Open Flows → Collector → Exporter signals, or call get_flow_collector_health.
Each exporter/protocol/observation-domain has independent last-received, records,
decode-error, pending-template and template-layout-change counters. An identical
template refresh is not a layout change. Invalid headers cannot consume exporter
slots; the collector caps namespaces at 128.
NetFlow v9 sequence gaps are observed gaps, not confirmed loss: UDP delivery can reorder, duplicate, or restart. Wraparound is handled. IPFIX sequence numbers count data records, including options records, so no loss estimate is fabricated from decoded flow counts. Silence for five minutes is a diagnostic hint, not an outage verdict. Sampling, FastTrack and hardware offload can hide traffic independently of collector health.
Failed storage batches are counted and shown as an incomplete-data warning. These records cannot be recovered by refreshing the dashboard. All health counters are process-local and reset at collector start; historical flow retention is unchanged. This feature does not start exports or alter any router configuration.