//tag::ref-doc[]
= Log Sink

The `log` sink uses the application logger to output the data for inspection.

Please understand that `log` sink uses type-less handler, which affects how the actual logging will be performed.
This means that if the content-type is textual, then raw payload bytes will be converted to String, otherwise raw bytes will be logged.
Please see more info in the https://docs.spring.io/spring-cloud-stream/docs/Elmhurst.RELEASE/reference/htmlsingle/#_content_type_versus_argument_type[user-guide].

== Options

The **$$log$$** $$sink$$ has the following options:


//tag::configuration-properties[]
$$log.expression$$:: $$A SpEL expression (against the incoming message) to evaluate as the logged message.$$ *($$String$$, default: `$$payload$$`)*
$$log.level$$:: $$The level at which to log messages.$$ *($$Level$$, default: `$$<none>$$`, possible values: `FATAL`,`ERROR`,`WARN`,`INFO`,`DEBUG`,`TRACE`)*
$$log.name$$:: $$The name of the logger to use.$$ *($$String$$, default: `$$<none>$$`)*
//end::configuration-properties[]

//end::ref-doc[]
