Monitoring & Metrics (Cue Cluster)
Cue exposes detailed Prometheus metrics for both partition-level and cluster-level observability.
All metrics are available at /metrics on the Admin API port (default: 8321).
Partition Metrics (Per Topic)
These metrics use the topic label.
| Metric | Type | Description |
|---|---|---|
cue_active_queue_depth{topic="..."} |
Gauge | Current number of jobs waiting to be dispatched |
cue_jobs_added_total{topic="..."} |
Counter | Total number of jobs added to the topic |
cue_jobs_completed_total{topic="..."} |
Counter | Total number of jobs successfully completed |
cue_jobs_retried_total{topic="..."} |
Counter | Total number of job retries |
cue_jobs_dead_letter_total{topic="..."} |
Counter | Total number of jobs moved to Dead Letter Queue |
Cluster Metrics
| Metric | Type | Description |
|---|---|---|
cluster_connection_opened_total |
Counter | Total connections opened |
cluster_connection_accepted_total |
Counter | Total connections accepted |
cluster_connection_rejected_total |
Counter | Total connections rejected |
cluster_connection_error_total |
Counter | Total connection errors |
cluster_connection_dropped_total |
Counter | Total connections dropped |
cluster_message_sent_total |
Counter | Total messages sent |
cluster_message_received_total |
Counter | Total messages received |
cluster_bytes_sent_total |
Counter | Total bytes sent |
cluster_bytes_received_total |
Counter | Total bytes received |
cluster_send_error_total |
Counter | Total send errors |
cluster_receive_error_total |
Counter | Total receive errors |
cluster_leader_changed_total |
Counter | Total leadership changes |
cluster_wal_flush_count_total |
Counter | Total WAL flushes |
cluster_last_applied_wal_index |
Gauge | Last applied WAL index |
Gateway Metrics (to Proxies)
| Metric | Type | Description |
|---|---|---|
cue_gateway_active_proxies |
Gauge | Number of currently connected CueProxy instances |
cue_gateway_active_connections |
Gauge | Number of active QUIC connections |
cue_gateway_messages_received_total |
Counter | Messages received from proxies |
cue_gateway_messages_sent_total |
Counter | Messages sent to proxies |
cue_gateway_connection_failures_total |
Counter | Failed connection attempts |
cue_gateway_network_errors_total |
Counter | Network errors (timeouts, resets, etc.) |
Topic Manager Metrics
| Metric | Type | Description |
|---|---|---|
cue_topic_manager_active_topics |
Gauge | Number of active topics |
cue_topic_manager_topics_created_total |
Counter | Total topics created |
cue_topic_manager_topics_removed_total |
Counter | Total topics removed |
Health Check:
curl http://localhost:8321/health