fixed performance issue with engine check

Author: ehazlett

controller/manager/manager.go

@@ -47,6 +47,7 @@ var (
 	ErrWebhookKeyDoesNotExist = errors.New("webhook key does not exist")
 	logger                    = logrus.New()
 	store                     = sessions.NewCookieStore([]byte(storeKey))
+	httpTimeout               = time.Duration(1 * time.Second)
 )
 
 type (
@@ -65,6 +66,10 @@ type (
 	}
 )
 
+func dialTimeout(network, addr string) (net.Conn, error) {
+	return net.DialTimeout(network, addr, httpTimeout)
+}
+
 func NewManager(addr string, database string, authKey string, version string, disableUsageInfo bool) (*Manager, error) {
 	session, err := r.Connect(r.ConnectOpts{
 		Address:     addr,
@@ -169,9 +174,8 @@ func (m *Manager) init() []*shipyard.Engine {
 	m.clusterManager = clusterManager
 	// start extension health check
 	go m.extensionHealthCheck()
-	// FIXME: these have been temporarily disabled due to performance issues
-	//// start engine check
-	//go m.engineCheck()
+	// start engine check
+	go m.engineCheck()
 	// anonymous usage info
 	go m.usageReport()
 	return engines
@@ -280,7 +284,10 @@ func (m *Manager) engineCheck() {
 			for _, eng := range engs {
 				health := &shipyard.Health{}
 				start_time := time.Now()
-				stat, _ := m.pingEngine(eng.Engine.Addr)
+				stat, err := m.pingEngine(eng.Engine.Addr)
+				if err != nil {
+					logger.Warnf("unable to ping engine: %s", err)
+				}
 				if stat != 200 {
 					health.Status = EngineHealthDown
 				} else {
@@ -292,18 +299,27 @@ func (m *Manager) engineCheck() {
 				version, err := eng.Engine.Version()
 				if err != nil {
 					logger.Warnf("unable to detect docker version: %s", err)
-					return
 				}
-				eng.DockerVersion = version.Version
+				ver := "unknown"
+				if version != nil {
+					ver = version.Version
+				}
+				eng.DockerVersion = ver
 				m.SaveEngine(eng)
 			}
 		}
 	}
 }
 
 func (m *Manager) pingEngine(addr string) (status int, err error) {
+	transport := http.Transport{
+		Dial: dialTimeout,
+	}
+	client := http.Client{
+		Transport: &transport,
+	}
 	uri := fmt.Sprintf("%s/_ping", addr)
-	resp, err := http.Get(uri)
+	resp, err := client.Get(uri)
 	if err != nil {
 		return 0, err
 	} else {

controller/static/templates/engines.html

@@ -18,29 +18,28 @@
 <table class="ui sortable table segment" ng-show="engines">
     <thead>
         <tr>
-            <!--<th class="healthcolumn" ng-click="selectSortColumn('health.status')"><i class="medkit icon"></i></th>-->
+            <th class="healthcolumn" ng-click="selectSortColumn('health.status')"><i class="medkit icon"></i></th>
             <th ng-class="sortedTableHeading('engine.id')" ng-click="selectSortColumn('engine.id')">Name</th>
             <th ng-class="sortedTableHeading('engine.cpus')" ng-click="selectSortColumn('engine.cpus')">CPUs</th>
             <th ng-class="sortedTableHeading('engine.memory')" ng-click="selectSortColumn('engine.memory')">Memory</th>
             <th ng-class="sortedTableHeading('engine.addr')" ng-click="selectSortColumn('engine.addr')">Addr</th>
             <th ng-class="sortedTableHeading('engine.labels')" ng-click="selectSortColumn('engine.labels')">Labels</th>
-            <!--<th ng-class="sortedTableHeading('health.response_time')" ng-click="selectSortColumn('health.response_time')">Response Time (ms)</th>-->
+            <th ng-class="sortedTableHeading('health.response_time')" ng-click="selectSortColumn('health.response_time')">Response Time (ms)</th>
             <th ng-class="sortedTableHeading('engine.docker_version')" ng-click="selectSortColumn('engine.docker_version')">Docker Version</th>
         </tr>
     </thead>
     <tbody>
         <tr ng-repeat="e in engines | orderBy:orderByField:reverseSort" ng-click="go();" class="rowlink">
-            <!--
             <td class="healthcolumn">
-            <span class="ui circular label ng-class:{'green': e.health.status = 'up', 'red': e.health.status == 'down'}" title="{{e.health.status}}" />-->
+            <span class="ui circular label ng-class:{'green': e.health.status = 'up', 'red': e.health.status == 'down'}" title="{{e.health.status}}" />
             <td>
                 <a href="/#/engines/{{e.id}}">{{e.engine.id}}</a>
             </td>
             <td>{{e.engine.cpus}}</td>
             <td>{{e.engine.memory}} MB</td>
             <td>{{e.engine.addr}}</td>
             <td>{{e.engine.labels.join(', ')}}</td>
-            <!--<td>{{((e.health.response_time / 1000000) | number:1) || "-" }}</td>-->
+            <td>{{((e.health.response_time / 1000000) | number:1) || "-" }}</td>
             <td>{{e.docker_version}}</td>
         </tr>
     </tbody>