Skip to main content
The Sources view combines authored source definitions with records retained in ClickHouse and read-only Kafka metadata. Browsing source health never consumes Kafka records or advances consumer offsets.

​
Source health

The Sources index summarizes every authored source. Open a managed Kafka source to inspect:
  • retained row count and storage
  • oldest and newest replay boundaries
  • arrival freshness and throughput
  • the effective consumer group
  • landed, committed, and broker-end offsets by partition
Kafka lag and last arrival are different signals:
  • Kafka lag is the broker high-water offset minus the effective consumer group’s committed offset, summed across partitions.
  • Last arrival is the elapsed time since the newest _replay_landed_at value in the ClickHouse landing table.
Kafka metadata is loaded without joining or consuming from the group. If broker metadata or a required committed offset is unavailable, the UI reports Kafka lag as unavailable; it never substitutes last-arrival age. Broker metadata is cached and refreshed outside the main state request, so a first load may briefly show unavailable.
Source health showing retained history, Kafka lag, and three partition offsets
See Topics for broker inventory, Messages for retained payloads, and Replay and Lineage for normalized replay columns and boundary semantics.