(PECL gearman >= 0.5.0)
GearmanClient::setFailCallback — Set callback for job failure
Sets the callback function to be used when a task does not complete successfully.
Nota: The callback will only be triggered for tasks that are added (e.g. by calling GearmanClient::addTask()) after calling this method.
callbackGEARMAN_SUCCESS.
taskcontextcontext.