuseSeconds: proto.Float64(1)})
+	}
+}
+
+func (sched *ExampleScheduler) StatusUpdate(driver sched.SchedulerDriver, status *mesos.TaskStatus) {
+	log.Infoln("Status update: task", status.TaskId.GetValue(), " is in state ", status.State.Enum().String())
+	if status.GetState() == mesos.TaskState_TASK_FINISHED {
+		sched.tasksFinished++
+	}
+
+	if sched.tasksFinished >= sched.totalTasks {
+		log.Infoln("Total tasks completed, stopping framework.")
+		driver.Stop(false)
+	}
+
+	if status.GetState() == mesos.TaskState_TASK_LOST ||
+		status.GetState() == mesos.TaskState_TASK_KILLED ||
+		status.GetState() == mesos.TaskState_TASK_FAILED {
+		log.Infoln(
+			"Aborting because task", status.TaskId.GetValue(),
+			"is in unexpected state", status.State.String(),
+			"with message", status.GetMessage(),
+		)
+		driver.Abort()
+	}
+}
+
+func (sched *ExampleScheduler) OfferRescinded(sched.SchedulerDriver, *mesos.OfferID) {}
+
+func (sched *ExampleScheduler) FrameworkMessage(sched.SchedulerDriver, *mesos.ExecutorID, *mesos.SlaveID, string) {
+}
+func (sched *ExampleScheduler) SlaveLost(sched.SchedulerDriver, *mesos.SlaveID) {}
+func (sched *ExampleScheduler) ExecutorLost(sched.SchedulerDriver, *mesos.ExecutorID, *mesos.SlaveID, int) {
+}
+
+func (sched *ExampleScheduler) Error(driver sched.SchedulerDriver, err string) {
+	log.Infoln("Scheduler received error:", err)
+}
+
+// ----------------------- func init() ------------------------- //
+
+func init() {
+	flag.Parse()
+	log.Infoln("Initializing the Example Scheduler...")
+}
+
+// returns (downloadURI, basename(path))
+func serveExecutorArtifact(path string) (*string, string) {
+	serveFile := func(pattern string, filename string) {
+		http.HandleFunc(pattern, func(w http.ResponseWriter, r *http.Request) {
+			http.ServeFile(w, r, filename)
+		})
+	}
+
+	// Create base path (http://foobar:5000/<base>)
+	pathSplit := strings.Split(path, "/")
+	var base string
+	if len(pathSplit) > 0 {
+		base = pathSplit[len(pathSplit)-1]
+	} else {
+		base = path
+	}
+	serveFile("/"+base, path)
+
+	hostURI := fmt.Sprintf("http://%s:%d/%s", *address, *artifactPort, base)
+	log.V(2).Infof("Hosting artifact '%s' at '%s'", path, hostURI)
+
+	return &hostURI, base
+}
+
+func prepareExecutorInfo() *mesos.ExecutorInfo {
+	executorUris := []*mesos.CommandInfo_URI{}
+	uri, executorCmd := serveExecutorArtifact(*executorPath)
+	executorUris = append(executorUris, &mesos.CommandInfo_URI{Value: uri, Executable: proto.Bool(true)})
+
+	executorCommand := fmt.Sprintf("./%s", executorCmd)
+
+	go http.ListenAndServe(fmt.Sprintf("%s:%d", *address, *artifactPort), nil)
+	log.V(2).Info("Serving executor artifacts...")
+
+	// Create mesos scheduler driver.
+	return &mesos.ExecutorInfo{
+		ExecutorId: util.NewExecutorID("default"),
+		Name:       proto.String("Test Executor (Go)"),
+		Source:     proto.String("go_test"),
+		Command: &mesos.CommandInfo{
+			Value: proto.String(executorCommand),
+			Uris:  executorUris,
+		},
+	}
+}
+
+func parseIP(address string) net.IP {
+	addr, err := net.LookupIP(address)
+	if err != nil {
+		log.Fatal(err)
+	}
+	if len(addr) < 1 {
+		log.Fatalf("failed to parse IP from address '%v'", address)
+	}
+	return addr[0]
+}
+
+// ----------------------- func main() ------------------------- //
+
+func main() {
+
+	// build command executor
+	exec := prepareExecutorInfo()
+
+	// the framework
+	fwinfo := &mesos.FrameworkInfo{
+		User: proto.String(""), // Mesos-go will fill in user.
+		Name: proto.String("Test Framework (Go)"),
+	}
+
+	cred := (*mesos.Credential)(nil)
+	if *mesosAuthPrincipal != "" {
+		fwinfo.Principal = proto.String(*mesosAuthPrincipal)
+		secret, err := ioutil.ReadFile(*mesosAuthSecretFile)
+		if err != nil {
+			log.Fatal(err)
+		}
+		cred = &mesos.Credential{
+			Principal: proto.String(*mesosAuthPrincipal),
+			Secret:    secret,
+		}
+	}
+	bindingAddress := parseIP(*address)
+	config := sched.DriverConfig{
+		Scheduler:      newExampleScheduler(exec),
+		Framework:      fwinfo,
+		Master:         *master,
+		Credential:     cred,
+		BindingAddress: bindingAddress,
+		WithAuthContext: func(ctx context.Context) context.Context {
+			ctx = auth.WithLoginProvider(ctx, *authProvider)
+			ctx = sasl.WithBindingAddress(ctx, bindingAddress)
+			return ctx
+		},
+	}
+	driver, err := sched.NewMesosSchedulerDriver(config)
+
+	if err != nil {
+		log.Errorln("Unable to create a SchedulerDriver ", err.Error())
+	}
+
+	if stat, err := driver.Run(); err != nil {
+		log.Infof("Framework stopped with status %s and error: %s\n", stat.String(), err.Error())
+	}
+
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor.go
index 05ed98581ee..2f6352c7f54 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor.go
@@ -185,6 +185,8 @@ func (driver *MesosExecutorDriver) setStatus(stat mesosproto.Status) {
 }
 
 func (driver *MesosExecutorDriver) Stopped() bool {
+	driver.lock.RLock()
+	defer driver.lock.RUnlock()
 	return driver.stopped
 }
 
@@ -195,6 +197,8 @@ func (driver *MesosExecutorDriver) setStopped(val bool) {
 }
 
 func (driver *MesosExecutorDriver) Connected() bool {
+	driver.lock.RLock()
+	defer driver.lock.RUnlock()
 	return driver.connected
 }
 
@@ -338,6 +342,8 @@ func (driver *MesosExecutorDriver) statusUpdateAcknowledgement(from *upid.UPID,
 	taskID := msg.GetTaskId()
 	uuid := uuid.UUID(msg.GetUuid())
 
+	driver.lock.Lock()
+	defer driver.lock.Unlock()
 	if driver.stopped {
 		log.Infof("Ignoring status update acknowledgement %v for task %v of framework %v because the driver is stopped!\n",
 			uuid, taskID, frameworkID)
@@ -526,7 +532,9 @@ func (driver *MesosExecutorDriver) SendStatusUpdate(taskStatus *mesosproto.TaskS
 	log.Infof("Executor sending status update %v\n", update.String())
 
 	// Capture the status update.
