VCR Receiver

The OpenTelemetry Verbatim Capture & Replay (VCR) toolset enables full-fidelity capture and replay of all telemetry data stored on disk. It replays previously captured telemetry while preserving original event timestamps, allowing you to simulate realistic traffic timing independent of when the data was captured.

Status
Stability	development: traces, metrics, logs, profiles
Distributions	[]
Issues
Code coverage
Code Owners	@atoulme, @robertgustafsonsplunk, @garrett-splunk

Overview

The receiver reads telemetry from JSON files stored in a "TAPE" (Telemetry Archive for Playback & Emulation). Each tape contains OpenTelemetry data encoded using Protobuf JSON and follows the OpenTelemetry Protocol (OTLP).

1. Raw Input Files

The receiver watches a directory for files named: raw_(metrics|traces|logs|profiles)_#.json. They contain contain OTLP data serialized using the OpenTelemetry File Exporter.

2. Tape Creation

Raw files are converted into tapes, named: tape_(metrics|traces|logs|profiles)_<earliest_event_ts>-<latest_event_ts>.json. Tapes are organized by event time, not by file creation time or capture time.

3. Replay Engine

• Tapes are read in chronological order based on original event timestamps.
• Telemetry is replayed according to the original timing between events, accurately reproducing real-world telemetry flow.
• Once the end of the final tape is reached, the receiver loops back and begins replaying from the first event.

Key Features

• True Time-Based Replay
  Honors original event timestamps and relative timing between events.

• Deterministic Telemetry Playback
  Ideal for testing pipelines, demos, load simulations, and debugging without live data.

• Continuous Looping
  Automatically restarts playback after reaching the end of the tape set.

• OTLP-Compatible
  Works with telemetry serialized via the OpenTelemetry File Exporter.

Quick Start

The following settings are required:

• include_raw: set a directory where to look for raw files to include in data collection
• include_tape: set a directory where to look for and place processed raw files

Example:

receivers:
  vcr:
    include_raw:
      - "/var/log/raw/*.log"
    exclude_raw:
      - "/var/log/raw/example.log"
    include_tape:
      - "/var/log/tape/"