OVERVIEW.md

Overview

Directories

• input/
  • Struct definitions of input models, e.g. Intake v2, RUM v3, OTel
  • Decoding and translation logic from these input models to the internal model APMEvent
• model/proto
  • Protobuf definitions of the internal model APMEvent
• model/modelpb
  • Struct definitions of the internal model APMEvent
  • Automatically generated from the protobuf definitions
• model/internal/modeljson
  • JSON serialization logic for indexing into Elasticsearch

Data Flow (APM Server)

1. As an event is sent from an agent to APM server, it is deserialized to an input model (e.g. Intake v2, RUM v3, OTel).
2. The input model will then be decoded and translated to the internal model APMEvent.
3. The APMEvent is used throughout APM server for all processing and aggregation.
4. The internal model APMEvent is converted to modeljson.
5. At last, modeljson will be serialized into JSON and indexed into Elasticsearch.

(All of the above is done in batches.)