+	driver.lock.Lock()
 	driver.updates[uuid.UUID(update.GetUuid()).String()] = update
+	driver.lock.Unlock()
 
 	// Put the status update in the message.
 	message := &mesosproto.StatusUpdateMessage{
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor_intgr_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor_intgr_test.go
index 38b72731872..86199a94102 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor_intgr_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor_intgr_test.go
@@ -193,7 +193,7 @@ func TestExecutorDriverExecutorRegisteredEvent(t *testing.T) {
 	}
 	c := testutil.NewMockMesosClient(t, server.PID)
 	c.SendMessage(driver.self, pbMsg)
-	assert.True(t, driver.connected)
+	assert.True(t, driver.Connected())
 	select {
 	case <-ch:
 	case <-time.After(time.Millisecond * 2):
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor_test.go
index a2894b2c299..067e21cebfe 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/executor/executor_test.go
@@ -98,8 +98,10 @@ func TestExecutorDriverStartFailedToParseEnvironment(t *testing.T) {
 	clearEnvironments(t)
 	exec := NewMockedExecutor()
 	exec.On("Error").Return(nil)
-	driver := newTestExecutorDriver(t, exec)
+	dconfig := DriverConfig{Executor: exec}
+	driver, err := NewMesosExecutorDriver(dconfig)
 	assert.Nil(t, driver)
+	assert.Error(t, err)
 }
 
 func TestExecutorDriverStartFailedToStartMessenger(t *testing.T) {
@@ -206,7 +208,7 @@ func TestExecutorDriverRun(t *testing.T) {
 		assert.Equal(t, mesosproto.Status_DRIVER_STOPPED, stat)
 	}()
 	time.Sleep(time.Millisecond * 1) // allow for things to settle
-	assert.False(t, driver.stopped)
+	assert.False(t, driver.Stopped())
 	assert.Equal(t, mesosproto.Status_DRIVER_RUNNING, driver.Status())
 
 	// mannually close it all
@@ -394,3 +396,19 @@ func TestExecutorDriverSendFrameworkMessage(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, mesosproto.Status_DRIVER_RUNNING, stat)
 }
+
+func TestStatusUpdateAckRace_Issue103(t *testing.T) {
+	driver, _, _ := createTestExecutorDriver(t)
+	_, err := driver.Start()
+	assert.NoError(t, err)
+
+	msg := &mesosproto.StatusUpdateAcknowledgementMessage{}
+	go driver.statusUpdateAcknowledgement(nil, msg)
+
+	taskStatus := util.NewTaskStatus(
+		util.NewTaskID("test-task-001"),
+		mesosproto.TaskState_TASK_STAGING,
+	)
+
+	driver.SendStatusUpdate(taskStatus)
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/health_checker.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/health_checker.go
new file mode 100644
index 00000000000..a87ce133d59
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/health_checker.go
@@ -0,0 +1,40 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package healthchecker
+
+import (
+	"time"
+
+	"github.com/mesos/mesos-go/upid"
+)
+
+// HealthChecker defines the interface of a health checker.
+type HealthChecker interface {
+	// Start will start the health checker, and returns a notification channel.
+	// if the checker thinks the slave is unhealthy, it will send the timestamp
+	// via the channel.
+	Start() <-chan time.Time
+	// Pause will pause the slave health checker.
+	Pause()
+	// Continue will continue the slave health checker with a new slave upid.
+	Continue(slaveUPID *upid.UPID)
+	// Stop will stop the health checker. it should be called only once during
+	// the life span of the checker.
+	Stop()
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/mocked_slave_health_checker.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/mocked_slave_health_checker.go
new file mode 100644
index 00000000000..0bee139a530
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/mocked_slave_health_checker.go
@@ -0,0 +1,61 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package healthchecker
+
+import (
+	"time"
+
+	"github.com/mesos/mesos-go/upid"
+	"github.com/stretchr/testify/mock"
+)
+
+type MockedHealthChecker struct {
+	mock.Mock
+	ch chan time.Time
+}
+
+// NewMockedHealthChecker returns a new mocked health checker.
+func NewMockedHealthChecker() *MockedHealthChecker {
+	return &MockedHealthChecker{ch: make(chan time.Time, 1)}
+}
+
+// Start will start the checker and returns the notification channel.
+func (m *MockedHealthChecker) Start() <-chan time.Time {
+	m.Called()
+	return m.ch
+}
+
+// Pause will pause the slave health checker.
+func (m *MockedHealthChecker) Pause() {
+	m.Called()
+}
+
+// Continue will continue the slave health checker with a new slave upid.
+func (m *MockedHealthChecker) Continue(slaveUPID *upid.UPID) {
+	m.Called()
+}
+
+// Stop will stop the checker.
+func (m *MockedHealthChecker) Stop() {
+	m.Called()
+}
+
+func (m *MockedHealthChecker) TriggerUnhealthyEvent() {
+	m.ch <- time.Now()
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/slave_health_checker.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/slave_health_checker.go
new file mode 100644
index 00000000000..3627b59ddec
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/slave_health_checker.go
@@ -0,0 +1,138 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package healthchecker
+
+import (
+	"fmt"
+	"net/http"
+	"sync"
+	"time"
+
+	log "github.com/golang/glog"
+	"github.com/mesos/mesos-go/upid"
+)
+
+const (
+	defaultTimeout       = time.Second
+	defaultCheckDuration = time.Second
+	defaultThreshold     = 5
+)
+
+// SlaveHealthChecker is for checking the slave's health.
