Function init_default_subscriber_with_writer

pub fn init_default_subscriber_with_writer<Writer>(writer: Writer)
where
    Writer: for<'writer> MakeWriter<'writer> + Send + Sync + 'static,

Available on crate feature tracing only.

Initialize tracing-subscriber with default logging options, and a custom writer.

You might want to avoid writing to STDOUT in the local context via init_default_subscriber(), if you have a high-throughput Lambdas that involve a lot of async concurrency. Since, writing to STDOUT can briefly block your tokio runtime - ref tracing #2653. In that case, you might prefer to use tracing_appender::NonBlocking instead - particularly if your Lambda is fairly long-running and stays warm. Though, note that you are then responsible for ensuring gracefuls shutdown. See [examples/graceful-shutdown] for a complete example.

This function uses environment variables set with Lambda’s advanced logging controls if they’re configured for your function.

This subscriber sets the logging level based on environment variables: - if AWS_LAMBDA_LOG_LEVEL is set, it takes precedence over any other environment variables. - if AWS_LAMBDA_LOG_LEVEL is not set, check if RUST_LOG is set. - if none of those two variables are set, use INFO as the logging level.

The logging format can also be changed based on Lambda’s advanced logging controls. If the AWS_LAMBDA_LOG_FORMAT environment variable is set to JSON, the log lines will be formatted as json objects, otherwise they will be formatted with the default tracing format.