Debugging Tooling

Grapl has several tools to aid in debugging issues.

  • Grapl Debugger Container

  • Distributed Tracing

Grapl Debugger Container

This is a container that can attach to running containers and includes debug tools inside. See the debugger docs for details.

Distributed Tracing

We currently have tracing enabled for local grapl. Our current backend is Jaeger

Usage

  1. Run make up

  2. In your browser go to http://localhost:16686. You should see the Jaeger front-end.

  3. On the left side, are search options.

  4. Select the service you’re interested in and click search. You can also use any of the additional filters on the left (such as http code, etc). If your service does not appear, it’s possible that a) it doesn’t have any traffic (ie the web ui needs a web request), b) there are no traces from within the Lookback window if

  5. In the center a list of traces will appear.

  6. Click on one. You will go to a page with detailed trace information, including performance data for each span.

  7. Click on a span, and then click on tags to get more detailed information, such as http code, etc

  8. On the top-right, there is a drop-down menu with Trace Timeline selected. Clicking on it will provide a few additional options

Tracing docker buildx bake

docker buildx supports sending traces to a backend. Since we build prior to running Jaeger, you will need to explicitly set Jaeger up, either via running make up first or by running it manually in either docker or as a standalone nomad job.

This tracing is meant to help debug docker build issues including performance issues.

Warning!

  1. This generates a LOT of traces, enough to potentially crash Jaeger.

  2. This slows down the build process significantly :(

To run tracing for the docker build:

  1. Do a one-time setup make setup-docker-tracing if you haven’t already.

  2. Run WITH_TRACING=1 make build-local-infrastructure or any other build command that uses bake such as build-test-e2e. Alternatively, you can run traces for individual services via docker buildx bake --file $FILE --builder=grapl-tracing-builder