+type SlaveHealthChecker struct {
+	sync.RWMutex
+	slaveUPID                *upid.UPID
+	client                   *http.Client
+	threshold                int
+	checkDuration            time.Duration
+	continuousUnhealthyCount int
+	stop                     chan struct{}
+	ch                       chan time.Time
+	paused                   bool
+}
+
+// NewSlaveHealthChecker creates a slave health checker and return a notification channel.
+// Each time the checker thinks the slave is unhealthy, it will send a notification through the channel.
+func NewSlaveHealthChecker(slaveUPID *upid.UPID, threshold int, checkDuration time.Duration, timeout time.Duration) *SlaveHealthChecker {
+	checker := &SlaveHealthChecker{
+		slaveUPID:     slaveUPID,
+		client:        &http.Client{Timeout: timeout},
+		threshold:     threshold,
+		checkDuration: checkDuration,
+		stop:          make(chan struct{}),
+		ch:            make(chan time.Time, 1),
+	}
+	if timeout == 0 {
+		checker.client.Timeout = defaultTimeout
+	}
+	if checkDuration == 0 {
+		checker.checkDuration = defaultCheckDuration
+	}
+	if threshold <= 0 {
+		checker.threshold = defaultThreshold
+	}
+	return checker
+}
+
+// Start will start the health checker and returns the notification channel.
+func (s *SlaveHealthChecker) Start() <-chan time.Time {
+	go func() {
+		ticker := time.Tick(s.checkDuration)
+		for {
+			select {
+			case <-ticker:
+				s.RLock()
+				if !s.paused {
+					s.doCheck()
+				}
+				s.RUnlock()
+			case <-s.stop:
+				return
+			}
+		}
+	}()
+	return s.ch
+}
+
+// Pause will pause the slave health checker.
+func (s *SlaveHealthChecker) Pause() {
+	s.Lock()
+	defer s.Unlock()
+	s.paused = true
+}
+
+// Continue will continue the slave health checker with a new slave upid.
+func (s *SlaveHealthChecker) Continue(slaveUPID *upid.UPID) {
+	s.Lock()
+	defer s.Unlock()
+	s.paused = false
+	s.slaveUPID = slaveUPID
+}
+
+// Stop will stop the slave health checker.
+// It should be called only once during the life span of the checker.
+func (s *SlaveHealthChecker) Stop() {
+	close(s.stop)
+}
+
+func (s *SlaveHealthChecker) doCheck() {
+	path := fmt.Sprintf("http://%s:%s/%s/health", s.slaveUPID.Host, s.slaveUPID.Port, s.slaveUPID.ID)
+	resp, err := s.client.Head(path)
+	unhealthy := false
+	if err != nil {
+		log.Errorf("Failed to request the health path: %v\n", err)
+		unhealthy = true
+	} else if resp.StatusCode != http.StatusOK {
+		log.Errorf("Failed to request the health path: status: %v\n", resp.StatusCode)
+		unhealthy = true
+	}
+	if unhealthy {
+		s.continuousUnhealthyCount++
+		if s.continuousUnhealthyCount >= s.threshold {
+			select {
+			case s.ch <- time.Now(): // If no one is receiving the channel, then just skip it.
+			default:
+			}
+			s.continuousUnhealthyCount = 0
+		}
+		return
+	}
+	s.continuousUnhealthyCount = 0
+	resp.Body.Close()
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/slave_health_checker_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/slave_health_checker_test.go
new file mode 100644
index 00000000000..07cdb7cecbd
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/healthchecker/slave_health_checker_test.go
@@ -0,0 +1,262 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package healthchecker
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/mesos/mesos-go/upid"
+	"github.com/stretchr/testify/assert"
+)
+
+type thresholdMonitor struct {
+	cnt       int32
+	threshold int32
+}
+
+func newThresholdMonitor(threshold int) *thresholdMonitor {
+	return &thresholdMonitor{threshold: int32(threshold)}
+}
+
+// incAndTest returns true if the threshold is reached.
+func (t *thresholdMonitor) incAndTest() bool {
+	if atomic.AddInt32(&t.cnt, 1) >= t.threshold {
+		return false
+	}
+	return true
+}
+
+// blockedServer replies only threshold times, after that
+// it will block.
+type blockedServer struct {
+	th *thresholdMonitor
+	ch chan struct{}
+}
+
+func newBlockedServer(threshold int) *blockedServer {
+	return &blockedServer{
+		th: newThresholdMonitor(threshold),
+		ch: make(chan struct{}),
+	}
+}
+
+func (s *blockedServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if s.th.incAndTest() {
+		return
+	}
+	<-s.ch
+}
+
+func (s *blockedServer) stop() {
+	close(s.ch)
+}
+
+// eofServer will close the connection after it replies for threshold times.
+// Thus the health checker will get an EOF error.
+type eofServer struct {
+	th *thresholdMonitor
+}
+
+func newEOFServer(threshold int) *eofServer {
+	return &eofServer{newThresholdMonitor(threshold)}
+}
+
+func (s *eofServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if s.th.incAndTest() {
+		return
+	}
+	hj := w.(http.Hijacker)
+	conn, _, err := hj.Hijack()
+	if err != nil {
+		panic("Cannot hijack")
+	}
+	conn.Close()
+}
+
+// errorStatusCodeServer will reply error status code (e.g. 503) after the
+// it replies for threhold time.
+type errorStatusCodeServer struct {
+	th *thresholdMonitor
+}
+
+func newErrorStatusServer(threshold int) *errorStatusCodeServer {
+	return &errorStatusCodeServer{newThresholdMonitor(threshold)}
+}
+
+func (s *errorStatusCodeServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if s.th.incAndTest() {
+		return
+	}
+	w.WriteHeader(http.StatusServiceUnavailable)
+}
+
+// goodServer always returns status ok.
+type goodServer bool
+
+func (s *goodServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {}
+
+// partitionedServer returns status ok at some first requests.
