The long, lost application delivery spell compendium has been found! Its once hidden, arcane knowledge is slowly being translated for the good of all web applications. Luckily, you don’t have to be Elminster or Gandalf or to cast this spell over your infrastructure

Contingency image_thumb6[5]

   School of Magic: Evocation

   Components: Somatic (requires gestures), Material (requires physical component)

   Saving Throw: None

   Spell Resistance: No

Through the use of the contingency spell, application delivery professionals can dictate the conditions of the execution of another spell. The contingency spell and the companion spell(s) are cast at the same time, but the companion spell fires only when the conditions specified by the contingency spell are met.

The material component for this spell is a network-side scripting capable application delivery controller. The somatic component requires the caster to complete a series of mouse clicks and keyboard strokes that deploy a network-side script that fires when the specified event occurs. A verbal component is not necessary, but some casters find it satisfying to complete the invocation of contingency with some sort of joyful noise (defensive casters belonging to the InfoSec Guild tend to call out “Huzzah! Beat that!” for some reason).

The spell to be brought into effect by the contingency can be one that affects layers 2 through 7 and can either be narrow or broad in its targeting. For example, the contingency can be based upon specified triggers such as: HTTP_REQUEST, HTTP_RESPONSE, CLIENT_DATA, ASM_REQUEST_VIOLATION, SIP_RESPONSE, DNS_REQUEST, and ASM_RESPONSE_VIOLATION. Consult your player’s handbook for a complete list of possible triggers. You can use multiple contingency spells at a time, but each will fire according to the order of events specified in the player’s handbook. 

Like many illusionist spells the effects of the companion spell(s) are heavily dependent upon your imagination. Existing spells that have been cast along with contingency that have been made available by their casters can be explored in the companion spell compendium.