Semantic Conventions for SignalR server metrics

Status: Stable

This article defines semantic conventions for SignalR metrics emitted by .NET components and runtime.

Metric: signalr.server.connection.duration

this metric SHOULD be specified with ExplicitBucketBoundaries of [ 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 1, 2, 5, 10, 30, 60, 120, 300 ].

Name	Instrument Type	Unit (UCUM)	Description	Stability
signalr.server.connection.duration	Histogram	s	The duration of connections on the server. [1]

[1]: Meter name: Microsoft.AspNetCore.Http.Connections; Added in: ASP.NET Core 8.0

Attribute	Type	Description	Examples	Requirement Level	Stability
signalr.connection.status	string	SignalR HTTP connection closure status.	app_shutdown; timeout	Recommended
signalr.transport	string	SignalR transport type	web_sockets; long_polling	Recommended

signalr.connection.status has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
app_shutdown	The connection was closed because the app is shutting down.
normal_closure	The connection was closed normally.
timeout	The connection was closed due to a timeout.

signalr.transport has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
long_polling	LongPolling protocol
server_sent_events	ServerSentEvents protocol
web_sockets	WebSockets protocol

Metric: signalr.server.active_connections

Name	Instrument Type	Unit (UCUM)	Description	Stability
signalr.server.active_connections	UpDownCounter	{connection}	Number of connections that are currently active on the server. [1]

[1]: Meter name: Microsoft.AspNetCore.Http.Connections; Added in: ASP.NET Core 8.0

Attribute	Type	Description	Examples	Requirement Level	Stability
signalr.connection.status	string	SignalR HTTP connection closure status.	app_shutdown; timeout	Recommended
signalr.transport	string	SignalR transport type	web_sockets; long_polling	Recommended

signalr.connection.status has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
app_shutdown	The connection was closed because the app is shutting down.
normal_closure	The connection was closed normally.
timeout	The connection was closed due to a timeout.

signalr.transport has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
long_polling	LongPolling protocol
server_sent_events	ServerSentEvents protocol
web_sockets	WebSockets protocol