Glossary

Aggregation

Aggregation controls the way samples in the same time series are combined together in the same time bin. The aggregations in use inside cernan are defined in the Data Model documentation.

Filters

A Filter in cernan is a structure that receives and emits metrics, potentially modifying, delaying or dropping the metric in-flight. See the filter documentation for more details.

LogLines

A line from a newline delimited log file, plus associated metadata like tags and time of receipt. The definition in source is src/metric/logline.rs.

Metrics

A union concept of Telemetry and LogLines. This is a shorthand for discussion and is not reflected in the source of cernan.

Sink

A Sink in cernan is a structure that recives metrics and emits them to some external service. Please see sink documentation for more details.

Source

A Source in cernan is a structure that emits metrics into Filters or Sinks. A Source may produce metrics independently or ingest information from the outside world. Please see source documentation for more details.

Telemetry

One or more numeric values associated in time, plus associated metadata including preferred aggregation and tags. The definition in source is src/metric/telemetry.rs.

Tags

Tags are key / value pairs of unstructured text that ride inside Telemetry and LogLines, are manipulable by Filters and can be used to distinguish metrics with the same name.