Disappearing messages
If your exchange body is a stream you cannot read this stream twice (by default). So if you want to print the content of a stream to your logfile but also process this stream within a following component for example, you should use the cConvertBodyTo component to change the body type from stream to e.g. String. A String can read as often as you need to.
Always keep in mind the lifespan of the data that you are using and passing on.