This invention provides methods, systems and apparatus for processing a message of a large number of agents. An example of an apparatus includes: a memory; means for managing a state of an agent based on whether the agent is in the memory and whether there is a message, by determining a priority level of the agent based on a message inserted into the agent; means for assigning a thread to the agent if the agent is in the memory and for assigning a thread to the agent after calling the agent to the memory if the agent is not in the memory, on condition that the agent having a highest priority level has been detected; and message processing means for repeating message processing until a predetermined criterion is satisfied, in relation to the agent to which a thread has been assigned.