Drop Pending size and count from replication metrics (#12378)

Real-time metrics calculated in-memory rely on the initial
replication metrics saved with data usage. However, this can
lag behind the actual state of the cluster at the time of server 
restart leading to inaccurate Pending size/counts reported to
Prometheus. Dropping the Pending metrics as this can be more 
reliably monitored by applications with replication notifications.

Signed-off-by: Poorna Krishnamoorthy <poorna@minio.io>

cmd/bucket-replication-stats.go

@@ -26,11 +26,9 @@ import (
 )
 
 func (b *BucketReplicationStats) hasReplicationUsage() bool {
-	return b.PendingSize > 0 ||
+	return b.FailedSize > 0 ||
-		b.FailedSize > 0 ||
 		b.ReplicatedSize > 0 ||
 		b.ReplicaSize > 0 ||
-		b.PendingCount > 0 ||
 		b.FailedCount > 0
 }
 
@@ -67,38 +65,23 @@ func (r *ReplicationStats) Update(bucket string, n int64, status, prevStatus rep
 	}
 	r.RUnlock()
 	switch status {
-	case replication.Pending:
-		if opType == replication.ObjectReplicationType {
-			atomic.AddUint64(&b.PendingSize, uint64(n))
-		}
-		atomic.AddUint64(&b.PendingCount, 1)
 	case replication.Completed:
 		switch prevStatus { // adjust counters based on previous state
-		case replication.Pending:
-			atomic.AddUint64(&b.PendingCount, ^uint64(0))
 		case replication.Failed:
 			atomic.AddUint64(&b.FailedCount, ^uint64(0))
 		}
 		if opType == replication.ObjectReplicationType {
 			atomic.AddUint64(&b.ReplicatedSize, uint64(n))
 			switch prevStatus {
-			case replication.Pending:
-				atomic.AddUint64(&b.PendingSize, ^uint64(n-1))
 			case replication.Failed:
 				atomic.AddUint64(&b.FailedSize, ^uint64(n-1))
 			}
 		}
 	case replication.Failed:
-		// count failures only once - not on every retry
-		switch prevStatus { // adjust counters based on previous state
-		case replication.Pending:
-			atomic.AddUint64(&b.PendingCount, ^uint64(0))
-		}
 		if opType == replication.ObjectReplicationType {
 			if prevStatus == replication.Pending {
 				atomic.AddUint64(&b.FailedSize, uint64(n))
 				atomic.AddUint64(&b.FailedCount, 1)
-				atomic.AddUint64(&b.PendingSize, ^uint64(n-1))
 			}
 		}
 	case replication.Replica:
@@ -125,11 +108,9 @@ func (r *ReplicationStats) GetInitialUsage(bucket string) BucketReplicationStats
 		return BucketReplicationStats{}
 	}
 	return BucketReplicationStats{
-		PendingSize:    atomic.LoadUint64(&st.PendingSize),
 		FailedSize:     atomic.LoadUint64(&st.FailedSize),
 		ReplicatedSize: atomic.LoadUint64(&st.ReplicatedSize),
 		ReplicaSize:    atomic.LoadUint64(&st.ReplicaSize),
-		PendingCount:   atomic.LoadUint64(&st.PendingCount),
 		FailedCount:    atomic.LoadUint64(&st.FailedCount),
 	}
 }
@@ -149,11 +130,9 @@ func (r *ReplicationStats) Get(bucket string) BucketReplicationStats {
 	}
 
 	return BucketReplicationStats{
-		PendingSize:    atomic.LoadUint64(&st.PendingSize),
 		FailedSize:     atomic.LoadUint64(&st.FailedSize),
 		ReplicatedSize: atomic.LoadUint64(&st.ReplicatedSize),
 		ReplicaSize:    atomic.LoadUint64(&st.ReplicaSize),
-		PendingCount:   atomic.LoadUint64(&st.PendingCount),
 		FailedCount:    atomic.LoadUint64(&st.FailedCount),
 	}
 }
@@ -177,11 +156,9 @@ func NewReplicationStats(ctx context.Context, objectAPI ObjectLayer) *Replicatio
 
 	for bucket, usage := range dataUsageInfo.BucketsUsage {
 		b := &BucketReplicationStats{
-			PendingSize:    usage.ReplicationPendingSize,
 			FailedSize:     usage.ReplicationFailedSize,
 			ReplicatedSize: usage.ReplicatedSize,
 			ReplicaSize:    usage.ReplicaSize,
-			PendingCount:   usage.ReplicationPendingCount,
 			FailedCount:    usage.ReplicationFailedCount,
 		}
 		if b.hasReplicationUsage() {

