Chromite Telemetry Collection

This folder contains shared utilities for initializing telemetry collection in Chromite code paths, as well as telemetry configuration settings.

Which chromite apps collect trace data?

The Build team is actively working on instrumenting frequently used code paths in Chromite. Currently supported code paths include:

• chromite/bin/build_packages
• chromite/cli/cros/cros_build_packages
• emerge-$board
• cros_run_unit_test
• chromite/scripts/cros_workon_make
• chromite/bin/build_image

We intend to expand to the following code paths in 2023:

• cros CLI commands, namely cros flash and cros deploy

If there is an application you want to instrument, you are empowered to do so!

Can I opt out of trace collection?

Yes! To opt out, or opt in, you can run:

$ cros telemetry --disable
$ cros telemetry --enable

How do I instrument a chromite application?

In the script you wish to instrument, you will want to add the following lines of code:

from chromite.lib import telemetry

tracer = telemetry.get_tracer(__name__)

def main(argv: Optional[List[str]] = None) -> Optional[int]:
    commandline.RunInsideChroot()
    parser, opts = parse_args(argv)

    telemetry.initialize()

From here, you can trace individual code blocks and method calls as you see fit under service/, lib/, or any other relevant chromite code path. Each instrumented file will need a reference to a Tracer object.

from chromite.lib import telemetry

tracer = telemetry.get_tracer(__name__)

@tracer.start_as_current_span("chromite.lib.my_important_method")
def my_important_method():
    do_cool_thing()

or

from chromite.lib import telemetry

tracer = telemetry.get_tracer(__name__)

def my_important_method():
    with tracer.start_as_current_span("my_important_method.do_thing") as span:
        do_cool_thing()
        span.add_event("cool thing has been done!")

For specific advice about instrumenting code, you can contact chromeos-build-discuss@.

OpenTelemetry documentation is also a worthy read.

How do I view/query telemetry data?

If you are a Googler and have a reasonable need to access the telemetry dataset, contact chromeos-build-discuss@ to be added to the relevant MDB group.

The dataset which supports most of the Build team's dashboards and monitoring from this dataset is chromeos_ci_data.local_build_telemetry_trace_spans.