Metrics and Alerts

MinIO publishes cluster and node metrics using the Prometheus Data Model. You can use any scraping tool to pull metrics data from MinIO for further analysis and alerting.

MinIO provides scraping endpoints for the following metric groups:

Cluster Metrics

You can scrape cluster-level metrics using the following URL endpoint:

http://HOSTNAME:PORT/minio/v2/metrics/cluster

Replace HOSTNAME:PORT with the FQDN and port of the MinIO deployment. For deployments with a load balancer managing connections between MinIO nodes, specify the address of the load balancer.

Bucket Metrics

Changed in version RELEASE.2023-08-31T15-31-16Z.

You can scrape bucket-level metrics using the following URL endpoint:

http://HOSTNAME:PORT/minio/v2/metrics/bucket

Replace HOSTNAME:PORT with the FQDN and port of the MinIO deployment. For deployments with a load balancer managing connections between MinIO nodes, specify the address of the load balancer.

MinIO by default requires authentication for scraping the metrics endpoints. Use the mc admin prometheus generate command to generate the necessary bearer tokens. You can alternatively disable metrics endpoint authentication by setting MINIO_PROMETHEUS_AUTH_TYPE to public.

MinIO Console Metrics Dashboard

The MinIO Console provides a point-in-time metrics dashboard by default:

MinIO Console with Point-In-Time Metrics

The Console also supports displaying time-series and historical data by querying a Prometheus service configured to scrape data from the MinIO deployment. Specifically, the MinIO Console uses Prometheus query API to retrieve stored metrics data and display the following visualizations:

Usage - provides historical and on-demand visualization of overall usage and status
Traffic - provides historical and on-demand visualization of network traffic
Resources - provides historical and on-demand visualization of resources (compute and storage)
Info - provides point-in-time status of the deployment

MinIO Console displaying Prometheus-backed Monitoring Data

To enable historical data visualization in MinIO Console, set the following environment variables on each node in the MinIO deployment:

Set MINIO_PROMETHEUS_URL to the URL of the Prometheus service
Set MINIO_PROMETHEUS_JOB_ID to the unique job ID assigned to the collected metrics

MinIO Grafana Dashboard

MinIO also publishes two Grafana Dashboards for visualizing collected metrics. For more complete documentation on configuring a Prometheus-compatible data source for Grafana, see the Prometheus documentation on Grafana Support.

Available Metrics

MinIO publishes a number of metrics at the cluster, node, or bucket levels. Each metric includes a label for the MinIO server which generated that metric.

Changed in version MinIO: RELEASE.2023-07-21T21-12-44Z

Bucket metrics have moved to use their own, separate endpoint.

Cluster Metrics
Bucket Metrics

Cluster Metrics

MinIO collects the following metrics at the cluster level. Metrics may include one or more labels, such as the server that calculated that metric.

These metrics can be obtained from any MinIO server once per collection by using the following URL:

https://HOSTNAME:PORT/minio/metrics/v2/cluster

Replace HOSTNAME:PORT with the hostname of your MinIO deployment. For deployments behind a load balancer, use the load balancer hostname instead of a single node hostname.

Audit Metrics

Name	Description
`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.

Cache Metrics

Name	Description
`minio_cache_hits_total`	Total number of drive cache hits.
`minio_cache_missed_total`	Total number of drive cache misses.
`minio_cache_sent_bytes`	Total number of bytes served from cache.
`minio_cache_total_bytes`	Total size of cache drive in bytes.
`minio_cache_usage_info`	Total percentage cache usage, value of 1 indicates high and 0 low, label level is set as well.
`minio_cache_used_bytes`	Current cache usage in bytes.

Cluster Capacity Metrics

Name	Description
`minio_cluster_capacity_raw_free_bytes`	Total free capacity online in the cluster.
`minio_cluster_capacity_raw_total_bytes`	Total capacity online in the cluster.
`minio_cluster_capacity_usable_free_bytes`	Total free usable capacity online in the cluster.
`minio_cluster_capacity_usable_total_bytes`	Total usable capacity online in the cluster.
`minio_cluster_objects_size_distribution`	Distribution of object sizes across a cluster
`minio_cluster_objects_version_distribution`	Distribution of object sizes across a cluster
`minio_cluster_usage_object_total`	Total number of objects in a cluster
`minio_cluster_usage_total_bytes`	Total cluster usage in bytes
`minio_cluster_usage_version_total`	Total number of versions (includes delete marker) in a cluster
`minio_cluster_usage_deletemarker_total`	Total number of delete markers in a cluster
`minio_cluster_usage_total_bytes`	Total cluster usage in bytes
`minio_cluster_buckets_total`	Total number of buckets in the cluster

Cluster Drive Metrics

Name	Description
`minio_cluster_drive_offline_total`	Total drives offline in this cluster.
`minio_cluster_drive_online_total`	Total drives online in this cluster.
`minio_cluster_drive_total`	Total drives in this cluster.

