Open Streaming Architecture

A standard, open set of rules and services for streaming telemetry data over a broker. Includes full definition of the Protobuf schema for transmitting messages, along with documentation describing the messages.

Components

Stream API

A standard API to expose streaming data from SECU units and abstract away proprietary implementation details. Consumers of this API will be able to write software that interfaces with any viewer, network protocol, or storage technology of their choice. All the data from the SECU unit (after RDA filtering) will be available on the stream. This will be integrated with a protocol for streaming engineering (calibrated) telemetry, interoperating with ATLAS clients and the surrounding data processing ecosystem.

Bridge Service

Standalone service that decodes a raw stream of quads from an ADS, converting the data to engineering values then into the Stream Protocol via the Stream API. Will include components to manage sessions, configuration, metadata etc. All RDA protected data will be filtered out at this point, based on the active team license, so any downstream components will only receive data available to the team.

Virtual Parameter Service

Virtual parameters are defined as simple FDL functions in the ECU logging config, and are traditionally calculated on demand by clients rather than the values being persisted like other parameters. However, this requires knowledge of the proprietary FDL grammar, so a service will be developed as part of the McLaren Applied Bridge Service to calculate virtual parameters in real time and written to the broker, eliminating the need for downstream clients to recalculate them.

Multicaster Service

An optional service to reduce network bandwidth in situations where a large number of clients are reading the same set of data from the same broker. Can be configured to consume specific streams of data from the broker, and forward all the packets over multicast to listening clients.