Some improvment in mesos input plugin, (#1572)

* Some improvment in mesos input plugin,
     Removing uneeded statistics prefix for task's metric,
     Adding framework id tags into each task's metric,
     Adding state (leader/follower) tags to master's metric,
     Make sure the slave's metrics are tags with slave

* typo, replacing cpus_total with elected to determine leader

* Remove remaining statistics_ from sample

* using timestamp from mesos as metric timestamp

* change mesos-tasks to mesos_tasks, measurement

* change measurement name in test

* Replace follower by standby

plugins/inputs/mesos/README.md

@@ -241,7 +241,7 @@ Mesos tasks metric groups
 - executor_name
 - framework_id
 - source
-- statistics (all metrics below will have `statistics_` prefix included in their names
+- statistics
     - cpus_limit
     - cpus_system_time_secs
     - cpus_user_time_secs
@@ -266,14 +266,20 @@ Mesos tasks metric groups
     - server
     - role (master/slave)
 
+- All master measurements have the extra tags:
+	- state (leader/follower)
+
 - Tasks measurements have the following tags:
     - server
+	- framework_id
+	- task_id
 
 ### Example Output:
 ```
 $ telegraf -config ~/mesos.conf -input-filter mesos -test
 * Plugin: mesos, Collection 1
-mesos,host=172.17.8.102,server=172.17.8.101 allocator/event_queue_dispatches=0,master/cpus_percent=0,
+mesos,role=master,state=leader,host=172.17.8.102,server=172.17.8.101 
+allocator/event_queue_dispatches=0,master/cpus_percent=0,
 master/cpus_revocable_percent=0,master/cpus_revocable_total=0,
 master/cpus_revocable_used=0,master/cpus_total=2,
 master/cpus_used=0,master/disk_percent=0,master/disk_revocable_percent=0,
@@ -293,13 +299,13 @@ master/messages_deactivate_framework=0 ...
 
 Meoso tasks metrics (if enabled):
 ```
-mesos-tasks,host=172.17.8.102,server=172.17.8.101,task_id=hello-world.e4b5b497-2ccd-11e6-a659-0242fb222ce2
+mesos-tasks,host=172.17.8.102,server=172.17.8.101,framework_id=e3060235-c4ed-4765-9d36-784e3beca07f-0000,task_id=hello-world.e4b5b497-2ccd-11e6-a659-0242fb222ce2
-statistics_cpus_limit=0.2,statistics_cpus_system_time_secs=142.49,statistics_cpus_user_time_secs=388.14,
+cpus_limit=0.2,cpus_system_time_secs=142.49,cpus_user_time_secs=388.14,
-statistics_mem_anon_bytes=359129088,statistics_mem_cache_bytes=3964928,
+mem_anon_bytes=359129088,mem_cache_bytes=3964928,
-statistics_mem_critical_pressure_counter=0,statistics_mem_file_bytes=3964928,
+mem_critical_pressure_counter=0,mem_file_bytes=3964928,
-statistics_mem_limit_bytes=767557632,statistics_mem_low_pressure_counter=0,
+mem_limit_bytes=767557632,mem_low_pressure_counter=0,
-statistics_mem_mapped_file_bytes=114688,statistics_mem_medium_pressure_counter=0,
+mem_mapped_file_bytes=114688,mem_medium_pressure_counter=0,
-statistics_mem_rss_bytes=359129088,statistics_mem_swap_bytes=0,statistics_mem_total_bytes=363094016,
+mem_rss_bytes=359129088,mem_swap_bytes=0,mem_total_bytes=363094016,
-statistics_mem_total_memsw_bytes=363094016,statistics_mem_unevictable_bytes=0,
+mem_total_memsw_bytes=363094016,mem_unevictable_bytes=0,
-statistics_timestamp=1465486052.70525 1465486053052811792...
+timestamp=1465486052.70525 1465486053052811792...
 ```

plugins/inputs/mesos/mesos.go

@@ -116,7 +116,7 @@ func (m *Mesos) Gather(acc telegraf.Accumulator) error {
 	for _, v := range m.Slaves {
 		wg.Add(1)
 		go func(c string) {
-			errorChannel <- m.gatherMainMetrics(c, ":5051", MASTER, acc)
+			errorChannel <- m.gatherMainMetrics(c, ":5051", SLAVE, acc)
 			wg.Done()
 			return
 		}(v)
@@ -420,8 +420,15 @@ var client = &http.Client{
 	Timeout:   time.Duration(4 * time.Second),
 }
 
+// TaskStats struct for JSON API output /monitor/statistics
+type TaskStats struct {
+	ExecutorID  string                 `json:"executor_id"`
+	FrameworkID string                 `json:"framework_id"`
+	Statistics  map[string]interface{} `json:"statistics"`
+}
+
 func (m *Mesos) gatherSlaveTaskMetrics(address string, defaultPort string, acc telegraf.Accumulator) error {
-	var metrics []map[string]interface{}
+	var metrics []TaskStats
 
 	host, _, err := net.SplitHostPort(address)
 	if err != nil {
@@ -452,16 +459,18 @@ func (m *Mesos) gatherSlaveTaskMetrics(address string, defaultPort string, acc t
 	}
 
 	for _, task := range metrics {
-		tags["task_id"] = task["executor_id"].(string)
+		tags["task_id"] = task.ExecutorID
+		tags["framework_id"] = task.FrameworkID
 
 		jf := jsonparser.JSONFlattener{}
-		err = jf.FlattenJSON("", task)
+		err = jf.FlattenJSON("", task.Statistics)
 
 		if err != nil {
 			return err
 		}
+		timestamp := time.Unix(int64(jf.Fields["timestamp"].(float64)), 0)
 
-		acc.AddFields("mesos-tasks", jf.Fields, tags)
+		acc.AddFields("mesos_tasks", jf.Fields, tags, timestamp)
 	}
 
 	return nil
@@ -510,6 +519,14 @@ func (m *Mesos) gatherMainMetrics(a string, defaultPort string, role Role, acc t
 		return err
 	}
 
+	if role == MASTER {
+		if jf.Fields["master/elected"] != 0.0 {
+			tags["state"] = "leader"
+		} else {
+			tags["state"] = "standby"
+		}
+	}
+
 	acc.AddFields("mesos", jf.Fields, tags)
 
 	return nil

plugins/inputs/mesos/mesos_test.go

@@ -345,7 +345,10 @@ func TestMesosSlave(t *testing.T) {
 		t.Errorf(err.Error())
 	}
 
-	acc.AssertContainsFields(t, "mesos-tasks", jf.Fields)
+	acc.AssertContainsFields(
+		t,
+		"mesos_tasks",
+		slaveTaskMetrics["statistics"].(map[string]interface{}))
 }
 
 func TestSlaveFilter(t *testing.T) {