cmd/metrics-v2.go

@@ -98,8 +98,6 @@ const (
 	failedCount   MetricName = "failed_count"
 	failedBytes   MetricName = "failed_bytes"
 	freeBytes     MetricName = "free_bytes"
-	pendingBytes  MetricName = "pending_bytes"
-	pendingCount  MetricName = "pending_count"
 	readBytes     MetricName = "read_bytes"
 	rcharBytes    MetricName = "rchar_bytes"
 	receivedBytes MetricName = "received_bytes"
@@ -400,15 +398,7 @@ func getBucketUsageObjectsTotalMD() MetricDescription {
 		Type:      gaugeMetric,
 	}
 }
-func getBucketRepPendingBytesMD() MetricDescription {
+
-	return MetricDescription{
-		Namespace: bucketMetricNamespace,
-		Subsystem: replicationSubsystem,
-		Name:      pendingBytes,
-		Help:      "Total bytes pending to replicate.",
-		Type:      gaugeMetric,
-	}
-}
 func getBucketRepFailedBytesMD() MetricDescription {
 	return MetricDescription{
 		Namespace: bucketMetricNamespace,
@@ -436,15 +426,7 @@ func getBucketRepReceivedBytesMD() MetricDescription {
 		Type:      gaugeMetric,
 	}
 }
-func getBucketRepPendingOperationsMD() MetricDescription {
+
-	return MetricDescription{
-		Namespace: bucketMetricNamespace,
-		Subsystem: replicationSubsystem,
-		Name:      pendingCount,
-		Help:      "Total number of objects pending replication",
-		Type:      gaugeMetric,
-	}
-}
 func getBucketRepFailedOperationsMD() MetricDescription {
 	return MetricDescription{
 		Namespace: bucketMetricNamespace,
@@ -1318,11 +1300,6 @@ func getBucketUsageMetrics() MetricsGroup {
 				})
 
 				if stat.hasReplicationUsage() {
-					metrics = append(metrics, Metric{
-						Description:    getBucketRepPendingBytesMD(),
-						Value:          float64(stat.PendingSize),
-						VariableLabels: map[string]string{"bucket": bucket},
-					})
 					metrics = append(metrics, Metric{
 						Description:    getBucketRepFailedBytesMD(),
 						Value:          float64(stat.FailedSize),
@@ -1338,11 +1315,6 @@ func getBucketUsageMetrics() MetricsGroup {
 						Value:          float64(stat.ReplicaSize),
 						VariableLabels: map[string]string{"bucket": bucket},
 					})
-					metrics = append(metrics, Metric{
-						Description:    getBucketRepPendingOperationsMD(),
-						Value:          float64(stat.PendingCount),
-						VariableLabels: map[string]string{"bucket": bucket},
-					})
 					metrics = append(metrics, Metric{
 						Description:    getBucketRepFailedOperationsMD(),
 						Value:          float64(stat.FailedCount),

cmd/metrics.go

@@ -18,6 +18,7 @@
 package cmd
 
 import (
+	"math"
 	"net/http"
 	"strings"
 	"sync/atomic"
@@ -441,56 +442,23 @@ func getLatestReplicationStats(bucket string, u madmin.BucketUsageInfo) (s Bucke
 	for _, bucketStat := range bucketStats {
 		replStats.FailedCount += bucketStat.ReplicationStats.FailedCount
 		replStats.FailedSize += bucketStat.ReplicationStats.FailedSize
-		replStats.PendingCount += bucketStat.ReplicationStats.PendingCount
-		replStats.PendingSize += bucketStat.ReplicationStats.PendingSize
 		replStats.ReplicaSize += bucketStat.ReplicationStats.ReplicaSize
 		replStats.ReplicatedSize += bucketStat.ReplicationStats.ReplicatedSize
 	}
 	usageStat := globalReplicationStats.GetInitialUsage(bucket)
-	replStats.FailedCount += usageStat.FailedCount
-	replStats.FailedSize += usageStat.FailedSize
-	replStats.PendingCount += usageStat.PendingCount
-	replStats.PendingSize += usageStat.PendingSize
 	replStats.ReplicaSize += usageStat.ReplicaSize
 	replStats.ReplicatedSize += usageStat.ReplicatedSize
 
