Traviz

Trace visualizer for NEAR

Traviz is a tool which can visualize OpenTelemetry traces collected while running neard. This allows to see what the program is doing at every point in time, making debugging and performance analysis easier.

How to use

1. Start tracing collector

git clone https://github.com/near/nearcore
cd tracing/collector
docker compose up

2. Modify log_config.json to output traces from nodes, for example:

{
  "rust_log": "debug",
  "verbose_module": null,
  "opentelemetry": "debug"
}

3. Set the OTEL_EXPORTER_OTLP_TRACES_ENDPOINT environment variable to send traces to the collector, for example:

OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://<collector-server-ip>:4317

By default the exporter will send traces to localhost, you don't need to set this variable if both the node and collector are running on the same machine.

4. Run the nodes, collector should be outputting:

Persisting trace of size .. bytes
Persisting trace of size .. bytes
Persisting trace of size .. bytes

5. Download the trace from the collector

curl -X POST http://127.0.0.1:8080/raw_trace -H 'Content-Type: application/json' -d "{\"start_timestamp_unix_ms\": $START_TIME, \"end_timestamp_unix_ms\": $END_TIME, \"filter\": {\"nodes\": [],\"threads\": []}}" -o trace.json

6. Start traviz and open the trace file. Choose the right display mode and explore. Watch out - sometimes the file picker opens behind the main window!

cargo run --release

Controls

See CONTROLS.md

Display modes

There are different display modes, each is meant to show the system from a different angle. The current display mode can be chosen using the dropdown menu on the top bar.

They are implemented in src/modes.rs. Each mode is a function which reads the raw trace data and outputs spans that will be displayed to the user. Each mode can filter, modify, or generate new spans based on the raw trace data, as needed to visualize things.