One mini-demo run as a single trace, across gRPC, the JSON Ledger API and PQS

[monsieurleberre]

This is one run of the mini-demo (v0.7.0, LocalNet 0.9.1-1) in Grafana's Tempo view. It is a single trace of 40 spans, all under one parent mini-demo run. It contains the gRPC submits (SubmissionClient.*), the JSON Ledger API calls (POST / GET) and the PQS reads (PqsQuery with their Npgsql postgresql children).

What it shows is the client side only. The spans come from the SDK, and the demo's own parent activity is what ties them together. There are no Canton or PQS server-side spans in it. The two red spans are the failure lane's deliberate duplicate-command rejections.

Reproducing it. The demo doesn't export OTLP out of the box, so I used a throwaway copy with a small patch: two package references (Canton.Ledger.OpenTelemetry, OpenTelemetry.Exporter.OpenTelemetryProtocol) and this in Program.cs:

using var tracerProvider = Sdk.CreateTracerProviderBuilder()
    .ConfigureResource(resource => resource.AddService("mini-demo"))
    .AddSource("MiniDemo")
    .AddCantonLedgerInstrumentation()
    .AddOtlpExporter()
    .Build();
using var demoSource = new ActivitySource("MiniDemo");
// in RunDemoAsync: using var run = demoSource.StartActivity("mini-demo run");

Then, from the LocalNet clone:

make up PQS=true OBS=true
OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:14001 dotnet run --project src/MiniDemo

Grafana is at http://localhost:3030. LocalNet doesn't publish the collector's OTLP port (14001) to the host, so I added that port mapping with a compose override.

In your own app, AddCantonLedgerInstrumentation() registers all five SDK ActivitySources (Canton.Ledger.Grpc.Client.LedgerClient, ...Grpc.Client.AdminClient, ...Rest.Client.RestLedgerClient, ...Rest.Client.RestAdminClient, Canton.Ledger.Pqs.Client.PqsClient) plus Npgsql. AddSource("Canton.Ledger.*") also works. Docs: Observability.

Questions are welcome below.