The number of large software systems in the world is growing steadily. Old first generation solutions get improvements and grow more sophisticated. Completely new areas open up for automation. More systems, more lines of code. More complexity everywhere. Inevitably, more questions about the behaviour - why did it do that??? And, of course, more errors, from bugs in the systems themselves to malfunctioning of external dependencies and processes. There are various tools that software developers can utilise in order to deal with the complexities of their systems. One of the core ones is known as logging. The sea captains of the old kept meticulous records of their voyages in the ship’s log, allowing those who followed to know more about the state of the currents and the winds, the lands and their natives. In similar fashion, software developers of today add their own log entries at various points of execution to indicate what the program is doing or planning to do, together with other relevant morsels of information. At some later point these records can be examined in order to learn what the system was doing at that particular time.