Add 4 missing duration and queue size metrics

This adds the following metrics:
```
logstash_node_queue_size_bytes{pipeline="main"} 1.4235844e+07
logstash_node_pipeline_queue_push_duration_seconds_total{pipeline="main"} 382
logstash_node_plugin_queue_push_duration_seconds_total{pipeline="main",plugin="beats",plugin_id="beats",plugin_type="input"} 0
logstash_node_plugin_duration_seconds_total{pipeline="main",plugin="elasticsearch",plugin_id="es",plugin_type="output"} 67
```

VERSION

@@ -1 +1 @@
-0.1.2
+0.1.3

collector/nodestats_api.go

@@ -3,17 +3,19 @@ package collector
 // Pipeline type
 type Pipeline struct {
 	Events struct {
-		DurationInMillis int `json:"duration_in_millis"`
-		In               int `json:"in"`
-		Filtered         int `json:"filtered"`
-		Out              int `json:"out"`
+		DurationInMillis          int `json:"duration_in_millis"`
+		In                        int `json:"in"`
+		Filtered                  int `json:"filtered"`
+		Out                       int `json:"out"`
+		QueuePushDurationInMillis int `json:"queue_push_duration_in_millis"`
 	} `json:"events"`
 	Plugins struct {
 		Inputs []struct {
 			ID     string `json:"id"`
 			Events struct {
-				In  int `json:"in"`
-				Out int `json:"out"`
+				QueuePushDurationInMillis int `json:"queue_push_duration_in_millis"`
+				In                        int `json:"in"`
+				Out                       int `json:"out"`
 			} `json:"events"`
 			Name string `json:"name"`
 		} `json:"inputs,omitempty"`
@@ -35,8 +37,9 @@ type Pipeline struct {
 		Outputs []struct {
 			ID     string `json:"id"`
 			Events struct {
-				In  int `json:"in"`
-				Out int `json:"out"`
+				DurationInMillis int `json:"duration_in_millis"`
+				In               int `json:"in"`
+				Out              int `json:"out"`
 			} `json:"events"`
 			Name string `json:"name"`
 		} `json:"outputs"`
@@ -52,6 +55,7 @@ type Pipeline struct {
 		Events   int    `json:"events"`
 		Type     string `json:"type"`
 		Capacity struct {
+			QueueSizeInBytes    int   `json:"queue_size_in_bytes"`
 			PageCapacityInBytes int   `json:"page_capacity_in_bytes"`
 			MaxQueueSizeInBytes int64 `json:"max_queue_size_in_bytes"`
 			MaxUnreadEvents     int   `json:"max_unread_events"`

collector/nodestats_collector.go

@@ -32,21 +32,24 @@ type NodeStatsCollector struct {
 	ProcessMemTotalVirtualInBytes *prometheus.Desc
 	ProcessCPUTotalInMillis       *prometheus.Desc
 
-	PipelineDuration       *prometheus.Desc
-	PipelineEventsIn       *prometheus.Desc
-	PipelineEventsFiltered *prometheus.Desc
-	PipelineEventsOut      *prometheus.Desc
-
-	PipelinePluginEventsDuration *prometheus.Desc
-	PipelinePluginEventsIn       *prometheus.Desc
-	PipelinePluginEventsOut      *prometheus.Desc
-	PipelinePluginMatches        *prometheus.Desc
-	PipelinePluginFailures       *prometheus.Desc
+	PipelineDuration          *prometheus.Desc
+	PipelineQueuePushDuration *prometheus.Desc
+	PipelineEventsIn          *prometheus.Desc
+	PipelineEventsFiltered    *prometheus.Desc
+	PipelineEventsOut         *prometheus.Desc
+
+	PipelinePluginEventsDuration          *prometheus.Desc
+	PipelinePluginEventsQueuePushDuration *prometheus.Desc
+	PipelinePluginEventsIn                *prometheus.Desc
+	PipelinePluginEventsOut               *prometheus.Desc
+	PipelinePluginMatches                 *prometheus.Desc
+	PipelinePluginFailures                *prometheus.Desc
 
 	PipelineQueueEvents          *prometheus.Desc
 	PipelineQueuePageCapacity    *prometheus.Desc
 	PipelineQueueMaxQueueSize    *prometheus.Desc
 	PipelineQueueMaxUnreadEvents *prometheus.Desc
+	PipelineQueueSizeInBytes     *prometheus.Desc
 