 	// use in memory replication stats if it is ahead of usage info.
+	s.ReplicatedSize = u.ReplicatedSize
 	if replStats.ReplicatedSize >= u.ReplicatedSize {
 		s.ReplicatedSize = replStats.ReplicatedSize
-	} else {
-		s.ReplicatedSize = u.ReplicatedSize
 	}
-
+	// Reset FailedSize and FailedCount to 0 for negative overflows which can
-	if replStats.PendingSize > u.ReplicationPendingSize {
+	// happen since data usage picture can lag behind actual usage state at the time of cluster start
-		s.PendingSize = replStats.PendingSize
+	s.FailedSize = uint64(math.Max(float64(replStats.FailedSize), 0))
-	} else {
+	s.FailedCount = uint64(math.Max(float64(replStats.FailedCount), 0))
-		s.PendingSize = u.ReplicationPendingSize
+	s.ReplicaSize = uint64(math.Max(float64(replStats.ReplicaSize), float64(u.ReplicaSize)))
-	}
-
-	if replStats.FailedSize > u.ReplicationFailedSize {
-		s.FailedSize = replStats.FailedSize
-	} else {
-		s.FailedSize = u.ReplicationFailedSize
-	}
-
-	if replStats.ReplicaSize > u.ReplicaSize {
-		s.ReplicaSize = replStats.ReplicaSize
-	} else {
-		s.ReplicaSize = u.ReplicaSize
-	}
-
-	if replStats.PendingCount > u.ReplicationPendingCount {
-		s.PendingCount = replStats.PendingCount
-	} else {
-		s.PendingCount = u.ReplicationPendingCount
-	}
-
-	if replStats.FailedCount > u.ReplicationFailedCount {
-		s.FailedCount = replStats.FailedCount
-	} else {
-		s.FailedCount = u.ReplicationFailedCount
-	}
-
 	return s
 }
 
@@ -537,15 +505,6 @@ func bucketUsageMetricsPrometheus(ch chan<- prometheus.Metric) {
 			float64(usageInfo.ObjectsCount),
 			bucket,
 		)
-		ch <- prometheus.MustNewConstMetric(
-			prometheus.NewDesc(
-				prometheus.BuildFQName("bucket", "replication", "pending_size"),
-				"Total capacity pending to be replicated",
-				[]string{"bucket"}, nil),
-			prometheus.GaugeValue,
-			float64(stat.PendingSize),
-			bucket,
-		)
 		ch <- prometheus.MustNewConstMetric(
 			prometheus.NewDesc(
 				prometheus.BuildFQName("bucket", "replication", "failed_size"),
@@ -573,15 +532,6 @@ func bucketUsageMetricsPrometheus(ch chan<- prometheus.Metric) {
 			float64(stat.ReplicaSize),
 			bucket,
 		)
-		ch <- prometheus.MustNewConstMetric(
-			prometheus.NewDesc(
-				prometheus.BuildFQName("bucket", "replication", "pending_count"),
-				"Total replication operations pending",
-				[]string{"bucket"}, nil),
-			prometheus.GaugeValue,
-			float64(stat.PendingCount),
-			bucket,
-		)
 		ch <- prometheus.MustNewConstMetric(
 			prometheus.NewDesc(
 				prometheus.BuildFQName("bucket", "replication", "failed_count"),

docs/metrics/prometheus/list.md

@@ -9,10 +9,8 @@ These metrics can be from any MinIO server once per collection.
 |:---------------------------------------------|:--------------------------------------------------------------------------------------------------------------------|
 | `minio_bucket_objects_size_distribution`     | Distribution of object sizes in the bucket, includes label for the bucket name.                                     |
 | `minio_bucket_replication_failed_bytes`      | Total number of bytes failed at least once to replicate.                                                            |
-| `minio_bucket_replication_pending_bytes`     | Total bytes pending to replicate.                                                                                   |
 | `minio_bucket_replication_received_bytes`    | Total number of bytes replicated to this bucket from another source bucket.                                         |
 | `minio_bucket_replication_sent_bytes`        | Total number of bytes replicated to the target bucket.                                                              |
-| `minio_bucket_replication_pending_count`     | Total number of replication operations pending for this bucket.                                                     |
 | `minio_bucket_replication_failed_count`      | Total number of replication foperations failed for this bucket.                                                     |
 | `minio_bucket_usage_object_total`            | Total number of objects                                                                                             |
 | `minio_bucket_usage_total_bytes`             | Total bucket size in bytes                                                                                          |