+// Then it will block for a while, and then reply again.
+type partitionedServer struct {
+	healthyCnt   int32
+	partitionCnt int32
+	cnt          int32
+	mutex        *sync.Mutex
+	cond         *sync.Cond
+}
+
+func newPartitionedServer(healthyCnt, partitionCnt int) *partitionedServer {
+	mutex := new(sync.Mutex)
+	cond := sync.NewCond(mutex)
+	return &partitionedServer{
+		healthyCnt:   int32(healthyCnt),
+		partitionCnt: int32(partitionCnt),
+		mutex:        mutex,
+		cond:         cond,
+	}
+}
+
+func (s *partitionedServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	cnt := atomic.AddInt32(&s.cnt, 1)
+	if cnt < s.healthyCnt {
+		return
+	}
+	if cnt < s.healthyCnt+s.partitionCnt {
+		s.mutex.Lock()
+		defer s.mutex.Unlock()
+		s.cond.Wait()
+		return
+	}
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+	s.cond.Broadcast()
+}
+
+func TestSlaveHealthCheckerFailedOnBlockedSlave(t *testing.T) {
+	s := newBlockedServer(5)
+	ts := httptest.NewUnstartedServer(s)
+	ts.Start()
+	defer ts.Close()
+
+	upid, err := upid.Parse(fmt.Sprintf("slave@%s", ts.Listener.Addr().String()))
+	assert.NoError(t, err)
+
+	checker := NewSlaveHealthChecker(upid, 10, time.Millisecond*10, time.Millisecond*10)
+	ch := checker.Start()
+	defer checker.Stop()
+
+	select {
+	case <-time.After(time.Second):
+		s.stop()
+		t.Fatal("timeout")
+	case <-ch:
+		s.stop()
+		assert.True(t, atomic.LoadInt32(&s.th.cnt) > 10)
+	}
+}
+
+func TestSlaveHealthCheckerFailedOnEOFSlave(t *testing.T) {
+	s := newEOFServer(5)
+	ts := httptest.NewUnstartedServer(s)
+	ts.Start()
+	defer ts.Close()
+
+	upid, err := upid.Parse(fmt.Sprintf("slave@%s", ts.Listener.Addr().String()))
+	assert.NoError(t, err)
+
+	checker := NewSlaveHealthChecker(upid, 10, time.Millisecond*10, time.Millisecond*10)
+	ch := checker.Start()
+	defer checker.Stop()
+
+	select {
+	case <-time.After(time.Second):
+		t.Fatal("timeout")
+	case <-ch:
+		assert.True(t, atomic.LoadInt32(&s.th.cnt) > 10)
+	}
+}
+
+func TestSlaveHealthCheckerFailedOnErrorStatusSlave(t *testing.T) {
+	s := newErrorStatusServer(5)
+	ts := httptest.NewUnstartedServer(s)
+	ts.Start()
+	defer ts.Close()
+
+	upid, err := upid.Parse(fmt.Sprintf("slave@%s", ts.Listener.Addr().String()))
+	assert.NoError(t, err)
+
+	checker := NewSlaveHealthChecker(upid, 10, time.Millisecond*10, time.Millisecond*10)
+	ch := checker.Start()
+	defer checker.Stop()
+
+	select {
+	case <-time.After(time.Second):
+		t.Fatal("timeout")
+	case <-ch:
+		assert.True(t, atomic.LoadInt32(&s.th.cnt) > 10)
+	}
+}
+
+func TestSlaveHealthCheckerSucceed(t *testing.T) {
+	s := new(goodServer)
+	ts := httptest.NewUnstartedServer(s)
+	ts.Start()
+	defer ts.Close()
+
+	upid, err := upid.Parse(fmt.Sprintf("slave@%s", ts.Listener.Addr().String()))
+	assert.NoError(t, err)
+
+	checker := NewSlaveHealthChecker(upid, 10, time.Millisecond*10, time.Millisecond*10)
+	ch := checker.Start()
+	defer checker.Stop()
+
+	select {
+	case <-time.After(time.Second):
+		assert.Equal(t, 0, checker.continuousUnhealthyCount)
+	case <-ch:
+		t.Fatal("Shouldn't get unhealthy notification")
+	}
+}
+
+func TestSlaveHealthCheckerPartitonedSlave(t *testing.T) {
+	s := newPartitionedServer(5, 9)
+	ts := httptest.NewUnstartedServer(s)
+	ts.Start()
+	defer ts.Close()
+
+	upid, err := upid.Parse(fmt.Sprintf("slave@%s", ts.Listener.Addr().String()))
+	assert.NoError(t, err)
+
+	checker := NewSlaveHealthChecker(upid, 10, time.Millisecond*10, time.Millisecond*10)
+	ch := checker.Start()
+	defer checker.Stop()
+
+	select {
+	case <-time.After(time.Second):
+		assert.Equal(t, 0, checker.continuousUnhealthyCount)
+	case <-ch:
+		t.Fatal("Shouldn't get unhealthy notification")
+	}
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/mesos/doc.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/mesos/doc.go
new file mode 100644
index 00000000000..6c0973f34c2
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/mesos/doc.go
@@ -0,0 +1,3 @@
+// This package was previously the home of the native bindings. Please use the
+// native branch if you need to build against the native bindings.
+package mesos
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/README.md b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/README.md
index da0673e78a0..d3535253d31 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/README.md
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/README.md
@@ -1,7 +1,7 @@
 ####Benchmark of the messenger.
 
 ```shell
-$ go test -v -run=Benckmark* -bench=.
+$ go test -v -run=Benckmark* -bench=. 
