Logging Configuration

Overview 

Within the SIL Kit, the Logger provides features for local and distributed logging on different log levels.

Logging output is configured through sinks, where each sink defines where messages are written (for example Stdout, File, or Remote) and which minimum log level is emitted.
Log messages can be classified by topics (for example middleware internals, service controllers, or user-level logging). Topic-based filtering can be configured per sink to include or exclude specific topics.
For sinks of type Stdout and File, the output format can be selected as Simple (human-readable text) or Json (structured one-object-per-line output).

The Logging configuration allows to configure the logging behavior of the simulation participant. Within the SIL Kit, the Logger uses so-called sinks to store log messages. Multiple sinks can be configured at the same time. For example, to send log messages with log level Debug or higher to a remote logger and write Trace level logs to a file, the following configuration could be used:

Logging:
  Sinks:
  - Type: Stdout
    Level: Info
  - Type: Remote
    Level: Debug
  - Type: File
    Level: Trace
    LogName: ParticipantLog

Table 17 Logger Configuration
Property Name	Description
Sinks	A list of logger sink configurations
FlushLevel	The log level at which flushes are triggered. Valid options are Critical, Error, Warn, Info, Debug, Trace, and Off.
LogFromRemotes	A boolean flag whether to log messages from other participants with remote sinks. Log messages received from other participants are only sent to local sinks, i.e., Stdout and File

Table 18 Sink Configuration
Property Name	Description
Type	The sink type determines where the log messages are stored or sent to. Valid options are Stdout, File, and Remote. Sinks of type Remote send the log messages over the underlying middleware. Note that this can result in a significant amount of traffic, which can impact the simulation performance, in particular when using a low log level.
Format	The output format used for log messages written by the sink. Valid options are Simple and Json (see Log message format). Applies to sinks of type Stdout and File. If not set, sinks of type File default to Json, while all other sinks default to Simple.
Level	The minimum log level of a message to be logged by the sink. All messages with a lower log level are ignored. Valid options are Critical, Error, Warn, Info, Debug, Trace, and Off.
LogName	The filename used by sinks of type File. The resulting filename is `<LogName>_<Sanitized-Participant-Name>_<ISO-TimeStamp>.txt` for the Simple format and `<LogName>_<Sanitized-Participant-Name>_<ISO-TimeStamp>.jsonl` for the Json format.
Experimental: EnabledTopics	Optional allow-list of logging topics for this sink. If this list is non-empty, only messages with topics from this list are written to the sink.
Experimental: DisabledTopics	Optional block-list of logging topics for this sink. Disabled topics are always filtered out, even if they are also listed in EnabledTopics.

Log message format 

The Format property of a sink controls how log messages are rendered. It applies to sinks of type Stdout and File. Sinks of type Remote always transmit the messages in the Simple format.

Note

If the Format property is not set explicitly, sinks of type File default to Json, while sinks of type Stdout default to Simple.

Simple

Human-readable, single-line text output. This is the default for Stdout sinks. For File sinks, the messages are written to a .txt file.

[2026-07-09 11:59:50.287] [CanWriter] [trace] [TimeSync] Finished Simulation Step., ExecutionTime: 0.4058, VirtualTimeNS: 60000000

Json

One JSON object per line, which is convenient for automated processing of the log.

{"ts":"1783591190287458","log":"CanWriter","lvl":"trace", "topic": "TimeSync", "msg": "Finished Simulation Step.", "kv": {"ExecutionTime":"0.4058","VirtualTimeNS":"60000000"} }

Each entry contains the UNIX epoch timestamp in microseconds (ts), the participant name (log), the log level (lvl), and the message (msg). Depending on the message, the topic (see logging topics) and the optional field kv (structured key-value data) are added. For File sinks, the messages are written to a .jsonl file.

The following example configures a File sink using the Simple format and a Stdout sink using the Json format:

Logging:
  Sinks:
  - Type: File
    Format: Simple
    Level: Trace
    LogName: ParticipantLog
  - Type: Stdout
    Format: Json
    Level: Info

Experimental: Topic-based sink filtering 

A topic classifies the origin of a log message (for example middleware internals, service controllers, or user-level logging). Topic filters can be configured per sink by using EnabledTopics and/or DisabledTopics.

If EnabledTopics is empty or not set, all topics are allowed.
If EnabledTopics is set, only listed topics are allowed.
DisabledTopics always has precedence and filters matching topics out.
Topic names are parsed case-insensitively.
User-level logging uses the User topic.

Example:

In the following example, only the user-level and Ethernet log messages are enabled:

Logging:
  Sinks:
  - Type: Stdout
    Level: Trace
    Experimental:
      EnabledTopics:
        - User
        - Ethernet

With the next example, topics that produce verbose log messages at startup are disabled:

Logging:
  Sinks:
  - Type: Stdout
    Level: Trace
    Experimental:
      DisabledTopics:
        - Participant
        - Asio
        - ServiceDiscovery

The following topic names are currently assigned by SIL Kit components:

Asio: Logging from middleware communication and connection handling.
Can: Logging related to CAN services and controllers.
Dashboard: Logging from dashboard integration and dashboard clients.
Ethernet: Logging related to Ethernet services and controllers.
Extension: Logging from SIL Kit extension components.
Flexray: Logging related to FlexRay services and controllers.
LifeCycle: Logging from lifecycle state transitions and lifecycle management.
Lin: Logging related to LIN services and controllers.
MessageTracing: Logging from message tracing internals.
Metrics: Logging from metrics collection and processing.
NetSim: Logging from experimental network simulation components.
Participant: Logging from participant-level internal functionality.
Pubsub: Logging related to publish/subscribe data services.
RequestReply: Logging related to internal request/reply coordination.
Rpc: Logging related to RPC clients, servers, and discovery.
ServiceDiscovery: Logging related to service discovery.
SystemMonitor: Logging related to system monitor internals.
SystemState: Logging related to system state tracking and monitoring.
TimeConfig: Logging related to time synchronization configuration.
TimeSync: Logging from runtime time synchronization.
Tracing: Logging related to tracing, replay, and trace sinks.
User: Logging emitted by user application code.

Logging Configuration

Overview

Configuration

Log message format

Experimental: Topic-based sink filtering

Overview 

Configuration 

Log message format 

Experimental: Topic-based sink filtering 