Sorcerer's Apprentice mode (named from Johann Wolfgang von Goethe's Der Zauberlehrling via the Walt Disney film Fantasia) is a bug in a protocol where, under some circumstances, the receipt of a message causes multiple messages to be sent, each of which, when received, triggers the same bug. Used especially of such behaviour caused by bounce message loops in electronic mail software.

In the poem and film a sorcerer's apprentice, left alone, tries out a spell to make a broom fetch water for him. Unfortunately he has forgotten the spell that makes the broom stop. In desperation, the house filling with water, he attacks the broom with an axe; but it simply splits into two brooms, both of which continue to fetch water.

Compare broadcast storm, network meltdown, software laser, ARMM, infinite loop.


Article based on Sorcerer's Apprentice mode at FOLDOC, used with permission.