metrics: Use milliseconds instead of microseconds as the time unit fo…

…r scheduling latency

The current time unit cannot accurately reflect the actual scheduling time like below
```
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="5"} 0
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="10"} 0
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="20"} 0
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="40"} 0
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="80"} 0
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="160"} 0
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="320"} 1
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="640"} 1
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="1280"} 68550
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="2560"} 198253
volcano_action_scheduling_latency_microseconds_bucket{action="allocate",le="+Inf"} 243524
volcano_action_scheduling_latency_microseconds_sum{action="allocate"} 5.505664439029926e+08
```

Signed-off-by: Liang Zheng <zhengliang0901@gmail.com>

pkg/scheduler/metrics/metrics.go

@@ -40,7 +40,7 @@ var (
 			Subsystem: VolcanoNamespace,
 			Name:      "e2e_scheduling_latency_milliseconds",
 			Help:      "E2e scheduling latency in milliseconds (scheduling algorithm + binding)",
-			Buckets:   prometheus.ExponentialBuckets(5, 2, 10),
+			Buckets:   prometheus.ExponentialBuckets(5, 2, 15),
 		},
 	)
 
@@ -83,18 +83,18 @@ var (
 	pluginSchedulingLatency = promauto.NewHistogramVec(
 		prometheus.HistogramOpts{
 			Subsystem: VolcanoNamespace,
-			Name:      "plugin_scheduling_latency_microseconds",
-			Help:      "Plugin scheduling latency in microseconds",
-			Buckets:   prometheus.ExponentialBuckets(5, 2, 10),
+			Name:      "plugin_scheduling_latency_milliseconds",
+			Help:      "Plugin scheduling latency in milliseconds",
+			Buckets:   prometheus.ExponentialBuckets(5, 2, 15),
 		}, []string{"plugin", "OnSession"},
 	)
 
 	actionSchedulingLatency = promauto.NewHistogramVec(
 		prometheus.HistogramOpts{
 			Subsystem: VolcanoNamespace,
-			Name:      "action_scheduling_latency_microseconds",
-			Help:      "Action scheduling latency in microseconds",
-			Buckets:   prometheus.ExponentialBuckets(5, 2, 10),
+			Name:      "action_scheduling_latency_milliseconds",
+			Help:      "Action scheduling latency in milliseconds",
+			Buckets:   prometheus.ExponentialBuckets(5, 2, 15),
 		}, []string{"action"},
 	)
 
@@ -103,7 +103,7 @@ var (
 			Subsystem: VolcanoNamespace,
 			Name:      "task_scheduling_latency_milliseconds",
 			Help:      "Task scheduling latency in milliseconds",
-			Buckets:   prometheus.ExponentialBuckets(5, 2, 10),
+			Buckets:   prometheus.ExponentialBuckets(5, 2, 15),
 		},
 	)
 
@@ -150,12 +150,12 @@ var (
 
 // UpdatePluginDuration updates latency for every plugin
 func UpdatePluginDuration(pluginName, onSessionStatus string, duration time.Duration) {
-	pluginSchedulingLatency.WithLabelValues(pluginName, onSessionStatus).Observe(DurationInMicroseconds(duration))
+	pluginSchedulingLatency.WithLabelValues(pluginName, onSessionStatus).Observe(DurationInMilliseconds(duration))
 }
 
 // UpdateActionDuration updates latency for every action
 func UpdateActionDuration(actionName string, duration time.Duration) {
-	actionSchedulingLatency.WithLabelValues(actionName).Observe(DurationInMicroseconds(duration))
+	actionSchedulingLatency.WithLabelValues(actionName).Observe(DurationInMilliseconds(duration))
 }
 
 // UpdateE2eDuration updates entire end to end scheduling latency