SyntaxCircus.Observability 0.1.4

SyntaxCircus.Observability

Opt-in OpenTelemetry/OTLP, Serilog OTLP, and Sentry-compatible error-reporting support for .NET 10 server hosts.

No support guaranteed. Published as-is and maintained on a best-effort basis.

Install

dotnet add package SyntaxCircus.Observability

Quick start

using SyntaxCircus.Observability;
using SyntaxCircus.AspNetCore.Serilog;

var builder = WebApplication.CreateBuilder(args);
var telemetry = builder.AddSyntaxCircusObservability("my-service", ["MyCompany.MyMeter"]);
builder.AddStandardSerilog(configureEnrichment: telemetry.ConfigureSerilog);

if (telemetry.Options.Sentry.IsEnabled)
{
    builder.WebHost.UseSentry(sentry => telemetry.ConfigureSentry(
        sentry,
        context => context.TransactionContext.Name.Contains("/_blazor", StringComparison.OrdinalIgnoreCase) ? 0d : null));
}

var app = builder.Build();
telemetry.LogStartupWarning(app.Logger);

The registration also works with HostApplicationBuilder for OTLP traces, metrics, and Serilog logs. Sentry web capture is configured through WebApplicationBuilder.WebHost and is intentionally web-only in v1.

Blazor Server circuit-disposal noise (opt-in)

Components that dispose JS modules in an async void Dispose() (for example Blazor-ApexCharts) leave an unobserved JSDisconnectedException when a circuit drops. It is harmless but is reported as an error. Opt in to ignore it:

DisconnectedCircuitNoiseFilter.AddTo(sentry);            // inside UseSentry(...); drops matching Sentry events
DisconnectedCircuitNoiseFilter.Register(app.Logger);     // after Build(); observes the task, logs at Debug

Only exceptions made up entirely of JSDisconnectedException are affected.

Broker-unreachable noise (opt-in)

While a message broker is down, its client (for example RabbitMQ.Client's dual-stack connect) can leave faulted tasks nobody observes. The bus keeps retrying, but Sentry reports each stray task as a fatal AggregateException. Opt in to ignore them:

BrokerUnreachableNoiseFilter.AddTo(sentry);            // inside UseSentry(...); drops matching Sentry events
BrokerUnreachableNoiseFilter.Register(app.Logger);     // after Build(); observes the task, logs at Warning

Only an AggregateException made up entirely of broker connection failures (SocketException, RabbitMQ BrokerUnreachableException/ConnectFailureException, MassTransit RabbitMqConnectionException) is affected; the package takes no broker dependency. Keep a readiness check on the broker to catch a real outage.

Configuration

The package reads standard OpenTelemetry and Sentry sections. Telemetry is disabled by default and an enabled but invalid OTLP endpoint produces a safe warning without exporting data. Sentry remains disabled until a DSN is supplied; it sends error-level events only, disables default PII collection, and has a trace sample rate of 0.0 by default.

Keep OTLP headers and Sentry DSNs in deployment secrets. Use the Sentry sampling callback for application-specific noisy routes.

License

Deferred architecture proposal: web-neutral observability. No package split is implemented yet.

MIT. See LICENSE.txt.