Cluster ILM Metrics

Name	Description
`minio_cluster_ilm_transitioned_bytes`	Total bytes transitioned to a tier.
`minio_cluster_ilm_transitioned_objects`	Total number of objects transitioned to a tier.
`minio_cluster_ilm_transitioned_versions`	Total number of versions transitioned to a tier.

Cluster KMS Metrics

Name	Description
`minio_cluster_kms_online`	Reports whether the KMS is online (1) or offline (0).
`minio_cluster_kms_request_error`	Number of KMS requests that failed due to some error. (HTTP 4xx status code).
`minio_cluster_kms_request_failure`	Number of KMS requests that failed due to some internal failure. (HTTP 5xx status code).
`minio_cluster_kms_request_success`	Number of KMS requests that succeeded.
`minio_cluster_kms_uptime`	The time the KMS has been up and running in seconds.

Cluster Health Metrics

Name	Description
`minio_cluster_nodes_offline_total`	Total number of MinIO nodes offline.
`minio_cluster_nodes_online_total`	Total number of MinIO nodes online.
`minio_cluster_write_quorum`	Maximum write quorum across all pools and sets
`minio_cluster_health_status`	Get current cluster health status

Cluster Replication Metrics

Metrics marked as Site Replication Only only populate on deployments with Site Replication configurations. For deployments with bucket or batch configurations, these metrics populate instead under the Bucket Metrics endpoint.

Name	Description
`minio_cluster_replication_current_active_workers`	Total number of active replication workers
`minio_cluster_replication_average_active_workers`	Average number of active replication workers
`minio_cluster_replication_max_active_workers`	Maximum number of active replication workers seen since server start
`minio_cluster_replication_link_online`	Reports whether the replication link is online (1) or offline (0).
`minio_cluster_replication_link_offline_duration_seconds`	Total duration of replication link being offline in seconds since last offline event
`minio_cluster_replication_link_downtime_duration_seconds`	Total downtime of replication link in seconds since server start
`minio_cluster_replication_average_link_latency_ms`	Average replication link latency in milliseconds
`minio_cluster_replication_max_link_latency_ms`	Maximum replication link latency in milliseconds seen since server start
`minio_cluster_replication_current_link_latency_ms`	Current replication link latency in milliseconds
`minio_cluster_replication_current_transfer_rate`	Current replication transfer rate in bytes/sec
`minio_cluster_replication_average_transfer_rate`	Average replication transfer rate in bytes/sec
`minio_cluster_replication_max_transfer_rate`	Maximum replication transfer rate in bytes/sec seen since server start
`minio_cluster_replication_last_minute_queued_count`	Total number of objects queued for replication in the last full minute
`minio_cluster_replication_last_minute_queued_bytes`	Total number of bytes queued for replication in the last full minute
`minio_cluster_replication_average_queued_count`	Average number of objects queued for replication since server start
`minio_cluster_replication_average_queued_bytes`	Average number of bytes queued for replication since server start
`minio_cluster_replication_max_queued_bytes`	Maximum number of bytes queued for replication seen since server start
`minio_cluster_replication_max_queued_count`	Maximum number of objects queued for replication seen since server start
`minio_cluster_replication_recent_backlog_count`	Total number of objects seen in replication backlog in the last 5 minutes
`minio_cluster_replication_last_minute_failed_bytes`	Total number of bytes failed at least once to replicate in the last full minute.
`minio_cluster_replication_last_minute_failed_count`	Total number of objects which failed replication in the last full minute.
`minio_cluster_replication_last_hour_failed_bytes`	(Site Replication Only) Total number of bytes failed at least once to replicate in the last full hour.
`minio_cluster_replication_last_hour_failed_count`	(Site Replication Only) Total number of objects which failed replication in the last full hour.
`minio_cluster_replication_total_failed_bytes`	(Site Replication Only) Total number of bytes failed at least once to replicate since server start.
`minio_cluster_replication_total_failed_count`	(Site Replication Only) Total number of objects which failed replication since server start.
`minio_cluster_replication_received_bytes`	(Site Replication Only) Total number of bytes replicated to this cluster from another source cluster.
`minio_cluster_replication_received_count`	(Site Replication Only) Total number of objects received by this cluster from another source cluster.
`minio_cluster_replication_sent_bytes`	(Site Replication Only) Total number of bytes replicated to the target cluster.
`minio_cluster_replication_sent_count`	(Site Replication Only) Total number of objects replicated to the target cluster.
`minio_cluster_replication_credential_errors`	(Site Replication Only) Total number of replication credential errors since server start

Healing Metrics

Name	Description
`minio_heal_objects_errors_total`	Objects for which healing failed in current self healing run.
`minio_heal_objects_heal_total`	Objects healed in current self healing run.
`minio_heal_objects_total`	Objects scanned in current self healing run.
`minio_heal_time_last_activity_nano_seconds`	Time elapsed (in nano seconds) since last self healing activity.

