Observation

Trace streaming and recording for Vantle

This document describes the Observation system, a peer-to-peer trace streaming framework for Vantle.

Architecture

Observation uses a peer-to-peer model with no central server. Applications stream traces directly to:

  • Files : Local recording via log:// and chrome:// URIs
  • Peers : Remote streaming via grpc:// URIs

Each application decides where to send its traces. See Forge for an example of configuring trace destinations.

Trace

The #[trace] macro instruments functions for observation.

Usage

Source
# [trace (channels = [core])] fn view<Source, T>(&self, mut source: T) -> Result<Translation<u8>> where T: Translator::<Source, u8>, { source.view(&*self.filter, &*self.terminator, self.limiter) }

Channels

Channels filter which spans to emit. Common channels include:

  • core : Core runtime operations
  • document : Documentation generation
  • hypergraph : Hypergraph evaluation
  • matching : Pattern matching
  • query : Graph queries