This expression simply emits a message to the application log (by default logs/openwferu.log).

    <sequence>
        <log>before participant alpha</log>
        <participant ref="alpha" />
        <log>after participant alpha</log>
        <log level="warn">after participant alpha</log>
    </sequence>

And an example with a Ruby process definition :

    sequence do
        log "simple debug message"
        log do
            "another debug message"
        end
        log :message => "yet another debug message"
        log :message => "an info level message", :level => "info"
    end

Possible log levels are ‘debug’ (the default), ‘info’, ‘warn’ and ‘fatal’.