Inter Node Metrics

Name	Description
`minio_inter_node_traffic_dial_avg_time`	Average time of internodes TCP dial calls.
`minio_inter_node_traffic_dial_errors`	Total number of internode TCP dial timeouts and errors.
`minio_inter_node_traffic_errors_total`	Total number of failed internode calls.
`minio_inter_node_traffic_received_bytes`	Total number of bytes received from other peer nodes.
`minio_inter_node_traffic_sent_bytes`	Total number of bytes sent to the other peer nodes.

Bucket Notification Metrics

Name	Description
`minio_notify_current_send_in_progress`	Number of concurrent async Send calls active to all targets.
`minio_notify_target_queue_length`	Number of unsent notifications in queue for target.

S3 API Request Metrics

Name	Description
`minio_s3_requests_4xx_errors_total`	Total number S3 requests with (4xx) errors.
`minio_s3_requests_5xx_errors_total`	Total number S3 requests with (5xx) errors.
`minio_s3_requests_canceled_total`	Total number S3 requests canceled by the client.
`minio_s3_requests_errors_total`	Total number S3 requests with (4xx and 5xx) errors.
`minio_s3_requests_incoming_total`	Volatile number of total incoming S3 requests.
`minio_s3_requests_inflight_total`	Total number of S3 requests currently in flight.
`minio_s3_requests_rejected_auth_total`	Total number S3 requests rejected for auth failure.
`minio_s3_requests_rejected_header_total`	Total number S3 requests rejected for invalid header.
`minio_s3_requests_rejected_invalid_total`	Total number S3 invalid requests.
`minio_s3_requests_rejected_timestamp_total`	Total number S3 requests rejected for invalid timestamp.
`minio_s3_requests_total`	Total number S3 requests.
`minio_s3_requests_waiting_total`	Number of S3 requests in the waiting queue.
`minio_s3_requests_ttfb_seconds_distribution`	Distribution of the time to first byte across API calls.
`minio_s3_traffic_received_bytes`	Total number of s3 bytes received.
`minio_s3_traffic_sent_bytes`	Total number of s3 bytes sent.

Software Metrics

Name	Description
`minio_software_commit_info`	Git commit hash for the MinIO release.
`minio_software_version_info`	MinIO Release tag for the server.

Drive Metrics

Name	Description
`minio_node_drive_free_bytes`	Total storage available on a drive.
`minio_node_drive_free_inodes`	Total free inodes.
`minio_node_drive_latency_us`	Average last minute latency in µs for drive API storage operations.
`minio_node_drive_offline_total`	Total drives offline in this node.
`minio_node_drive_online_total`	Total drives online in this node.
`minio_node_drive_total`	Total drives in this node.
`minio_node_drive_total_bytes`	Total storage on a drive.
`minio_node_drive_used_bytes`	Total storage used on a drive.

Identity and Access Management (IAM) Metrics

Name	Description
`minio_node_iam_last_sync_duration_millis`	Last successful IAM data sync duration in milliseconds.
`minio_node_iam_since_last_sync_millis`	Time (in milliseconds) since last successful IAM data sync.
`minio_node_iam_sync_failures`	Number of failed IAM data syncs since server start.
`minio_node_iam_sync_successes`	Number of successful IAM data syncs since server start.

Information Lifecycle Management (ILM) Metrics

Name	Description
`minio_node_ilm_expiry_pending_tasks`	Number of pending ILM expiry tasks in the queue.
`minio_node_ilm_transition_active_tasks`	Number of active ILM transition tasks.
`minio_node_ilm_transition_pending_tasks`	Number of pending ILM transition tasks in the queue.
`minio_node_ilm_versions_scanned`	Total number of object versions checked for ilm actions since server start.

System Metrics

Name	Description
`minio_node_file_descriptor_limit_total`	Limit on total number of open file descriptors for the MinIO Server process.
`minio_node_file_descriptor_open_total`	Total number of open file descriptors by the MinIO Server process.
`minio_node_go_routine_total`	Total number of go routines running.
`minio_node_io_rchar_bytes`	Total bytes read by the process from the underlying storage system including cache, /proc/[pid]/io rchar.
`minio_node_io_read_bytes`	Total bytes read by the process from the underlying storage system, /proc/[pid]/io read_bytes.
`minio_node_io_wchar_bytes`	Total bytes written by the process to the underlying storage system including page cache, /proc/[pid]/io wchar.
`minio_node_io_write_bytes`	Total bytes written by the process to the underlying storage system, /proc/[pid]/io write_bytes.
`minio_node_process_cpu_total_seconds`	Total user and system CPU time spent in seconds.
`minio_node_process_resident_memory_bytes`	Resident memory size in bytes.
`minio_node_process_starttime_seconds`	Start time for MinIO process per node, time in seconds since Unix epoc.
`minio_node_process_uptime_seconds`	Uptime for MinIO process per node in seconds.