 PASS
 BenchmarkMessengerSendSmallMessage	   50000	     70568 ns/op
 BenchmarkMessengerSendMediumMessage	   50000	     70265 ns/op
@@ -29,7 +29,7 @@ BenchmarkMessengerSendRecvLargeMessage-4	   50000	     45472 ns/op
 BenchmarkMessengerSendRecvMixedMessage-4	   50000	     47393 ns/op
 ok  	github.com/mesos/mesos-go/messenger	105.173s
 ```
-
+ 
 ####environment:
 
 ```
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/http_transporter.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/http_transporter.go
index 30370b04835..cfd7f2583a9 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/http_transporter.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/http_transporter.go
@@ -21,7 +21,6 @@ package messenger
 import (
 	"bytes"
 	"fmt"
-	"github.com/mesos/mesos-go/upid"
 	"io/ioutil"
 	"net"
 	"net/http"
@@ -33,6 +32,7 @@ import (
 	"time"
 
 	log "github.com/golang/glog"
+	"github.com/mesos/mesos-go/upid"
 	"golang.org/x/net/context"
 )
 
@@ -235,7 +235,14 @@ func (t *HTTPTransporter) listen() error {
 	} else {
 		host = t.upid.Host
 	}
-	port := t.upid.Port
+
+	var port string
+	if t.upid.Port != "" {
+		port = t.upid.Port
+	} else {
+		port = "0"
+	}
+
 	// NOTE: Explicitly specifies IPv4 because Libprocess
 	// only supports IPv4 for now.
 	ln, err := net.Listen("tcp4", net.JoinHostPort(host, port))
@@ -245,7 +252,15 @@ func (t *HTTPTransporter) listen() error {
 	}
 	// Save the host:port in case they are not specified in upid.
 	host, port, _ = net.SplitHostPort(ln.Addr().String())
-	t.upid.Host, t.upid.Port = host, port
+
+	if len(t.upid.Host) == 0 {
+		t.upid.Host = host
+	}
+
+	if len(t.upid.Port) == 0 || t.upid.Port == "0" {
+		t.upid.Port = port
+	}
+
 	t.listener = ln
 	return nil
 }
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/http_transporter_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/http_transporter_test.go
index e1d14096526..f3dc1e56bf4 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/http_transporter_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/http_transporter_test.go
@@ -2,6 +2,7 @@ package messenger
 
 import (
 	"fmt"
+	"net"
 	"net/http"
 	"net/http/httptest"
 	"regexp"
@@ -266,6 +267,66 @@ func TestTransporterStartAndStop(t *testing.T) {
 	}
 }
 
+func TestMutatedHostUPid(t *testing.T) {
+	serverId := "testserver"
+	serverPort := getNewPort()
+	serverHost := "127.0.0.1"
+	serverAddr := serverHost + ":" + strconv.Itoa(serverPort)
+
+	// override the upid.Host with this listener IP
+	addr := net.ParseIP("127.0.0.2")
+
+	// setup receiver (server) process
+	uPid, err := upid.Parse(fmt.Sprintf("%s@%s", serverId, serverAddr))
+	assert.NoError(t, err)
+	receiver := NewHTTPTransporter(uPid, addr)
+
+	err = receiver.listen()
+	assert.NoError(t, err)
+
+	if receiver.upid.Host != "127.0.0.1" {
+		t.Fatalf("reciever.upid.Host was expected to return %s, got %s\n", serverHost, receiver.upid.Host)
+	}
+
+	if receiver.upid.Port != strconv.Itoa(serverPort) {
+		t.Fatalf("receiver.upid.Port was expected to return %d, got %s\n", serverPort, receiver.upid.Port)
+	}
+}
+
+func TestEmptyHostPortUPid(t *testing.T) {
+	serverId := "testserver"
+	serverPort := getNewPort()
+	serverHost := "127.0.0.1"
+	serverAddr := serverHost + ":" + strconv.Itoa(serverPort)
+
+	// setup receiver (server) process
+	uPid, err := upid.Parse(fmt.Sprintf("%s@%s", serverId, serverAddr))
+	assert.NoError(t, err)
+
+	// Unset upid host and port
+	uPid.Host = ""
+	uPid.Port = ""
+
+	// override the upid.Host with this listener IP
+	addr := net.ParseIP("127.0.0.2")
+
+	receiver := NewHTTPTransporter(uPid, addr)
+
+	err = receiver.listen()
+	assert.NoError(t, err)
+
+	// This should be the host that overrides as uPid.Host is empty
+	if receiver.upid.Host != "127.0.0.2" {
+		t.Fatalf("reciever.upid.Host was expected to return %s, got %s\n", serverHost, receiver.upid.Host)
+	}
+
+	// This should end up being a random port, not the server port as uPid
+	// port is empty
+	if receiver.upid.Port == strconv.Itoa(serverPort) {
+		t.Fatalf("receiver.upid.Port was not expected to return %d, got %s\n", serverPort, receiver.upid.Port)
+	}
+}
+
 func makeMockServer(path string, handler func(rsp http.ResponseWriter, req *http.Request)) *httptest.Server {
 	mux := http.NewServeMux()
 	mux.HandleFunc(path, handler)
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/messenger.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/messenger.go
index 5b242e5bce3..c81ad31853c 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/messenger.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/messenger.go
@@ -76,41 +76,62 @@ type MesosMessenger struct {
 	tr                Transporter
 }
 
-// create a new default messenger (HTTP). If a non-nil, non-wildcard bindingAddress is
-// specified then it will be used for both the UPID and Transport binding address. Otherwise
-// hostname is resolved to an IP address and the UPID.Host is set to that address and the
-// bindingAddress is passed through to the Transport.
+// ForHostname creates a new default messenger (HTTP), using UPIDBindingAddress to
+// determine the binding-address used for both the UPID.Host and Transport binding address.
 func ForHostname(proc *process.Process, hostname string, bindingAddress net.IP, port uint16) (Messenger, error) {
 	upid := &upid.UPID{
 		ID:   proc.Label(),
 		Port: strconv.Itoa(int(port)),
 	}
+	host, err := UPIDBindingAddress(hostname, bindingAddress)
+	if err != nil {
+		return nil, err
+	}
+	upid.Host = host
+	return NewHttpWithBindingAddress(upid, bindingAddress), nil
+}
+
+// UPIDBindingAddress determines the value of UPID.Host that will be used to build
+// a Transport. If a non-nil, non-wildcard bindingAddress is specified then it will be used
+// for both the UPID and Transport binding address. Otherwise hostname is resolved to an IP
+// address and the UPID.Host is set to that address and the bindingAddress is passed through
+// to the Transport.
