metrics = append(metrics, MetricV2{
				Description: MetricDescription{
					Namespace: minioNamespace,
					Subsystem: auditSubsystem,
					Name:      "target_queue_length",
					Help:      "Number of unsent messages in queue for target",
					Type:      gaugeMetric,
				},
				VariableLabels: map[string]string{"target_id": id},
				Value:          float64(st.QueueLength),
			})

| `minio_cluster_audit_failed_messages`     | `counter` | Total number of messages that failed to send since start | `target_id` |
| `minio_cluster_audit_target_queue_length` | `gauge`   | Number of unsent messages in queue for target            | `target_id` |
| `minio_cluster_audit_total_messages`      | `counter` | Total number of messages sent since start                | `target_id` |

### `/cluster/usage/objects`

|:----------------------------------|:----------------------------------------------------------|
| `minio_audit_failed_messages`     | Total number of messages that failed to send since start. |
| `minio_audit_target_queue_length` | Number of unsent messages in queue for target.            |
| `minio_audit_total_messages`      | Total number of messages sent since start.                |

## Cluster Capacity Metrics

)

var (
	auditFailedMessagesMD = NewCounterMD(auditFailedMessages,
		"Total number of messages that failed to send since start",
		targetID)
	auditTargetQueueLengthMD = NewGaugeMD(auditTargetQueueLength,
		"Number of unsent messages in queue for target",
		targetID)
	auditTotalMessagesMD = NewCounterMD(auditTotalMessages,
		"Total number of messages sent since start",
		targetID)
)