Scanner Metrics

Name	Description
`minio_node_scanner_bucket_scans_finished`	Total number of bucket scans finished since server start.
`minio_node_scanner_bucket_scans_started`	Total number of bucket scans started since server start.
`minio_node_scanner_directories_scanned`	Total number of directories scanned since server start.
`minio_node_scanner_objects_scanned`	Total number of unique objects scanned since server start.
`minio_node_scanner_versions_scanned`	Total number of object versions scanned since server start.
`minio_node_syscall_read_total`	Total read SysCalls to the kernel. /proc/[pid]/io syscr.
`minio_node_syscall_write_total`	Total write SysCalls to the kernel. /proc/[pid]/io syscw.
`minio_usage_last_activity_nano_seconds`	Time elapsed (in nano seconds) since last scan activity.

Bucket Metrics

MinIO collects the following metrics at the bucket level. Each metric includes the bucket label to identify the corresponding bucket. Metrics may include one or more additional labels, such as the server that calculated that metric.

These metrics can be obtained from any MinIO server once per collection by using the following URL:

https://HOSTNAME:PORT/minio/metrics/v2/bucket

Replace HOSTNAME:PORT with the hostname of your MinIO deployment. For deployments behind a load balancer, use the load balancer hostname instead of a single node hostname.

Distribution Metrics

Name	Description
`minio_bucket_objects_size_distribution`	Distribution of object sizes in the bucket, includes label for the bucket name.
`minio_bucket_objects_version_distribution`	Distribution of object sizes in a bucket, by number of versions

Replication Metrics

These metrics only populate on deployments with Bucket Replication or Batch Replication configurations. For deployments with Site Replication configured, select metrics populate under the Cluster Metrics endpoint.

Name	Description
`minio_bucket_replication_last_minute_failed_bytes`	Total number of bytes failed at least once to replicate in the last full minute.
`minio_bucket_replication_last_minute_failed_count`	Total number of objects which failed replication in the last full minute.
`minio_bucket_replication_last_hour_failed_bytes`	Total number of bytes failed at least once to replicate in the last full hour.
`minio_bucket_replication_last_hour_failed_count`	Total number of objects which failed replication in the last full hour.
`minio_bucket_replication_total_failed_bytes`	Total number of bytes failed at least once to replicate since server start.
`minio_bucket_replication_total_failed_count`	Total number of objects which failed replication since server start.
`minio_bucket_replication_latency_ms`	Replication latency in milliseconds.
`minio_bucket_replication_received_bytes`	Total number of bytes replicated to this bucket from another source bucket.
`minio_bucket_replication_received_count`	Total number of objects received by this bucket from another source bucket.
`minio_bucket_replication_sent_bytes`	Total number of bytes replicated to the target bucket.
`minio_bucket_replication_sent_count`	Total number of objects replicated to the target bucket.
`minio_bucket_replication_credential_errors`	Total number of replication credential errors since server start

Traffic Metrics

Name	Description
`minio_bucket_traffic_received_bytes`	Total number of S3 bytes received for this bucket.
`minio_bucket_traffic_sent_bytes`	Total number of S3 bytes sent for this bucket.

Usage Metrics

Name	Description
`minio_bucket_usage_object_total`	Total number of objects.
`minio_bucket_usage_version_total`	Total number of versions (includes delete marker)
`minio_bucket_usage_deletemarker_total`	Total number of delete markers.
`minio_bucket_usage_total_bytes`	Total bucket size in bytes.
`minio_bucket_quota_total_bytes`	Total bucket quota size in bytes.

Requests Metrics

Name	Description
`minio_bucket_requests_4xx_errors_total`	Total number of S3 requests with (4xx) errors on a bucket.
`minio_bucket_requests_5xx_errors_total`	Total number of S3 requests with (5xx) errors on a bucket.
`minio_bucket_requests_inflight_total`	Total number of S3 requests currently in flight on a bucket.
`minio_bucket_requests_total`	Total number of S3 requests on a bucket.
`minio_bucket_requests_canceled_total`	Total number S3 requests canceled by the client.
`minio_bucket_requests_ttfb_seconds_distribution`	Distribution of time to first byte across API calls per bucket.