+func UPIDBindingAddress(hostname string, bindingAddress net.IP) (string, error) {
+	upidHost := ""
 	if bindingAddress != nil && "0.0.0.0" != bindingAddress.String() {
-		upid.Host = bindingAddress.String()
+		upidHost = bindingAddress.String()
 	} else {
-		ips, err := net.LookupIP(hostname)
-		if err != nil {
-			return nil, err
+		if hostname == "" || hostname == "0.0.0.0" {
+			return "", fmt.Errorf("invalid hostname (%q) specified with binding address %v", hostname, bindingAddress)
 		}
-		// try to find an ipv4 and use that
-		ip := net.IP(nil)
-		for _, addr := range ips {
-			if ip = addr.To4(); ip != nil {
-				break
-			}
+		ip := net.ParseIP(hostname)
+		if ip != nil {
+			ip = ip.To4()
 		}
 		if ip == nil {
-			// no ipv4? best guess, just take the first addr
-			if len(ips) > 0 {
-				ip = ips[0]
-				log.Warningf("failed to find an IPv4 address for '%v', best guess is '%v'", hostname, ip)
-			} else {
-				return nil, fmt.Errorf("failed to determine IP address for host '%v'", hostname)
+			ips, err := net.LookupIP(hostname)
+			if err != nil {
+				return "", err
+			}
+			// try to find an ipv4 and use that
+			for _, addr := range ips {
+				if ip = addr.To4(); ip != nil {
+					break
+				}
+			}
+			if ip == nil {
+				// no ipv4? best guess, just take the first addr
+				if len(ips) > 0 {
+					ip = ips[0]
+					log.Warningf("failed to find an IPv4 address for '%v', best guess is '%v'", hostname, ip)
+				} else {
+					return "", fmt.Errorf("failed to determine IP address for host '%v'", hostname)
+				}
 			}
 		}
-		upid.Host = ip.String()
+		upidHost = ip.String()
 	}
-	return NewHttpWithBindingAddress(upid, bindingAddress), nil
+	return upidHost, nil
 }
 
 // NewMesosMessenger creates a new mesos messenger.
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/messenger_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/messenger_test.go
index 096f201116c..4a189537004 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/messenger_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/messenger/messenger_test.go
@@ -3,6 +3,7 @@ package messenger
 import (
 	"fmt"
 	"math/rand"
+	"net"
 	"net/http"
 	"net/http/httptest"
 	"strconv"
@@ -431,3 +432,35 @@ func BenchmarkMessengerSendRecvMixedMessage(b *testing.B) {
 	}
 	globalWG.Wait()
 }
+
+func TestUPIDBindingAddress(t *testing.T) {
+	tt := []struct {
+		hostname string
+		binding  net.IP
+		expected string
+	}{
+		{"", nil, ""},
+		{"", net.IPv4(1, 2, 3, 4), "1.2.3.4"},
+		{"", net.IPv4(0, 0, 0, 0), ""},
+		{"localhost", nil, "127.0.0.1"},
+		{"localhost", net.IPv4(5, 6, 7, 8), "5.6.7.8"},
+		{"localhost", net.IPv4(0, 0, 0, 0), "127.0.0.1"},
+		{"0.0.0.0", nil, ""},
+		{"7.8.9.1", nil, "7.8.9.1"},
+		{"7.8.9.1", net.IPv4(0, 0, 0, 0), "7.8.9.1"},
+		{"7.8.9.1", net.IPv4(8, 9, 1, 2), "8.9.1.2"},
+	}
+
+	for i, tc := range tt {
+		actual, err := UPIDBindingAddress(tc.hostname, tc.binding)
+		if err != nil && tc.expected != "" {
+			t.Fatalf("test case %d failed; expected %q instead of error %v", i+1, tc.expected, err)
+		}
+		if err == nil && actual != tc.expected {
+			t.Fatalf("test case %d failed; expected %q instead of %q", i+1, tc.expected, actual)
+		}
+		if err != nil {
+			t.Logf("test case %d; received expected error %v", i+1, err)
+		}
+	}
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/scheduler/scheduler.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/scheduler/scheduler.go
index 439e9977f87..90204994af5 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/scheduler/scheduler.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/scheduler/scheduler.go
@@ -478,7 +478,7 @@ func (driver *MesosSchedulerDriver) frameworkReregistered(from *upid.UPID, pbMsg
 }
 
 func (driver *MesosSchedulerDriver) resourcesOffered(from *upid.UPID, pbMsg proto.Message) {
-	log.V(1).Infoln("Handling resource offers.")
+	log.V(2).Infoln("Handling resource offers.")
 
 	msg := pbMsg.(*mesos.ResourceOffersMessage)
 	if driver.Status() == mesos.Status_DRIVER_ABORTED {
@@ -500,7 +500,7 @@ func (driver *MesosSchedulerDriver) resourcesOffered(from *upid.UPID, pbMsg prot
 	for i, offer := range msg.Offers {
 		if pid, err := upid.Parse(pidStrings[i]); err == nil {
 			driver.cache.putOffer(offer, pid)
-			log.V(1).Infof("Cached offer %s from SlavePID %s", offer.Id.GetValue(), pid)
+			log.V(2).Infof("Cached offer %s from SlavePID %s", offer.Id.GetValue(), pid)
 		} else {
 			log.Warningf("Failed to parse offer PID '%v': %v", pid, err)
 		}
@@ -822,11 +822,15 @@ func (driver *MesosSchedulerDriver) Stop(failover bool) (mesos.Status, error) {
 		return stat, fmt.Errorf("Unable to Stop, expected driver status %s, but is %s", mesos.Status_DRIVER_RUNNING, stat)
 	}
 
-	if driver.connected && failover {
+	if driver.connected && !failover {
 		// unregister the framework
+		log.Infoln("Unregistering the scheduler driver")
 		message := &mesos.UnregisterFrameworkMessage{
 			FrameworkId: driver.FrameworkInfo.Id,
 		}
+		//TODO(jdef) this is actually a little racy: we send an 'unregister' message but then
+		// immediately afterward the messenger is stopped in driver.stop(). so the unregister message
+		// may not actually end up being sent out.
