Open
Description
Background and Motivation
In Net10 we are adding new diagnostic metrics for Blazor. This is not C# API but about OTEL names.
Implementation is in #61609 and #62286
There was already feedback about names in both implementation PRs
There is also feedback in external OTEL repo that guides the naming conventions open-telemetry/semantic-conventions#2235
Proposed API
new meter Microsoft.AspNetCore.Components
- Instrument name:
aspnetcore.components.navigation- Description: Total number of route changes.
- Unit:
{route} - Type:
Counter<long> - Tag:
aspnetcore.components.type- class name of the Page component - Tag:
aspnetcore.components.route- URL path pattern of the Blazor page - Tag:
error.type- exception type full name, optional - Usage: how many different Blazor pages users visited ?
- Instrument name:
aspnetcore.components.event_handler- Description: Duration of processing browser event. It includes business logic of the component but not affected child components.
- Unit:
s - Type:
Histogram<double> - Tag:
aspnetcore.components.type- full name of target C# component that receives the event - Tag:
aspnetcore.components.method- C# method name of the handler - Tag:
aspnetcore.components.attribute.name- name of the HTML attribute that triggers the event, i.e.onClick - Tag:
error.type- exception type full name, optional - Usage: click to which component is slow ?
- Usage: which buttons are clicked often ?
new meter Microsoft.AspNetCore.Components.Lifecycle
- Instrument name:
aspnetcore.components.update_parameters- Description: Duration of processing component parameters. It includes business logic of the component.
- Unit:
s - Type:
Histogram<double> - Tag:
aspnetcore.components.type- C# full name of Blazor component receiving parameters - Tag:
error.type- exception type full name, optional - Usage: which components are slow to update ?
- Usage: which components are updated often ?
- Instrument name:
aspnetcore.components.render_diff- Description: Duration of rendering component tree and producing HTML diff. It includes business logic of the changed components.
- Unit:
s - Type:
Histogram<double> - Tag:
aspnetcore.components.diff.length- size of the batch, bucketed - Tag:
error.type- exception type full name, optional - Usage: is (server) rendering slow ?
- Usage: do I render too large diffs ? (network bandwidth, DOM update)
new meter Microsoft.AspNetCore.Components.Server.Circuits
- Instrument name:
aspnetcore.components.circuit.active- Description: Number of active circuits in memory.
- Unit:
{circuit} - Type:
UpDownCounter<long> - Usage: how much memory the sessions state holds ?
- Instrument name:
aspnetcore.components.circuit.connected- Description: Number of circuits connected to client.
- Unit:
{circuit} - Type:
UpDownCounter<long> - Usage: how many signalR connections are open ?
- Instrument name:
aspnetcore.components.circuit.duration- Description: Duration of circuit lifetime and their total count.
- Unit:
s - Type:
Histogram<double> - Usage: how many sessions I processed today ?
- Usage: how long my users keep the session/tab open ?
Alternatives
- OTEL feedback was that they don't use plurals in names and that our namespace
aspnetcore.componentsis breaking that rule.- I prefer to stick to existing .NET namespace.
Usage Examples
builder.Services.ConfigureOpenTelemetryMeterProvider(meterProvider =>
{
meterProvider.AddMeter("Microsoft.AspNetCore.Components");
meterProvider.AddMeter("Microsoft.AspNetCore.Components.Lifecycle");
meterProvider.AddMeter("Microsoft.AspNetCore.Components.Server.Circuits");
});Risks
Small perf impact when enabled/subscribed to.