 	PipelineDeadLetterQueueSizeInBytes *prometheus.Desc
 }
@@ -191,6 +194,13 @@ func NewNodeStatsCollector(logstashEndpoint string) (Collector, error) {
 			nil,
 		),
 
+		PipelineQueuePushDuration: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "pipeline_queue_push_duration_seconds_total"),
+			"pipeline_queue_push_duration_seconds_total",
+			[]string{"pipeline"},
+			nil,
+		),
+
 		PipelineEventsIn: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "pipeline_events_in_total"),
 			"pipeline_events_in_total",
@@ -219,6 +229,13 @@ func NewNodeStatsCollector(logstashEndpoint string) (Collector, error) {
 			nil,
 		),
 
+		PipelinePluginEventsQueuePushDuration: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "plugin_queue_push_duration_seconds_total"),
+			"plugin_queue_push_duration_seconds_total",
+			[]string{"pipeline", "plugin", "plugin_id", "plugin_type"},
+			nil,
+		),
+
 		PipelinePluginEventsIn: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "plugin_events_in_total"),
 			"plugin_events_in",
@@ -275,6 +292,13 @@ func NewNodeStatsCollector(logstashEndpoint string) (Collector, error) {
 			nil,
 		),
 
+		PipelineQueueSizeInBytes: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, subsystem, "queue_size_bytes"),
+			"queue_size_bytes",
+			[]string{"pipeline"},
+			nil,
+		),
+
 		PipelineDeadLetterQueueSizeInBytes: prometheus.NewDesc(
 			prometheus.BuildFQName(Namespace, subsystem, "dead_letter_queue_size_bytes"),
 			"dead_letter_queue_size_bytes",
@@ -514,6 +538,13 @@ func (c *NodeStatsCollector) collect(ch chan<- prometheus.Metric) (*prometheus.D
 			pipelineID,
 		)
 
+		ch <- prometheus.MustNewConstMetric(
+			c.PipelineQueuePushDuration,
+			prometheus.CounterValue,
+			float64(pipeline.Events.QueuePushDurationInMillis/1000),
+			pipelineID,
+		)
+
 		ch <- prometheus.MustNewConstMetric(
 			c.PipelineEventsIn,
 			prometheus.CounterValue,
@@ -554,6 +585,15 @@ func (c *NodeStatsCollector) collect(ch chan<- prometheus.Metric) (*prometheus.D
 				plugin.ID,
 				"input",
 			)
+			ch <- prometheus.MustNewConstMetric(
+				c.PipelinePluginEventsQueuePushDuration,
+				prometheus.CounterValue,
+				float64(plugin.Events.QueuePushDurationInMillis/1000),
+				pipelineID,
+				plugin.Name,
+				plugin.ID,
+				"input",
+			)
 		}
 
 		for _, plugin := range pipeline.Plugins.Filters {
@@ -623,6 +663,15 @@ func (c *NodeStatsCollector) collect(ch chan<- prometheus.Metric) (*prometheus.D
 				plugin.ID,
 				"output",
 			)
+			ch <- prometheus.MustNewConstMetric(
+				c.PipelinePluginEventsDuration,
+				prometheus.CounterValue,
+				float64(plugin.Events.DurationInMillis/1000),
+				pipelineID,
+				plugin.Name,
+				plugin.ID,
+				"output",
+			)
 		}
 
 		if pipeline.Queue.Type != "memory" {
@@ -653,6 +702,13 @@ func (c *NodeStatsCollector) collect(ch chan<- prometheus.Metric) (*prometheus.D
 				float64(pipeline.Queue.Capacity.MaxUnreadEvents),
 				pipelineID,
 			)
+
+			ch <- prometheus.MustNewConstMetric(
+				c.PipelineQueueSizeInBytes,
+				prometheus.CounterValue,
+				float64(pipeline.Queue.Capacity.QueueSizeInBytes),
+				pipelineID,
+			)
 		}
 
 		if pipeline.DeadLetterQueue.QueueSizeInBytes != 0 {

collector/nodestats_collector_test.go

@@ -186,6 +186,7 @@ var queueJSON = []byte(`
       "events" : 0,
       "type" : "persisted",
       "capacity" : {
+        "queue_size_in_bytes": 123456,
         "page_capacity_in_bytes" : 262144000,
         "max_queue_size_in_bytes" : 8589934592,
         "max_unread_events" : 12