 		if err := driver.send(driver.MasterPid, message); err != nil {
 			log.Errorf("Failed to send UnregisterFramework message while stopping driver: %v\n", err)
 			return driver.stop(mesos.Status_DRIVER_ABORTED)
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/scheduler/scheduler_unit_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/scheduler/scheduler_unit_test.go
index 423459f6a8a..add643262fa 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/scheduler/scheduler_unit_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/scheduler/scheduler_unit_test.go
@@ -20,7 +20,6 @@ package scheduler
 
 import (
 	"fmt"
-	"os"
 	"os/user"
 	"sync"
 	"testing"
@@ -38,6 +37,7 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/suite"
+	"golang.org/x/net/context"
 )
 
 var (
@@ -137,7 +137,7 @@ func TestSchedulerDriverNew(t *testing.T) {
 	driver := newTestSchedulerDriver(t, NewMockScheduler(), &mesos.FrameworkInfo{}, masterAddr, nil)
 	user, _ := user.Current()
 	assert.Equal(t, user.Username, driver.FrameworkInfo.GetUser())
-	host, _ := os.Hostname()
+	host := util.GetHostname("")
 	assert.Equal(t, host, driver.FrameworkInfo.GetHostname())
 }
 
@@ -335,9 +335,19 @@ func (suite *SchedulerTestSuite) TestSchedulerDriverStopUnstarted() {
 	suite.Equal(mesos.Status_DRIVER_NOT_STARTED, stat)
 }
 
-func (suite *SchedulerTestSuite) TestSchdulerDriverStopOK() {
+type msgTracker struct {
+	*messenger.MockedMessenger
+	lastMessage proto.Message
+}
+
+func (m *msgTracker) Send(ctx context.Context, upid *upid.UPID, msg proto.Message) error {
+	m.lastMessage = msg
+	return m.MockedMessenger.Send(ctx, upid, msg)
+}
+
+func (suite *SchedulerTestSuite) TestSchdulerDriverStop_WithoutFailover() {
 	// Set expections and return values.
-	messenger := messenger.NewMockedMessenger()
+	messenger := &msgTracker{MockedMessenger: messenger.NewMockedMessenger()}
 	messenger.On("Start").Return(nil)
 	messenger.On("UPID").Return(&upid.UPID{})
 	messenger.On("Send").Return(nil)
@@ -357,9 +367,54 @@ func (suite *SchedulerTestSuite) TestSchdulerDriverStopOK() {
 
 	suite.False(driver.Stopped())
 	suite.Equal(mesos.Status_DRIVER_RUNNING, driver.Status())
+	driver.connected = true // pretend that we're already registered
 
 	driver.Stop(false)
-	time.Sleep(time.Millisecond * 1)
+
+	msg := messenger.lastMessage
+	suite.NotNil(msg)
+	_, isUnregMsg := msg.(proto.Message)
+	suite.True(isUnregMsg, "expected UnregisterFrameworkMessage instead of %+v", msg)
+
+	suite.True(driver.Stopped())
+	suite.Equal(mesos.Status_DRIVER_STOPPED, driver.Status())
+}
+
+func (suite *SchedulerTestSuite) TestSchdulerDriverStop_WithFailover() {
+	// Set expections and return values.
+	messenger := &msgTracker{MockedMessenger: messenger.NewMockedMessenger()}
+	messenger.On("Start").Return(nil)
+	messenger.On("UPID").Return(&upid.UPID{})
+	messenger.On("Send").Return(nil)
+	messenger.On("Stop").Return(nil)
+	messenger.On("Route").Return(nil)
+
+	driver := newTestSchedulerDriver(suite.T(), NewMockScheduler(), suite.framework, suite.master, nil)
+	driver.messenger = messenger
+	suite.True(driver.Stopped())
+
+	stat, err := driver.Start()
+	suite.NoError(err)
+	suite.Equal(mesos.Status_DRIVER_RUNNING, stat)
+	suite.False(driver.Stopped())
+	driver.connected = true // pretend that we're already registered
+
+	go func() {
+		// Run() blocks until the driver is stopped or aborted
+		stat, err := driver.Join()
+		suite.NoError(err)
+		suite.Equal(mesos.Status_DRIVER_STOPPED, stat)
+	}()
+
+	// wait for Join() to begin blocking (so that it has already validated the driver state)
+	time.Sleep(200 * time.Millisecond)
+
+	driver.Stop(true) // true = scheduler failover
+	msg := messenger.lastMessage
+
+	// we're expecting that lastMessage is nil because when failing over there's no
+	// 'unregister' message sent by the scheduler.
+	suite.Nil(msg)
 
 	suite.True(driver.Stopped())
 	suite.Equal(mesos.Status_DRIVER_STOPPED, driver.Status())
@@ -410,7 +465,7 @@ func (suite *SchedulerTestSuite) TestSchdulerDriverLunchTasksUnstarted() {
 	suite.True(driver.Stopped())
 
 	stat, err := driver.LaunchTasks(
-		[]*mesos.OfferID{&mesos.OfferID{}},
+		[]*mesos.OfferID{{}},
 		[]*mesos.TaskInfo{},
 		&mesos.Filters{},
 	)
@@ -514,7 +569,7 @@ func (suite *SchedulerTestSuite) TestSchdulerDriverLaunchTasks() {
 	tasks := []*mesos.TaskInfo{task}
 
 	stat, err := driver.LaunchTasks(
-		[]*mesos.OfferID{&mesos.OfferID{}},
+		[]*mesos.OfferID{{}},
 		tasks,
 		&mesos.Filters{},
 	)
@@ -565,7 +620,7 @@ func (suite *SchedulerTestSuite) TestSchdulerDriverRequestResources() {
 
 	stat, err := driver.RequestResources(
 		[]*mesos.Request{
-			&mesos.Request{
+			{
 				SlaveId: util.NewSlaveID("test-slave-001"),
 				Resources: []*mesos.Resource{
 					util.NewScalarResource("test-res-001", 33.00),
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/testutil/testingutil.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/testutil/testingutil.go
new file mode 100644
index 00000000000..5ec1d58ca12
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/testutil/testingutil.go
@@ -0,0 +1,135 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//Collection of resources for teting mesos artifacts.
