Monitoring & Analytics

Monitoring and analytics capabilities of CybusMQ.

CybusMQ leverages the monitoring and analytics capabilities of VerneMQ with minor extensions. For comprehensive documentation on metrics collection, health checks, and monitoring integration, refer to the official VerneMQ documentation.

Scraping in a Cluster

Node-Level Metrics in Clusters

All metrics are node-level. Each broker node exposes its own metrics independently. The cluster does not aggregate them into a single endpoint. When running a multi-node broker cluster, you must scrape every node individually to capture complete cluster metrics.

If you need cluster-level aggregates (for example, total connected clients across all nodes), calculate them at query time in Prometheus or Grafana.

Additional Metrics

Beyond the standard VerneMQ metrics, CybusMQ provides the following additional metrics:

Metric Name	Description
mqtt_max_packet_size_exceeded	The number of packets discarded due to exceeding the maximum size specified by the client.
mqtt_publish_waited_flow_control	The number of publish packets needed to wait for flow control, multiplied by the number of cycles the packet waited for.
queue_size_qos0	The number of QoS 0 messages kept in memory by queues.
queue_size_qos1	The number of QoS 1 messages kept in memory by queues.
queue_size_qos2	The number of QoS 2 messages kept in memory by queues.
topics_api_request	The number of topics API requests.
topics_api_error_response	The number of error responses from the topics API. Counts errors by type.
histogram.metadata_put_sync_microseconds_bucket_10	Histogram metric for the synchronous metadata store update operations used in synchronous subscribe handling (≤ 10µs).
histogram.metadata_put_sync_microseconds_bucket_100	Histogram metric for synchronous metadata store updates (≤ 100µs).
histogram.metadata_put_sync_microseconds_bucket_1000	Histogram metric for synchronous metadata store updates (≤ 1000µs).
histogram.metadata_put_sync_microseconds_bucket_10000	Histogram metric for synchronous metadata store updates (≤ 10000µs).
histogram.metadata_put_sync_microseconds_bucket_100000	Histogram metric for synchronous metadata store updates (≤ 100000µs).
histogram.metadata_put_sync_microseconds_bucket_1000000	Histogram metric for synchronous metadata store updates (≤ 1000000µs).
histogram.metadata_put_sync_microseconds_bucket_infinity	Histogram metric for synchronous metadata store updates (> 1000000µs).
histogram.metadata_put_sync_microseconds_count	Number of synchronous metadata store updates.
histogram.metadata_put_sync_microseconds_sum	Total time spent in synchronous metadata store updates.