Session properties | Documentation

Session properties provide a powerful way for client sessions to target actions at a specific session or set of sessions whose session properties match a given criteria. Client sessions can use session filtering to select a set of client sessions upon which to perform one of the following actions:

Send messages directly to that session or set of sessions.
For more information, see Sending request messages to a session filter.
Subscribe that session or set of sessions to a topic.
For more information, see Managing subscriptions.
Unsubscribe that session or set of sessions from a topic.
For more information, see Managing subscriptions.

For more information, see Session filtering.

A client session with the appropriate permissions can also view all of the session properties and modify the user-defined session properties. For more information, see Working with session properties.

Fixed properties

Fixed properties are set by the Diffusion server when a client opens a session with it. Fixed property keys are prefixed by a dollar sign ($). The fixed session properties are:

$SessionId: The session identifier.
$Principal: The security principal the session uses to connect to the Diffusion server .
$Roles: Authorization roles assigned to the session, represented as quoted strings (for example "client", "topic_control"). For more information, see Role-based authorization.
$ClientType: The client type of the session. For more information, see Client types.
$Transport: The transport the client session uses to connect to the Diffusion server . For more information, see Client types.
$Environment: The environment in which the client is running. One of JAVA_<jvm_runtime_name>_<java_version>, BROWSER_<browser>_<browser_version>, NODE_<platform>_<node_version>, DOTNET_<operating_system>_<.net_version>, C_<architecture>_<compiler>:<compiler_version>, ANDROID_<hardware>_<version>, Apple_iOS_<ios_version>, Apple_MacOS_<macos_version>, Apple_TvOS_<tvos_version>, PYTHON_<implementation_name>_<python_version>. Clients older than version 6.11 return "UNKNOWN".
$ServerName: The name of the Diffusion server that the client connects to.
$Connector: The name of the connector on which the client connected to the Diffusion server .
$Country: The two letter country code for the country where the client's internet address is located. The value is uppercase.
$Language: The two letter language code for the most common language of the country where the client's internet address is located. The value is lowercase.
$ClientIP: The session's IP address represented as a string.
$Latitude: The client session's geographic latitude, if this can be ascertained, or 'NaN' if not.
$Longitude: The client session's geographic longitude, if this can be ascertained, or 'NaN' if not.
$MQTTClientId: The MQTT client identifier. Only set for MQTT sessions. If present, the value of the $ClientType session property will be MQTT.
$StartTime: The client session's start time in milliseconds since the epoch.

User-defined properties

An authentication handler that allows the client session to connect can assign additional properties to the session. The keys of these properties are case sensitive, non-empty strings, and cannot contain any of ' ', '\t', '\r', '\n', '"', ''', '(', ')'

Client-proposed properties

A client can propose user-defined session properties when it opens a session. You can configure the system authentication handler to accept client-proposed properties. You can also write an authentication handler with the Authenticator interface to accept client-proposed properties and apply them to the session.