+package testutil
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/gogo/protobuf/proto"
+	log "github.com/golang/glog"
+	"github.com/mesos/mesos-go/upid"
+	"github.com/stretchr/testify/assert"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"reflect"
+	"testing"
+)
+
+//MockMesosHttpProcess represents a remote http process: master or slave.
+type MockMesosHttpServer struct {
+	PID    *upid.UPID
+	Addr   string
+	server *httptest.Server
+	t      *testing.T
+	when   map[string]http.HandlerFunc
+}
+
+type When interface {
+	Do(http.HandlerFunc)
+}
+
+type WhenFunc func(http.HandlerFunc)
+
+func (w WhenFunc) Do(f http.HandlerFunc) {
+	w(f)
+}
+
+func (m *MockMesosHttpServer) On(uri string) When {
+	log.V(2).Infof("when %v do something special", uri)
+	return WhenFunc(func(f http.HandlerFunc) {
+		log.V(2).Infof("registered callback for %v", uri)
+		m.when[uri] = f
+	})
+}
+
+func NewMockMasterHttpServer(t *testing.T, handler func(rsp http.ResponseWriter, req *http.Request)) *MockMesosHttpServer {
+	var server *httptest.Server
+	when := make(map[string]http.HandlerFunc)
+	stateHandler := func(rsp http.ResponseWriter, req *http.Request) {
+		if "/state.json" == req.RequestURI {
+			state := fmt.Sprintf(`{ "leader": "master@%v" }`, server.Listener.Addr())
+			log.V(1).Infof("returning JSON %v", state)
+			io.WriteString(rsp, state)
+		} else if f, found := when[req.RequestURI]; found {
+			f(rsp, req)
+		} else {
+			handler(rsp, req)
+		}
+	}
+	server = httptest.NewServer(http.HandlerFunc(stateHandler))
+	assert.NotNil(t, server)
+	addr := server.Listener.Addr().String()
+	pid, err := upid.Parse("master@" + addr)
+	assert.NoError(t, err)
+	assert.NotNil(t, pid)
+	log.Infoln("Created test Master http server with PID", pid.String())
+	return &MockMesosHttpServer{PID: pid, Addr: addr, server: server, t: t, when: when}
+}
+
+func NewMockSlaveHttpServer(t *testing.T, handler func(rsp http.ResponseWriter, req *http.Request)) *MockMesosHttpServer {
+	server := httptest.NewServer(http.HandlerFunc(handler))
+	assert.NotNil(t, server)
+	addr := server.Listener.Addr().String()
+	pid, err := upid.Parse("slave(1)@" + addr)
+	assert.NoError(t, err)
+	assert.NotNil(t, pid)
+	assert.NoError(t, os.Setenv("MESOS_SLAVE_PID", pid.String()))
+	assert.NoError(t, os.Setenv("MESOS_SLAVE_ID", "test-slave-001"))
+	log.Infoln("Created test Slave http server with PID", pid.String())
+	return &MockMesosHttpServer{PID: pid, Addr: addr, server: server, t: t}
+}
+
+func (s *MockMesosHttpServer) Close() {
+	s.server.Close()
+}
+
+//MockMesosClient Http client to communicate with mesos processes (master,sched,exec)
+type MockMesosClient struct {
+	pid *upid.UPID
+	t   *testing.T
+}
+
+func NewMockMesosClient(t *testing.T, pid *upid.UPID) *MockMesosClient {
+	return &MockMesosClient{t: t, pid: pid}
+}
+
+// sendMessage Mocks sending event messages to a processes such as master, sched or exec.
+func (c *MockMesosClient) SendMessage(targetPid *upid.UPID, message proto.Message) {
+	if c.t == nil {
+		panic("MockMesosClient needs a testing context.")
+	}
+
+	messageName := reflect.TypeOf(message).Elem().Name()
+	data, err := proto.Marshal(message)
+	assert.NoError(c.t, err)
+	hostport := net.JoinHostPort(targetPid.Host, targetPid.Port)
+	targetURL := fmt.Sprintf("http://%s/%s/mesos.internal.%s", hostport, targetPid.ID, messageName)
+	log.Infoln("MockMesosClient Sending message to", targetURL)
+	req, err := http.NewRequest("POST", targetURL, bytes.NewReader(data))
+	assert.NoError(c.t, err)
+	req.Header.Add("Libprocess-From", c.pid.String())
+	req.Header.Add("Content-Type", "application/x-protobuf")
+	resp, err := http.DefaultClient.Do(req)
+	assert.NoError(c.t, err)
+	assert.Equal(c.t, http.StatusAccepted, resp.StatusCode)
+}
diff --git a/Godeps/_workspace/src/github.com/mesos/mesos-go/upid/upid_test.go b/Godeps/_workspace/src/github.com/mesos/mesos-go/upid/upid_test.go
index a7470b47ff8..99d446bfd34 100644
--- a/Godeps/_workspace/src/github.com/mesos/mesos-go/upid/upid_test.go
+++ b/Godeps/_workspace/src/github.com/mesos/mesos-go/upid/upid_test.go
@@ -1,21 +1,12 @@
 package upid
 
 import (
-	"math/rand"
-	"strings"
 	"testing"
+	"testing/quick"
 
 	"github.com/stretchr/testify/assert"
 )
 
-func generateRandomString() string {
-	b := make([]byte, rand.Intn(1024))
-	for i := range b {
-		b[i] = byte(rand.Int())
-	}
-	return strings.Replace(string(b), "@", "", -1)
-}
-
 func TestUPIDParse(t *testing.T) {
 	u, err := Parse("mesos@foo:bar")
 	assert.Nil(t, u)
@@ -29,17 +20,10 @@ func TestUPIDParse(t *testing.T) {
 	assert.Nil(t, u)
 	assert.Error(t, err)
 
-	// Simple fuzzy test.
-	for i := 0; i < 100000; i++ {
-		ra := generateRandomString()
-		u, err = Parse(ra)
-		if u != nil {
-			println(ra)
-		}
-		assert.Nil(t, u)
-		assert.Error(t, err)
-	}
-
+	assert.Nil(t, quick.Check(func(s string) bool {
+		u, err := Parse(s)
+		return u == nil && err != nil
+	}, &quick.Config{MaxCount: 100000}))
 }
 
 func TestUPIDString(t *testing.T) {